Structural characterization of a homogalacturonan from Capparis spinosa L. fruits and anti-complement activity of its sulfated derivative Huijun Wang & Hongwei Wang & Songshan Shi & Jinyou Duan & Shunchun Wang Received: 11 April 2012 / Revised: 7 June 2012 / Accepted: 12 June 2012 # Springer Science+Business Media, LLC 2012 Abstract A water-soluble polysaccharide CSPS-2B-2 with a molecular mass of 8.8 kDa, was obtained from the fruits of Capparis spinosa L. Chemical and NMR spec- tral analysis verified CSPS-2B-2 was a linear poly-(1- 4)- α-D-galactopyranosyluronic acid in which 12.9± 0.4 % of carboxyl groups existed as methyl ester and 2.6±0.1 % of D-GalpA residues were acetylated. A sulfated derivative Sul-2B-2 with a sulfation degree of 0.88±0.02 was prepared via the substitution of C-2 and/ or C-3 of GalpA residues in CSPS-2B-2. Bioassay on the complement and coagulation system demonstrated that Sul-2B-2 (CH 50 : 3.5±0.2 μg/mL) had a stronger inhibitory effect on the activation of complement system through the classic pathway than that of heparin (CH 50 : 8.9±0.3 μg/mL). Interestingly, Sul-2B-2 at low dose even middle dose (for example 52 μg/mL) had no effect on coagulation system, which was totally different from heparin. Thus, our observation indicated that Sul-2B-2 was more efficient than heparin in inhibiting the activa- tion of the complement system through classical path- way and exhibiting a relatively less anti-coagulant activity. These results suggested that the sulfated derivative Sul- 2B-2 prepared from the homogalacturonan in the fruits of Capparis spinosa L, might be a promising drug candidate in case of necessary therapeutic complement inhibition. Keywords Anti-complement . Homogalacturonan . Sulfated derivative . Inhibition hemolysis . Anti-coagulant Abbreviations HG homogalacturonan HPGPC high performance gel permeation chromatography NMR nuclear magnetic resonance spectroscopy CP classical pathway AP alternative pathway MBL mannan binding lectin pathway ARDS acute respiratory distress syndrome TFA trifluoroacetic acid TLC thin-layer chromatography GPC gel-permeation chromatography GC-MS gas chromatograph-mass spectrometer GC-FID gas chromatograph-flame ionization detector CMC 1-cyclohexyl-3-(2-morpholinoethyl) carbodiimidemetho-p-toluenesulphonate DMSO dimethyl sulfoxide IR infrared absorption spectroscopy NHS normal human serum PPP platelet poor plasma BBS barbital buffered saline RT recalcification time TT thrombin time DS degree of substitution CH 50 50 % complement hemolysis J. Duan College of Science, Northwest A&F University, Yangling 712100 Shaanxi, China H. Wang : H. Wang : S. Shi : S. Wang Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China S. Wang (*) Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China e-mail: shunchunwang@126.com Glycoconj J DOI 10.1007/s10719-012-9418-x