%0 Journal Article
%T Synthesis of New 1,3,4-Thiadiazole and 1,2,3,4-Oxathiadiazole Derivatives from Carbohydrate Precursors and Study of Their Effect on Tyrosinase Enzyme
%A Mohamed M. El-Sadek
%A Seham Y. Hassan
%A Huda E. Abdelwahab
%A Galila A. Yacout
%J Molecules
%D 2012
%I MDPI AG
%R 10.3390/molecules17078378
%X 5-(1,2,3,4-Tetrahydroxybutyl)-2-methylfuran-3-carbohydrazide (2) was condensed with a variety of ketones to afford carbohydrazide derivatives 3每6. Acetylation of 3每5 afforded the acetyl derivatives 7每9, while periodate oxidation of 3每6 afforded the formyl derivatives 10每13. Acid catalyzed condensation of thiosemicarbazide or o-tolylthiosemicarbazide with the prepared aldehydes 10每12 gave thiosemicarbazone derivatives 14每19. Cyclization of the latter with acetic anhydride afforded 4,5-dihydro-1,3,4-thiadiazolyl derivatives 20每25. On the other hand, condensation of p-tosylhydrazine with the prepared aldehydes 10每12 afforded p-tosylhydrazone derivatives 26每28. Cyclization of 26每28 with acetic anhydride afforded 1,2,3,4-oxathiadiazole derivatives 29每31 respectively. Moreover, the obtained results regarding to the effect of some of the prepared compounds on tyrosinase enzyme showed that the majority of these compounds having an inhibitory effect; especially compounds 12, 16, 17, and 28.
%K carbohydrazide
%K thiosemicarbazone
%K thiadiazole
%K oxathiadiazole
%K tyrosinase
%U http://www.mdpi.com/1420-3049/17/7/8378