Inhibitory effects of leaf extract of Lawsonia inermis on Curvularia lunata and characterization of novel inhibitory compounds by GC–MS analysis

Abstract

Plants produce a high diversity of natural products with a prominent function in the protection against microbial pathogens on the basis of their toxic effect on growth and reproduction. In the present study, effect of partially purified acetone fraction of L. inermis leaves on various cytomorphological parameters i.e. mycelium width, conidial size, etc. of test fungi and fraction was subjected to confirming the presence of primary and secondary metabolites by rapid qualitative phytochemical tests, chromatographic methods such as TLC, column chromatography, GC–MS, etc. which were responsible for the inhibition of growth of test pathogen conidial size of Curvularia lunata decreased up to 64.76% at 0.039 μg/ml concentration of the extract. Mycelial width of C. lunata increased up to 55.91% at 0.312 μg/ml concentration of the extract. Carbohydrate, steroids, volatile oils, flavonoids, and tannins were found to be present in acetone extract of L. inermis leaf. Total of 7 bands were observed in TLC fingerprinting of L. inermis acetone fraction. Total of 10 fractions were collected from the column chromatography. Fractions which show the most significant antifungal activity against the test fungus was subjected to further GC–MS analysis for the separation and identification of active principle. GC–MS analyses show the presence of total 6 constituents i.e. hexacosane, octadecane, docosane, heptacosane methyl, octacosane, and tetracosane.