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

摘要

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 CC1 PI having the repeating structure (2→)[α-D-Gal(l→3)]α-L-Rha(l→4)α-D-GalA(l →] as determined by NMR and GC/MS. α-Linked Gal is unusual in pectins. The M_w of 135 kDa was determined by SEC-MALLS. CCIP2 (1400 kDa), another polymer, having the same backbone, but this was substituted with α-4-OMe-GlcA, α-2-OMe-Gal and α-Gal as terminal units. CC1P1 shows a high complement-fixing activity, IC_(50) being 2.2 times lower than the positive pectin control PMI1 (IC_(50) appr. 71 μg/mL) while IC_(50) of CC1P2 is 1.8 times lower. The simple structure of CO1P1 did not activate macrophages, while CC1P2 (100μg/mL) showed the same potency as the positive controls PMII (100 μg/mL) and LPS (500 ng/mL). No cytotoxicity was detected.