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摘要
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 2,3-dihydroxytaraxer-14-en-28-oic acid (1). Its derivatives, 2,3-diacetyltaraxer-14-en-28-oic acid (2), 2,3-di-O-carbonyl-2,3-dihydroxytaraxer-14-en-28-oic acid (3) and 2,3-dipropionyltaraxer-14-en-28-oic acid (4) were obtained by semisynthesis. The known compounds were identified as 3-hydroxytaraxer-14-en-28-oic acid or aleuritolic acid (5) (McPhail, A.T., McPhail, D.R., Wani, M.C., Wall, M.E. %26 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), 3-hydroxytaraxer-14-en-28-oic acid or isoaleuritolic acid (6), 3-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, 19), 3-oxo-taraxer-14-ene or taraxerone (8) -sitosterol (9) and stigmasterol (10) (Kamboj %26 Saluja, 2011), together with fatty acids. Their structures were established on the basis of spectroscopic studies and chemical transformations.
- 出版日期2013-1-1
