Solandelactones A-I, lactonized cyclopropyl oxylipins isolated from the hydroid Solanderia secunda
作者:Youngwan Seo、Ki Woong Cho、Jung-Rae Rho、Jongheon Shin、Byoung-Mog Kwon、Song-Hae Bok、Jun-Im Song
DOI:10.1016/0040-4020(96)00606-0
日期:1996.8
novel docosanoids have been isolated from the hydroid Solanderia secunda. The structures of these compounds have been elucidated by combined spectral and chemical studies. Configuration of the cyclopropyl ring has been assigned as the opposite of related oxylipins by NOESY experiments. Absolute stereochemistry has been determined on the basis of chemicaltransformations and CD measurements of synthetic
Structure and stereochemistry of constanolactones A-G, lactonized cyclopropyl oxylipins from the red marine alga Constantinea simplex
作者:Dale G. Nagle、William H. Gerwick
DOI:10.1021/jo00103a012
日期:1994.12
Extracts of the Oregon marine alga Constantinea simplex were found to contain a mixture of omega 6 and omega 3 unsaturated constanolactones, lactonized cyclopropyl-containing metabolites that logically derive from arachidonic and eicosapentaenoic acids, respectively. Detailed spectroscopic analysis of the isolated compounds, as natural products and various ester derivatives, afforded the planar structures of seven structurally related constanolactones. Constanolactones A-D possess 1,4-diol functionalities while constanolactones E-G contain a vicinal diol functionality. The absolute stereochemistry at all stereocenters in constanolactones A-D and at two stereocenters in constanolactones E and F were determined by chiral chromatography of fragments and chiroptical measurements of various mono- and dibenzoate derivatives and by comparable rotations within the two series (A-D and E-G). Isolation of these various diastereomeric diols, as well as of two presumed methanol adducts from CHCl3/MeOH extraction of C. simplex, leads us to speculate on the occurrence of highly unstable allylic epoxides in this red alga.
Intermediacy of 8-(R)-HPETE in the conversion of arachidonic acid to pre-clavulone a by Clavularia viridis. Implications for the biosynthesis of marine prostanoids
作者:E. J. Corey、Marc D'Alarcao、Seiichi P. T. Matsuda、Peter T. Lansbury、Yasuji Yamada
DOI:10.1021/ja00235a053
日期:1987.1
Synthesis of 12-hydroperoxyeicosatetraenoic acid (12-HPETE). On the stereochemistry in the conversion of 12(S)-HETE to 12-HPETE
12(S)-hydroxyeicosatetraenoic acid methyl ester 1 was synthesized. 1 was converted to phosphite 17 which upon treatment with hydrogen peroxide afforded the corresponding hydroperoxide 18 (12-HPETE methyl ester) with partially retained configuration.