Synthesis and SAR study of novel anticancer and antimicrobial naphthoquinone amide derivatives

A series of novel naphthoquinone amide derivatives of the bioactive quinones, plumbagin, juglone, menadione and lawsone, with various amino acids were synthesized. The compounds were characterized by 1H NMR, 13C NMR, Mass, IR and elemental analysis. All the compounds were evaluated for their anticancer activity against HeLa and SAS cancer cell lines and 3D-QSAR indicated the presence of electron donating group near sulphur enhanced the activity against HeLa cells. Among the derivatives synthesized, compounds 11f, 10a, 10b and 10g were the most active with IC50 values of 16, 12, 14 and 24.5 μM, respectively. The analogues were also screened for antimicrobial activity against two human bacterial pathogens, the Gram-positive Methicillin resistant Staphylococcus aureus (MRSA) and the Gram-negative Pseudomonas aeruginosa and a human yeast pathogen, Fluconazole resistant Candida albicans (FRCA). Among the synthesized compounds, 8g, 10g and 11g exhibited maximum antibacterial activity towards MRSA and antifungal activity against FRCA in well diffusion method.