Novel indolyl-pyrimidine derivatives: synthesis, antimicrobial, and antioxidant evaluations

In the present study, a novel series of indolyl-pyrimidines (1-13) were synthesized starting from 4-hydrazinopyrimidine-5-carbonitrile 3. Elemental analysis, IR, H-1-NMR, C-13-NMR, and mass spectral data elucidated structure of newly synthesized compounds. All compounds were screened for their in vitro antibacterial, antifungal, and some for antioxidant activities. Compounds 5, 9g, 9i, and 9j showed pronounced antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Candida albicans, and Aspergillus flavus compared to the reference drugs, while compounds 3 and 9g displayed promising free radical scavenging activity and found to be more potent than standard, ascorbic acid (vitamin C). Further, some compounds were evaluated for cytotoxic activity by SRB assay method against human colon carcinoma (CaCo-2) and showed that compounds 4 and 9g were found to be the highly active compared to the reference drug doxorubicin. Their structure and activity relationship were discussed.