Chemical Constituents And Antioxidant Activity Of Grape Seed And Three Fungi

Grape is widely used in human social life.On the one hand,it is one of the most edible fruits in people's daily life.On the other hand,it is also a very important raw material in the wine making industry.Grape seeds become the waste residue after wine making.In order to improve the utilization rate of grape seed resources,the activity tracking method was used to study the antioxidant components in grape seeds.In this paper,grape seeds were extracted with 60% ethanol,and the antioxidant activity of grape seed extract was determined by DPPH spectrophotometry,ABTS spectrophotometry and hydroxyl radical spectrophotometry.The results showed that the crude extract of grape seed had scavenging effect on three kinds of free radicals.The grape seed extract was extracted to obtain ethyl acetate phase and aqueous phase.The ethyl acetate phase and the aqueous phase were respectively passed through the macroporous resin column and eluted with ethanol solution gradient to obtain the antioxidant activity of each component.The results showed that the active component was 30% ethanol elution part.By using normal-phase silica gel column chromatography,reverse-phase silica gel column chromatography and dextran gel chromatography and other conventional column separation techniques,through nuclear magnetic resonance,mass spectrometry and other spectroscopic methods,from the 30% ethanol elution fraction of the ethyl acetate phase,two compounds were isolated and identified,namely(-)-epicatechin(1)and(+)-epicatechin(2);seven compounds were isolated and identified from the 30%ethanol elution fraction of the aqueous phase,namely n-hexadecane(3),linoleic acid(4),?-sitosterol(5),?-nigerose(6),dibutyl phthalate(7),diisobutyl phthalate(8),isovanillic acid(9).The antioxidant activity test of the isolated compounds showed that the active component in ethyl acetate phase was(-)-epicatechin and the active component in aqueous phase was linoleic acid(4)and ?-sitosterol(5).In addition,the chemical constituents of the fermentation products of Suillus graulatus,Melanoleuca cognata and Talaromyces aurantiacus were also studied.Four compounds were isolated from the Suillus graulatus.They were triglyceride(10),ergosta-5,7,22-trien-3?-ol(11),2-nitroethan-1-amine(12),5?,8?-epidioxy-(22E,24R)-ergosta-6,22-dien-3?-ol(13).Two compounds were isolated from the fermentation broth of Melanoleuca cognata,and their structures were identified as 5?,8?-epidioxy-(22E,24R)-ergosta-6,22-dien-3?-ol(13),4-(aminomethyl)phenol(14).Two compounds were isolated from the fermentation of Talaromyces aurantiacus,and their structures were identified as 5?,8?-epidioxy-(22E,24R)-ergosta-6,22-dien-3?-ol(13),5?,8?-epidioxy-(22E,24R)-ergosta-6,9(11),22-dien-3?-ol(15),respectively.The antioxidant activities of three kinds of fungal fermentation products were studied.The results showed that the extracts of Talaromyces aurantiacus only scavenged ABTS radicals and hydroxyl radicals,while the extracts of Suillus graulatus and Melanoleuca cognata all scavenged DPPH radicals,ABTS radicals and hydroxyl radicals.