Claudio
Curti
a,
Michael N.
Clifford
bc,
Colin D.
Kay
d,
Pedro
Mena
ef,
Ana
Rodriguez-Mateos
g,
Daniele
Del Rio
ef,
Gordon J.
McDougall
h,
Gary
Williamson
c,
Cristina
Andres-Lacueva
ij,
Letizia
Bresciani
e,
Britt
Burton Freeman
k,
Aedin
Cassidy
l,
Yves
Desjardin
m,
Cesar G.
Fraga
n,
Chris. C. I.
Gill
o,
Paul A.
Kroon
p,
Nikolai
Kuhnert
q,
Iziar A.
Ludwig
r,
Claudine
Manach
s,
Dragan
Milenkovic
t,
Cláudia
Nunes dos Santos
u,
Patricia I.
Oteiza
n,
Gema
Pereira-Caro
v,
Francisco A.
Tomás Barberán
w,
David S.
Wishart
x and
Alan
Crozier
*yz
aBioOrganic Synthesis Unit, Department of Food and Drug, University of Parma, Parma, Italy
bSchool of Bioscience and Medicine, University of Surrey, Guildford, UK
cDepartment of Nutrition, Dietetics and Food, Monash University, Notting Hill, Victoria, Australia
dDepartment of Pediatrics, University of Arkansas Medical School, Little Rock, AR, USA
eHuman Nutrition Unit, Department of Food and Drug, University of Parma, Parma, Italy
fMicrobiome Research Hub, University of Parma, Parma, Italy
gDepartment of Nutritional Sciences, Kings College, London, UK
hThe James Hutton Research Institute, Invergowrie, Dundee, UK
iDepartment of Nutrition, Food Science and Gastronomy, University of Barcelona, Barcelona, Spain
jCIBER Frailty and Healthy Aging (CIBERfes), Institute of Health Carlos III, Barcelona, Spain
kDepartment of Food Science and Nutrition, Illinois Institute of Technology, Chicago, ILL, USA
lInstitute for Food Security, Queen's University, Belfast, Northern Ireland, UK
mInstitute for Nutrition and Functional Food, Laval University, Québec, Canada
nDepartment of Nutrition, University of California, Davis, CA, USA
oNutrition Innovation Centre for Food and Health, Ulster University, Coleraine, UK
pQuadram Institute, Norwich, UK
qSchool of Science, Constructor University, Bremen, Germany
rCenter for Nutrition Research, University of Navarra, Pamplona, Spain
sUniversité Clermont Auvergne, INRAE, Human Nutrition Unit, Clermont-Ferrand, France
tPlants for Human Health Institute, Food Bioprocessing and Nutrition Sciences Department, North Carolina State University, Kannapolis, NC, USA
uNOVA Medical School, NOVA University of Lisbon, Lisbon, Portugal
vDepartment of Food Science and Health, Andalusian Institute of Agricultural and Fisheries Research and Training, Córdoba, Spain
wQuality, Safety and Bioactivity of Plant-Derived Foods CEBAS-CSIC, Espinardo University Campus, Murcia, Spain
xDepartment of Biological Sciences, University of Alberta, Edmonton, Canada
yDepartment of Chemistry, King Saud University, Riyadh, Saudi Arabia. E-mail: alan.crozier44@gmail.com
zSchool of Medicine, Dentistry and Nursing, University of Glasgow, Glasgow, UK
First published on 23rd April 2025
There is an increasing body of evidence indicating that phenolic compounds derived from microbiota-mediated breakdown of dietary (poly)phenolics in the colon are at least partially responsible for the beneficial effects of a plant-based diet. Investigating the role of these catabolites and defining their particular biological effects is challenging due to the complex microbial pathways and the diversity of structures that are produced. When reviewing the data this is further exacerbated by the inconsistency and lack of standardization in naming the microbial phenolics. Here we update the nomenclature of colonic catabolites of dietary (poly)phenols, extending the proposals of Kay et al. (Am. J. Clin. Nutr., 2020, 112, 1051–1068, DOI: 10.1093/ajcn/nqaa204), by providing additional structures, and addressing the difficulties that can arise when investigating regioisomers and stereoisomers, where subtle differences in structure can have a substantial impact on bioactivity. The information provided will help to better harmonize the literature, facilitate data retrieval and provide a reference for researchers in several fields, especially nutrition and biochemistry.
Investigations of the catabolism of dietary (poly)phenols in the lower gastrointestinal tract and the elucidation of protective effects of the resultant phenolic catabolites, and their use as biomarkers to modulate human health,24–28 are compounded by the sheer number of catabolites involved, not just in biofluids but also plants and derived foods. This is further complicated by the variety of nomenclatures and trivial names used to describe the phenolic compounds involved.
In October 2020 a consortium of researchers published proposals for a convenient and unambiguous nomenclature for dietary (poly)phenol catabolites.29 The current paper is an extension of this publication providing an expanded list of phenolics, accompanied by figures illustrating the listed structures. It is the natural consequence of testing the proposed standardized nomenclature and addresses some of the difficulties arising when naming catabolites that were not included in the first version. It also sheds light on the potential problems arising when dealing with regioisomers and stereoisomers. Isomers are known to differ in absorption, metabolism, pharmacokinetics and associated biological effects and these differences are an important topic that is frequently overlooked. The nomenclature of glutathione derivatives, which are produced in the upper GI tract, and the microbial catabolites of lignans, the so-called enterolignans, are also reviewed. This paper will serve as a new guideline for harmonized research approaches in the field of dietary (poly)phenols. The main groups of phenolics that are included are outlined in ESI.†
Recommended names | Non-prime names, synonyms and incorrect nomenclature [italics] | CAS | IUPAC (InChIKey; Monoisotopic Mass Da.) |
---|---|---|---|
a Cinnamic acids and stilbenes have cis (Z) and trans (E) geometric isomers. In nature the trans isomer is more common.
b In rare instances compounds appear to have two different InChIKey formulas in online databases which are generally associated with different CAS or registry numbers and possibly reflect uncharacterized isomeric configuration. For example: 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone or IUPAC 5-[(3,4-dihydroxyphenyl)methyl]oxolan-2-one is listed as having two different CAS/RN, 21618-92-8 and 191666-22-5, two different standard 27 character InchIKey ZNXXWTPQHVLMQT-UHFFFAOYSA-N and ZNXXWTPQHVLMQT-MRVPVSSYSA-N and sharing the same SMILES formula C1CC(![]() ![]() ![]() ![]() |
|||
1. Hydroxybenzenes (C 6 –C 0 ) | |||
1,2-Dihydroxybenzene [1.1] | Benzene-1,2-diol | 120-80-9 | Benzene-1,2-diol |
Catechol | (YCIMNLLNPGFGHC-UHFFFAOYSA-N; 110.036779 g mol−1) | ||
Pyrocatechol | |||
Brenzcatechin | |||
1,3-Dihydroxybenzene [1.2] | Benzene-1,3-diol | 108-46-3 | Benzene-1,3-diol |
Resorcinol | (GHMLBKRAJCXXBS-UHFFFAOYSA-N; 110.036779 g mol−1) | ||
1,2,3-Trihydroxybenzene [1.3] | Benzene-1,2,3-triol | 87-66-1 | Benzene-1,2,3-triol |
Pyrogallol | (WQGWDDDVZFFDIG-UHFFFAOYSA-N; 126.031694 g mol−1) | ||
1,3,5-Trihydroxybenzene [1.4] | Benzene-1,3,5-triol | 108-73-6 | Benzene-1,3,5-triol |
Phloroglucinol | (QCDYQQDYXPDABM-UHFFFAOYSA-N; 126.031694 g mol−1) | ||
4-Methyl-1,2-dihydroxybenzene [1.5] | 4-Methyl-1,2-benzenediol | 452-86-8 | 4-Methylbenzene-1,2-diol |
4-Methylcatechol | (ZBCATMYQYDCTIZ-UHFFFAOYSA-N; 124.052429 g mol−1) | ||
[3,4-Dihydroxytoluene] | |||
2-Hydroxybenzene-1-sulfate [1.6] | [Catechol-2-sulfate pyrocatechol sulfate] | 4918-96-1 | (2-Hydroxyphenyl) hydrogen sulfate |
(MZPWKJZDOCIALD-UHFFFAOYSA-N; 189.993594 g mol−1) | |||
2-Hydroxybenzene-1-glucuronide [1.7] | [catechol-2-glucuronide catechol-glucuronide] | 28623-57-6 | (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(2-hydroxyphenoxy)oxane-2-carboxylic acid |
(ICPYZFZFSLTYID-GOVZDWNOSA-N; 286.068867 g mol−1) | |||
2,3-Dihydroxybenzene-1-sulfate [1.8] | [pyrogallol-3-sulfate pyrogallol-1-sulfate] | — | (2,3-Dihydroxyphenyl) hydrogen sulfate |
(NGVLEQPKHLWZLN-UHFFFAOYSA-N; 205.988509 g mol−1) | |||
2,3-Dihydroxybenzene-1-glucuronide [1.9] | [pyrogallol-3-glucuronide pyrogallol-1-glucuronide] | — | — |
