Wei-guo Su

Total synthesis of leukotriene B5

A practical, stereocontrolled synthesis of leukotriene B5 is described which makes this substance readily available for the first time.

Actions of arachidonic acid and hepoxilin A3 on mammalian hippocampal CA1 neurons

The effects of arachidonic acid and its lipoxygenase metabolites, the hepoxilins, were investigated in rat hippocampal CA1 neurons in vitro by intracellular electrophysiological recordings. Both arachidonic acid and the hepoxilins cause a hyperpolarization which is sometimes followed by a later depolarization, augment the postspike train long-lasting afterhyperpolarization (AHP) and increase orthodromic inhibitory postsynaptic potentials (IPSPs). These data show that this arachidonic acid metabolic pathway has significant actions on mammalian central neurons, and may represent an important mechanism of neuromodulation.

Enantioselective total synthesis of bilobalide, A C15 ginkgolide

Abstract An enantioselective total synthesis of bilobalide 1 has been effected from diester 5 using stereospecific conversion to 7 via intermediate 6 .

Endogenous release of hepoxilin A3 from isolated perifused pancreatic islets of Langerhans

Pancreatic islets of Langerhans were perifused with Krebs-bicarbonate solution containing glucose (5 and 10 mM). The perifusate was spiked with tetradeuterated hepoxilin A3 and was extracted and analysed by gas chromatography-mass spectrometry using NICI detection. Evidence is presented showing the presence of hepoxilin A3 as the hydrolysis product trioxilin A3. These results demonstrate for the first time that this pathway is active in intact cells; this finding, taken together with our previous evidence that hepoxilins possess insulin secretagogue properties further supports our hypothesis that these products could play a role as endogenous mediators of insulin release.

Total synthesis of biologically active metabolites of arachidonic acid. The two 8-hydroxy-11,12(S,S)-epoxyeicosa-5,14(Z),9(E)-trienoic acids.

Abstract An efficient and simple total synthesis of the two C(8) diastereomers of 3, of interest as possible hormonal releasing agents, is described.

On the synthesis and structure of lipoxin B

Abstract A synthesis of lipoxin B, a recently discovered biologically active eicosanoid, and the assignment of stereoformula 2 is reported.

Simple synthesis and assignment of stereochemistry of lipoxin A

Abstract A synthesis of lipoxin A, a recently discovered biologically active eicosanoid, and the assignment of stereoformula 1 is reported herein.

New products in the hepoxilin pathway: isolation of 11-glutathionyl hepoxilin A3 through reaction of hepoxilin A3 with glutathione S-transferase.

We describe herein the metabolism of hepoxilin A3 (HxA3) by glutathione S-transferase (GST) into a glutathione conjugate. The reaction was carried out with HxA3 (unlabelled and 14C-labelled) and glutathione (unlabelled and tritium labelled). When two isomers of HxA3 were reacted with GST, two products were formed. Only one product was formed when a single isomer of HxA3 was used. The isomeric product HxB3 was marginally active indicating considerable specificity in the reaction with GST. The products were characterized by retention of tritium from glutathione and by comparison of their migration on high performance liquid chromatography with authentic reference compounds. The products bear the structure, 11-glutathionyl HxA3.

Useful new annulation reactions of vicinal dicarboxylic esters

Abstract A new annulation process has been developed for the efficient synthesis of the bicyclic keto esters 1 and 6 , desired intermediates for the total synthesis of bilobalide ( 2 ). A number of other annulations are described which allow the generation from 3 of a variety of functionalized products ( 7–11 ).

A simple and efficient synthesis of (7E, 9E, 11Z, 13E)-(5S, 6R, 15S)-trihydroxyeicosatetraenoic acid (6R-lipoxin A)

Abstract A practical seven-step synthetic route to 6 R -lipoxin A from arachidonic acid is described which makes this biologically interesting eicosanoid easily available.