Ent-15α-(3-methoxy-3-methyl-butanoyl)-kaur-16-en-19-oic acid a new ent-kaurenic acid derivative isolated from Coespeletia moritziana (Sch. Bip. ex Wedd) Cuatrec. (Asteraceae)

Abstract

The acid fraction of the resin obtained from the leaves of Coespeletia moritziana, a “frailejón” collected at Páramo of Piedras Blancas, Mérida State, Venezuela, yielded ent-kaurenic acid, ent-kaur-9(11)-dien-19-oic acid (grandiflorenic acid), ent-15α-hydroxy-kaur-16-en-19-oic acid (grandiflorolic acid), ent-15α-acetoxy-kaur-16-en-19-oic acid, ent-16α-hydroxy-kauranic acid, and ent-15α-(3-methoxy-3-methyl-butanoyl)-kaur-16-en-19-oic acid, a diterpene acid not reported in the literature whose structure was established by spectroscopic methods