Masahiko Ueno

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Cytosolic phospholipase A(2)alpha (cPLA(2)alpha), one of the three subtypes of cPLA(2) (alpha, beta and gamma), is thought to be a rate-limiting enzyme in eicosanoid biosynthesis. We developed a novel and potent cPLA(2)alpha inhibitor with an optically active pyrrolidine, termed pyrrophenone, and characterized this compound in detail using enzyme and(More)
Although group IIA phospholipase A(2) has been suggested to be implicated in inflammatory bowel disease, its pathophysiological role in colitis remains unclear. We investigated whether group IIA phospholipase A(2) had pro-inflammatory roles in dextran sulfate sodium-induced colitis in the rat. Secretory phospholipase A(2) activity was markedly increased in(More)
We investigated the efficacy of a potent inhibitor of secretory phospholipase A2 (sPLA2), S-5920/LY315920Na, in an experimental model of acute pancreatitis in rats. Combined intraductal injection of sodium taurocholate (5 mg/rat) and porcine pancreatic sPLA2-IB (300 microg/rat) caused severe hemorrhagic necrotizing pancreatitis resulting in high mortality,(More)
π-Extended thiadiazoloquinoxaline (TQ) derivatives 1a,b-3a,b, in which a tetraalkoxyphenanthrene moiety is annulated with the TQ core and benzene rings are incorporated via the ethynylene spacer, were synthesized. They display absorption bands reaching into 750 nm and possess the electron-affinity comparable to [60]fullerene. The CF3- and OMe-substituents(More)
Tetraalkoxyphenanthrene-fused hexadecadehydro[20]- and tetracosadehydro[30]annulenes possessing octatetrayne linkages were synthesized and their properties together with those of phenanthrene-fused octadehydro[12]- and dodecadehydro[18]annulenes have been investigated. Various spectroscopic and electrochemical measurements as well as quantum chemical(More)
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