(302.066378 g mol−1) | |||
2-Hydroxybenzene-1-glucuronide-3-sulfate [1.10] | [pyrogallol-2-sulfate-3-glucuronide] | — | — |
(382.02060 g mol−1) | |||
2. Benzaldehydes (C 6 –C 1 ) | |||
4-Hydroxybenzaldehyde [2.1] | 4-Formylphenol | 123-08-0 | 4-Hydroxybenzaldehyde |
(RGHHSNMVTDWUBI-UHFFFAOYSA-N; 122.036779 g mol−1) | |||
3,4-Dihydroxybenzaldehyde [2.2] | Protocatechualdehyde | 139-85-5 | 3,4-Dihydroxybenzaldehyde |
(IBGBGRVKPALMCQ-UHFFFAOYSA-N; 138.031694 g mol−1) | |||
2,4,6-Trihydroxybenzaldehyde [2.3] | Phloroglucinaldehyde | 487-70-7 | 2,4,6-Trihydroxybenzaldehyde |
(BTQAJGSMXCDDAJ-UHFFFAOYSA-N; 154.026609 g mol−1) | |||
3-Hydroxy-4-methoxybenzaldehyde [2.4] | Isovanillin | 621-59-0 | 3-Hydroxy-4-methoxybenzaldehyde |
(JVTZFYYHCGSXJV-UHFFFAOYSA-N; 152.047344 g mol−1) | |||
4-Hydroxy-3-methoxybenzaldehyde [2.5] | 3-Methoxy-4-hydroxybenzaldehyde | 121-33-5 | 4-Hydroxy-3-methoxybenzaldehyde |
Vanillin | (MWOOGOJBHIARFG-UHFFFAOYSA-N; 152.047344 g mol−1) | ||
3. Benzoic acids (C 6 –C 1 ) | |||
3-Hydroxybenzoic acid [3.1] | 3-Hydroxybenzene carboxylic acid | 99-06-9 | 3-Hydroxybenzoic acid |
(IJFXRHURBJZNAO-UHFFFAOYSA-N; 138.031694 g mol−1) | |||
4-Hydroxybenzoic acid [3.2] | 4-Hydroxybenzene carboxylic acid | 99-96-7 | 4-Hydroxybenzoic acid |
(FJKROLUGYXJWQN-UHFFFAOYSA-N; 138.031694 g mol−1) | |||
2,5-Dihydroxybenzoic acid [3.3] | Gentisic acid | 490-79-9 | 2,5-Dihydroxybenzoic acid |
5-Hydroxy-salicylic acid | (WXTMDXOMEHJXQO-UHFFFAOYSA-N; 154.026611 g mol−1) | ||
hydroquinone carboxylic acid | |||
3,4-Dihydroxybenzoic acid [3.4] | protocatechuic acid | 99-50-3 | 3,4-Dihydroxybenzoic acid |
(YQUVCSBJEUQKSH-UHFFFAOYSA-N; 154.026609 g mol−1) | |||
3,5-Dihydroxybenzoic acid [3.5] | α-Resorcylic acid | 99-10-5 | 3,5-Dihydroxybenzoic acid |
(UYEMGAFJOZZIFP-UHFFFAOYSA-N; 154.026609 g mol−1) | |||
3,4,5-Trihydroxybenzoic acid [3.6] | Gallic acid | 149-91-7 | 3,4,5-Trihydroxybenzoic acid |
(LNTHITQWFMADLM-UHFFFAOYSA-N; 170.021523 g mol−1) | |||
5-Hydroxy-2-aminobenzoic acid [3.7] | 5-Hydroxyanthranilic acid | 394-31-0 | 2-Amino-5-hydroxybenzoic acid |
(HYNQTSZBTIOFKH-UHFFFAOYSA-N; 153.042593 g mol−1) | |||
Benzoic acid-4-glucuronide [3.8] | — | — | 6-(4-Carboxyphenoxy)-3,4,5-trihydroxyoxane-2- carboxylic acid |
(DKNOHNCMCYDVLT-UHFFFAOYSA-N; 314.063782 g mol−1) | |||
Benzoic acid-4-sulfate [3.9] | [4-Hydroxybenzoic acid-4-O-sulphate] | 3233-38-3 | 4-(Sulfooxy)benzoic acid |
(RJTYSXVYCZAUHE-UHFFFAOYSA-N; 217.988509 g mol−1) | |||
3-Hydroxybenzoic acid-4-glucuronide [3.10] | [Protocatechuic acid-4-glucuronide] | — | 6-(4-Carboxy-2-hydroxyphenoxy)-3,4,5-trihydroxyoxane-2-carboxylic acid |
(NLCBCVGRBFNEJE-UHFFFAOYSA-N; 330.058697 g mol−1) | |||
4-Hydroxybenzoic acid-3-glucuronide [3.11] | [protocatechuic acid-3-glucuronide] | 953037-17-7 | 6-(5-Carboxy-2-hydroxyphenoxy)-3,4,5-trihydroxyoxane-2-carboxylic acid |
(CXNFDJSOAJNKSU-UHFFFAOYSA-N; 330.058697 g mol−1) | |||
3-Hydroxybenzoic acid-4-sulfate [3.12] | [protocatechuic acid-4-sulfate] | 38339-04-7 | 2-[3-Hydroxy-4-(sulfooxy)phenyl]acetic acid |
(ZQTJTTSZJNFQGJ-UHFFFAOYSA-N; 233.983423 g mol−1) | |||
4-Hydroxybenzoic acid-3-sulfate [3.13] | [Protocatechuic acid-3-sulfate] | 76496-11-2 | 4-Hydroxy-3-(sulfooxy)benzoic acid |
(GSFKEOSQCKWCLH-UHFFFAOYSA-N; 233.983423 g mol−1) | |||
3-Hydroxy-4-methoxybenzoic acid [3.14] | Isovanillic acid | 645-08-9 | 3-Hydroxy-4-methoxybenzoic acid |
(LBKFGYZQBSGRHY-UHFFFAOYSA-N; 168.042259 g mol−1) | |||
4-Methoxybenzoic acid-3-glucuronide[3.15] | [Isovanillic acid-3-glucuronide] | — | 6-(5-Carboxy-2-methoxyphenoxy)-3,4,5-trihydroxyoxane-2-carboxylic acid |
(WREVRVHLTSYMIJ-UHFFFAOYSA-N; 344.074347 g mol−1) | |||
4-Methoxybenzoic acid-3-sulfate [3.16] | [isovanillic acid-3-sulfate] | — | 4-methoxy-3-(sulfooxy)benzoic acid |
(VSFFJSSUGMYRMP-UHFFFAOYSA-N; 247.999073 g mol−1) | |||
4-Hydroxy-3-methoxybenzoic acid [3.17] | Vanillic acid | 121-34-6 | 4-hydroxy-3-methoxybenzoic acid |
(WKOLLVMJNQIZCI-UHFFFAOYSA-N; 168.042259 g mol−1) | |||
3-Methoxybenzoic acid-4-glucuronide [3.18] | [Vanillic acid-4-glucuronide] | — | (2S,3S,4R,5R,6S)-6-(4-Carboxy-2-methoxyphenoxy)-3,4-dihydroxy-5-methyloxane-2-carboxylic acid |
(MBNPZIKKKDDLLL-QGZCQISNSA-N; 344.074347 g mol−1) | |||
3-Methoxybenzoic acid-4-sulfate[3.19] | [Vanillic acid-4-sulfate] | 71235-86-4 | 3-Methoxy-4-sulfooxybenzoic acid |
(TXRKUXPAEPOCIX-UHFFFAOYSA-N; 247.999073 g mol−1) | |||
4-Hydroxy-3,5-dimethoxybenzoic acid [3.20] | Syringic acid | 530-57-4 | 4-Hydroxy-3,5-dimethoxybenzoic acid |
(JMSVCTWVEWCHDZ-UHFFFAOYSA-N; 198.052823 g mol−1) | |||
3,4-Dimethoxybenzoic acid [3.21] | veratric acid | 93-07-2 | 3,4-Dimethoxybenzoic acid |
(DAUAQNGYDSHRET-UHFFFAOYSA-N; 182.057909 g mol−1) | |||
4. Cinnamic acids (C 6 –C 3 unsaturated) | |||
cinnamic acid [4.1] | trans-Cinnamic acid | 621-82-9 | (2E)-3-Phenylprop-2-enoic acid |
140-10-3 | (WBYWAXJHAXSJNI-VOTSOKGWSA-N; 148.052429 g mol−1) | ||
2′-Hydroxycinnamic acid [4.2] | 2-Hydroxycinnamic acid | 614-60-8 | (2E)-3-(2-Hydroxyphenyl)prop-2-enoic acid |
o-Coumaric acid | (PMOWTIHVNWZYFI-AATRIKPKSA-N; 164.047344 g mol−1) | ||
trans-2-Coumaric acid | |||
trans-2-Hydroxycinnamic acid | |||
3-(2-Hydroxyphenyl)acrylic acid | |||
3′-Hydroxycinnamic acid [4.3] | 3-Hydroxycinnamic acid | 588-30-7 | (2E)-3-(3-Hydroxyphenyl)prop-2-enoic acid |
m-Coumaric acid | (KKSDGJDHHZEWEP-SNAWJCMRSA-N; 164.047344 g mol−1) | ||
3-Coumaric acid | |||
trans-3-Coumaric acid | |||
3-(3-Hydroxyphenyl)acrylic acid | |||
4′-Hydroxycinnamic acid [4.4] | 4-hydroxycinnamic acid | 501-98-4 | (2E)-3-(4-Hydroxyphenyl)prop-2-enoic acid |
Coumaric acid | (NGSWKAQJJWESNS-ZZXKWVIFSA-N; 164.047344 g mol−1) | ||
p-Coumaric acid | |||
4-Coumaric acid | |||
trans-4-Hydroxycinnamic acid | |||
4-Hydroxyphenyl)acrylic acid | |||
3′,4′-Dihydroxycinnamic acid [4.5] | 3,4-Dihydroxycinnamic acid | 331-39-5 | (2E)-3-(3,4-dihydroxyphenyl)prop-2-enoic acid |
Caffeic acid | 501-16-6 | (QAIPRVGONGVQAS-DUXPYHPUSA-N; 180.042259 g mol−1) | |
trans-Caffeic acid | |||
3-(3,4-Dihydroxyphenyl)acrylic acid | |||
Cinnamic acid-4′-glucuronide [ 4.6 ] | Cinnamic acid-4-glucuronide | — | (2S,3S,4R,5R,6S)-6-{4-[(1E)-2-Carboxyeth-1-en-1-yl]phenoxy}-3,4,5-trihydroxyoxane-2-carboxylic acid |
[p-Coumaric acid-4′-glucuronide] | (SOKJXEKPKWKYKR-LZJCFMAWSA-N; 340.079432 g mol−1) | ||
4′-Hydroxy-3′-methoxycinnamic acid [4.7] | 4-Hydroxy-3-methoxycinnamic acid | 537-98-4 | (2E)-3-(4-Hydroxy-3-methoxyphenyl)prop-2-enoic acid |
Ferulic acid | (KSEBMYQBYZTDHS-HWKANZROSA-N; 194.057909 g mol−1) | ||
trans-Ferulic acid | |||
3-(4-Hydroxy-3-methoxyphenyl)acrylic acid | |||
3′-Methoxycinnamic acid-4′-glucuronide [4.8] | 3-Methoxycinnamic acid-4-glucuronide | 86321-24-6 | — |
[Ferulic acid-4-glucuronide] | 370.089996 g mol−1 | ||
3′-Methoxycinnamic acid-4′-sulfate [ 4.9 ] | 3-Methoxycinnamic acid-4-sulfate | 86321-29-1 | (E)-3-(3-Methoxy-4-sulfooxyphenyl)prop-2-enoic acid |
[Ferulic acid-4′-sulfate | (PZPATWACAAOHTJ-HWKANZROSA-N; 274.014723 g mol−1) | ||
Ferulic acid-4-sulfate] | |||
3′-Hydroxy-4′-methoxycinnamic acid [4.10] | 3-hydroxy-4-methoxycinnamic acid | 537-73-5 | (2E)-3-(3-Hydroxy-4-methoxyphenyl)prop-2-enoic acid |
Isoferulic acid | (QURCVMIEKCOAJU-HWKANZROSA-N; 194.057909 g mol−1) | ||
Hesperetate | |||
3-(3-Hydroxy-4-methoxyphenyl)acrylic acid | |||
4′-Methoxycinnamic acid-3′-glucuronide [ 4.11 ] | 4-Methoxycinnamic acid-3-glucuronide | 1065272-10-7 | (2S,3S,4S,5R,6S)-6-[5-[(E)-2-carboxyethenyl]-2-methoxyphenoxy]-3,4,5-trihydroxyoxane-2-carboxylic acid |
[Isoferulic acid-3 ′-glucuronide | (SHJZLGVIOYFHCB-MBAOVNHDSA-N; 370.089996 g mol−1) | ||
Isoferulic acid-3-glucuronide] | |||
4′-Methoxycinnamic acid-3′-sulfate [ 4.12 ] | 4-methoxycinnamic acid-3-sulfate | 1258842-19-1 | (E)-3-(4-Methoxy-3-sulfooxyphenyl)prop-2-enoic acid |
[Isoferulic acid-3-sulfate | (DCMKMHVTKFJMAU-HWKANZROSA-N; 274.014723 g mol−1) | ||
Isoferulic acid-3-sulfate] | |||
5. Phenylpropanoic acids (C 6 –C 3 ) | |||
3-Phenylpropanoic acid [5.1] | 3-(Phenyl)propanoic acid | 501-52-0 | 3-Phenylpropanoic acid |
