81(P2-11) カルモジュリン依存性ホスホジエステラーゼ阻害物質KS-506類の構造決定(ポスター発表の部)  [in Japanese] 81(P2-11) STRUCTURE DETERMINATION OF CALMODULIN-DEPENDENT PHOSPHODIESTERASE INHIBITORS KS-506 COMPOUNDS  [in Japanese]

KS-506f(1), p(2), a(3), x(4), g(5) have been isolated from culture broth of Mortuerella vinacea as a potent inhibitors of calmodulin-dependent phosphodiesterase. Structures of these novel sulfer-containing depsides are described. KS-506f and p were identified to be 1 and 2. 3, 4, 5 were found to be the dimeric compounds composed by component I and II through S-S linkage, which are converted each other by disproportionation reaction. The structure of 3 was determined to be dimeric thiocarboxylic acid of component I by COLOC experiment, degradation to afford 1 by methanolysis, and chemical conversion to methylthioester (8) and cyclic diester (9). Confirmation of the structures of 4 and 5 were accomplished using COLOC data of 3-oxobutylthio ether of component II (10) to be dithioester and disulfide, respectively. Methanolysis of KS-506s gave KS-506h(6) and m(7). 6 was methyl ester of component I. The COLOC spectrum of 7 suggested that 7 is the 3-oxobutylthio ester of component I. 7 was produced on treatment 4 with Ph_3P and methyl vinyl ketone, which also assisted its structure.