Phyto-chemical, analytical evaluation and biological attributes of rare medicinal species of flowering shrub Bauhinia racemosa L.

The current investigation compared the efficacy of an ethanol extract of B. racemosa L. leaf against standard bacterial and fungal cultures. Quantitative phytochemical analysis of Phenol, Flavonoid and Tanin was studied by the appropriate methods; Heavy metal test was done by Atomic Absorption Spectrometer; Antimicrobial activity was done by disc diffusion and agar well diffusion method; MIC through 96 well method and antioxidant assay was performed by DPPH and ABTS. Ethanol extract of B. racemosa L. showed significantly higher inhibitory effect against E. coli, S. aureus and B. cereus, and moderate antimicrobial activity against K. pneumoniae, but it was inactive on fungal strain at lower concentrations. The minimum bactericidal concentration of B. racemosa L. extract against the pathogenic bacteria tested was 1.25 mg/ml for P. aeruginosa, 2.5 mg/ml for E. coli and 5 mg/ml for B. cereus, K. pnuemoniae, and S. aureus. The extract has exhibited antioxidant activity which was evaluated by DPPH and ABTS as 61.61 ± 0.61 and 64.45 ± 0.49% of inhibition in 250 µg/ml concentration. Prominent phytochemical bioconstituents, as determined by phytochemical investigation, comprise flavonoids (8.712 ± 0.7 mg/g Rutin equivalents), tannins (2.930 ± 0.73 mg/g Tannic acid equivalents) and phenol (12.06 ± 0.25 mg/g Gallic acid equivalents) etc. Lethality experiment was performed by using brine shrimp to determine the cytotoxicity of plant extract and the substantial mortality rate observed as LC50 = 22.8435 µg/mL. The result of fluorescence analysis showed various shades of green and brown fluorescence in visible light and various shades of green, blue and brown were found under UV light. HPTLC, FTIR and GCMS were done to find out the bioactive phytocompounds.