Hydrazide

About: Hydrazide is a research topic. Over the lifetime, 4389 publications have been published within this topic receiving 50063 citations. The topic is also known as: hydrazides.

A new reaction for colorimetric determination of carbohydrates.

Abstract: Acid hydrazides react in alkaline solutions with reducing carbohydrates to give yellow anions. The reaction with p-hydroxybenzoic acid hydrazide (PAHBAH), can be used in a simple colorimetric method to detect less than 1 μg glucose or similar sugar. Calcium and very high protein concentrations are the only interfering factors that have been found.

Site-directed conjugation of nonpeptide groups to peptides and proteins via periodate oxidation of a 2-amino alcohol. Application to modification at N-terminal serine

Abstract: The 2-amino alcohol structure -CH(NH2)CH(OH)- exists in proteins and peptides in N-terminal Ser or Thr and in hydroxylysine. Its very rapid oxidation by periodate at pH 7 generates an aldehyde in the peptide and is the first step in a method for site-directed labeling with biotin or a fluorescent reporter. The modifying group is a hydrazide, RCONHNH2, which reacts with the new aldehyde to form a hydrazone-peptide conjugate, RCONHN = CH-peptide. Experiments with two synthetic peptides, Ser-Ile-Gly-Ser-Leu-Ala-Lys and Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly, and with recombinant murine interleukin-1 alpha (an 18-kDa cytokine with N-terminal Ser) demonstrated this method of peptide tagging. The use of a low molar ratio of periodate to peptide minimized the potential for side reactions during the oxidation, and the desired oxidation was rapid and highly specific. The hydrazones formed were stable at pH 6-8 for at least 12 h at 22 degrees C, but were labile at more acidic pH values. Potential uses of this method include the attachment of biotin, reporter groups, metal chelating groups, imaging agents, and cytotoxic drugs to peptides.

2-Acetylpyridine thiosemicarbazones. 4. Complexes with transition metals as antimalarial and antileukemic agents.

Abstract: Reaction of the 2-acetylpyridine thiosemicarbazones, 3-azabicyclo[3.2.2]nonane-3-thiocarboxylic acid 2-[1-(2-pyridyl)ethylidene]hydrazide (IIIa), its selenium analogue (IIIb), 1H-hexahydroazepine-1-thiocarboxylic acid 2-[1-(2-pyridyl)ethylidene]hydrazide (IV), and 1H-octahydroazocine-1-thiocarboxylic acid 2-[1-(2-pyridyl)ethylidene]hydrazide (V) with Cu(II), Ni(II), Fe(III), and Mn(II) salts gave crystalline complexes. Relative to the free ligands, these complexes show reduced antimalarial activity in mice infected with Plasmodium berghei; however, antileukemic properties are enhanced by coordination with the above-mentioned metals.

Diamide: an oxidant probe for thiols.

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.

Synthesis and Antimicrobial Activity of Some New Benzimidazole Derivatives

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.