A facile synthesis and evaluation of new biomolecule-based coumarin–thiazoline hybrids as potent anti-tubercular agents with cytotoxicity, DNA cleavage and X-ray studies

An efficient and rapid synthesis of coumarin–thiazoline hybrids (1a–1j) under microwave irradiation is described with high yields. The synthesized compounds were characterized using elemental and spectroscopic analysis; in addition, the structures of compounds 1a, 1b, 1e and 1h have been elucidated using single crystal X-ray diffraction techniques. All the newly synthesized compounds were screened for their in vitro anti-tubercular activity and in a DNA cleavage study, while the most active compounds were subjected to a cytotoxicity assay on Vero cell lines. Among those tested, compound 1b exhibited excellent anti-tubercular activity (MIC 0.09 μg ml−1) with a low level of cytotoxicity, suggesting that compound 1b is a promising lead for subsequent investigations in search of new anti-tubercular agents. Furthermore, a DNA cleavage study using an agarose gel electrophoresis method revealed that compounds 1b, 1d, 1f and 1i cleaved DNA more efficiently and thereby exhibit nuclease activity