Anti-Babesial Compounds from Rosa damascena Mill

Abstract

Bioassay-guided investigation of extracts of the flowers of Rosa damascena Mill. led to the isolation of four anti-babesial compounds, 3,4-dihydroxy benzoic acid (1), gallic acid (2), 2-phenylethyl 6-O-galloyl-β-D-glucopyranoside (3), and quercetin 3-O-β-D-(6-O-acetyl)-glucopyranosyl-(1→4)-α-L-rhamnopyranoside (9), in addition to five flavonoid compounds which possessed weak anti-babesial activity, kaempferol 3-O-β-D-glucopyranoside (4), kaempferol 3-O-β-D-xylopyranoside (5), kaempferol 3-O-α-L-rhamnopyranoside (6), quercetin 3-O-β-D-glucopyranoside (7), and quercetin 3-O-α-L-rhamnopyranoside (8). Among the isolated compounds, 3 possessed the greatest anti-babesial activity with an IC₅₀ value of 11.78 μg/mL. Although compound 3 is known, no published reports list detailed spectroscopic data for the molecule. Therefore, the first complete structural elucidation of 3 using 1D and 2D NMR spectroscopic analysis is reported here. This is the first report of the isolation of compounds 1, 5, and 9 from R. damascena.