In this study, we have investigated a series of indole-based compounds for their inhibitory study against pancreatic α-amylase and intestinal α-glucosidase activity. Inhibitors of carbohydrate degrading enzymes appear to have an essential role as antidiabetic drugs. All analogous exhibited good to moderate α-amylase (IC50 = 3.80 to 47.50 μM), and α-glucosidase inhibitory interactions (IC50 = 3.10-52.20 μM) in comparison with standard acarbose (IC50 = 12.28 μM and 11.29 μM). The analogues 4, 11, 12, 15, 14 and 17 had good activity potential both for enzymes inhibitory interactions. Structure activity relationships were deliberated to propose the influence of substituents on the inhibitory potential of analogues. Docking studies revealed the interaction of more potential analogues and enzyme active site. Further, we studied their kinetic study of most active compounds showed that compounds 15, 14, 12, 17 and 11 are competitive for α-amylase and non- competitive for α-glucosidase.
We have synthesized new hybrid class of indole bearing sulfonamide scaffolds (1-17) as α-glucosidase inhibitors. All scaffolds were found to be active except scaffold 17 and exhibited IC50 values ranging from 1.60 to 51.20 µM in comparison with standard acarbose (IC50 = 42.45 µM). Among the synthesized hybrid class scaffolds 16 was the most potent analogue with IC50 value 1.60 μM, showing many folds better potency as compared to standard acarbose. Whereas, synthesized scaffolds 1-15 showed good α-glucosidase inhibitory potential. Based on α-glucosidase inhibitory effect, Scaffold 16 was chosen due to highest activity in vitro for further evaluation of antidiabetic activity in Streptozotocin induced diabetic rats. The Scaffold 16 exhibited significant antidiabetic activity. All analogues were characterized through 1H, 13CNMR and HR MS. Structure-activity relationship of synthesized analogues was established and confirmed through molecular docking study.
Human A3 adenosine receptor hA3AR has been implicated in gastrointestinal cancer, where its cellular expression has been found increased, thus suggesting its potential as a molecular target for novel anticancer compounds. Observation made in our previous work indicated the importance of the carbonyl group of amide in the indolylpyrimidylpiperazine (IPP) for its human A2A adenosine receptor (hA2AAR) subtype binding selectivity over the other AR subtypes. Taking this observation into account, we structurally modified an indolylpyrimidylpiperazine (IPP) scaffold, 1 (a non-selective adenosine receptors' ligand) into a modified IPP (mIPP) scaffold by switching the position of the carbonyl group, resulting in the formation of both ketone and tertiary amine groups in the new scaffold. Results showed that such modification diminished the A2A activity and instead conferred hA3AR agonistic activity. Among the new mIPP derivatives (3-6), compound 4 showed potential as a hA3AR partial agonist, with an Emax of 30% and EC50 of 2.89 ± 0.55 μM. In the cytotoxicity assays, compound 4 also exhibited higher cytotoxicity against both colorectal and liver cancer cells as compared to normal cells. Overall, this new series of compounds provide a promising starting point for further development of potent and selective hA3AR partial agonists for the treatment of gastrointestinal cancers.