Abstract
1, 3, 4-Thiadiazole derivatives having a partial structure of 2-ethylsulfonyl-7-methyl-5H-1, 3, 4-thiadiazolo[3, 2-α]pyrimidin-5-one (TPSO2-2) were synthesized, and their chemical reactivities and biological activities were investigated. TPSO2-2 readily reacted with SH compounds and showed a high inhibitory effect against "SH enzyme, " but 2-acetylamino-5-ethylsulfonyl-1, 3, 4-thiadiazole (AEST), a TPSO2-2 analog without a pyrimidine structure, did not react with those compounds and showed a smaller inhibitory effect against the enzyme. Furthermore, TPSO2-2 showed a strong anti-yeast activity, while AEST did not. It is presumed that not only the electron-withdrawing sulfonyl group at the 2-position but also the pseudopurine skeleton appear to be responsible for revealing the biological and chemical activities of TPSO2-2.
