Study On Extraction, Isolation And Antioxidant Activity Of Resveratrol From Peanut Vine

Resveratrol (3,4',5 -trihydroxystilbene) is a phytoalexin, producted by plants in reponse to damage, having been shown to possess antioxidative, blood lipid lowering, anticarcinogenic, and anticancer properties, existed widely in many kinds of natural plants ,such as Polygonum Cuspidate, grape skin and seed, mulberry, peanut and pineapple et.al. Functional food containing resveratrol extraction has a great favor and demand in the world market. At present resveratrol was mostly extracted from grape and its seed in overseas and from Chinese medicine Polygonum Cuspidate in domestic, faced with lack of raw material resource and high cost. It is reported that the content of resveratrol from peanut roots, stems and leaves are several tens to hundreds higher than from grape skin and seeds, but now peanut vine hasn't been used as scale industrial raw materials, and partly used as animal feed and others as waste or burned out, and faced two problems including agriculture resources waste and environmental pollution.so studying and developing resveratrol from peanut vine is significance to enlarge plant resources containing reaveratrol and improve economic benefit of peanut by-products.Peanut vine was used as raw material in this study. The analysis methods, extract process, purification methods and antioxidant activity of resveratrol from peanut vine were studied, which can provide evidence for development and utilization of peanut vine. The specific contents are as follows:The high performance liquid chromatography (HPLC) method was studied to determine the content of resveratrol from peanut vine. Many impurities were included especially lipid-soluble impurities having severe pollution in peanut vine extracts, which can seriously affect service life of chromatographic column, so a determination method of resveratrol on the extracts of peanut vine pre-treated by one step silica gel column concentration is 60%, solvent to material ratio is 25mL/g material, the extraction time is 1h, the number of extraction times is one, the extraction content of resveratrol above condition was 855.05μg/g. This extraction process could be used for the extraction of the resveratrol from peanut vine.The aqueous two-phase extraction resveratrol system was studied. Purifying resveratrol from Polygonum Cuspidate was reported, however, It's not seen that the theory research of the aqueous two-phase extraction resveratrol system. The distribution coefficient and the recovery rate were used as the indicators and the method of ultraviolet spectrophotometry was used for detecting the extraction content of resveratrol in this study. The best two-phase aqueous system (ethanol-ammonium-sulphate -water) was determined. The turbidity titration drip was used to establish the solubility phase diagram of ethanol - ammonium sulfate - water system. Affecting extraction factors of the aqueous two-phase system were studied. The results showed that the fraction of ethanol and ammonium sulfate were the main factors.The process of aqueous two-phase extraction resveratrol from peanut vine was established. Resveratrol was upper extract liquid and its recovery rate was 97.5% after extracting by aqueous two-phase system and desalting by stripping process. the content of resveratrol in the upper extraction samples was 1.83%, in contrast, the content(0.2%) of resveratrol in crude extracts increased 9 times, the aqueous two-phase system can be used for purify resveratrol from peanut vine.Antioxidant activity on resveratrol crude extracts of peanut vine, smples after extracting by aqueous two-phase system and resveratrol content reached 96.93% were studied, and compared with VC. The scavenging result of samples on DPPH, hydroxyl and super oxide anion radicals were determined by UV method. The results showed that the radical-scavenging activity of Samples including resveratrol crude extracts of peanut vine, sample after extracting by aqueous two-phase system and resveratrol which its content reached 96.93% were increased with the increase of their concentration. When the concentration of samples was less than 2.664mg/mL, the radical-scavenging activity of resveratrol crude extracts of peanut vine was better than of sample after extracting by aqueous two-phase system, but less than of resveratrol which its content reached 96.93%; when the concentration of samples was higher than 2.664mg/mL, the radical-scavenging activity of three samples tended to coincide. The IC₅₀ of resveratrol crude extracts of peanut vine on scavenging DPPH ?, hydroxyl and super oxide anion radicals was 0.0529 mg/mL, 0.589 mg/mL and 0.610mg/mL, respectively; the IC₅₀ of sample after extracting by aqueous two-phase system on scavenging DPPH ?, hydroxyl and super oxide anion radicals wasO.0625 mg/mL, 1.684 mg/mL and 2.469mg/mL, respectively; the IC₅₀ of resveratrol which its content reached 96.93% on scavenging DPPH ?, hydroxyl and super oxide anion radicals was 0.00624 mg/mL,0.485 mg/mL and 0.200mg/mL,respectively; the IC50 of VC on scavenging DPPH ?, hydroxyl and super oxide anion radicals was 0.009 mg/mL,0.255 mg/mL and 0.190mg/mL, it showed that the radical-scavenging activity of three samples was less than of VC; but antioxidant rank order of them was consistency: resveratrol which its content reached 96.93%> resveratrol crude extracts of peanut vine>sample after extracting by aqueous two-phase system;the radical-scavenging activity of resveratrol which its content reached 96.93% were equivalent with VC, and the radical-scavenging activity of resveratrol crude extracts of peanut vine were close to VC, but the radical-scavenging activity of sample after extracting by aqueous two-phase system was less than them.The antioxidant mechanism of peanut vine extracts need further study.