Extraction, Identification, And Antioxidation Study Of Procyanidins From Elaeagnus Angustifolia .L Jujubes Sarcocarp

Procyanidins is a large type of polyphenols compound which is a strong natural antioxidant and widely exists in nature plant and food fields. Much emphasis has been put on studies of procyanidins in recent years, and a great amount of work has made clear that procyanidins has many outstanding characteristics such as the ability of antioxidation ,the ability of scavenging OH, and excellent biological and pharmacologic activities. Today Procyanidins has been widely used in such fields as healthy food, medicine, cosmetics in the foreign. In the field of procyanidins, grape is an everlasting study subject. In 1997, a type of well-known healthy food which was made from the procyanidins of grape seeds, with its commerial name Pu An Le, quickly spreaded in American market and met with great popularity. Although the functional food made from procyanidins has been playing an active roll in foreign food market since 1997, but it was very expensive as imported in our country. Therefore taking full advantage of the abundant plant resources in our country to extract the natural antioxidant OPC is really an impending task.Elaeagnus angustifolia L. Jujubes sarcocarp has abundant nutrition which contains a large amount of sugar, many kinds of necessary amino acids, rich minerals, a certain amount of flavones, lactoflavin and carotene. All these are of great importance to human bodies. However, at present few reports are found on the research of the procyanidins of Elae'agnus angustifolia L Jujubes. Some simple studies related to Elaeagnus angustifolia L. Jujubes have been carried on once before in the laboratory of Professor Xie Bijun in The Food Science and Technology Department of Huazhong Agricultural University. In my research, the extraction, separation,purification, antioxidation and scavenging OH effects of Elaeagnus angustifolia .L Jujubes sarcocarp procyanidins (abbreviated to ESPC) is studied ,so we can find more nature plant to replace the sole grape resources. On the other hand, we can make full advantage of the Elaeagnus angustifolia L and promote its products developing further more. My main research results are as follows:1.My studies firstly focused on measuring the main nutrition contents in the Elaeagnus angustifolia .L Jujubes sarcocarp. Then two different chemical methods, namely BuOH-HCl method and Folinfen-Ciocalteau method, were taken to determine the percentof ESPC. The study results illustrated that a certain type of Elaeagnus angustifolia .L Jujubes, which grows in Wuwei Town of Gansu Province in our country has a high rate of procyanidins. Therefore this type of Elaeagnus angustifolia .L Jujubes is chosen as my researching material.2.The extraction technics of ESPC was studied .The dried Elaeagnus angustifolia .L jujubes were used as starting material. The extraction conditions was optimized by orthorhombic analysis. The optimal conditions of extraction were as follows: the rate of solution/material rate 9:l,the temperature 76.30℃,the extraction time 85.93minx3, the concentration of ethanol 72.18%, pH5. Under these conditions, the extraction yield was more than 90%.3.Following the optimal extraction, the produced procyanidins was purified by solid-phase extraction. Results showed that the purity of coarse extraction of ESPC was 89.91%; the yields of procyanidins was 4.23%. In order to isolate and purify the procyanidins by the solid-phase extraction further more, two methods were taken, namely Ethyl Acetate leaching and Petroleum ether precipitation.The results explains that the two chemical methods both have obvious isolation effects. Therefore four types of ESPC extractions were produced .namely: procyanidins of Ethyl Acetate phase, procyanidins of water phase during Ethyl Acetate leaching process, procyanidins of Petroleum ether precipitation and procyanidins of water phase during Petroleum ether precipitating process.4.Having been isolated and purified by the two different chemical methods mentioned above, the five types of ESPC extractions, namely coarse extraction of ESPC, procyanidins of Ethyl Acetate phase, procyanidins of water phase during Ethyl Acetate leaching process, procyanidins of Petroleum ether precipitation and procyanidins of water phase during Petroleum ether precipitating process, were further studied by such means as IR and HPLC. Study results indicate that oligomers such as dimers and timers are abundant in the procyanidins of Ethyl Acetate phase and Petroleum ether precipitation. However polymers are the main contents in the procyanidins of the water phase extractions of the two methods.5.In the next process, the antioxidation of ESPC was measured .The experiments werearranged and designed as the following three groups: ?Comparing of antioxidation ability of different concentrations of ESPC;(§)Comparing of antioxidation effects of ESPC and other antioxidants(Vc, Citrate, Tarirate). ?Comparing of antioxidation effects of different other antioxidants (Vc, Citrate, Tarirate) cooperating with ESPC. The comparison of the three groups' study results firstly exposes that there is a certain quantitative relationship between the antioxidation and the concentration of ESPC, which means the antioxidation accrues gradually with the increasing of the concentration of ESPC. Secondly the results illustrates that the antioxidation effect of ESPC was superior to the three other antioxidants. The specific sequence is as follows: ESPOVc> Citrate > Tarirate. Finally, the study results indicates the antioxidation effect strengthens when ESPC cooperates with other antioxidants. The specific sequence is as follows: ESPC+Vc >ESPC+Citrate>ESPC+Tarirate. The above analysis indicates that the antioxidation of ESPC is very strong and the cooperating effect is strengthened when compared with the sole ESPC.6.At the end of my research, the abilities of scavenging *OH of five types of ESPC, namely coarse extractions of ESPC (A4),procyanidins of Ethyl Acetate phase (A2), procyanidins of water phase during Ethyl Acetate leaching process(A3), procyanidins of Petroleum ether precipitation (A4) and procyanidins of water phase during Petroleum ether precipitating process(As), were evaluated comparing with Tea Polyphenols(TPE )and GSPC(grape seeds procyanidins).The study results illustrates that the specific sequence as follows: GSPC>A4>A2>Ai>A3>A5>TPE. The rates of scavenging ?OH of the five types of ESPC are all above 88%,more than that of TPE ,which is 88.03%.Among the five types of procyanidins, the rate of scavenging ?OH of A4 is 98.5%,slightly inferior to that of GSPC, which is 99.57%.The above analysis illustrates that the five types ESPC all have prominent abilities to scavenge *OH. Therefore the extractions of ESPC are virtually promising products to scavenge ?OH.