Structure of a pectic polysaccharide from Pseudostellaria heterophylla and stimulating insulin secretion of INS-1 cell and distributing in rats by oral.

A water-soluble, pectic polysaccharide named as 0.5MSC-F isolated from Pseudostellaria Heterophylla with a molecular weight of 4.8×104Da that was composed of rhamnose, galactose, arabinose, and galacturonic acid which the major monosaccharide contents range up to 63.20%. Where the main chain was consists of 1,4-linked galacturonic acid and a small amount of 1,2-linked rhamnose was embedded into backbone to connect alternative galacturonic acid in the form of Rhamnogalacturonan I (RG-I) structure. 1, 5-linked arabinose through C-4 of 1, 2-linked rhamnose, another 1, 3 or 1,6-linked galactose through C-4 of 1, 2-linked rhamnose, was interconnected to branch chain. 0.5MSC-F could obviously stimulated insulin secretion of islet cells cultured in high glucose are of potential practical value in the hypoglycemic action. Radioisotopes 99mTc-labeled-0.5MSC-F was analyzed by SPECT/CT image after oral in rats. At 2h post ingestion, above 40% of the radioactivity was observed in the intestine, but no found in the heart, liver, and kidney. Conjecturing absorption of 99mTc-labeled 0.5MSC-F might via intestinal mucosa absorption into the systemic circulation.