[Dihydrocinnamic acid | (XMIIGOLPHOKFCH-UHFFFAOYSA-N; 150.06808 g mol−1) | ||
Hydrocinnamic acid] | |||
3-(3′-Hydroxyphenyl)propanoic acid [5.2] | 3-(3-Hydroxyphenyl)propanoic acid | 621-54-5 | 3-(3-Hydroxyphenyl)propanoic acid |
3-(3-Hydroxyphenyl)propionic acid | (QVWAEZJXDYOKEH-UHFFFAOYSA-N; 166.062994 g mol−1) | ||
3-Hydroxy-dihydrocinnamic acid | |||
m-Hydroxy-dihydrocinnamic acid | |||
3-(4′-Hydroxyphenyl)propanoic acid [5.3] | 3-(4-Hydroxyphenyl)propanoic acid | 501-97-3 | 3-(4-Hydroxyphenyl)propanoic acid |
3-(4-Hydroxyphenyl)propionic acid | (NMHMNPHRMNGLLB-UHFFFAOYSA-N; 166.062994 g mol−1) | ||
4-Hydroxy-dihydrocinnamic acid | |||
m-Hydroxy-dihydrocinnamic acid | |||
m-Hydroxy-hydrocinnamic acid | |||
Phloretic acid | |||
3-(3′,4′-Dihydroxyphenyl)propanoic acid [5.4] | 3-(3,4-Dihydroxyphenyl)propanoic acid | 1078-61-1 | 3-(3,4-Dihydroxyphenyl)propanoic acid |
3-(3,4-Dihydroxyphenyl)propionic acid | (DZAUWHJDUNRCTF-UHFFFAOYSA-N; 182.057909 g mol−1) | ||
Dihydrocaffeic acid | |||
Hydrocaffeic acid | |||
3,4-Dihydroxybenzenepropanoic acid | |||
3,4-Dihydroxy-dihydrocinnamic acid | |||
3-(3′,5′-Dihydroxyphenyl)propanoic acid [5.5] | 3-(3,5-Dihydroxyphenyl)propanoic acid | 26539-01-5 | 3-(3,5-Dihydroxyphenyl)propanoic acid |
3-(3,5-Dihydroxyphenyl)propionic acid | (ITPFIKQWNDGDLG-UHFFFAOYSA-N; 182.057909 g mol−1) | ||
3,5-Dihydroxybenzenepropanoic acid | |||
3,5-Dihydroxy-dihydrocinnamic acid | |||
3,5-Dihydroxy-hydrocinnamic acid | |||
3-(Phenyl)propanoic acid-4′-glucuronide [5.6] | 3-(Phenyl)propanoic acid-4-glucuronide | — | — |
3-(Phenyl)propionic acid-4-glucuronide | 342.095082 g mol−1 | ||
[4-Hydroxy-dihydrocinnamic acid-4-glucuronide | |||
p-Hydroxy-dihydrocinnamic acid-glucuronide] | |||
3-(3′-Methoxyphenyl)propanoic acid [5.7] | 3-(3-Methoxyphenyl)propanoic acid | 10516-71-9 | 3-(3-Methoxyphenyl)propanoic acid |
3-(3-Methoxyphenyl)propionic acid | (BJJQJLOZWBZEGA-UHFFFAOYSA-N; 180.07864425 g mol−1) | ||
3-Methoxy-dihydrocinnamic acid | |||
3-(4′-Methoxyphenyl)propanoic acid [5.8] | 3-(4-Methoxyphenyl)propanoic acid | 1929-29-9 | 3-(4-Methoxyphenyl)propanoic acid |
3-(4-Methoxyphenyl)propionic acid | (FIUFLISGGHNPSM-UHFFFAOYSA-N; | ||
4-Methoxy-dihydrocinnamic acid | 180.078644 g mol−1) | ||
3-(3′-Hydroxy-4′-methoxyphenyl)propanoic acid [5.9] | 3-(3-Hydroxy-4-methoxyphenyl)propanoic acid | 1135-15-5 | 3-(3-Hydroxy-4-methoxyphenyl)propanoic acid |
Dihydro-isoferulic acid | (ZVIJTQFTLXXGJA-UHFFFAOYSA-N; 196.073559 g mol−1) | ||
3-(3-Hydroxy-4-methoxyphenyl)dihydrocinnamic acid | |||
3-(4′-Hydroxy-3′-methoxyphenyl)propanoic acid [5.10] | 3-(4-Hydroxy-3-methoxyphenyl)propanoic acid | 1135-23-5 | 3-(4-hydroxy-3-methoxyphenyl) propanoic acid |
3-(4-Hydroxy-3-methoxyphenyl)propionic acid | (BOLQJTPHPSDZHR-UHFFFAOYSA-N; 196.073559 g mol−1) | ||
Dihydroferulic acid | |||
[Hydroferulic acid] | |||
3-(4-Hydroxy-3-methoxyphenyl)dihydrocinnamic acid | |||
3-(4′-Hydroxyphenyl)propanoic acid-3′-glucuronide [5.11] | 3-(4-Hydroxyphenyl)propanoic acid-3-glucuronide | 1187945-71-6 | (2S,3S,4S,5R,6S)-6-[5-(2-Carboxyethyl)-2-hydroxyphenoxy]-3,4,5-trihydroxyoxane-2-carboxylic acid |
3-(4-Hydroxyphenyl)propionic acid-3-glucuronide | |||
[Dihydrocaffeic acid-3′-glucuronide | |||
Dihydrocaffeic acid-3-glucuronide] | (AELQNMHOLDHBFA-DKBOKBLXSA-N; 358.089997 g mol−1) | ||
3-(3′-Hydroxyphenyl)propanoic acid-4′-glucuronide [5.11] | 3-(3-Hydroxyphenyl)propanoic acid-4-glucuronide | — | (2S,3S,4S,5R)-6-[4-(2-CARBOXYETHYL)-2-hydroxyphenoxy]-3,4,5-trihydroxyoxane-2-carboxylic acid |
3-(3-Hydroxyphenyl)propionic acid-4-glucuronide | |||
[Dihydrocaffeic acid-4′-glucuronide | |||
Dihydrocaffeic acid-4-glucuronide] | (DUTJMLCURMYWCW-HXMBFPRCSA-N; 358.089997 g mol−1) | ||
3-(3′-Hydroxyphenyl)propanoic acid-4′-sulfate [5.13] | 3-(3-Hydroxyphenyl)propanoic acid-4-sulfate | — | 3-(3-Hydroxy-4-sulfooxyphenyl)propanoic acid |
3-(3-Hydroxyphenyl)propionic acid-4-sulfate | (WEPNMLSXEATIJK-UHFFFAOYSA-N; 262.014723 g mol−1) | ||
[Dihydrocaffeic acid-4′-sulfate | |||
Dihydrocaffeic acid-4-sulfate] | |||
3-(4′-Hydroxyphenyl)propanoic acid-3′-sulfate [5.14] | 3-(4-Hydroxyphenyl)propanoic acid-3-sulfate | 1187945-70-5 | 3-[4-Hydroxy-3-(sulfooxy)phenyl]propanoic acid |
3-(4-Hydroxyphenyl)propionic acid-3-sulfate | (MIMULQQHBAZGER-UHFFFAOYSA-N; 262.014724 g mol−1) | ||
[Dihydrocaffeic acid-3′-sulfate | |||
Dihydrocaffeic acid-3-sulfate] | |||
3-(3′-Methoxyphenyl)propanoic acid-4′-glucuronide [5.15] | 3-(3-Methoxyphenyl)propanoic acid-4-glucuronide | 86321-28-0 | (2S,3S,4S,5R,6S)-6-[4-(2-carboxyethyl)-2-methoxyphenoxy]-3,4,5-trihydroxyoxane-2-carboxylic acid |
3-(3-Methoxyphenyl)propionic acid-4-glucuronide | (KYERCTIKYSSKPA-JHZZJYKESA-N; 372.105646 g mol−1) | ||
[Dihydroferulic acid-4′-glucuronide | |||
Dihydroferulic acid-4-glucuronide] | |||
3-(3′-Methoxyphenyl)propanoic acid-4′-sulfate [5.16] | 3-(3-Methoxyphenyl)propanoic acid-4-sulfate | 86321-33-7 | 3-(3-Methoxy-4-sulfooxyphenyl)propanoic acid |
3-(3-Methoxyphenyl)propionic acid-4-sulfate | (UMCDODPBPQMWQP-UHFFFAOYSA-N; 276.030374 g mol−1) | ||
[Dihydroferulic acid-4′-sulfate | |||
Dihydroferulic acid-4-sulfate] | |||
3-(4′-Methoxyphenyl)propanoic acid-3′-glucuronide [5.17] | 3-(4-Methoxyphenyl)propanoic acid-3-glucuronide | 1187945-72-7 | (2S,3S,4S,5R,6S)-6-[5-(2-Carboxyethyl)-2-methoxyphenoxy]-3,4,5-trihydroxyoxane-2-carboxylic acid |
3-(4-Methoxyphenyl)propionic acid-3-Glucuronide | (SYLIYWIQUHQCPY-UHFFFAOYSA-N; 372.105647 g mol−1) | ||
[Dihydro-isoferulic acid-3′-glucuronide] | |||
3-(4′-Methoxyphenyl)propanoic acid-3′-sulfate [5.18] | 3-(4-Methoxyphenyl)propanoic acid-3-sulfate | 1258842-21-5 | 3-(4-Methoxy-3-sulfooxyphenyl)propanoic acid |
3-(4-Methoxyphenyl)propionic acid-3-sulfate | (QZIYZVFIROFZCV-UHFFFAOYSA-N; 276.030374 g mol−1) | ||
[Dihydro-isoferulic acid-3′-sulfate | |||
Dihydro-isoferulic acid-3-sulfate] | |||
6. Hydroxy-3-(phenyl)propanoic acids (C 6 –C 3 ) | |||
(R/S)-3-Hydroxy-3-(phenyl)propanoic acid [6.1] | 3-(Phenyl)-3-hydroxypropanoic acid | 3480-87-3 | 3-Hydroxy-3-phenylpropanoic acid |
3-(Phenyl)hydracrylic acid | (AYOLELPCNDVZKZ-UHFFFAOYSA-N; 166.062994 g mol−1) | ||
(R/S)-3-Hydroxy-3-(3′-hydroxyphenyl)propanoic acid [6.2] | 3-Hydroxy-3-(3-hydroxyphenyl)propanoic acid | 3247-75-4 | 3-Hydroxy-3-(3-hydroxyphenyl)propanoic acid |
3-(3-Hydroxyphenyl)-3-hydroxypropionic acid | (KHTAGVZHYUZYMF-UHFFFAOYSA-N; 182.057909 g mol−1) | ||
3-Hydroxy-3-(3′-hydroxyphenyl)propionic acid | |||
3-Hydroxy-3-(3-hydroxyphenyl)propionic acid | |||
β, m-Dihydroxyphenylpropionic acid | |||
β, meta-dihydroxyphenylpropionic acid | |||
3-(3-Hydroxyphenyl)hydracrylic acid | |||
3-(3′-Hydroxyphenyl)hydracrylic acid | |||
m-Hydroxyphenylhydracrylic acid | |||
(R/S)-3-Hydroxy-3-(3′-hydroxy-4′-methoxyphenyl)propanoic acid [6.3] | 3-Hydroxy-3-(3-hydroxy-4-methoxyphenyl)propanoic acid | 28030-22-0 | 3-Hydroxy-3-(3-hydroxy-4-methoxyphenyl)propanoic acid |
3-Hydroxy-3-(3-hydroxy-4-methoxyphenyl)propionic acid | (JEXBTMWMYGBBHO-UHFFFAOYSA-N; 212.068473 g mol−1) | ||
3-(3-Hydroxy-4-methoxyphenyl)-3-hydroxypropanoic acid | |||
3-(3-Hydroxy-4-methoxyphenyl)-3-hydroxypropionic acid | |||
3-(3′-Hydroxy-4′-methoxyphenyl)hydracrylic acid | |||
3-(3-Hydroxy-4-methoxyphenyl)hydracrylic acid | |||
(R/S)-2-Hydroxy-3-(phenyl)propanoic acid [6.4] | 3-(Phenyl)-2-hydroxypropanoic acid | 828-01-3 | 2-Hydroxy-3-phenylpropionic acid; |
2-Hydroxy-3-(phenyl)propionic acid | (VOXXWSYKYCBWHO-UHFFFAOYSA-N; 166.062994 g mol−1) | ||
3-(Phenyl)-2-hydroxypropionic acid | |||
3-(Phenyl)lactic acid | |||
(R/S)-2-Hydroxy-3-(4′-hydroxyphenyl)propanoic acid [6.5] | 2-Hydroxy-3-(4-hydroxyphenyl)propanoic acid | 306-23-0 | 2-Hydroxy-3-(4-hydroxyphenyl)propanoic acid |
3-(4-Hydroxyphenyl)-2-hydroxypropanoic acid | (JVGVDSSUAVXRDY-UHFFFAOYSA-N; 182.057909 g mol−1) | ||
2-Hydroxy-3-(4-hydroxyphenyl)propionic acid | |||
3-(4′-Hydroxyphenyl)-2-hydroxypropionic acid | |||
3-(4′-Hydroxyphenyl)lactic acid | |||
3-(4-Hydroxyphenyl)lactic acid | |||
(R/S)-2-Hydroxy-3-(3′,4′-dihydroxyphenyl)propanoic acid [6.6] | 2-Hydroxy-3-(3,4-dihydroxyphenyl)propanoic acid | 23028-17-3 | 3-(3,4-Dihydroxyphenyl)-2-hydroxypropanoic acid |
