Comparative analysis of plant essential oils by GC-MS coupled with integrated chemometric resolution methods

Abstract

The volatile components obtained from drug pair (DP) Pogostemon cablin (P. cablin)–Perilla frutescens (P. frutescens) and its single herbs were analyzed for the first time by gas chromatography–mass spectrometry (GC-MS) combined with three chemometric resolution methods, namely alternative moving window factor analysis (AMWFA), heuristic evolving latent projections (HELP) and selective ion analysis (SIA). Temperature-programmed retention indices (PTRIs) were also used together with mass spectra for tentative identification of the essential oil constituents. A total of 66, 75 and 84 volatile compounds in the essential oils of the studied samples were qualitatively and quantitatively determined, representing 84.17%, 96.19% and 93.44% of the total content, respectively. Comparative analysis between the DP and its single herbs was done, which showed that the number of essential components of the DP is a little less than the sum of the number of its two single herbs, and the major components of the volatile oil of the DP, except the compound of Patchouli alcohol coming from P. cablin's essential oil, are mainly from that of P. frutescens. The results obtained may provide a useful chemical basis for future research on the correlation between the pharmacodynamic action and chemical constituents of the DP and its single herbs. Our work demonstrated that chemometric resolution techniques and PTRIs could provide a complementary and convenient method for accurate analysis of complex systems once again.