Extraction,Physiochemical Properties And Biological Activities Of Polysaccharides From Camptotheca Acuminata Fruit

Camptotheca acuminate(Nyssaceae)is the second importent national protected plant which was native in China,distributing in Yangtze River and southwest provinces.As a traditional Chinese medicine,it has been proved to have the effect of anti-cancer,heat-clearing and insecticidal.Camptothecin(CPT)is an anticancer produced by the Camptotheca acuminate and possessed good anticancer activity.With the development of the camptothecin research,the demand of the plant material is vastly increased.It's very important to exploit the resource more rationally and use of them in an integrated manner.A large number of researches showed that plant polysaccharides have a wide range of biological activities.Polysaccharide is one of the effective active ingredient of Camptotheca acuminate,and possesses great development potential.In this research polysaccharide is extracted from Camptotheca acuminate fruit by hot water extraction,ultrasonic-assisted extraction,and microwave-assisted extraction.The physic-chemical prorerties,and antioxidant activities of crude polysaccarides with different extraction methods were compared.Among the three kinds of methods,the results showed that microwave-assisted extraction was the most optimal.The optimal extraction parameters of microwave-assisted extraction were obtained by Response surface methodology.We further identified the purified fruit polysaccharide physic-chemical characters and evaluate the antioxidant activities,antibacterial activities,anticancer,and other biological activities.This research could provide a scientific basis for exploitation and utilization reasonable of the Camptotheca acuminate.The main results are as follows:1.The crude polysaccharides,named CAP-H,CAP-M,and CAP-U,were extracted from Camptotheca acuminate fruit by hot water extraction,micro-assisted extraction and ultrasonic-assisted extraction.Among the three kinds of the methods,the micro-assisted extraction is the best method and with the highest yield of 7.25%.Physico-chemical characteristic analysis indicated that those three crude polysaccharides were all acid polysaccharides with little proteins,but the structure of them were different.Meanwhile,the prepared crude polysaccharides showed strongly capability of hydroxyl free radical and DPPH free radical scavenging in vitro and great total reducing power and iron ion chelation ability,while those capabilities showed no significant differences.To sum up,the micro-assisted extraction is the optimal extraction method.2.Extracting polysaccharides from Camptotheca acuminate fruit by micro-assisted extraction method was optimized by Response Surface Analysis.The optimal extraction conditions were microwave time of 14 min,extraction temperature of 70?,microwave power of 600W,and ratio of water to solid of 40:1(mL/g).Under the selected optimal condition,the actual extraction yield is 8.53%and it is quite approach to the predicted value.These results showed that the optimal parameters is credible and possess good practicability.3.Polysaccharide was extracted by the optimization conditions,reoving the starch and proteins with ?-amylase and Sevag assay,respectively.Then,the polysaccharides isolated by DEAE-52 cellulose and purified by Sephadex-G 100 column chromatography,three kinds of purified polysaccharides CAP-1,CAP-2,and CAP-5,which relative molecular weights were 84.33 kD,121.34 kD,and 134.58 kD,respectively,were obtained from Camptotheca acuminate fruit.4.The functional groups and main chemical components characterized by FTIR and UV spectrum analysis showed no differences among CAP-1,CAP-2,and CAP-5.The main monosaccharide components of three purified polysaccharides were glucose and mannose,while the polysaccharides were different with the other components and enthalpy.5.Antioxidant ability analysis indicated that all of the three purified polysaccharides exhibited significant antioxidant activities in a dose-dependent manner and CAP-1 showed the highest antioxidant activity.And all of the three purified polysaccharides showed a markedly protective effect on DNA oxidative damage.6.All of the three purified polysaccharides could inhibit the proliferation of HepG2 cells.CAP-1 exhibited the best effect on HepG2 with the IC50 183.82 ?g/mL.Camptotheca acuminate fruit polysaccharide is worth to further investigation.