Studıes on Some Aryloxymethyl Thıosemıcarbazıde, 1,3,4-Thıadıazole and 1,2,4-Trıazole-5-Thıone Derıvatıves

Abstract

In this study, twelve 1-(7-methoxy-2-naphthyloxyacetyl)-4-subtituted-3-thiosemicarbazide, 5-(7-methoxy-2-naphthyloxymethyl)-2-substituted amino-1,3,4-thiadiazole and 3-(7-methoxy-2-naphthyloxymethyl)-4-substituted- 1,2,4-triazole-5-thione derivatives have been synthesized and the compounds having 2-substitutedamino-1,3,4-thiadiazole and 4-substituted-1,2,4-triazole-5-thione structure were evaluated for inhibitory effects on COX-1 and COX-2 enzymes. The interaction between the Compound 2b and the COX-2 enzyme was interpreted by using “Molecular Operating Environment” MOE program. 5-(7-Methoxy-2-naphthyloxymethyl)-2-substitutedamino-1,3,4-thiadiazole (Compounds 2a-d) and 3-(7-methoxy-2-naphthyloxymethyl)-4-substituted-1,2,4- triazole-5-thione derivatives (Compounds 3a-d) were synthesized by cyclization of 1-(7-methoxy-2-naphthyloxyacetyl)-4-subtituted-3-thiosemicarbazides (Compounds 1a-d). Chemical structures of the compounds were elucidated by IR, 1H-NMR, 13CNMR and mass spectra and elemental analysis. The synthesized compounds (Compounds 2a-d and 3a-d) showed lower inhibitory activities on COX-2 enzyme then standard compounds NS-398 and indomethacin. 2-(7-Methoxy-2-naphthyloxymethyl)-5-ethylamino-1,3,4-thiadiazole (Compound 2b) is more selective against COX-2, 3-(7-methoxy-2-naphthyloxy methyl)-4-ethyl-1,2,4-triazole-5-thione and 3-(7-methoxy-2-naphthyloxymethyl)-4- allyl-1,2,4-triazole-5-thione (Compounds 3b and 3c) are more selective against COX-1 than rest of the compounds. As a result of the docking studies on COX-2 enzyme, it was observed that the Compound 2b is fitted and interacted with the hydrophobic parts in the active pocket of COX-2, Val349, Tyr355, Leu359 and Leu531.