3-(3,4-Dihydroxyphenyl)-2-hydroxypropanoic acid | (PAFLSMZLRSPALU-UHFFFAOYSA-N; 198.052823 g mol−1) | ||
2-Hydroxy-3-(3′,4′-dihydroxyphenyl)propionic acid | |||
3-(3,4-Dihydroxyphenyl)-2-hydroxypropionic acid | |||
3-(3′,4′-Dihydroxyphenyl)lactic acid | |||
3-(3,4-Dihydroxyphenyl)lactic acid | |||
Danshensu | |||
Salvianic acid | |||
7. Phenylacetic acids (C 6 –C 2 ) | |||
phenylacetic acid [7.1] | Phenylethanoic acid | 103-82-2 | 2-Phenylacetic acid |
2-Phenylethanoate | (WLJVXDMOQOGPHL-UHFFFAOYSA-N; 136.052429 g mol−1) | ||
3′-Hydroxyphenylacetic Acid [7.2] | 3-Hydroxyphenylacetic acid | 621-37-4 | 2-(3-Hydroxyphenyl)acetic acid |
3-Hydroxyphenylethanoic acid | (FVMDYYGIDFPZAX-UHFFFAOYSA-N; 152.047344 g mol−1) | ||
3′-Methoxyphenylacetic acid [7.3] | 3-Methoxyphenylacetic acid | 1798-09-0 | 2-(3-Methoxyphenyl)acetic acid |
3-Methoxyphenylethanoic acid | (LEGPZHPSIPPYIO-UHFFFAOYSA-N; 166.062994 g mol−1) | ||
4′-Hydroxyphenylacetic acid [7.4] | 4-Hydroxyphenylacetic acid | 156-38-7 | 2-(4-Hydroxyphenyl)acetic acid |
4-Hydroxyphenylethanoic acid | (XQXPVVBIMDBYFF-UHFFFAOYSA-N; 152.047344 g mol−1) | ||
3′,4′-Dihydroxyphenylacetic acid [7.5] | 3,4-Dihydroxyphenylacetic acid | 102-32-9 | 2-(3,4-Dihydroxyphenyl)acetic acid |
3,4-Dihydroxyphenylethanoic acid | (CFFZDZCDUFSOFZ-UHFFFAOYSA-N; 168.042259 g mol−1) | ||
Homoprotocatechuic acid | |||
DOPAC | |||
4′-Hydroxy-3′-methoxyphenylacetic acid [7.6] | 4-Hydroxy-3-methoxyphenylacetic acid | 306-08-1 | 2-(4-Hydroxy-3-methoxyphenyl)acetic acid |
4-Hydroxy-3-methoxyphanylethanoic acid | (QRMZSPFSDQBLIX-UHFFFAOYSA-N; 182.057909 g mol−1) | ||
Homovanillic acid | |||
8. Hydroxy-2-(phenyl)acetic acids (C 6 –C 2 ) | |||
(R/S)-2-Hydroxy-2-(3′-hydroxyphenyl)acetic acid [8.1] | 2-Hydroxy-2-(3-hydroxyphenyl)acetic acid | 17119-15-2 | 2-Hydroxy-2-(3-hydroxyphenyl)acetic acid |
(3-Hydroxyphenyl)-2-hydroxyacetic acid | (OLSDAJRAVOVKLG-UHFFFAOYSA-N; 168.042259 g mol−1) | ||
2-Hydroxy-2-(3-hydroxyphenyl)ethanoic acid | |||
(3-Hydroxyphenyl)-2-hydroxyethanoic acid | |||
3-Hydroxymandelic acid | |||
(R/S)-2-Hydroxy-2-(4′-hydroxyphenyl)acetic acid [8.2] | 2-Hydroxy-2-(4-hydroxyphenyl)acetic acid | 1198-84-1 | 2-Hydroxy-2-(4-hydroxyphenyl)acetic acid |
(4-Hydroxyphenyl)-2-hydroxyacetic acid | (YHXHKYRQLYQUIH-UHFFFAOYSA-N; 168.042259 g mol−1) | ||
2-Hydroxy-2-(4′-hydroxyphenyl)ethanoic acid | |||
(4-Hydroxyphenyl)-2-hydroxyethanoic acid | |||
4′-Hydroxymandelic acid | |||
4-Hydroxymandelic acid | |||
4-Hydroxy-D-mandelic acid | |||
4-Hydroxy-L-mandelic acid | |||
(R/S)-2-hydroxy-2-(4′-hydroxy-3′-methoxyphenyl)acetic acid [8.3] | 2-Hydroxy-2-(4-hydroxy-3-methoxyphenyl)acetic acid | 2394-20-9 | 2-Hydroxy-2-(4-hydroxy-3-methoxyphenyl)acetic acid |
(4-Hydroxy-3-methoxyphenyl)-2-hydroxyacetic acid | 55-10-7 | (CGQCWMIAEPEHNQ-UHFFFAOYSA-N; 198.052823 g mol−1) | |
2-Hydroxy-2-(4-hydroxy-3-methoxyphenyl)ethanoic acid | |||
(4-Hydroxy-3-methoxyphenyl)-2-hydroxyethanoic acid | |||
4′-Hydroxy-3′-methoxymandelic acid | |||
4-Hydroxy-3-methoxymandelic acid | |||
3-Methoxy-4-hydroxymandelic acid | |||
4-Hydroxy-3-methoxy-L-mandelic acid | |||
Vanillylmandelic acid | |||
9. Hippuric acids (C 6 –C 1 –N<) and other amino acid conjugates | |||
hippuric acid [9.1] | — | 495-69-2 | 2-Benzamidoacetic acid |
(QIAFMBKCNZACKA-UHFFFAOYSA-N; 179.058243 g mol−1) | |||
2′-Hydroxyhippuric acid [9.2] | 2-Hydroxyhippuric acid | 487-54-7 | 2-[(2-Hydroxybenzoyl)amino]acetic acid |
2-(2-Hydroxybenzamido)acetic acid | (ONJSZLXSECQROL-UHFFFAOYSA-N; 195.053158 g mol−1) | ||
N-(2-Hydroxybenzoyl)glycine | |||
Salicyluric acid | |||
3′-Hydroxyhippuric acid [9.3] | 3-Hydroxyhippuric acid | 1637-75-8 | 2-[(3-hydroxybenzoyl)amino]acetic acid |
2-(3-Hydroxybenzamido)acetic acid | (XDOFWFNMYJRHEW-UHFFFAOYSA-N; 195.053158 g mol−1) | ||
N-(3-Hydroxybenzoyl)glycine | |||
4′-Hydroxyhippuric acid [9.4] | 4-Hydroxyhippuric acid | 2482-25-9 | 2-[(4-Hydroxybenzoyl)amino]acetic acid |
2-(4-Hydroxybenzamido)acetic acid | (ZMHLUFWWWPBTIU-UHFFFAOYSA-N; 195.053158 g mol−1) | ||
N-(4-Hydroxybenzoyl)glycine | |||
4′-Methoxyhippuric acid [9.5] | 4-Methoxyhippuric acid | 13214-64-7 | 2-[(4-Methoxybenzoyl)amino]acetic acid |
2-(4-Ethoxybenzamido)acetic acid | (SIEIOUWSTGWJGE-UHFFFAOYSA-N; 209.068808 g mol−1) | ||
N-(4-Methoxybenzoyl)glycine | |||
(R/S)-2-Hydroxyhippuric acid [9.6] | α-Hydroxyhippuric acid | 16555-77-4 | 2-Hydroxy-2-(phenylformamido)acetic acid |
α-Hydroxybenzoylglycine | (GCWCVCCEIQXUQU-UHFFFAOYSA-N; | ||
[2-hydroxyhipuric acid] | 195.053158 g mol−1) | ||
4′-Hydroxy-3′-methoxyhippuric acid [9.7] | 4′-Hydroxy-3′-methoxybenzoyl-glycine | 1212-04-0 | 2-[(4-Hydroxy-3-methoxybenzoyl)amino]acetic acid |
vanilloyl-glycine | (LOODYTDRRBLQNH-UHFFFAOYSA-N; 225.063722 g mol−1) | ||
3′-Hydroxy-4′-methoxyhippuric acid [9.8] | 3′-Hydroxy-4′-methoxybenzoyl-glycine | 22005-43-2 | 2-[(3-Hydroxy-4-methoxybenzoyl)amino]acetic acid |
Isovanilloyl-glycine | (HOZJFFMWTLPBCS-UHFFFAOYSA-N; 225.063722 g mol−1) | ||
Phenylacetyl-glycine [9.9] | Phenaceturic acid | 500-98-1 | 2-[(2-Phenyacetyl)amino]acetic acid |
[Phenylaceturic acid] | (UTYVDVLMYQPLQB-UHFFFAOYSA-N; 193.073893 g mol−1) | ||
4′-Hydroxyphenylacetyl-glycine [9.10] | 4-Hydroxyphenylacetyl-glycine | 28116-23-6 | 2-[[2-(4-Hydroxyphenyl)acetyl]amino]acetic acid |
2-[-2-(4-Hydroxyphenyl)acetamido]acetic acid | (CPPDWYIPKSSNNM-UHFFFAOYSA-N; 209.068808 g mol−1) | ||
(S)-Phenyacetyl-glutamine [9.11] | (2S)-5-Amino-5-oxo-2-(2-phenylacetamido)pentanoic acid | 28047-15-6 | (2S)-5-Amino-5-oxo-2-(2-phenylacetamido)pentanoic |
Phenylacetyl-L-glutamine | acid | ||
(JFLIEFSWGNOPJJ-JTQLQIEISA-N; 264.111007 g mol−1) | |||
(S)-4′-Hydroxyphenylacetyl-glutamine [9.12] | 4-Hydroxyphenylacetyl-glutamine | — | 2-[[2-(4-Hydroxyphenyl)acetyl]amino]pentanedioic acid |
2-[2-(4-Hydroxyphenyl)acetamido]pentanedioic acid | (CYRKYXZJUIBBJX-UHFFFAOYSA-N; 281.089937 g mol−1) | ||
Cinnamoyl-glycine [9.13] | 2-Cinnamamidoacetic acid | 16534-24-0 | 2-[[(E)-3-Phenylprop-2-enoyl]amino]acetic acid |
(YAADMLWHGMUGQL-VOTSOKGWSA-N; 205.073893 g mol−1) | |||
4′-Hydroxycinnamoyl-glycine [9.14] | 4-Hydroxycinnamoyl-glycine | — | 2-[[(E)-3-(4-Hydroxyphenyl)prop-2-enoyl]amino]acetic acid |
p-coumaroyl-glycine | (NZSACLXQEHBCNF-ZZXKWVIFSA-N; 221.068807 g mol−1) | ||
4′-Hydroxy-3′-methoxycinnamoyl-glycine [9.15] | 4-Hydroxy-3-methoxycinnamoyl-glycine | 1220-05-9 | 2-[[(E)-3-(4-Hydroxy-3-methoxyphenyl)prop-2-enoyl]amino]acetic acid |
Feruloyl-glycine | (CLGNQAIRBLDHIN-HWKANZROSA-N; 251.079373 g mol−1) | ||
N-(3-Methoxycoumaroyl)-glycine | |||
2-(3-Phenylpropanoylamino)acetic acid | |||
3-(Phenyl)propanoyl-glycine [9.16] | N-(3-Phenylpropanoyl)glycine | 56613-60-6 | 2-(3-Phenylpropanoylamino)acetic acid |
2-(3-Phenylpropanoylamino)acetic acid | (YEIQSAXUPKPPBN-UHFFFAOYSA-N; 207.089543 g mol−1) | ||
10. Phenyl-γ-valerolactones (C 6 –C 5 ) (All compounds may occur as R- and S-enantiomers) | |||
(R/S)-5-(3′,4′-Dihydroxyphenyl)-γ-valerolactone [10.1] | 5-(3,4-Dihydroxyphenyl)-γ-valerolactone | 21618-92-8 | 5-[(3,4-Dihydroxyphenyl)methyl]oxolan-2-one |
δ-(3,4-Dihydroxyphenyl)-γ-valerolactone | 1108192-01-3 (4S) | (ZNXXWTPQHVLMQT-UHFFFAOYSA-N; 208.073559 g mol−1) | |
5-(dihydroxyphenyl)-γ-valerolactone | 191666-22-5 (4R) | ||
5-(dihydroxyphenyl)-valerolactone | |||
[M6] | |||
(R/S)-5-(4′-Hydroxyphenyl)-γ-valerolactone-3′-glucuronide [10.2] | 5-(4-Hydroxyphenyl)-γ-valerolactone-3-glucuronide | — | 3,4,5-Trihydroxy-6-[2-hydroxy-5-[(5-oxooxolan-2-yl)methyl]phenoxy]oxane-2-carboxylic acid |
[M6-glucuronide | (UVGDTVGPBRLMQY-UHFFFAOYSA-N; 384.105647 g mol−1) | ||
5-(3′,4′-dihydroxyphenyl)-γ-valerolactone-3′-glucuronide] | |||
(R/S)-5-(3′-Hydroxyphenyl)-γ-valerolactone-4′-glucuronide [10.3] | 5-(3-Hydroxyphenyl)-γ-valerolactone-4-glucuronide | — | 3,4,5-Trihydroxy-6-{2-hydroxy-4-[(5-oxooxolan-2-yl)methyl]phenoxy}oxane-2-carboxylic acid |
[M6-glucuronide-5-(3′,4′-dihydroxyphenyl)-γ-valerolactone-4′-glucuronide] | (OTBJYBQGMPICIK-UHFFFAOYSA-N; 384.105647 g mol−1) | ||
