Purification and biological activity of acidic polysaccharide from leaves of Thymus vulgaris L.

Polysaccharides are involved in biological responses and can activate compl ement system, which plays an important role in primary host defense mechani sms. We investigated anticomplementary activities from spice plants and sel ected thyme (Thymus vulgaris L.) as a potent complementary activator. Acidi c polysaccharide (TV-3-IIIA-IIa) purified from the hot-water extract of thy me leaves by DEAE-Toyopearl 650C, Butyl-Toyopearl 650M and Sepharose CL-6B column chromatography and preparative HPLC. The purified polysaccharide, TV -3-IIIA-IIa showed potent anticomplementary activity via classical and alte rnative pathway with the increase proportional to dosage. TV-3-IIIA-IIa see med to be a homogenous polymer from the results of HPLC and its molecular m ass was estimated as 180 kDa. TV-3-IIIA-IIa mainly consisted of galacturoni c acid (44.8 mol%), glucuronic acid (16.7 mol%), arabinose (11.1 mol%), rha mnose (9.2 mol%), galactose (8.9 mol%) and small amounts of glucose, xylose , mannose and fucose. By methylation analysis and reactivity to beta -gluco syl Yariv reagent, TV-3-III-AIIa was assumed to contain small amounts of ty pe II arabinogalactan and large amounts of pectin-like polysaccharides in t he structure. Based upon these results, TV-3-IIIA-IIa was suggested to be a complement activator.