Design, Synthesis, Antimicrobial Evaluation, and Molecular Modeling Studies of Novel Indolinedione-Coumarin Molecular Hybrids.

Keeping in view various pharmacological attributes of indole and coumarin derivatives, a new series of indolindione-coumarin molecular hybrids was rationally designed and synthesized. All synthesized hybrid molecules were evaluated for their antimicrobial potential against Gram-negative bacterial strains (Escherichia coli and Salmonella enterica), Gram-positive bacterial strains (Staphylococcus aureus and Mycobacterium smegmatis), and four fungal strains (Candida albicans, Alternaria mali, Penicillium sp., and Fusarium oxysporum) by using the agar gel diffusion method. Among all synthetics, compounds K-1 and K-2 were found to be the best antimicrobial agents with the minimum inhibitory concentration values of 30 and 312 µg/mL, against Penicillium sp. and S. aureus, respectively. The biological data revealed some interesting facts about the structure-activity relationship which state that the electronic environment on the indolinedione moiety and carbon chain length between indolinedione and triazole moieties considerably affect the antimicrobial potential of the synthesized hybrids. Various types of binding interactions of K-2 within the active site of S. aureus dihydrofolate reductase were also streamlined by molecular modeling studies, which revealed the possible mechanism for potent antibacterial activity of the compound.

Molecular and functional characterization of endophytic fungi from traditional medicinal plants.

This study reports the isolation of 63 endophytic fungal isolates from two traditional medicinal plants, Ocimum sanctum and Sapindus detergens from different locations of Amritsar, India. The functional characterization of the fungi for their ability to produce anti bacterial and anti cancer agent was carried out. Sixteen strains were characterized at molecular level by sequencing the amplified ITSI-5.8-ITSII region of rDNA. The phylogenetic tree resolved the endophytic fungi into different clades. The fungal endophytes belonging to order Pleosporales (Alternaria sp., Phoma sojicola and Exserohilum sp.) were functionally versatile as they produced diverse biomolecules including antibacterial agent active against Mycobacterium smegmatis, as well as cytotoxic activity against different human cancer cell lines of lung, ovary, breast, prostrate, neuroblastoma and colon.