Seiichi P.T. Matsuda

Biosynthesis of 8-R-HPETE and preclavulone-A from arachidonate in several species of caribbean coral. A widespread route to marine prostanoids.

Abstract The Caribbean coral species Plexaura homomalla, Plexaura nina, Plexaura flexuosa, Pseudopterogorgia americana, Muriceopsis flavida , and Eunicea asperula have all been found to convert arachidonate to 8- R -HPETE ( 4 ) and preclavulone-A ( 3 ) demonstrating that this route to marine prostanoids is widespread among such coral.

Generality of marine prostanoid biosynthesis by the 2-oxidopentadienylcation pathway

Abstract The prostanoid, preclavulone-A ( 5 ), which is produced by the Okinawan coral Clavularia viridis is also biosynthesized by the unrelated Caribbean coral, Pseudoplexaura porosa , indicating that the biosynthesis of 5 may be widespread in coral. The biogenesis of preclavulone-A from arachidonic acid occurs by lipoxygenation at C(8), migration of oxygen from C(8) to C(9) and ring closure, in a process (marine pathway) which contrasts sharply with the mammalian (endoperoxide) route. Preclavulone-A may be a key intermediate from which other more highly oxygenated, bioactive marine prostanoids are formed.

A new irreversible inhibitor of soybean lipoxygenase; relevance to mechanism

Abstract The mechanism of the oxidation of arachidonic acid by soybean lipoxygenase has been studied kinetically with the help of a newly designed inhibitor. It is proposed that olefin complexation with Fe(III) activates arachidonic acid for deprotonation by a basic group on the enzyme leading to an intermediate which then combines with dioxygen.

Catalytic enatioselective synthesis of (3S)-2,3-oxidosqualene

Abstract An efficient and simple enantioselective process is described for the synthesis of (3S)-2,3-oxidosqualene (1) which provides this valuable compound contaminated with only 4% of the R enantiomer. The synthesis employs a chiral catalyst which is efficiently recovered for reuse.