Isolation and Characterization of Flavonoids from Myosotis scorpioides L. (Boraginaceae) and Evaluation of Antimalarial Efficacy of Dichloromethane Extract of the Plant

Abstract

The plant sample (Myosotis scorpioides L (Boraginaceae)) was selected based on its ethnomedicinal usage by the traditional Lala people in Adamawa State as a remedy to malarial disease. The extract was initially screened for the presence of phytocompounds and antiplasmodial assay and was run in the Vacuum Liquid Chromatography followed by Column Chromatography to obtain the pure compounds. The result of the phytochemical screening revealed that extract of the plant contained most of the important secondary metabolites such as alkaloids, flavonoids, terpenes, steroids, saponins etc. The antimalarial evaluation revealed a potential drug candidate to remedy malaria disease. The Vacuum Liquid Chromatography (VLC) followed by Column Chromatography of the plant extract afforded two pure Compounds: Ms-25-3 (1) and Ms-10-102 (2). The two Compounds were analyzed on FT-IR machine, BRUKER NMR-spectrophotometer (700MHz) and a HR-MS machine. The data obtained were used for the structural elucidation of the Compounds. 5,7-dihydroxy-2-(3-hydroxyphenyl)-3-((3,4,5,6tetrahydroxytetrahydro-2H-pyran-2-yl)methoxy)-4H-chromen-4-one (1) a new flavonoid and 2-(3,4-Dihydroxy-phenyl)-5,7-dihydroxy-3-[3,4,5-trihydroxy-6-(3,4,5-trihydroxy-6-hydroxymethyl-tetrahydro-pyran-2-yloxymethyl)-tetrahydro-pyran-2-yloxy]-chromen-4-one (2). The two flavonoids might be responsible for the antimalarial activity observed in the crude extract of the plant. The result has supported the ethnomedicinal use of the plant, confirmed its activity and has also provided a baseline data for future research on the plant. However, further phytochemical, biological, pharmacological investigations and exhaustive isolation and purification methods are highly recommended on the solvent extracts of the plants.