Cycloartane Glycosides from Sutherlandia frutescens

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• 作者：Xiang Fu ; Xing-Cong Li ; Troy J. Smillie ; Paulo Carvalho ; Wilfred Mabusela ; James Syce ; Quinton Johnson ; William Folk ; Mitchell A. Avery ; Ikhlas A. Khan
• 刊名：Journal of Natural Products
• 出版年：2008
• 出版时间：October 24, 2008
• 年：2008
• 卷：71
• 期：10
• 页码：1749-1753
• 全文大小：144K
• 年卷期：v.71,no.10(October 24, 2008)
• ISSN：1520-6025

文摘

Four new cycloartane glycosides, sutherlandiosides A−D (1−4), were isolated from the South African folk medicine Sutherlandia frutescens and their structures established by spectroscopic methods and X-ray crystallography as 1S,3R,24S,25-tetrahydroxy-7S,10S-epoxy-9,10-seco-9,19-cyclolanost-9(11)-ene 25-O-β-d-glucopyranoside (1), 3R,7S,24S,25-tetrahydroxycycloartan-1-one 25-O-β-d-glucopyranoside (2), 3R,24S,25-trihydroxycycloartane-1,11-dione 25-O-β-d-glucopyranoside (3), and 7S,24S,25-trihydroxycycloart-2-en-1-one 25-O-β-d-glucoyranoside (4). Compound 1 represents the first secocycloartane skeleton possessing a 7,10-oxygen bridge. Compounds 2−4 are also the first examples of naturally occurring cycloartanes with a C-1 ketone functionality. Biosynthetic considerations and chemical evidence suggest that the presence of the C-1 ketone in 2 may facilitate the ring opening of the strained cyclopropane system.