title: Homogalacturonans from preinfused green tea: structural characterization and anticomplementary activity of their sulfated derivatives.
abstract: Two homogeneous water-soluble polysaccharides (TPSR4-2B and TPSR4-2C) were obtained from preinfused green tea. Their average molecular weights were estimated to be 41 kDa and 28 kDa, respectively. A combination of composition, methylation, and configuration analysis, as well as NMR spectroscopy, indicated that both TPSR4-2B and TPSR4-2C were poly-(1-4)-α-d-galactopyranosyluronic acid in which 30.5 ± 0.3% and 28.3 ± 0.5%, respectively, of uronic acid existed as methyl ester. Two sulfated derivatives (Sul-R4-2B and Sul-R4-2C) from TPSR4-2B and TPSR4-2C were prepared after sulfation with a 2:1 chlorosulfonic acid-pyridine ratio. The anticomplementary assay showed that Sul-R4-2B and Sul-R4-2C demonstrated a stronger inhibitory effect on the complement activation through the classic pathway, compared to that of heparin. Preliminary mechanism studies by using complement component depleted-sera indicated that both Sul-R4-2B and Sul-R4-2C selectively interact with C1q, C1r, C1s, C2, C5, and C9 but not with C3 and C4. The relationship between DS and the anticomplementary activity of sulfated derivatives of homogalacturonans showed that low sulfated derivatives of homogalacturonans also exhibited potent anticomplementary effect, which might greatly reduce the side effects related to heparin and oversulfated chondroitin sulfate, such as anticoagulant activity and allergic-type reaction. These results suggested that sulfated derivatives of homogalacturonans might be promising drug candidates for therapeutic complement inhibition.
authors.affiliation: Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine , 1200 Cailun Road, Shanghai 201203, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Wang
authors.forename: Songshan
authors.initials: S
authors.lastname: Shi
authors.forename: Xuelan
authors.initials: X
authors.lastname: Gu
authors.forename: Chao
authors.initials: C
authors.lastname: Zhu
authors.forename: Guodong
authors.initials: G
authors.lastname: Wei
authors.forename: Hongwei
authors.initials: H
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Bao
authors.forename: Hongwei
authors.initials: H
authors.lastname: Fan
authors.forename: Wuxia
authors.initials: W
authors.lastname: Zhang
authors.forename: Jinyou
authors.initials: J
authors.lastname: Duan
authors.forename: Shunchun
authors.initials: S
authors.lastname: Wang
mesh_terms: D000818:Animals; D028241:Camellia sinensis / Q000737:chemistry*; D003167:Complement Activation / Q000187:drug effects; D003169:Complement Inactivator Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D003165:Complement System Proteins / Q000276:immunology; D006801:Humans; D015394:Molecular Structure; D010368:Pectins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D012756:Sheep; D013662:Tea / Q000737:chemistry
chemical_list: D003169:Complement Inactivator Proteins; D010936:Plant Extracts; D013662:Tea; C012749:anticomplement; D010368:Pectins; D003165:Complement System Proteins; C003181:polygalacturonic acid