Synthesis, crystal structure and antiproliferative evaluation of some new substituted benzothiazoles and styrylbenzothiazoles

The multistep synthesis of a series of new substituted-benzothiazoles as hydrochloride or quaternary salts is described. 6-Amidino substituted 2-aminobenzothiazoles ( 5, 6), N-methyl-2-(4-cyanostyryl)benzothiazolium iodide ( 8), cyano-substituted-2-styrylbenzothiazoles ( 9-11) and amidino and bis-amidino-substituted 2-styrylbenzothiazoles ( 12-17) were prepared. The crystal structure of amidino derivative ( 6) was determined by single crystal X-ray analysis. All new prepared compounds were tested on the cytostatic activities against malignant cell lines: (SW620, colon carcinoma; Hep2, laryngeal carcinoma; HBL, melanoma; HeLa, cervical carcinoma and WI38, human normal fibroblasts). The compounds exerted a different inhibitory effect, depended on concentration and type of the cells. The best inhibitory effect was achieved with compounds ( 12-15), with slight differences among them. All of them inhibited the growth of examined tumor cell lines and also normal fibroblasts. Other examined compounds exhibited a moderate inhibitory effect, depending on type of the cells. Majority of them inhibited the growth of HeLa cells and WI38.