Terpenoids in four Inula species from Bulgaria Scientific paper

Abstract

Phytochemical study of the chloroform extract of the aerial parts of Inula germanica L., I. ensifolia L., I. conyza (Griess.) DC. and I. salicina L. led to the identification of 33 terpenoids. β- and α-amyrin, lupeol, taraxasterol, ψ-tar­axasterol and their 3-O-acetates and 3-O-palmitates were identified by GC/MS. In addition, the structures of 3-O-palmitates of mainaladiol, arnidiol, faradiol and 16-hydroxylupeol were confirmed by NMR. ent-Kaur-16-en-19-oic acid and its 15α-(3-methylpentanoyloxy) and 15α-(3-methylbutanoyloxy) deriva­tives were isolated from I. conyza. Ten closely related sesquiterpene lac­tones (germacrano­lides and melampolides) were found in I. germanica and their struc­tural iden­tification was performed by spectral analyses. I. ensifolia and I. salicina were free of sesquiterpene lactones and diterpenoids. All tri­ter­penoids and diterpenoids, grazielia acid, desacetylovatifolin and 8-(2-methyl­butan­oyloxy)-1(10),4,11(13)-germacrutrien-6,12-olide-14-oic acid are des­cribed for the first time in the studied species. The principal component ana­lysis was used to find a relationship between thе investigated up to now Inula species, growing in Bulgaria.