engleski

ESI MS/MS Investigations of Aroylhydrazones Derived From Nicotinic Acid Hydrazide

The chemistry of aroylhydrazones has been intensively studied due to their analytical and biological applications. Many compounds of this type possess antimicrobial, antituberculosis and antitumor activities. Recent studies have shown that nicotinic acid hydrazones could be considered as anti-inflammatory and analgesic agents, and as a novel pharmacophore in the design of anticonvulsant drugs. The aroylhydrazones derived from nicotinic acid hydrazide (Scheme 1) were prepared according to the published procedure [1]. In this work the comprehensive mass spectrometric analysis of the title compounds is presented. The ESI MS spectra were acquired both in positive and negative ion mode. The influence of the solvent (methanol, acetonitrile, addition of sodium acetate) on the signal intensities was investigated. MS/MS analyses of protonated molecule M+H+ and of fragments ions, as well as of sodiated molecule M+Na+ were performed, and fragmentation pathways were proposed. In the MS/MS spectra of all singly protonated aroylhydrazones the signals at m/z 148, 123, 121, 106, 105, 80 and 78 were observed and assigned to the fragments arise from the part of molecules originated from nicotinic acid hydrazide. Fragmentation reactions of M+H+ ions involved heterolytic or inductive cleavage and a proton rearrangement. In MS/MS spectra of M+Na+ ions the signal at m/z 23, assigned to the Na+, was the most intensive one.

Aroylhydrazones; Tandem mass spectrometry

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