Studies On Extraction,Purification,Bioactivity And Structure Of Polysaccharides From Cicer Arietinum Hull

Chickpea(Cicer arietinum),looked like olecranon,is an annual or perennial herbaceous plant belonging to chickpea genus of leguninosae.Chickpea is a kind of high nutritional value of edible beans,are rich in a variety of plant amino acid,protein,vitamins,minerals,crude fiber and other components.It has many bioactivities,such as balance diet,reduce blood sugar and pressure,improve children's mental development,enhance bone growth,and anti-aging.However,there is no reports about the polysaccharides from chickpea hull(CHPS)up to now.In this investigation,the extraction optimization,purification,antioxidant activity,immumomodulatory activity and structure from CHPS was studied.1?Research on optimal extraction condition of CHPSAfter hot water extraction,vacuum concentration,ethanol precipitation,pure water dissolution and freeze drying,the crude polysaccharides from chickpea hull were obtained.Extraction time,extraction temperature and ratio of water to raw material were selected in single effect experiments.Results showed that the extraction yield was from 1.73%to 5.60%.Based on single effect experiments,Box-Behnken design(BBD)was used to obtain the optimal extraction condition.By using design of expert software,the data was analyzed and the optimal extraction condition was as follow:extraction temperature of 99?,extraction time of 2.8 h and ratio of water to raw material of 24 mL/g.Under these optimal conditions,the extraction yield was 5.37±0.15%.2?Isolation,purification and physicochemical property of CHPSThe crude CHPS was purified by chromatography of DEAE Fast Flow and Sephadex G-100.Three purified fractions were obtained,named CHPS-1,CHPS-2 and CHPS-3.The total sugar contents of CHPS-1,CHPS-2 and CHPS-3 were 76.92%,87.99%and 84.11%.The protein contents of CHPS-1,CHPS-2 and CHPS-3 were 0.53%,1.02%and 3.60%.The uronic acid contents of CHPS-1,CHPS-2 and CHPS-3 were 2.33%,3.16%and 5.94%.The sulfuric radical contents of CHPS-1,CHPS-2 and CHPS-3 were 1.76%,1.26%and 1.26%.The acetyl group contents of CHPS-1,CHPS-2 and CHPS-3 were 1.20%,1.38%and 1.25%.3?The preliminary structure of purified polysaccharidesThe homogeneity and molecular weight of CHPS-1,CHPS-2 and CHPS-3 were determined by HPLC.The results showed that three fractions gave a single narrow peak.The molecular weight were 3097 KDa.1504 KDa and 782 KDa.The monosaccharide composition of CHPS-1,CHPS-2 and CHPS-3 were measured using PMP pre-column derivatization.The CHPS-1 was composed by mannose(Man),rhamnose(Rha),galacturonic acid(GalA),glucose(Glc),galactose(Gal),and arabinose(Ara)with the molar ratio of 0.03:0.43:0.06:0.06:0.43:0.11.CHPS-2 was composed of Man,Rhal GalA,Gal,Xyl and Ara with the molar ratio of 0.03:0.22:0.09:0.43:0.09:0.14,while CHPS-3 was composed of Rha,GalA and Gal with the molar ratio of 0.34:0.08:0.57.The result of FT-IR spectrum showed that CHPS-1,CHPS-2 and CHPS-3 have characteristic absorptions of polysaccharide.4?The antioxidant and immunomodulatory activity of polysaccharidesInvestigated the antioxidant activities in vitro of crude CHPS,CHPS-1,CHPS-2 and CHPS-3 by using chemical methods.Results indicated that crude CHPS and its purified fractions can eliminate DPPH radicals,ABTS radicals,superoxide anion radicals to different degrees and have certain reducing power.In cellular level,crude CHPS,CHPS-1,CHPS-2 and CHPS-3 can improve the survival rate of H2O2 induced PC 12 cell.Evaluated the immunomodulatory activity of CHPS-1,CHPS-2 and CHPS-3 by using RAW264.7 cell and cyclophosphamide induced immunodeficiency mice model.Results showed that CHPS-1,CHPS-2 and CHPS-3 can promote the proliferation of RAW264.7 and improve the phagocytosis ability of RAW264.7.CHPS?3 in high dose can increase the index of spleen and thymus,activity of LZM and hemolysin in serum.Furthermore,CHPS-3 can increase activities of SOD,GSH-Gx,CAT and the total antioxidant activity,and decrease the level of MDA in liver.