New 4alpha-methyl steroids from a Chinese soft coral Nephthea sp.
Three new 4alpha-methyl steroids, 4alpha-methyl-ergost-7,24(28)-diene-3beta-ol-23-one (1), 4alpha-methyl-ergost-8(14),24(28)-diene-3beta-ol-23-one (2), 4alpha-methyl-ergost-24(28)-en-3beta,11beta-diol-23-one (3), and two new polyoxygenated steroids, ergost-5,25-diene-3beta,24S,28-triol (4), ergost-5,24(28)-diene-3beta,23S-diol (5), along with one known steroid 24-methylencholesterol (6) were isolated from the soft coral Nephthea sp. Their structures including the relative configurations were elucidated by extensive 1D and 2D NMR spectra analysis. The absolute configurations of (4) and (5) were determined by the Mosher's method.
Ma
Ke
K
State Key Laboratory of Natural and Biomimetic Drugs, Peking University Health Science Center, Beijing, China.
Li
Wei
W
Fu
Hongwei
H
Koike
Kazuo
K
Lin
Wenhan
W
van Ofwegen
Leen
L
Fu
Hongzheng
H
D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D002681:China; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013256:Steroids / Q000737:chemistry* / Q000302:isolation & purification* / Q000633:toxicity
D013256:Steroids