Synthesis of Benzothiazolyl Guanidinyl Derivatives and their In-Vitro Antimicrobial and Antioxidant Activity

Abstract

Background: Compounds containing CN3 groups are named as guanidine derivatives, which have a rich history in biological and bio-inspired activity. Many guanidine moieties are reported for the antimicrobial activity. Present study aims to the enhancement of bio-activity of the guanidine subunits by conjugating with benzothiazole. Methods: A new series of benzothiazole guanidines have been synthesized from the reaction of thiourea derivatives of 6-substituted benzothiazoles with different substituted anilines in presence of HgCl2. The synthesized compounds were characterized through FT-IR, mass and 1H NMR spectral techniques. The synthesized compounds were screened for the Antimicrobial activity by disc diffusion method and antioxidant activity was assigned by DPPH and ABTS assay. Results: The products were screened for antimicrobial activity. They were found to exhibit moderate to potent activity against the tested microorganisms and have shown minimum inhibition concentration of 1.56 µg/mL for Candida albicans, 0.78 µg/mL for Aspergillus niger, 25 µg/mL for S. aureus and 12.5 µg/mL for E. coli. The derivatives were also tested for antioxidant DPPH and ABTS assays and they were found to have significant activities compared to the standards. Conclusion: In the present work, a new series of benzothiazole guanidinyl derivatives were synthesized in good yields by employing HgCl2 reagent. Synthesized compounds were screened for antimicrobial and antioxidant activities and compounds containing p-methoxy, o-hydroxy showed better antioxidant activities and antimicrobial activities.