(R/S)-5-(4′-Hydroxyphenyl)-γ-valerolactone-3′-sulfate [10.4] | 5-(4-Hydroxyphenyl)-γ-valerolactone-3-sulfate | — | [2-Hydroxy-5-[(5-oxooxolan-2-yl)methyl]phenyl] hydrogen sulfate |
[M6-sulfate 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone-3′-sulfate] | (YAXFVDUJDAQPTJ-UHFFFAOYSA-N; 288.030374 g mol−1) | ||
(R/S)-5-(3′-Hydroxyphenyl)-γ-valerolactone-4′-sulfate [10.5] | 5-(3-Hydroxyphenyl)-γ-valerolactone-4-sulfate | — | [2-Hydroxy-4-[(5-oxooxolan-2-yl)methyl]phenyl] hydrogen sulfate |
[M6-sulfate 5-(3′4′-dihydroxyphenyl)-γ-valerolactone-4′-sulfate] | (WAXYAOJFDCCESK-UHFFFAOYSA-N; 288.030374 g mol−1) | ||
(R/S)-5-(3′-Methoxyphenyl)-γ-valerolactone-4′-glucuronide [10.6] | 5-(3-Methoxyphenyl)-γ-valerolactone-4-glucuronide | — | 3,4,5-Trihydroxy-6-[2-methoxy-4-[(5-oxooxolan-2-yl)methyl]phenoxy]oxane-2-carboxylic acid |
[methyl-M6-glucuronide 5-(4′-hydroxy-3′-methoxyphenyl)-γ-valerolactone-4′-glucuronide 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone-3′-methoxy-4′-glucuronide] | (NGMVEYPQYAIGEI-UHFFFAOYSA-N; 398.121297 g mol−1) | ||
(R/S)-5-(3′-Methoxyphenyl)-γ-valerolactone-4′-sulfate [10.7] | 5-(3-Methoxyphenyl)-γ-valerolactone-4-sulfate | — | [2-Methoxy-4-[(5-oxooxolan-2-yl)methyl]phenyl] hydrogen sulfate |
[methyl-M6-sulfate 5-(4′-hydroxy-3′-methoxyphenyl)-γ-valerolactone-4′-sulfate 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone-3′-methoxy-4′-sulfate] | (FYRRHCSCZYSADR-UHFFFAOYSA-N; 302.046024 g mol−1) | ||
(R/S)-5-(4′-Methoxyphenyl)-γ-valerolactone-3′-glucuronide [10.8] | 5-(4-Methoxyphenyl)-γ-valerolactone-3-glucuronide | — | — |
[5-(3′,4′-Dihdroxyphenyl)-γ-valerolactone-4′-methoxy-3′-glucuronide] | 398.121297 g mol−1 | ||
(R/S)-5-(Phenyl)-γ-valerolactone-3′-sulfate-4′-glucuronide [10.9] | 5-(Phenyl)-γ-valerolactone-3-sulfate-4-glucuronide | — | — |
[M6-sulfate-glucuronide 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone-3′-sulfate-4′-glucuronide] | 464.062461 g mol−1 | ||
11. 4-Hydroxy-5-(phenyl)valeric acids (All compounds may occur as R- and S-enantiomers) | |||
(R/S)-4-hydroxy-5-(3′,4′-dihydroxyphenyl)valeric acid [11.1] | 4-Hydroxy-5-(3,4-dihydroxyphenyl)valeric acid | — | 5-(3,4-Dihydroxyphenyl)-4-hydroxypentanoic acid |
5-(3,4-Dihydroxyphenyl)-4-hydroxyvaleric acid | (JDBYFCLHVYVXCX-UHFFFAOYSA-N; 226.084124 g mol−1) | ||
4-Hydroxy-5-(3,4-dihydroxyphenyl)pentanoic acid | |||
5-(3,4-Dihydroxyphenyl)-4-hydroxypentanoic acid | |||
[5-(3,4-Dihydroxyphenyl)-γ-hydroxyvaleric acid 5-(3,4-dihydroxyphenyl)-γ-hydroxypentanoic acid] | |||
(R/S)-4-Hydroxy-5-(4′-hydroxyphenyl)valeric acid-3′-glucuronide [11.2] | 4-Hydroxy-5-(4-hydroxyphenyl)valeric acid-3-glucuronide | — | 6-[5-(4-Carboxy-2-hydroxybutyl)-2-hydroxyphenoxy]- |
5-(4-hydroxyphenyl)-4-hydroxyvaleric acid-3-glucuronide | 3,4,5-Trihydroxyoxane-2-carboxylic acid | ||
4-hydroxy-5-(4-hydroxyphenyl)pentanoic acid-3-glucuronide | (BKJQCPDRWDNBIN-UHFFFAOYSA-N; 402.116212 g mol−1) | ||
5-(4-hydroxyphenyl)-4-hydroxypentanoic acid-3-glucuronide | |||
[5-(3,4-dihydroxyphenyl-4-hydroxyvaleric acid-3-glucuronide] | |||
(R/S)-4-Hydroxy-5-(3′-hydroxyphenyl)valeric acid-4′-glucuronide [11.3] | 4-Hydroxy-5-(3-hydroxyphenyl)valeric acid-4-glucuronide | — | 6-[4-(4-Carboxy-2-hydroxybutyl)-2-hydroxyphenoxy]- |
5-(3-Hydroxyphenyl)-4-hydroxyvaleric acid-4-glucuronide | 3,4,5-Trihydroxyoxane-2-carboxylic acid | ||
4-Hydroxy-5-(3-hydroxyphenyl)pentanoic acid-4-glucuronide | (LLKUARGHNZMSRT-UHFFFAOYSA-N; 402.116212 g mol−1) | ||
5-(4-Hydroxyphenyl)-4-hydroxyvaleric acid-4-glucuronide | |||
[5-(3′,4′-Dihydroxyphenyl)-4-hydroxyvaleric acid-4′-glucuronide] | |||
(R/S)-4-Hydroxy-5-(4′-hydroxyphenyl)valeric acid-3′-sulfate [11.4] | 4-Hydroxy-5-(4-hydroxyphenyl)valeric acid-3-sulfate | — | 4-Hydroxy-5-(4-hydroxy-3-sulfooxyphenyl)pentanoic acid |
5-(4-Hydroxyphenyl)-4-hydroxyvaleric acid-3-sulfate | (HROSNTXKMPHTSL-UHFFFAOYSA-N; 306.040939 g mol−1) | ||
4-Hydroxy-5-(4-hydroxyphenyl)pentanoic acid-3-sulfate | |||
5-(4-Hydroxyphenyl)-4-hydroxypentanoic acid-3-sulfate | |||
[5-(3′,4′-Dihydroxyphenyl)-4-hydroxyvaleric acid-3′-sulfate] | |||
(R/S)-4-Hydroxy-5-(3′-hydroxyphenyl)valeric acid-4′-sulfate [11.5] | 4-Hydroxy-5-(3-hydroxyphenyl)valeric acid-4-sulfate | — | — |
5-(3-Hydroxyphenyl)-4-hydroxyvaleric acid-4-sulfate | 306.040938 g mol−1 | ||
4-Hydroxy-5-(3-hydroxyphenyl)pentanoic acid-4-sulfate | |||
5-(3-Hydroxyphenyl)-4-hydroxypentanoic acid-4-sulfate | |||
[5-(3′,4′-Dihydroxyphenyl)-4-hydroxyvaleric acid-4′-sulfate] | |||
(R/S)-4-Hydroxy-5-(3′-methoxyphenyl)valeric acid-4′-glucuronide [11.6] | 4-Hydroxy-5-(3-methoxyphenyl)valeric acid-4- glucuronide | — | 6-[4-(4-Carboxy-2-hydroxybutyl)-2-methoxyphenoxy]- |
5-(3-Methoxyphenyl)-4-hydroxyvaleric acid-4-glucuronide | 3,4,5-Trihydroxyoxane-2-carboxylic acid | ||
4-Hydroxy-5-(3-methoxyphenyl)pentanoic acid-4-glucuronide | (WOBDOUCWWPCYBL-UHFFFAOYSA-N; 416.131862 g mol−1) | ||
5-(3′-Methoxyphenyl)-4-hydroxypentanoic acid-4-glucuronide | |||
[4-Hydroxy-5-(3′,4′-dihydroxyphenyl)-valeric acid-3′-methoxy-4′-glucuronide] | |||
(R/S)-4-Hydroxy-5-(3′-methoxyphenyl)valeric acid-4′-sulfate [11.7] | 4-Hydroxy-5-(3-methoxyphenyl)valeric acid-4-sulfate | — | 4-Hydroxy-5-[3-methoxy-4-(sulfooxy)phenyl]pentanoic acid |
5-(3-Methoxyphenyl)-4-hydroxyvaleric acid-4-sulfate | (GUEAZORXKKSCMA-UHFFFAOYSA-N; 320.056589 g mol−1) | ||
4-Hydroxy-5-(3-methoxyphenyl)pentanoic acid-4-sulfate | |||
5-(3-Methoxyphenyl)-4-hydroxypentanoic acid-4-sulfate | |||
[4-Hydroxy-5-(3,4-dihydroxyphenyl)-valeric acid-3-methoxy-4-sulfate] | |||
(R/S)-4-Hydroxy-5-(4′-methoxyphenyl)valeric acid-3′-sulfate [11.8] | 4-Hydroxy-5-(4-methoxyphenyl)valeric acid-3-sulfate | — | — |
5-(4-Methoxyphenyl)-4-hydroxyvaleric acid-3-sulfate | (MFHSGCMDDUKYSZ-UHFFFAOYSA-N; 320.056589 g mol−1) | ||
4-Hydroxy-5-(4′-methoxyphenyl)pentanoic acid-3′-sulfate | |||
5-(4-Methoxyphenyl)-4-hydroxpentanoic acid-3-sulfate | |||
[4-hydroxy-5-(3,4-dihydroxyphenyl)-valeric acid-3-methoxy-4-sulfate] | |||
(R/S)-5-(3′,4′-Dihydroxyphenyl)valeric acid-4-sulfate [11.9] | 4-Sulfoxy-5-(3,4-dihydroxyphenyl)valeric acid | — | 5-(3,4-Dihydroxyphenyl)-4-sulfooxypentanoic acid |
5-(3,4-Dihydroxyphenyl)-4-sulfoxyvaleric acid | (NBKHZVHBUVNGQF-UHFFFAOYSA-N; 306.040939 g mol−1) | ||
4-Sulfoxy-5-(3,4-dihydroxyphenyl)pentanoic acid | |||
5-(3,4-Dihydroxyphenyl)-4-sulfoxypentanoic acid | |||
[5-(3-Hydroxyphenyl)-4-sulphoxyvaleric acid] | |||
(R/S)-5-(4′-Hydroxy-3′-methoxyphenyl)valeric acid-4-sulfate [11.10] | 4-Sulfoxy-5-(4-hydroxy-3-methoxyphenyl)valeric acid | – | 5-(4-Hydroxy-3-methoxyphenyl)-4-(sulfooxy)pentanoic acid |
5-(4-Hydroxy-3-methoxyphenyl)-4-sulfoxyvaleric acid | (JQISKEAFUDWLCF-UHFFFAOYSA-N; 320.056589 g mol−1) | ||
4-Sulfoxy-5-(4-hydroxy-3-methoxyphenyl)pentanoic acid | |||
5-(4-Hydroxy-3-methoxyphenyl)-4-sulfoxypentanoic acid | |||
[4-Hydroxy-5-(3,4-dihydroxyphenyl)-valeric acid-3-methoxy-4-sulfate] | |||
12. 5-Phenylvaleric acids (C 6 –C 5 ) | |||
5-(3′,5′-Dihydroxyphenyl)valeric acid [12.1] | 5-(3,5-Dihydroxyphenyl)valeric acid | 74356-41-5 | 5-(3,5-Dihydroxyphenyl)pentanoic acid |
5-(3,5-Dihydroxyphenyl)pentanoic acid | (QHXNJIMVPAFCPR-UHFFFAOYSA-N; 210.089203 g mol−1) | ||
[5-(Dihydroxyphenyl)valeric acid] | |||
5-(3′,4′,5′-Trihydroxyphenyl)valeric acid [12.2] | 5-(3,4,5-Trihydroxyphenyl)valeric acid | — | 5-(3,4,5-Trihydroxyphenyl)pentanoic acid |
5-(3,4,5-Trihydroxyphenyl)pentanoic acid | (MASHJJSDLKLZLA-UHFFFAOYSA-N; 226.084124 g mol−1) | ||
[5-(Trihydroxyphenyl)valeric acid] | |||
13. Urolithins (6H-dibenzo[b,d]pyran-6-ones) | |||
3-Hydroxy-urolithin [13.1] | urolithin B | 1139-83-9 | 3-Hydroxy-6H-benzo[c]chromen-6-one |
(WXUQMTRHPNOXBV-UHFFFAOYSA-N; 212.047344 g mol−1) | |||
Urolithin-3-glucuronide [13.2] | Urolithin B-3-glucuronide | 823806-74-2 | (2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-({6-oxo-6H-benzo[c]chromen-3-yl}oxy)oxane-2-carboxylic acid |
[Urolithin B-glucuronide] | |||
(MHBWCULXQBVPQT-KSPMYQCISA-N; 388.079432 g mol−1) | |||
Urolithin-3-sulfate [13.3] | Urolithin B-3-sulfate | — | 6-Oxobenzo[c]chromen-3-yl) hydrogen sulfate |
