1, 3, 4-Thiadiazole and 1, 2, 4-triazole-3(4 H )-thione bearing salicylate moiety: synthesis and evaluation as anti- Candida albicans

Abstract Dramatically increased occurrence of both superficial and invasive fungal infections has been observed. Candida albicans appear to be the main etiological agent of invasive fungal infections. The anti-C. albicans activity of thiosemicarbazide, 1,3,4-Thiadiazole, and 1,2,4-triazole-3(4H)-thione compounds (compounds 3-23) were investigated. The MIC values of thiadiazole and triazole derivatives 10-23 were in the range of 0.08-0.17 µmol mL-1, while that of fluconazole was 0.052 µmol mL-1. Compound 11 (5-(2-(4-chlorobenzyloxy)phenyl)-N-allyl-1,3,4-thiadiazol-2-amine) and compound 18 (5-(2-(4-chlorobenzyloxy)phenyl)-4-allyl-2H-1,2,4-triazole-3(4H)-thione) were found to be the most active compounds, with MIC values of 0.08 µmol mL-1. The newly synthesized thiadiazole and triazole compounds (compounds 10-23) showed promising anti-Candida activity. The allyl substituent-bearing compounds 11 and 18 exhibited significant anti-Candida albicans activity and showed a binding mode as well as the fluconazole x-ray structure.

Synthesis, characterization and biological activity of some 1, 3, 4-thiadiazol derivatives

Thiadiazoles are their derivatives exhibit a wide variety of pharmacological activities such as Antibacterial and anti-inflammatory. In the present study we have synthesized derivatives some 2,5 substituted 1,3,4-thiadiazoles. The structures of these synthesized compounds were confirmed by IR, NMR, and MASS spectra data. These compounds were evaluated for varies biological activities such as antibacterial and anti-inflammatory activity

Synthesis and characterization of benzylidene-[1,3,4] thaidiazol -2-yl-amine

This study was designed to synthesize chemically 2-aminothiadiazole derivatives and conversion to Schiffs base. The principle synthesis of these compounds was to involve three steps: First: by thermal cyclization of thiosemicarbazied with carbon disulfide in the presence of potassium hydroxide dissolved in anhydrous ethanol to yield 2-amino-5- mercapto-l,3.4-thiadiazole. Second: by thermal cyclization ofthiosemicarbazied with substituted carboxylic acid and sulphuric acid, to yield 2-amino-5-R-I,3,4-thiadiazole. Third: Schiff 's base formation by reflux of aromatic aldehyde with 2-amino-5-R-l, 3, 4-thiadiazole in the presence of ethanol. The chemical structures of all prepared compounds were confirmed by spectral data [UV-visible and 1 R spectroscopy] tables [1, 2, and 3]

Studies on dehydro-l-ascorbic acid 2-nitrophenyl-hydrazone: conversion into pyrazolinedione and thiadiazoline derivatives

The p-nitrophenylhydrazone of dehydro-L-ascorbic acid [I] reacted with methylhydrazine in MeOH giving the pyrazolinedione [V] and not the expected mixed bishydrazone [III]. The pyrazole derivative gave the tri-O-acetyl and tri-O-benzoyl derivatives [VI] and [VII], respectively. Periodate oxidation of [V] gave the 3-arboxaldehyde derivative [VIII] which was reduced by NaBH4 to the corresponding alcohol [IX] which formed the monoacetyl derivative [X]. The 3-carboxaldehyde condensed with hydroxylamine to give the 3-hydroxyiminomethyl derivative [XI], which upon acetylation gave the 3-acetoxyiminomethyl derivative [XII]. Similarly, benzoylation of [XI] gave the 3-benzoyl derivative [XIII]. The 3-thiosemicarbazone [XIV] of [VIII] gave the bicyclic derivative [XV] upon treatment with benzoyl chloride in pyridine. Treatment of [XV] with hydrazine hydrate gave [XVII]. which upon benzoylation gave [XVIII]