Anti-bacterial activity of neoandrographolide derivatives: In silico interaction with the bacterial target

Natural products and their semi synthesized molecules have been used as efficient antibiotics since a long time. The present global health scenario has raised the demand for novel antimicrobial agents and drug targets that are effective against drug resistant pathogens, emerging infections etc. The current study has promoted the antibacterial activity of the glucoside labdane ‘neoandrographolide’, isolated from the methanolic extract of the medicinal plant Andrographis paniculata. Further modification at its glucoside hydroxyl groups to generate ester and acetonide derivatives was done and the antibacterial potential of these compounds was screened against common bacterial pathogens. Among various derivatives, 4?,6?-O-(4-methoxybenzylidene) neoandrographolide exhibited promising results. In addition, molecular modeling study of the active compound was also explored to identify its probable binding mode on the bacterial target. The present study reported antibacterial activity of neoandrographolide derivatives for first time and also the bioactive molecule, 4?,6?-O-(4-methoxybenzylidene) neoandrographolide was examined as a potent antibacterial agent against different strains.

Cancer chemoprevention activity of labdane diterpenes from rhizomes of Hedychium coronarium

Hedychium coronarium J. Koenig, Zingiberaceae, is a medicinal plant popularly used to treat inflammatory conditions in different countries. Three labdane diterpenes [isocoronarin D (1), methoxycoronarin D (2), ethoxycoronarin D (3)] and benzoyl eugenol (4) were isolated from rhizomes and their chemopreventive potential was evaluated using in vitro assays, namely the inhibition of NF-κB, COX-1 and -2, the induction of antioxidant response element (ARE), and the inhibition of cell proliferation. Diterpene 1 activated ARE (EC50 57.6 ± 2.4 µM), while 2, 3 and 4 significantly inhibited NF-κB (IC50 of 7.3 ± 0.3, 3.2 ± 0.3 and 32.5 ± 4.9 µM, respectively). In addition, 2 and 3 selectively inhibited COX-1 (IC50 values of 0.9 ± 0.0 and 3.8 ± 0.0 µM, respectively). These data support the potential chemopreventive activity of constituents from H. coronarium rhizomes.