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.
5-(1,2,3,4-Tetrahydroxybutyl)-2-methylfuran-3-carbohydrazide (2) was condensed with a variety of ketones to afford carbohydrazide derivatives 3-6. Acetylation of 3-5 afforded the acetyl derivatives 7-9, while periodate oxidation of 3-6 afforded the formyl derivatives 10-13. Acid catalyzed condensation of thiosemicarbazide or o-tolylthiosemicarbazide with the prepared aldehydes 10-12 gave thiosemicarbazone derivatives 14-19. Cyclization of the latter with acetic anhydride afforded 4,5-dihydro-1,3,4-thiadiazolyl derivatives 20-25. On the other hand, condensation of p-tosylhydrazine with the prepared aldehydes 10-12 afforded p-tosylhydrazone derivatives 26-28. Cyclization of 26-28 with acetic anhydride afforded 1,2,3,4-oxathiadiazole derivatives 29-31 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.
Chemistry Department, Faculty of Science, Alexandria University, Alexandria 21231, Egypt. elsadek_mm@yahoo.com
Mohamed M
MM
El-Sadek
Seham Y
SY
Hassan
Huda E
HE
Abdelwahab
Galila A
GA
Yacout
D055162:Biocatalysis / Q000187:drug effects; D002241:Carbohydrates / Q000737:chemistry*; D057075:Enzyme Assays; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011522:Protons; D013830:Thiadiazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013997:Time Factors
D002241:Carbohydrates; D011522:Protons; D013830:Thiadiazoles; D014442:Monophenol Monooxygenase