New phenolic radical scavengers from saxifraga cuneifolia.

Thirteen compounds have been isolated from the methanol extract of Saxifraga cuneifolia L. (Saxifragaceae) whole plant. These were identified as five new compounds, (E)-5-O-ß-D-glucopyranosyl-stilbene-3,3', 4,5'-tetraol, (E)-4-O-ß-D-glucopyranosyl-5-methoxy-stilbene-3,3',5'-triol, 4-[4'-O-(6''-O-galloyl-ß-D-glucopyranosyl)-3'-hydroxyphenyl]butan-2-one, 3-O-(6''-O-galloyl-ß-D-glucopyranosyl)-epigallocatechin and 3-O-ß-D-glucopyranosyl-epigallocatechin, together with the known compounds 4-[4'-O-ß-D-glucopyranosyl-3'-hydroxyphenyl]-butan-2-one, (R)-rhododendrin, 1-O-galloyl-ß-D-glucose, catechin, 3-O-galloyl-epigallocatechin, gallocatechin, clitorin and rutin, by chemical and spectroscopic methods. Their free radical scavenging properties are also described.