earticle

영어

In the present study, we investigated structure and immune modulating activity of a polysaccharide (tentatively named JS-MP-1), previously purified from Mulberry fruits (Morus bombycis Koidz) pericarp. Based on HPAEC-PAD analysis, major monosaccharides of JS-MP-1 were shown to be galactose (37.6% in mole percentage), arabinose (36.3%) and rhamnose (18.4%), respectively. EA analysis did not show the presence of sulfur (0.07%). Biochemical analysis showed neutral sugars (35.25%), uronic acid (11.25%), sulfate (0.16%) and proteins (0.3%). FT-IR spectra of JS-MP1 confirmed the presence of carboxyl groups (uronic acid – α-GalAp in RG1) and COC, CO and CC stretching vibrations at 948 – 1150 cm-1 corresponding to polysaccharides. Peak at 894 cm-1 indicates the presence of β-Galp units. 1H-NMR spectrum (in D2O) confirmed the presence of α-1,2-Rhap, α-Araf, β -Galp and α-1,4-GalAp units. The most intense HMQS signals were observed for terminal α-Araf. The presence of methylester groups in the residues of α -1,4-GalAp was confirmed by the HMQS peak at C 54.3/H 4.01 ppm (OCH3). Taken collectively, the JS-MP-1 is probably a rhamnogalacturonan type 1 (RG1), which contains: (a) partially methyl esterified α-1,4-D-GalAp and α -1,2-L-Rhap units in backbone, and (b) α-L-Araf and β-Galp are bound to Rha as terminal units or more complex side chains (arabinan, galactan and/or arabinogalactan). The ELISA assay showed that JS-MP-1 remarkably stimulates the release of the proinflammatory cytokines, TNF-α and IL-6, in a dose-dependent manner, from the RAW 264.7 cells. RT-PCR analysis also showed a significant induction of the iNOS and COX-2 gene expression. These results suggest that JS-MP-1 isolated from the Mulberry fruits has immune modulating activities.