Medicinal And Edible Plant Extracts And Antioxidant Properties

Medicinal and edible plant, as the word suggests both can be edible, and can be preventing and curing diseases. This plant is widely distributed and abundant resources. There are thousands of plant species on land, but the medicinal and edible plants, especially there is less attention about the antioxidation activity. Therefore, in this paper, the work on the antioxidative evaluation of the extracts derived from fruit of Viburnum odoratissimum and the seeds of Michelia alba DC.as well as quantification of the bioactive compounds was performed in order to provide the basis for the development and application of novel natural antioxidants. The experiment is divided into four parts, the specific contents and results are as follows:1、The content of some bioactive compounds, including total flavonoids content (TFC), total phenolics content (TPC), ascorbic acid content (AAC) and polysaccharide content (PSC), antioxidant activities in five different assays, namely, the1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, the potassium ferricyanide reduction,the1,10-phenanthroline-Fe2+oxidative, the Marklund and the Schaal method tests in the seeds and peel of Viburnum odoratissimum, and the relationships between them were investigated in this study. The result showed that the content of bioactive compounds in the seeds was higher than that in the peel. The seeds of the n-butanol-soluble fraction (BF)in the study was the richest fraction in TFC and TPC, while the aqueous residue (AR) had the highest concentration of polysaccharide. The antioxidant activity of the seeds was also generally higher than that of the peel. In the extracts of seeds, EAF showed good DPPH radical-scavenging activity and reducing power (RP). The DPPH radical inhibition rate of EAF reached84.99%, followed by the inhibition rate of AR, which is84.55%at100μg/mL. They were higher than that of the synthetic antioxidant BHT at the same concentration. The methanol-chloroform crude extract (CE) possessed better hydroxyl radical-scavenging and chelating activity than other fractions. At the same concentration, the synthetic antioxidant showed little higher hydroxyl radical inhibition rate than that of CE. The petroleum ether-soluble fraction possessed the highest inhibiting lipid peroxidation activity. There were statistically significant correlations (p<0.01) between some antioxidants (TFC, TPC and AAC) and antioxidant activities (DPPH and RP).2、Then, the main bioactive compounds include total flavonoids and and total phenolics from BF in the seeds were studied using silica gel column chromatography. The results were as follows:The bioactive compounds was mainly distributed in chloroform:methanol (v:v)=50:50, and the DPPH radical inhibition rate reached87.35%at the concentration of50μg/mL.The extracts were further identified by GC-MS, the result was only two chemical compositions were identified.3、The content of some bioactive compounds, including total flavonoids content (TFC), total phenolics content (TPC) and ascorbic acid content (AAC), antioxidant activities in five different assays, namely, the1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, the potassium ferricyanide reduction,the1,10-phenanthroline-Fe2+oxidative, the Marklund and the Schaal method tests in the seeds of Michelia alba DC., and the relationships between them were investigated in this study. The result showed that the petroleum ether-soluble fraction (PEF)in the study was the richest fraction in TFC, while the ethyl acetate-soluble fraction (EAF) had the highest concentration of TPC and AAC. That EAF and BF showed good DPPH radical-scavenging activity and reducing power (RP). The DPPH radical inhibition rate of EAF reached94.95%, followed by the inhibition rate of BF, which is59.09%at500μg/mL. The methanol-chloroform crude extract (CE) possessed better hydroxyl radical-scavenging and chelating activity and inhibiting lipid peroxidation activitythan other fractions. They were higher than that of the synthetic antioxidant BHT at the same concentration. There were statistically significant correlations (p<0.01) between some antioxidants (TPC, AAC) and antioxidant activities (DPPH and RP).4, The single factors and orthogonal test were designed to study the condition of extracting total flavonoids from the seeds of Michelia alba DC. The result showed that the best extraction conditions were as follows:ethanol concentration was90%, extraction temperature was at70℃, ratio of solid to liquid was25:1(mL:g), an dextraction time was2.5h. Then, the extracts were purificated using silica gel column chromatography. The DPPH method is used to measure where the main bioactive compounds distributed, and the further identification with GC-MS. Results showed the main bioactive compounds distributed in chloroform:methanol (v:v)=90:10, It was ten kinds of chemical compositions identificated by GC-MS.