Extractives of Mammea americana L. Part I. The 4-n-alkylcoumarins. Isolation and structure of mammea B/BA, B/BB, B/BC, and C/BB

Abstract

Extraction of the seeds of Mammea americana L., an insecticide-bearing plant, has yielded a group of four closely related 4-alkyl-5,7-dihydroxycoumarins which are part of a larger family of coumarins which occur in this source. All four compounds have 3-methylbut-2-enyl groups at the 6-position and three, mammea B/BA, B/BB, and B/BC have 4-n-propyl substituents. They are differentiated by possession of a 3-methylbutyryl, a 2-methylbutyryl, or an unsubstituted butyryl group at the 8-position. Mammea C/BB is similar to B/BB except that is possesses a 4-n-pentyl group. Three of the compounds, mammea B/BA, B/BB, and B/BC, were also found in the related species Mammea africana L. Ferruol A from Mesua ferrea corresponds with mammea B/BB except that the 4-n-propyl is now replaced by a 4-s-butyl group. Ferruol C is slightly impure mammea B/BA. The mammein of the literature, previously isolated from M. americana, corresponds to mammea B/BA but samples also contain B/BC alone, or in further admixture with B/BB.

Structural evidence rests largely on a combination of mass, n.m.r., infrared, and ultraviolet spectral results. An ultraviolet method, which employs alkaline shifts to differentiate between 6- and 8-acylation in these coumarins, is reported.