Abstract

A new pentacyclic triterpenoid and three new derivatives based on the taraxer-14-ene skeleton with a C-28 attached a carboxylic acid group have been isolated from the stem bark of Hypodaphnis zenkeri, together with six known compounds. The new product was identified as 2α,3α-dihydroxytaraxer-14-en-28-oic acid (1). Its derivatives, 2α,3α-diacetyltaraxer-14-en-28-oic acid (2), 2α,3α-di-O-carbonyl-2α,3α-dihydroxytaraxer-14-en-28-oic acid (3) and 2α,3α-dipropionyltaraxer-14-en-28-oic acid (4) were obtained by semisynthesis. The known compounds were identified as 3β-hydroxytaraxer-14-en-28-oic acid or aleuritolic acid (5) (McPhail, A.T., McPhail, D.R., Wani, M.C., Wall, M.E. & A.W., Nicholas, A.W. (1989). Identity of maprounic acid with aleuritolic acid. Revision of the structure of maprounic acid: X-ray crystal structure of p-bromobenzyl acetylmaprounate. Journal Natural Products, 52, 212), 3α-hydroxytaraxer-14-en-28-oic acid or isoaleuritolic acid (6), 3α-acetyltaraxer-14-en-28-oic acid acetate or aleuritolic acid acetate (7) (Chaudhuri, S.K., Fullas, F., Brown, D.M., Wani, M.C., Wall, M.E., Cai, L., … Kinghorn, A.D. (1995). Isolation and structural elucidation of pentacyclic triterpenoids from Maprounea africana. Journal of Natural Products, 58, 1-9), 3-oxo-taraxer-14-ene or taraxerone (8) β-sitosterol (9) and stigmasterol (10) (Kamboj & Saluja, 2011), together with fatty acids. Their structures were established on the basis of spectroscopic studies and chemical transformations.

Links

Publisher Full Text

Authors

Momo IJ, Dufat TH, Wandji J, Michel S, Chiozem DD

Institution

Faculté des Sciences Pharmaceutiques et Biologiques, Laboratoire de Pharmacognosie de l'Université Paris Descartes, UMR/CNRS 8638, 4 Avenue de l'Observatoire, 75006 Paris, France. mocarre@yahoo.fr

Source

Natural product research 27:2 2013 pg 137-45

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22493952