Synthesis of bile acid-thiadiazole conjugates as antibacterial and antioxidant agents.

The synthesis, characterization, and antibacterial and antioxidant activity of thiadiazole-deoxycholic/lithocholic acid conjugates are described in this communication. The structures of the synthesised bile acid-thiadiazole conjugates were studied using H NMR, C NMR and FTIR. Compounds 4c (IC; 15.34 ± 0.07 μM) and 5c (IC; 13.45 ± 0.25 μM) demonstrated greater antioxidant activity than the reference compound ascorbic acid (IC; 20.72 ± 1.02 μM) in DPPH assay. The most effective conjugates against P. vulgarise were 4c (IC; 24 ± 2.3 μM), 4 g (IC; 29 ± 2.5 μM), and 5c (IC; 93 ± 3.6 μM), whereas the most effective conjugates against E. coli were 4e (IC; 55 ± 2.1 μM) and 4f (IC; 52 ± 3.5 μM). Conjugates 4c and 5c were the most effective against B. megaterium of all the synthesised conjugates, with IC values of 15 ± 1.08 and 20 ± 1.1 μM, respectively. Thus, a large library of compounds derived from bile acid can be easily synthesised for extensive structure-activity relationship studies in order to identify the most appropriate antibacterial agents and antioxidant activity.