DefinePK

Abstract

In this study, one species of algae, belongated to cyanophyta : Hapalosiphon aureus west and west 1897 were isolated, identified and purified. The extracts of algal isolates were testing to clarify their ability on growth inhibition on each of gram +ve and gram –ve bacteria E.coli & S. aureus, filamentous fungi A. fumigatus, and yeasts C.albican. The extracted alkaloid of species H.aureus showed higher inhibition activity. In our literature survey, the alkaloid compound analog N- methylcytisine was isolated for the first time from the H.aureus. This compound was characterized using Thin Layer Chromatography (TLC), Ultra Violet Spectrum (UV), Infrared Spectrum (IR), Proton Nuclear Magnetic Resonance Spectroscopy (1HNMR), Melting Point and Solubility in organic and inorganic solvents. The biological activity of this alkaloid was determined using the Minimal Inhibitory Concentration (MIC) against six bacterial isolates. The results showed inhibition in 33.3% growth of bacteria on 150 μg/ml concentration level, while the MIC against six fungi isolates showed inhibition of growth 33.3% at 50 μg/ml compared to standard antibiotic. The median lethal dose (LD50) showed no toxicity, no cytotoxicity and no effect on human red blood cells for 18 hours.