83187-97-7Relevant academic research and scientific papers
New Sterol Derivatives from the Marine Sponge Xestospongia sp.
Cheng, Zhongbin,Liu, Dong,de Voogd, Nicole J.,Proksch, Peter,Lin, Wenhan
, p. 588 - 596 (2016/08/24)
Chemical examination of a marine sponge Xestospongia sp. resulted in the isolation of 20 sterol derivatives (1 – 20), including eight new sterols namely aragusterols J – L (1 – 3), (5α,7α,12β,22E)-7,12,18-trihydroxystigmast-22-en-3-one (4), (5α,7α,12β,24R)- and (5α,7α,12β,24S)-7,12,20-trihydroxystigmastan-3-one (5/6), and (5α,7α,12β,22E,24R)- and (5α,7α,12β,22E,24S)-7,12,20-trihydroxyergost-22-en-3-one (7/8). The structures of new compounds were determined through extensive spectroscopic analyses and chemical conversion. The sterol diversity was mainly characterized by the presence of a cyclopropane unit at side chain, while compound 4 with 18-hydroxymethyl group was found in stigmasterol family for the first time. Cytotoxic test revealed the inhibitory effects of compounds 1, 4, and 17 against human leukemia cell line K562 with IC50values of 18.3, 24.1, and 34.3 μm, respectively.
Stereochmical Effects in Cyclopropane Ring Openings: Synthesis and Isomerization of Petrosterol and All Three of Its Trans Cyclopropane Diastereomers
Proudfoot, John R.,Djerassi, Carl
, p. 5613 - 5622 (2007/10/02)
All four trans isomers of the marine sterol petrosterol, with a side chain terminating in a cyclopropane ring, have been synthesized.The absolute stereochemistry of the diastereomers was determined by correlation with compounds of known absolute stereochemistry.The product distribution resulting from the acid-catalyzed isomerization of these four diastereomers shows a marked dependence on the relative stereochemistry between the cyclopropane ring and the adjacent chiral center at C24.A careful examination of the conformations available to the side chain leads to a rational explanation of this dependence, and sheds light on hitherto unrecognized subtle stereochemical features operating among aliphatic cyclopropanes.In addition we report the synthesis and acid-catalyzed ring opening of (24S,25S,26S)-22,22-dideuteriopetrosterol and the confirmation by this labeling study that one of the products of the isomerization reaction arises via a 1,5-hydride-shift mechanism.
