Synthesis of Heterocycles and Their Biological Evaluation

A new series of (bis)benzothiazole-pyrazolylpyrazoline derivatives were synthesized in one step by condensing suitably substituted chalcones, hydrazinobenzothiazoles and NaOH under ultrasonication method. All the newly synthesized compounds were screened for their antituberculosis and antimalarial activities. Among them, compounds 6a (MIC = 62.5 µg/mL), 6e (MIC = 25 µg/mL), 6f (MIC = 25 µg/mL), 6g (MIC = 12.5 µg/mL) and 6h (MIC = 12.5 µg/mL) were found to be good to excellent activity as compared to rifampicin (MIC = 40 µg/mL) against M. tuberculosis. In vitro activity against P. falciparum, compounds 6e (IC50 = 0.076 µg/mL), 6f (IC50 = 0.098 µg/mL) and 6g (IC50 = 0.085 µg/mL) exhibited the highest antimalarial activity and compounds 5e, 5g, 6a and 6h showed the good activity as compared to quinine (IC50 = 0.268 µg/mL). The brine shrimp bioassay was carried out to study the in vitro cytotoxic properties of the synthesized compounds. These results indicate that the synthesized compounds can leads to development of new potent member of antitubercular and antimalarial agents. This book is useful for researcher and Academia who are working in this field.