Analysis On The Content?Antioxidation Ability Of Flavonoids In Spartina Alterniflora And Some Other Halophytes,and Identification Of Flavonoids In Spartina Alterniflora

Spartina alterniflora Loisel,originally distributes along the Atlantic coasts of North America and the Gulf of Mexico,has been introduced into many countries including China,and has become invasive species,causing significant changes in both the structure and functioning of coastal ecosystems.The invasion mechanism and control strategy of this species is currently a hot topic in invasion ecology.Flavonoids are a class of secondary metabolites widely exist in plants,and considered to be one of the important components of plant antioxidant.It can scavenge reactive oxygen like hydroxyl free radicals,and plays a role in the process of light protection.Researches show that flavonoids are rich in many halophytes and invasive plants,and the substantial content in S.alterniflora has attracted more attention of scholars.In view of the wide application value of flavonoids in S.alterniflora and its potential anti-stress in S.alterniflora against abiotic stresses,This study focus on the content,antioxidation ability of flavonoids in S.alterniflora and some other halophytes,and identification of flavonoids in S.alterniflora.By exploring the potential value of flavonoids and hence the collection of biomass,we.hope of find new ways for controlling the S.alterniflora invasion.Through the research we draw the followingconclusions:1)The flavonoids are rich in the four halophytes including S.alterniflora and they vary greatly among the different organs.Except Suaeda salsa,the flavonoids contents in leaves are much higher than other organs in Kosteletzkya virginica?S.alterniflora and Phragmites communis(L.)Trin.Flavonoids contents in.the leaves of S.alterniflora(21.75 mg·g-1)and K.virginica(39.93 mg·g-1)are the most significant.2)Orthogonal test showed that the best extraction method for flavonoids from S.alterniflora leaves involved the following parameters:1:30(g:mL)material:solvent ratio,using 70%alcohol as solvent,and extraction in water bath at 80? for 2 h.The best extraction method for flavonoids from K.virginica leaves involved the following parameters:1:20(g:mL)material:solvent ratio,using 60%alcohol as solvent,and extraction in water bath at 80? for 1 h.3)The scavenging ability of flavonoids from S.on hydroxyl free radical is higher than that of K.virginica,but lower than ascorbic acid.There is a positive correlation between the scavenging ability and flavonoids concentration.4)The oxidation stability of flavonoids from S.alterniflora and K.virginica is influenced by the pH,temperature and illumination.The alkaline conditions,high temperature above 80? and light conditions can reduce the antioxidation ability of flavonoids.The flavonoids of S.alterniflora can help more with the antioxidant of colleseed oil than K.virginica,and in a certain range there is a positive correlation between antioxidation and flavonoids concentration.Its antioxidation ability is close to citric acid,but slightly lower than the ascorbic acid.5)Flavonoids from S.alterniflora can be preliminary identified into at least two classes,including a kind of dihydroflavone(dihydroflavonol)with 4'-hydroxy,no 7-hydroxy,no o-dihydroxy in B rings.The experiments show that S.alterniflora flavonoids possess the high antioxidant activity,which can be used as a source of natural antioxidants.The stability of S.alterniflora flavonoids is influenced by some factors that we should pay attention to its use and storage.The value of flavonoids as medicine may stimulate the active harvesting of S.alterniflora biomass,which could become a potential strategy in controlling its invasion.