Luminescent bis(benzo[d]thiazolyl)quinoxaline: facile synthesis, nucleic acid and protein BSA interaction, live-cell imaging, biopharmaceutical research and cancer theranostic application

A series of quinoxaline-2-hydroxyphenylbenzothiazole scaffolds were synthesized and characterized using NMR, UV, fluorescence spectroscopy and LCMS. These newly synthesized compounds were found to be cytotoxic in human epithelioid cervix carcinoma (HeLa) and human colon cancer cell lines (Caco-2). Selectivity of the compounds 7e and 7g are more than 9 fold higher in Caco-2 cells with respect to the normal cell line HEK-293. The most fluorescent compound 7e has displayed high cytoselectivity, significant cellular uptake in HeLa cells and strong binding efficacy with DNA and BSA. The most potent compound 7g has primarily classified as BCS class 4 and BDDCS class 4.