Physicochemical Characterization of Flavonoids from the Leaves of Catharanthus roseus and Narissus brussonetii and their Biological Activity

Abstract

Phytochemical screening of ethanolic extract of leaves of Catharanthus roseus and Narcissus brussonetii revealed the presence :saponins, alkaloids, steroids ,anthraquinones, tannins and flavonoids(Catharanthus roseus) ; saponins, tannins,alkaloids and flavonoids(Narcissus brussonetii ). Powdered shade- dried leaves (1kg) of Catharanthus roseus(or Narcissus brussonetii)were extracted with 95% ethanol at room temperature for 48 hours,.The crude extract was purified by silica gel TLC using BAW to give compounds I and II(from Catharanthus roseus) and compound III ( from Narcissus brussonetii). The structures of isolates were elucidated via spectroscopic tools : IR, UV, 1HNMR and Mass spectroscopy. The isolated compounds were tested for antimicrobial potential against four bacterial strains: Gram-positive (Staphylococus aureus and Bacillus subtilis), Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and fungal species (Candida albicans ). Agar well diffusion method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at concentrations of100mg/ml . Compound I showed significant activity against the bacterial strain Bacillus subtilis and the fungal species Candida albicans , while compound II was active against Escherichia coli ,Bacillus subtilis and the fungus Candida albicans. However, compound III gave significant antifungal activity and partial antibacterial activity.