Myxaoside A, a new triterpenoid saponin from L. (Boraginaceae).

The phytochemical study of L. led to the isolation, through chromatographic techniques, of a new triterpenoid saponin, 3--[--rhamnopyranosyl-(1→3)-(6--acetyl---glucopyranosyl)]-22-hydroxyolean-12-ene () namely Myxaoside A, together with three known compounds, Soyasaponine I (), oleanolic acid (), and 3--acetyl-oleanolic acid (). All structures were established, based on 1 & 2D-NMR spectroscopic analysis and comparison with previous published reports. Compound - were evaluated for their antibacterial activity on various strains of bacteria including and . It appears that compounds and were active on all the tested microbial species, while compounds and , shown no significant effect on and at low concentrations 6.5 mg/mL and 3.0 mg/mL.