Chemical and biological characterization of pectin-like polysaccharides from the bark of the Malian medicinal tree Cola cordifolia

The bark of Cola cordifolia used in Malian traditional medicine contains unusual types of polysaccharides with immunomodulating activities. We report for the first time on the structure of a polymer designated CC1P1 having the repeating structure [2 ->)[alpha-D-Gal(1 -> 3)]alpha-L-Rha(1 -> 4)alpha-D-GalA(1 ->] as determined by NMR and GC/MS. alpha-Linked Gal is unusual in pectins. The M-w of 135 kDa was determined by SEC-MALLS. CC1P2 (1400 kDa), another polymer, having the same backbone, but this was substituted with alpha-4-OMe-GlcA, alpha-2-OMe-Gal and alpha-Gal as terminal units. CC1P1 shows a high complement-fixing activity. IC50 being 2.2 times lower than the positive pectin control PMII (IC50 appr. 71 mu g/mL) while IC50 of CC1P2 is 1.8 times lower. The simple structure of CC1P1 did not activate macrophages, while CC1P2 (100 mu g/mL) showed the same potency as the positive controls PMII (100 mu g/mL) and LPS (500 ng/mL). No cytotoxicity was detected. (c) 2012 Elsevier Ltd. All rights reserved.