CHEMICAL STRUCTURE OF CPB64, AN ARABINOGALACTAN FROM CYNANCHUM PANICULATUM (BUNGE) KITAGAWA

AIM: To investigate the chemical structures of CPB64, a polysaccharide purified from Cynanchum paniculatum (Bunge) kitagawa. METHODS: HPLC, methylation analysis, partial and complete hydrolysis and 13 CNMR were used to determine sugar composition, linkage models, main chain, side chain and branch point of CPB64. RESULTS: Its molecular weight was estimated to be 530 000 and composed of arabinose and galactose in the molar ratios of 4∶5. Arabinose contained terminal and 1,5 linked residues, galactose contained terminal,1,3; 1,3,6 and 1,6 linked residues. Its main chain composed of 1,6 linked galactosyl residues and a few 1,3 linked galactosyl residues, arabinosyl residues and galactosyl residues as side chains attached to the O 3 of 1,6 linked galactosyl residues. CONCLUSION: CPB64 is a new arabinogalactan with stronger effect on proliferation of spleen cell.