Phytochemical screening, antimicrobial activity, TLC profiling, FTIR-ATR spectroscopic analysis and GC–MS profiling of Lepisanthes rubiginosa leaf extract

The discovery and ethnomedicinal applications of Lepisanthes rubiginosa were elucidated through comprehensive ethnobotanical observations among indigenous populations residing in forest and semi-forest ecosystems. It was utilized for its key role as medicament for long time with medicinal and economic value. Therefore, the primary objective of the current study was to perform a comprehensive phytochemical analysis, antimicrobial activity, chromatographic analysis and chemical profiling of L. rubiginosa leaf extract. The antibacterial activity was assessed using the disc diffusion method and in chromatographic analysis TLC was utilized to separate the methanolic extract using a solvent system consisting of n-Hexane, Ethyl Acetate (EtOAc), methanol (MeOH) and chloroform (CHCl 3 ). Moreover, methanolic extract was characterized using FTIR-ATR and GC–MS. Phytochemical screening showed the presence of sugar, glycosides, alkaloids, tannins, phenolic content (106.57 ± 11.25 mg GAE/g) and flavonoid content (88.72 ± 3.34 QE mg/g). In antimicrobial assessments, the dose of 500 μg/disc showed the highest inhibition against the gram-negative bacterium Shigella boydii and the inhibitory zone measured 26.2 ± 1.2 mm whereas in Bacillus subtilis , a gram-positive bacterium, the dosage of 250 μg/disc showed the least amount of inhibition and that was 9.0 ± 0.4 mm. TLC results showed ethyl acetate: n-hexane (4,1) ratio separates five compounds from the extract and their R f values were 0.14, 0.22, 0.33, 0.48, and 0.82 respectively. FTIR analysis confirms the presence of functional groups like aldehydes, ketones, ethers, esters, amines, alcohols etc. Twelve compounds were identified using GC–MS, with the highest percentage (64.10%) being phenol, 2,4-bis(1,1-dimethylethyl). Further investigation will be needed for isolation and characterization of bioactive compounds. • Polyphenolic chemicals like tannins, flavonoids, phenolic acids were found. • Moderate to potent antimicrobial activity was revealed. • TLC indicates five spots in solvent system of ethyl acetate and n-hexane in a 4:1 ratio. • FTIR-ATR analysis was performed with crude methanolic leaf extract of L. rubignosa. • GC–MS analysis identified 12 bioactive compounds including some new in the methanolic leaf extract of L. rubignosa.