Hydrazide

Abstract: Reaction of 3-(2-methylbenzimidazol-1-yl)propanoic acid hydrazide (1) with CS2/KOH gave oxadiazole 2 which underwent Mannich reaction to give 3. Compound 2 was treated with hydrazine hydrate to give triazole 4 which was treated with both aldehydes and acetic anhydride to give 5 and 6, respectively. Carbohydrazide 1 was reacted with ethyl acetoacetate, acetylacetone and aldehydes to give 7, 8 and 9, respectively. Cyclocondensation of 9 with thioglycolic and thiolactic acids gave 10 and 11, respectively. Some of these compounds showed potential antimicrobial activities.

Abstract: Publisher Summary The most convenient and chemically simple agent—diamide—is capable of producing a rapid diminution of the tripeptide thiol—glutathione (GSH)—within erythrocytes. An oxidant probe changes the oxidation state of the system; in the present case, diamide is an oxidant probe for thiols and changes the oxidation state of the thiols. Diamide perturbs the thiol status of a system. In most cases, the system can return to its original state by reduction. Information about the role of thiols in the biochemical, biophysical, and physiological economy of a biological system can be gained by the treatment of a system with an oxidant probe for thiols. The reaction of diamide with thiols can be followed spectrophotometrically between 300 and 325 nm and yields a second-order rate constant. The reduction of the diazene forms the diazane dicarboxylic acid bis( N,N -dimethylamide), a hydrazide that does not absorb down to 230 nm. The reaction of thiols with diazenecarbonyl derivatives—such as diamide—occurs in two observable stages, with thiolate anions (RS − ) as the reactive species. The reaction proceeds via addition and displacement steps. In the case of GSH, the GS − anion adds to the diazene double bond to form a sulfenylhydrazine, which, in a second step, reacts with a second GS − anion at sulfur to yield a disulfide and a hydrazine.

Abstract: The aim of this study was to identify a candidate drug for the development of anti-tuberculosis therapy from previously synthesized compounds based on the thiosemicarbazones, semicarbazones, dithiocarbazates and hydrazide/hydrazones compounds. The minimal inhibitory concentration (MIC) of these compounds against Mycobacterium tuberculosis was determined. Their in vitro cytotoxicity to J774 cells (IC50) was determined to establish a selectivity index (SI) (SI=IC50/MIC). The best compounds were the thiosemicarbazones (2, 3 and 4) and the hydrazide/hydrazones (14, 15, 16 and 18). The results are comparable to or better than those of "first line" or "second line" drugs commonly used to treat TB, suggesting these compounds as anti-TB drug candidates.