[Urolithin B-sulfate] | (LRRVKQQFGIEMSA-UHFFFAOYSA-N; 292.004159 g mol−1) | ||
3,8-Dihydroxy-urolithin [13.4] | Urolithin A | 1143-70-0 | 3,8-Dihydroxy-6H-benzo[c]chromen-6-one |
(RIUPLDUFZCXCHM-UHFFFAOYSA-N; 228.042259 g mol−1) | |||
3,9-Dihydroxy-urolithin [13.5] | Isourolithin A | 174023-48-4 | 3,9-Dihydroxy-6H-benzo[c]chromen-6-one |
(WDGSXHQNUPZEHA-UHFFFAOYSA-N; 228.042259 g mol−1) | |||
8-Hydroxy-urolithin-3-glucuronide [13.6] | Urolithin A-3-glucuronide | — | 3,4,5-Trihydroxy-6-(8-hydroxy-6-oxo-6H-benzo[c]chromen-3-yl)oxyoxane-2-carboxylic acid |
[urolithin A-glucuronide 3,8-dihydroxy-urolithin 3-glucuronide] | (KXBXNRJGUDTJQS-UHFFFAOYSA-N; 404.074347 g mol−1) | ||
3-Hydroxy-urolithin-8-glucuronide [13.7] | urolithin A-8-glucuronide | 1365982-52-0 | (2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-(3-hydroxy-6-oxobenzo[c]chromen-8-yl)oxyoxane-2-carboxylic acid |
[Urolithin A-glucuronide 3,8-dihydroxy-urolithin 8-glucuronide] | (QMPHAAMUHRNZSL-KSPMYQCISA-N; 404.074347 g mol−1) | ||
8-Hydroxy-urolithin-3-sulfate [13.8] | Urolithin A-3-sulfate | — | (8-Hydroxy-6-oxobenzo[c]chromen-3-yl) hydrogen sulfate |
[Urolithin A-sulfate 3,8-dihydroxy-urolithin 3-sulfate] | (WMPNAWQWWZFJTQ-UHFFFAOYSA-N; 307.999074 g mol−1) | ||
3-Hydroxy-urolithin-8-sulfate [13.9] | Urolithin A-8-sulfate | — | (3-Hydroxy-6-oxo-6H-benzo[c]chromen-8-yl)oxidanesulfonic acid |
[Urolithin A-sulfate 3,8-dihydroxy-urolithin 8-sulfate] | (307.999074 g mol−1) | ||
9-Hydroxy-urolithin-3-glucuronide [13.10] | Isourolithin A-3-glucuronide | — | — |
[Isourolithin A-glucuronide 3,9-dihydroxy-urolithin-3-glucuronide] | 404.074347 g mol−1 | ||
3-Hydroxy-urolithin-9-glucuronide [13.11] | isourolithin A-9-glucuronide | 1268248-75-4 | — |
[Isourolithin A-glucuronide, 3,9-dihydroxy-urolithin 9-glucuronide] | 404.074347 g mol−1 | ||
Urolithin-3,8-diglucuronide [13.12] | Urolithin A-3,8-diglucuronide | — | (2S,3S,4S,5R,6S)-6-[3-[(2S,3R,4S,5S,6S)-6-carboxy-3,4,5-trihydroxyoxan-2-yl]oxy-6-oxobenzo[c]chromen-8-yl]oxy-3,4,5-trihydroxyoxane-2-carboxylic acid |
[Urolithin A-diglucuronide 3,8-dihydroxy-urolithin-diglucuronide] | (SXMJSEFKPOZNAT-ILJCXFEASA-N; 580.106435 g mol−1) | ||
Urolithin-3-sulfate-8-glucuronide [13.13] | [Urolithin A-sulfate-glucuronide 3,8-dihydroxy-urolithin 3-sulfate-8-glucuronide] | — | — |
484.03116 g mol−1 | |||
3,8,9-Trihydroxy-urolithin [13.14] | Urolithin C | 165393-06-6 | 3,8,9-Trihydroxy-6H-benzo[c]chromen-6-one |
[Hydroxyurolithin A trihydroxyurolithin] | (HHXMEXZVPJFAIJ-UHFFFAOYSA-N; 244.037173 g mol−1) | ||
3,8,10-Trihydroxy-urolithin [13.15] | Urolithin M7 | 531512-26-2 | 3,8,10-Trihydroxy-6H-benzo[c]chromen-6-one |
(AKJHSPSPAOUDFT-UHFFFAOYSA-N; 244.037173 g mol−1) | |||
8,9-Dihydroxy-urolithin-3-glucuronide [13.16] | Urolithin C-3-glucuronide | 1268248-76-5 | (2S,3S,4S,5R,6S)-6-({8,9-Dihydroxy-6-oxo-6H-benzo[c]chromen-3-yl}oxy)-3,4,5-trihydroxyoxane-2-carboxylic acid |
[urolithin C-glucuronide] | (DDAQYQCCOWZGDO-KSPMYQCISA-N; 420.069261 g mol−1) | ||
3,4,8,9-Tetrahydroxy-urolithin [13.17] | Urolithin D | 131086-98-1 | 3,4,8,9-Tetrahydroxy-6H-benzo[c]chromen-6-one |
(NEZDQSKPNPRYAW-UHFFFAOYSA-N; 260.032088 g mol−1) | |||
3,8,9,10-Tetrahydroxy-urolithin [13.18] | Urolithin M6 | 1006683-97-1 | 3,8,9,10-Tetrahydroxy-6H-benzo[c]chromen-6-one |
(LGXFTZDSEIQMMP-UHFFFAOYSA-N; 260.032088 g mol−1) | |||
14. Stilbenoids | |||
dihydroresveratrol [14.1] | Dihydro-resveratrol | 58436-28-5 | 5-[2-(4-Hydroxyphenyl)ethyl]benzene-1,3-diol |
5-(4-Hydroxyphenethyl)benzene-1,3-diol | (HITJFUSPLYBJPE-UHFFFAOYSA-N; 230.094294 g mol−1) | ||
3,4′,5-Trihydroxybibenzyl | |||
Dihydro-3,4′,5-trihydroxystilbene | |||
lunularin [14.2] | 3-(4-Hydroxyphenethyl)phenol | 37116-80-6 | 3-[2-(4-Hydroxyphenyl)ethyl]phenol |
3,4′-Dihydroxydihydrostilbene | (ILEYXPCRQKRNIJ-UHFFFAOYSA-N; 214.099380 g mol−1) | ||
3,4′-Ethylenebisphenol | |||
3,4′-Dihydroxybibenzyl | |||
3,4′-Dihydroxy-trans-stilbene [14.3] | 3,4′-Dihydroxystilbene | 62574-04-3 | 3-[2-(4-Hydroxyphenyl)ethenyl]phenol |
Stilbene-3,4′-diol | (UFGKEFGYNRJIGO-UHFFFAOYSA-N; 212.083730 g mol−1) | ||
4-Hydroxydibenzyl [14.4] | 4-Phenylethylphenol | 6335-83-7 | 4-(2-Phenylethyl)phenol |
p-Phenylethylphenol | (YTLSTADDHMJUMW-UHFFFAOYSA-N; 198.104465 g mol−1) | ||
15. Anthranilic acid (2-aminobenzoic acid) derivatives | |||
Dihydroavenanthramide D [15.1] | 2-[[3-(4-Hydroxyphenyl)-1-oxopropyl]amino]benzoic acid | 697235-49-7 | 2-[3-(4-Hydroxyphenyl)propanoylamino]benzoic acid |
2-(3-(4-Hydroxyphenyl)propanamido)benzoic acid | (DLFOKZQWYFNKCL-UHFFFAOYSA-N; 285.100108 g mol−1) | ||
Hydroxyphenyl propamidobenzoic acid | |||
2-Acetamido-5-hydroxybenzoic acid [15.2] | 2-(Acetylamino)-5-hydroxybenzoic acid | 1882-76-4 | 2-Acetamido-5-hydroxybenzoic acid |
(DXKBECZFNWKIJC-UHFFFAOYSA-N; 195.053157 g mol−1) | |||
5-Hydroxy-2-aminobenzoic acid [15.3] | 2-Amino-5-hydroxybenzoic acid | 394-31-0 | 2-Amino-5-hydroxybenzoic acid |
5-Hydroxyanthranilic acid | (HYNQTSZBTIOFKH-UHFFFAOYSA-N; 153.042593 g mol−1) | ||
16. Phenylethanols (C 6 –C 2 ) | |||
2-(4′-Hydroxyphenyl)ethanol [16.1] | 2-(4-Hydroxyphenyl)ethanol | 501-94-0 | 4-(2-Hydroxyethyl)phenol |
4-Hydroxyphenyl alcohol | (YCCILVSKPBXVIP-UHFFFAOYSA-N; 138.06808 g mol−1) | ||
4-Hydroxyphenethyl alcohol | |||
Tyrosol | |||
p-HPEA | |||
2-(3′-4′-Dihydroxyphenyl)ethanol [16.2] | 2-(3,4-Hydroxyphenyl)ethanol | 10597-60-1 | 4-(2-Hydroxyethyl)-1,2-benzenediol |
3′-Hydroxytyrosol | (JUUBCHWRXWPFFH-UHFFFAOYSA-N; 154.062994 g mol−1) | ||
3,4-Dihydroxyphenylethanol | |||
3,4-Dihydroxyphenethyl alcohol | |||
DOPET | |||
Homoprotocatechuyl alcohol | |||
2-(Phenyl)ethanol-4′-glucuronide [16.3] | 2-(Phenyl)ethanol-4-glucuronide | 28116-28-1 | (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-[4-(2-hydroxyethyl)phenoxy]oxane-2-carboxylic acid |
Tyrosol-4-glucuronide | (HEIHXCBRTPYOMU-BYNIDDHOSA-N; 314.100167 g mol−1) | ||
Tyrosol-4′-glucuronide | |||
2-(Phenyl)ethanol-4′-sulfate [16.4] | 2-(Phenyl)ethanol-4-sulfate | — | [4-(2-Hydroxyethyl)phenyl] hydrogen sulfate |
Tyrosol-4-sulfate | (VCRXMIQBQGCAAL-UHFFFAOYSA-N; 218.024895 g mol−1) | ||
Tyrosol-4′-sulfate | |||
2-(4′-Hydroxyphenyl)ethanol-3′-glucuronide [16.5] | 2-(4-Hydroxyphenyl)ethanol-3-glucuronide | 425408-50-0 | (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-[2-hydroxy-5-(2-hydroxyethyl)phenoxy]oxane-2-carboxylic acid |
Hydroxytyrosol-3-glucuronide | (CPHMFZSEPDNJAZ-BYNIDDHOSA-N; 330.095082 g mol−1) | ||
Hydroxytyrosol-3′-glucuronide | |||
2-(3′-Hydroxyphenyl)ethanol-4′-glucuronide [16.6] | 2-(3-Hydroxyphenyl)ethanol-4-glucuronide | — | (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-[2-hydroxy-4-(2-hydroxyethyl)phenoxy]oxane-2-carboxylic acid |
Hydroxytyrosol-4-glucuronide | (JMDNSUMWVYKARS-BYNIDDHOSA-N; 330.095082 g mol−1) | ||
Hydroxytyrosol-4′-glucuronide | |||
2-(4′-Hydroxyphenyl)ethanol-3′-sulfate [16.7] | 2-(4-Hydroxyphenyl)ethanol-3-sulfate | 844639-92-5 | [2-hydroXy-5-(2-hydroxyethyl)phenyl] hydrogen sulfate |
Hydroxytyrosol-3-sulfate | (BZTHVCCNFBAISK-UHFFFAOYSA-N; 234.019809 g mol−1) | ||
Hydroxytyrosol-3′-sulfate | |||
2-(3′-Hydroxyphenyl)ethanol-4′-sulfate [16.8] | 2-(3-Hydroxyphenyl)ethanol-4-sulfate | 425408-51-1 | [2-Hydroxy-4-(2-hydroxyethyl)phenyl] hydrogen sulfate |
Hydroxytyrosol-4-sulfate | (VNPXBLBTQUFCHO-UHFFFAOYSA-N; 234.019809 g mol−1) | ||
Hydroxytyrosol-4′-sulfate |
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Fig. 1 Structures of hydroxybenzenes (1.1–1.10) and benzaldehydes (2.1–2.5). GlcUA – β-D-glucuronide. |
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Fig. 6 Structures of hippuric acids (9.1–9.8) and other amino acid conjugates (9.9–9.16). The asterisk “*” represents the presence of a chiral centre of unknown absolute configuration (R or S). |
Column 2 in Table 1 lists examples in bold of alternative “non-prime” nomenclature, followed by common synonyms, and often reported inaccurate nomenclature in italicized square brackets which should be avoided to prevent further confusion in the literature and in on-line databases.
