A chalcone (Pongamol) and phytoconstituents of Tephrosia purpurea.

Tephrosia purpurea stem extract fractions shows more amount of Cyclohexane, 1-ethenyl-1-methyl-2,4-bis(1-methylethenyl)-, (1α,2ß,4ß)- (62.32%). Secondary metabolites contents were higher in stem than root of T. purpurea. It is the first time a chalcone (Pongamol) was crystallised from the column chromatography fraction of T. purpurea stem extract identified by using FT-IR and XRD. Quantitative analysis of T. purpurea stem and root reveals that total saponins, tannins and phenols (mg/g plant powder) contents were higher in the former than the latter part of the plant, respectively.

Green preparation of seaweed-based silver nano-liquid for cotton pathogenic fungi management.

Silver nanoparticles (Ag NPs) were synthesised using the crude ethyl acetate extracts of Ulva lactuca and evaluated their bioefficacy against two crop-damaging pathogens. The sets of lattice planes in the XRD spectrum for the Ag NPs were indexed to the 111, 200, 220 and 311 orientations and support the crystalline nature of the Ag NPs. The 3414 and 2968 cm-1 peaks were observed in crude algal thallus extract and they were characteristic of terpenoids. Further, a peak at 1389 cm-1 was observed as fatty acids. The marine macroalgae terpenoids and palmitic acid acted as reducing agent and stabiliser, respectively. The size (3 and 50 nm) and shape (spherical) of Ag NPs were recorded. The energy-dispersive X-ray spectroscopy analysis exemplified the presence of silver in its elemental nature. Moreover, U. lactuca Ag NPs were effective against two cotton phytopathogens namely Fusarium oxysporum f.sp. vasinfectum (FOV) and Xanthomonas campestris pv. malvacearum (XAM). The minimum inhibitory concentration was found to be 80.0 and 43.33 µg ml-1 against FOV and XAM, respectively. Results confirmed the anti-microbial activity of green nanoparticles against select pathogens and suggest their possible usage in developing antifungal agents for controlling destructive pathogens in a cotton agroecosystem.