Phytochemical Screening and Antibacterial Activity of Cryptocoryne spiralis var. spiralis and Cryptocoryne retrospiralis (Roxb) Kunth

Abstract

Phytochemical screening and their antibacterial activity of plant are important parameters which lead to the isolation of new and novel compounds. Cryptocoryne spiralis (Retz) Fischer ex Wydler var. spiralis (CSS) and Cryptocoryne retrospiralis (Roxb) Kunth (CR), leaf and rhizome have been selected for phytochemical screening to identify the different classes of secondary metabolites. Antibacterial activity of different solvent extracts of leaf and rhizome were carried out by using agar well diffusion method. Minimum inhibitory concentration (MIC) was determined by serial dilution technique. The inhibitory effect was studied using the growth pattern of these test organisms. GC-MS analysis was also done to determine the secondary metabolite profile. Phytochemical screening showed the presence of active compounds such as alkaloids, coumarins, flavonoids, saponins, tannins and glycosides. The ethanolic and methanolic extracts of both rhizome and leaf of both the species of Cryptocoryne showed good antimicrobial activity against Gram positive bacteria. Ethanolic extract of rhizome of CSS was found with highest inhibition efficacy in terms of its MIC (200 μg/ml) against Micrococcus aureus (NCIM 2802) and Bacillus subtilis (NCIM 2045). This is primarily due to the presence of Neomenthol, Menthol, Santalol, Cis- alpha Santalol, and Bicyclo (2, 2, 1) heptane, 2-methyl-3-methylene-2-(4-methyl-3-pentenyl)-, (1S-exo) in the ethanolic extracts of rhizome of CSS and CR respectively. These extracts revealed the presence of bio-active constituents which are known to exhibit Med properties so it may act as effective sources of natural antimicrobials.