When dealing with compounds such as 2,3-dihydroxybenzene-1-sulfate, a phase-II metabolite of 1,2,3-trihydroxybenzene (aka pyrogallol), for convenience, rather than using the full nomenclature throughout the text, it is acceptable to use the synonym pyrogallol-1-sulfate provided the recommended nomenclature is used on its first occurrence in the article. All glucuronic acid conjugations are β-D-configured and, as only oxygen-linked glucuronides have been detected, it is not necessary to include the O-linkage in the recommended name, i.e., 3-(phenyl)propanoic acid-4′-glucuronide is sufficient. However, some journal editors/reviewers insist that the O-linkage is specified and, because it is not an incorrect notation it can, if necessary, be used.
Column 3 in Table 1 quotes the Chemical Abstracts Service (CAS) Registry Number which is a numeric identifier that can contain up to 10 digits, divided by hyphens into three parts. Each number is intended to be a unique numeric identifier that can link to information about the substance it refers to but has no chemical significance per se (https://www.cas.org/support/documentation/chemical-substances/). In principle, all compounds should have a distinct number, but some do not, presumably because they have a limited occurrence and/or no commercial source. Some compounds appear to have two numbers for reasons which are unclear.
In principle, each isomer should have a distinct number, with an additional number for a racemic mixture or a preparation where the constituent isomer(s) has not been determined, as illustrated in Table 1 with CAS numbers for 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone (21618-92-8 (racemic), 1108192-01-3 (4S) and 191666-22-5 (4R)). This is also the case for geometric isomers, for example trans-cinnamic acid (140-10-3) and cis-cinnamic acid (102-94-3), where CAS 621-82-9 is used when geometry is not specified. However, 501-16-6 and 331-39-5 are both associated with trans-3′,4′-dihydroxycinnamic acid (aka caffeic acid), and “racemic 2-hydroxy-2-(4′-hydroxy-3′-methoxyphenyl)acetic acid” is associated with 2394-20-9 and 55-10-7.
The International Union of Pure and Applied Chemistry (IUPAC) is described as the world authority on chemical nomenclature and terminology (https://iupac.org/who-we-are/). This nomenclature is found in column 4 together with the InChIKey, which is the IUPAC standard textual unique chemical identifier, along with the isotopic mass in daltons (Table 1).
New compounds in Table 1 since Kay et al.29 include the resveratrol catabolites dihydroresveratrol (14.1), lunularin (14.2), 3,4′-dihydroxy-trans-stilbene (14.3) and 4-hydroxydibenzyl (14.4)30,31 (see Fig. 9). For these stilbenes we recommend adoption of the IUPAC numbering system which uses numbers with primes for the acetate-derived, meta-hydroxylated A-ring. Other additions include catabolites of anthranilic acid (15.1–15.3)32,33 (Fig. 9).
The structures of 4′-hydroxyphenylethanol (tyrosol) and 3′,4-dihydroxyphenylethanol (3′-hydroxytyrosol) (16.1–16.2) are illustrated in Fig. 10. These phenylethanols are hydrolysis products of oleuropein and presumably of the glycosides which occur in bottle gourd. It has been reported that hydrolysis of oleuropein may occur at gastric pH, independent of the gut microbiota.34,35 Phase-II metabolites of the phenylethanols (16.3–16.8) are also illustrated in Fig. 10.
Enantiomers (optical isomers) have the same “scalar” physical properties but opposite “pseudo-scalar” ones such as specific rotation. Regioisomers and diastereomers can have distinct physical and chemical properties, often including different molar absorbance values as well as a different intensity of ionization in mass spectrometry, which potentially can make quantitative estimates of one isomer inaccurate if quantified with the alternative isomer. Regioisomers sometimes have different fragmentation patterns which facilitate identification. Proteins, receptors, and enzymes are chiral biomolecules that discriminate regioisomers and stereoisomers, which can therefore differ in their metabolism and physiological effects.
Enantiomers share the same connectivity but specular 3D-arrangement of atoms: namely, they present opposite “absolute” configuration. Such configuration, usually defined with one or more specific descriptors, such as R- or S-, which are assigned to every stereogenic element present in the molecule, does not vary with respect to how we rotate the molecule in a plane. Using a γ-valerolactone metabolite as an example, Fig. 11 illustrates how perspective influences the appearance of an enantiomer's 3D structure presented in two dimensions, in this case whether the lactone oxygen projects out from the plane of the page or projects into the plane, and whether the aryl ring is on the right or on the left. Note that the position of the aryl ring does not alter the chirality at C4.
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Fig. 11 Structures of the (4S)- and (4R)-enantiomers of 5-(3,4-dihydroxyphenyl)-γ-valerolactone from a front and rear perspective. |
When dealing with pure, chiral bioactive substances, the issue of defining the stereoisomeric composition of the sample is crucial: indeed, two stereoisomers, being diastereo- or enantiomers will also interact differently with another chiral, enantiopure (bio)molecule such as a protein or a sugar, enabling different, sometimes even opposite, (bio)activities. As an example, (R)-Ibuprofen (see Fig. 12) does not inhibit prostaglandin synthesis but is metabolized to a CoA-thioester, whereas (S)-ibuprofen does not form a CoA-thioester and is an inhibitor of prostaglandin synthesis in humans, with significant enantiomeric differences in human pharmacodynamics.36,37 Also, (S)-ibuprofen is ca. 2.5-times more efficiently absorbed through healthy skin and is a more efficient inhibitor of the human organic anion transporter (hOAT1): 2.84 mM for (S)-Ibuprofen for 50% inhibition compared with 6.14 mM for (R)-Ibuprofen.38 The (S)-isomer is also a slightly more potent inhibitor of lactic acid uptake by the mono-carboxylic acid transporter,39 and potentially also benzoic acid, 2-hydroxy-, 3-hydroxy and 4-hydroxybenzoic acid. There are also differences in the metabolism of the enantiomers of (R/S)-2-hydroxy-2-(phenyl)acetic acid in primary rat hepatocytes. The main metabolite of the (2S)-enantiomer is phenyl-glyoxylic acid, whereas the (2R)-enantiomer yields predominantly benzoic acid and hippuric acid (Fig. 12).40
We have located only two publications on the physiological effects of pure phenyl-γ-valerolactone enantiomers.41,42 Both reports used a numbering system different to that recommended by Kay et al.29 as the heterocyclic lactone oxygen was designated 1 and the centre of chirality was designated 5. For consistency with our recommendations for the various C6–C5 metabolites, this has been adjusted in the account which follows with the center of chirality designated 4 (see Fig. 7).
(S)-5-(3′,4′-Dihydroxyphenyl)-γ-valerolactone at 25 μmol L−1 is slightly more active in vitro than its (4R)-isomer in protecting rat intestinal epithelial IEC-6 cells against LPS-induced inflammation by inhibiting NF-κB activation.41 In a second investigation, 1 μmol L−1 of the (4S)-enantiomer reduced UV-induced MMP-1 protein expression in human dermal fibroblasts by ca. 50%, relative to control, whereas the (4R)-enantiomer was ineffective.42 The relative amounts of the (4R)- and (4S)-enantiomers in the human circulation are not known, but as (+)-catechin and (−)-epicatechin are commonly consumed together, it is likely that both enantiomers will be present.
Mandelic, phenyl-lactic, phenyl-hydracrylic, 4-hydroxy-5-phenylvaleric acids and associated γ-valerolactones are frequently reported metabolites, but apart from the examples given above, the metabolism and physiological effects of their enantiomers have not been compared, and such investigations are required. Many papers present metabolite structures where the ‘wiggly’ bond is not used to designate a centre of chirality when the chirality is unknown, and this is doubtless one factor which has led to reduced awareness of such isomers and a failure to investigate the associated phenomena. We recommend marking the centre of chirality with an asterisk for racemates or when the absolute configuration is unknown.
The limited number of commercially available pure enantiomers (see Table 2) and the impossibility of resolving the enantiomers on achiral reversed phase column packings (i.e. embedding stationary phases lacking any chiral discriminating groups) exacerbate the problem. Even if a standard of defined stereochemistry is believed to have been used, it does not automatically follow that the sample contains that specific enantiomer as it could be a mixture or merely the alternative enantiomer. To solve this problem, chiral column packings are available, but they are not well suited to the analysis of samples also containing fifty or more achiral metabolites as tedious fraction collection and reanalysis are required to determine if both enantiomers are present. However, in the absence of standards, further investigation is required to fully assign any enantiomer(s) that are detected. Interestingly, when such enantiomers are phase-II conjugated with a chiral, enantiopure β-D-glucuronic acid moiety, as is the norm at least for the C6–C5 enantiomers,43 and possibly for (R/S)-3-hydroxy-3-(3′-hydroxyphenyl)propanoic acid,44 the two enantiomers become diastereomers, and as such, they could potentially be resolved on an achiral column packing although we are not aware of any reports of the presence of both isomers and possibly these have been overlooked.
CAS Number | Recommended name | Suppliera | Supplier's webpage |
---|---|---|---|
a 1 – Shanghai Ichemical Co., Ltd; 2 – Toronto Research Chemicals; 3 – Ambeed; 4 – Sigma Aldrich; 5 – Fischer Scientific; 6 – ThermoFischer Scientific; 7 – AEChem Scientific Corporation; 8 – SelleckChem.com; 9 – SimSon Pharma Ltd. b This table was prepared purely for the convenience of readers and the authors have no connection with these companies and make no claims regarding the quality of the materials they supply. There may be other providers and compendia such as Chemspider https://www.chemspider.com/ and Pubchem https://pubchem.ncbi.nlm.nih.gov/ should also be consulted, particularly for the racemates. | |||
C 6 –C5acids and lactones | |||
21618-92-8 | (S)-4-Hydroxy-5-(3′,4′-dihydroxy)phenyl-γ-valerolactone | 1 | https://www.ichemical.com/products/21618-92-8.html |
191666-22-5 | (R)-4-Hydroxy-5-(3′,4′-dihydroxy)phenyl-γ-valerolactone | 2 | https://www.trc-canada.com/product-detail/?D454525 |
1190403-76-9 | (R)-4-Hydroxy-5-(3′,4′-dihydroxyphenyl)valeric acid | 2 | https://www.trc-canada.com/product-detail/?D454580 |
Mandelic acids | |||
17119-29-0 | (S)-2-Hydroxy-2-(phenyl)acetic acid | 3 | https://ambeed.com/products/17119-15-2.html |
611-71-2 | (R)-2-Hydroxy-2-(phenyl)acetic acid | 4 | https://www.sigmaaldrich.com/GB/en/search/611-71-2?focus=products&page=1&perpage=30&sort=relevance&term=611-71-2&type=cas_number |
90-64-2 | (R/S)-2-Hydroxy-2-(phenyl)acetic acid undefined | 4 | https://www.sigmaaldrich.com/GB/en/search/90-64-2?focus=products&page=1&perpage=30&sort=relevance&term=90-64-2&type=cas_number |
13244-78-5 | (R)-2-Hydroxy-2-(4′-hydroxyphenyl)acetic acid | 3 | https://ambeed.com/products/17119-15-2.html |
Phenyl-hydracrylic acids | |||
2768-42-5 | (R)-3-Hydroxy-3-(phenyl)propanoic acid | 5 | https://www.fishersci.com/shop/products/r-3-hydroxy-3-phenylpropionic-acid-98-thermo-scientific/AAL19040MD |
36567-72-3 | (S)-3-Hydroxy-3-(phenyl)propanoic acid | 4, 6 | https://www.sigmaaldrich.com/GB/en/product/aldrich/56193 |
https://www.thermofisher.com/order/catalog/product/L19041.03 | |||
Phenyl-lactic acids | |||
7326-19-4 | (R)-2-hydroxy-3-(phenyl)propanoic acid | 7 | https://www.aechemsc.com/info_products/AE1-008987.php |
20312-36-1 | (S)-2-hydroxy-3-(phenyl)propanoic acid | 8 | https://www.selleckchem.com/products/s-2-hydroxy-3-phenylpropanoic-acid.html |
828-01-3 | (R/S)-2)-hydroxy-3-(phenyl)propanoic acid | 9 | https://www.simsonpharma.com/product/dl-2-hydroxy-3-phenylpropionic-acid |
Of note, the resolution of both diastereomers of (R/S)-3-hydroxy-3-(3′,4′-dihydroxycinnamoyl)quinic acid on an achiral, reversed phase column has been noted: here, the quinic acid moiety effectively acted as a covalent chiral resolving agent, enabling the formal separation (identification) of both enantiomers of 3-hydroxy-3-(3′,4′-dihydroxyphenyl)cinnamic acid.45 This indicates that a similar resolution of the C6–C5-glucuronide conjugates is feasible.
