Benzothiazolium salts--relationships between their structure, toxicity and effect on the plastid system of Euglena gracilis

Synthesis, antimicrobial activity and bleaching effect of some reaction products of 4-oxo-4H-benzopyran-3-carboxaldehydes with aminobenzothiazoles and hydrazides

The synthesis of the biologically active novel systems derived from reaction of 3-formylchromones with three types of amino derivatives, 6-R2-2-aminobenzothiazoles, 6-amino-2-R3-thiobenzothiazoles and hydrazide derivatives (derived from cyanoacetic, isonicotine, salicylic and gallic acids) was carried out. The structures of the prepared compounds have been proved by elemental analysis, 1H NMR and IR spectra. Antimicrobial activity was studied against the following microorganisms--bacteria G+ (Staphylococcus aureus 29/58, Bacillus subtilis 18/66), G- (Escherichia coli 326/71, Pseudomonas aeruginosa); yeasts: Candida albicans, Saccharomyces cerevisiae; moulds: Microsporum gypseum, Aspergillus niger, Scopulariopsis brevicaulis; and against typical and atypical mycobacteria: Mycobacterium tuberculosis (H37Rv), Mycobacterium kansasii (PFG 8), Mycobacterium avium (My 80/72), Mycobacterium fortuitum (1021). The hereditary bleaching effect on the plastid system of Euglena gracilis, a unique phenomenon of the biological activity of chromone derivatives, is reported. The bleaching test on E. gracilis is used for detecting extranuclear mutations.

Qsar study of the toxicity of benzothiazolium salts against Euglena gracilis: the Free-Wilson approach

The Free-Wilson QSAR model in the Fujita-Ban modification was used to calculate the quantitative substituent activity contributions to the toxicity against Euglena gracilis in a series of 91 benzothiazolium salts. An important increase of activity was found for R1 = styryl or SCH2C6H5 group and for R2 = propargyl or allyl group. The substituents on benzene ring also enhance the activity. The possible relations between structure of active groups and their electronic or physicochemical properties are discussed. By using the calculated values it is possible to predict toxicity for 1300 compounds. New compounds with assumed high or low toxicity are predicted.