engleski

SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF NEW HYDRAZONE-BRIDGED BENZOTHIAZOLE DERIVATIVES

Benzothiazole represents an important class of compounds with a wide spectrum of biological activities such as antimicrobial, antitumor and antituberculostatic activity and possesses special significance in the field of medicinal chemistry [1, 2]. Hydrazones show strong therapeutic activity due to the presence of N ̶ N i C=N bonds [3] and well-known drug with the hydrazone group is Levosimendan, which is used in the treatment of acute decompensated congestive heart failure. This paper describes the solvent-free mechanochemical synthesis of targeted hydrazone- bridged benzothiazole derivatives. 6-substituted 2-hydrazinylbenzo[d]thiazoles were prepared by reaction of 2-amino benzothiazole with hydrazine hydrate in the presence of ethylene glycol and hydrochloric acid. Mechanochemical reaction of 2- hydrazinylbenzothiazole with an appropriate aromatic aldehydes gave the target 2-substituted benzothiazole derivatives bridged by hydrazone unit. Structural characterization of all newly prepared benzothiazole derivatives was performed by 1H and 13C-NMR spectroscopy. Furthermore, using the 2D-NOESY technique, it was confirmed that the prepared compounds were obtained in the form of the E-isomer. Of all evaluated compounds against bacterial cells of Escherichia coli, Enterococcus Faecalis, Klebsiella Pneumonia, Pseudomonas aeruginosa, Staphylococcus aureus, the most pronounced antibacterial activity on bacterial strain Pseudomonas aeruginosa was shown by the 6- chloro-benzothiazole derivative with N, N-diethyl substituent (MIC = 4 mg/L).

benzothiazole ; hydrazone ; mechanochemical synthesis ; antibacterial activity

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