To confound the confusion, Phytohub** lists three CAS numbers, 21618-92-8, 191666-22-5 and 1108192-01-3, all for a compound described as “5-(3′,4′-dihydroxyphenyl)-γ-valerolactone”. CAS 1108192-01-3 is also used by the Royal Society of Chemistry's Chemspider†† which lists 11 suppliers, all of whom associate it with the structure having undefined stereochemistry.
(S)-Mandelic acid is epimerized by humans but the enzyme responsible has not been identified. It is not the 2-arylpropanoyl-CoA epimerase (EC 5.1.99.4) which accepts ibuprofen and the isoflavone metabolite (R)-2-hydroxy-2-(4′-hydroxyphenyl)propanoic acid.46
Matrix Fine Chemicals have an entry on their website‡‡ for ‘rac-(2R)-2-hydroxy-2-(4-hydroxyphenyl)acetic acid’ which is internally inconsistent with ‘rac’ indicating racemic and ‘2R’ implying enantiomeric purity. Prospective purchasers who require a specific enantiomer are advised to obtain written confirmation of the identity of the product offered before making an expensive purchase.
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Fig. 15 (R)-, (S)- and (R/S)- and rac-(phenyl)hydracrylic acids. (a) (R)-enantiomer, (b) (S)-enantiomer, (c) (R/S)- a compound of unknown chirality which might prove to be a mixture of both enantiomers, (d) ‘rac’- a preparation known to contain both enantiomers. The asterisk “*” represents the presence of a chiral centre of unknown absolute configuration (R or S). Phenyl ring substituents do not alter the chirality, but the CAS Registry number will change. In the box: the two enantiomers of (3′-hydroxyphenyl)hydracrylic acid: the (−)-S-enantiomer was found in urine.45 |
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Fig. 19 trans- and cis-cinnamic acid and cis-3′-methyoxycinnamic acid-4′-glucuronide. GlcUA – β-D-glucuronide, hv – UV irradiation. |
Note that glutathione conjugates of caffeoylquinic acids and caftaric acids may also occur in foods and wine,63,64 but their presence in biological fluids at a normal dietary (poly)phenol intake could be more related to hepatic conjugation rather than direct absorption at gastrointestinal level. Indeed, single mercapturic acid conjugates of 3-(3′,4′-dihydroxyphenyl)propanoic acid, 3,4-dihydroxybenzaldehyde and 1,2-dihydroxy-4-methylbenzene, plus two isomeric conjugates of 3′,4′-dihydroxyphenylacetic acid, and three isomeric conjugates of 3′,4′-dihydroxycinnamic acid have been detected in urine after volunteers consumed 200 g cooked onion containing ca. 250 μmoles of quercetin glycosides.61 This bolus intake from onions is approximately an order of magnitude higher than the typical human daily consumption of quercetin glycosides from all sources throughout the day.
In vitro studies with 3′,4′-dihydroxycinnamic acid indicate that glutathione conjugation may occur at C2′, C5′ and C6′ on the phenyl ring, and at C3 of the side chain, theoretically producing two diastereomers, although whether both are formed is not known. The phenyl ring conjugates can be assigned to regioisomers only by NMR, but the benzylic side chain conjugates are saturated and distinguishable by their increased mass and fragmentation.62,63,65 Hence it might be possible to distinguish between the aromatic mercapturic acid adducts of 3-(3′,4′-dihydroxyphenyl)propanoic acid (Mr – 343.07257 amu) and the benzylic mercapturic acid adduct of 3′,4′-dihydroxycinnamic acid, (Mr – 341.05692 amu) (Fig. 22). Until authentic glutathione and mercapturic acid conjugates are available, or such phenyl-ring adducts are isolated and fully characterised, these metabolites can only be described as mercapturic acid (glutathionyl) conjugates of X, where X is described using the recommendations already established.
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Fig. 22 Benzylic (black) and aromatic mercapturic acid (blue) adducts. The asterisk “*” represents the presence of a chiral centre of unknown absolute configuration (R or S). |
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Fig. 24 Skeleton structures of the five classes of lignans of which the gut microbiota catabolism has been investigated. Red names – synonyms; black – IUPAC nomenclature. |
These aglycone transformation products are commonly referred to as enterolignans and include 2,3-dibenzyl-butan-1,4-diols, 2,3-dibenzyl-butyrolactones and 1,2-dibenzyl-cyclopentanes (for specimen structures see Fig. 25–27). The known substitution patterns of the aromatic moieties are 4′-hydroxy-3′,5′-dimethoxy-, 3′,4′-dimethoxy-, 4′-hydroxy-3′-methoxy-, 3′,4′-dihydroxy-, 3′,4′-methylenedioxy-, and 3′-hydroxy-(either benzyl or phenyl depending on the enterolignan class), and these occur in several combinations.66–70 Structures are shown in Fig. 25–27 for the unconjugated metabolites. Note that for matairesinols, which do not possess C2-symmetry, two regioisomers are possible if the aromatic substituents are different (Fig. 26).
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Fig. 25 Secoisolariciresinol and its associated gut microbiota catabolites. Red names – synonyms, blue – recommended nomenclature, black – IUPAC nomenclature. |
Quartieri et al.70 reported 25 enterolignan sulfate, glucuronide, and sulfo-glucuronide conjugates in human urine after volunteers consumed secoisolariciresinol-diglucoside and this is almost certainly an under-estimate because there was no allowance made for regioisomerism of either the aromatic moieties or for the phase-II conjugating moiety attached thereto. For example, it has previously been reported that human urine may contain two mono-glucuronides and two mono-sulfates of both enterodiol and enterolactone71–73 but note that human phase-II metabolism of enterodiol and enterolactone is predominantly mono-glucuronidation with only a small contribution from mono-sulfates.
The IUPAC rules for naming these unconjugated enterolignans are complex and clumsy, and the approach adopted varies significantly depending on the class of metabolite (see names in black in Fig. 24–26). The literature contains numerous approaches, which do not allow easy comparison and meta-analysis, so we propose a system which is more uniform across the main classes of metabolites and consistent with our previous recommendations.29 These proposals are straightforward for metabolites where both aromatic moieties are identical, less so for matairesinols when they are different, because there is no easy method for distinguishing the regioisomers.
As stated earlier, once the structure of a catabolite has been defined using the recommended nomenclature, it is acceptable to associate it with a trivial name, which is subsequently used in the text. Relatively few of the enterolignans, however, have trivial names, but the approach used by Quartieri et al.70 is convenient. This system of nomenclature utilizes the trivial name of the substrate and records how many demethylations and/or dehydroxylations have produced the metabolite. For example, the plant lignan secoisolariciresinol, for which we recommend (2R,3R)-bis(4′-hydroxy-3′-methoxybenzyl)butane-1,4-diol, is transformed by the gut microbiota yielding demethyl-, di-demethyl-, demethyl-dehydroxy-, di-demethyl-dehydroxy- and di-demethyl-di-dehydroxy-secoisolariciresinol as illustrated in Fig. 24. Fig. 26 and 27 provide the corresponding information for 2,3-dibenzyl-butyrolactones and 1,2-dibenzyl-cyclopentanes. This simplified nomenclature is particularly of interest when the positions where the demethylations and/or dehydroxylations take place are unknown.
Until such time as the phase-II conjugates are fully characterized and authentic standards are available, such conjugates should be described as “a sulfate/glucuronide/sulfo-glucuronide conjugate of secoisolariciresinol”, etc. This does not help to improve the accuracy of databases like PhytoHub and HMDB, but it represents a conservative approach that may avoid further mistakes.
As discussed for other classes of metabolites, the vendors’ literature is inconsistent. Some of the vendors listed on Pubchem¶¶ and Chemspider|||| show an undefined enterolignan structure, and others show one enantiomer, but these structures are presented from a variety of perspectives. The naturally occurring C2-symmetrical (−)-(2R,3R)-enantiomer of secoisolariciresinol, its antipode the (+)-(2S,3S)-enantiomer, and the racemic mixture are commercially available. The meso-form has been synthesized, and in vitro studies indicate that biological activity varies with the isomer tested.74,75 Similarly, racemic and optically pure (2R,3R)-matairesinol are to be found in vendors’ listings, but prospective purchasers should obtain written confirmation regarding enantiomeric purity if a specific isomer is required.
Recognition that such metabolites are inconsistently described in the literature and sometimes even overlooked, persuaded us to focus upon the stereoisomeric forms of chiral metabolites (enantiomers and diastereomers) and expand the proposals for the nomenclature of (poly)phenol metabolites made by Kay et al.29 Our intention is to establish a convenient, clear, and unambiguous nomenclature in a modality to be read and understood also by non-chemists who often have difficulty in ‘reading’ 3-dimensional structures expressed in 2-dimensions. We believe that the use of this consistent and unambiguous nomenclature will facilitate data retrieval for meta-analysis and the preparation of critical systematic reviews, which ultimately will improve our understanding of the biological effects of these metabolites.
We also recommend that identifications and tentative identifications are categorized as Metabolomics Standards Initiative levels 1 or 2 according to Sumner et al.76 Tentative level 2 identifications are made in the absence of authentic reference compounds and, consequently, quantitative data so obtained should be treated with caution and viewed only as estimates.
CAS | Chemical Abstracts Service Registry Number (also referred to as CASRN) |
C max | Peak plasma concentration |
InChIKey | IUPAC International Chemical Identifier |
IUPAC | International Union of Pure and Applied Chemistry |
L-DOPA | L-3′,4′-Dihydroxyphenylalanine |
Footnotes |
† Electronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/D4FO06152G |
‡ https://www.ichemical.com/products/21618-92-8.html |
§ https://www.trc-canada.com/product-detail/?D454525 |
¶ https://www.chemicalbook.com/ProdSupplierGWCB21302752_EN.htm |
|| https://www.scbt.com/p/4r-5-3prime-4prime-dihydroxyphenyl-gamma-valerolactone-minus-epicatechin-metabolite-191666-22-5 |
** https://phytohub.eu/entries/PHUB001993 |
†† https://www.chemspider.com/Chemical-Structure.134347.html?rid=d203472f-cd06-48d1-ab43-18cd7d078353 |
‡‡ https://www.matrix-fine-chemicals.com/products/catalog/secondary-alcohols/mm1704 |
§§ https://www.fishersci.co.uk/shop/products/r-3-hydroxy-3-phenylpropionic-acid-98-thermo-scientific/11349575 |
¶¶ https://pubchem.ncbi.nlm.nih.gov/compound/65373#section=Chemical-Vendors |
|||| https://www.chemspider.com/Chemical-Structure.58845.html?rid=3fab6e1e-69d3-4563-99b4-c7cc30aeb390&page_num=0 |
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