Analysis Of Flavonoids In Sea Buckthorn Fruits

Sea buckthorn(Hippophae L.)is a deciduous small shrub of the genus Hippophae in the family Elaeagnaceae.The roots,stems,leaves,flower and fruits of sea buckthorn contain high nutrients and various physiologically active ingredients.Sea buckthorn is one of the important medical and food homologous plants.Sea buckthorn fruits is an important small berry that contains high content of flavonoids.This study aims to promote the further development of the industry of sea buckthorn,and to evaluate and screen out sea buckthorn varieties(strains)with excellent traits.This study was based on picking the mature fruits of the excellent variety of sea buckthorn ‘Shenqiu Hong' and exploring the superior technology of ultrasonic assisted extraction of flavonoids in sea buckthorn fruits.Ultra-performance liquid chromatography-mass spectrometry(UHPLC-MS/MS)was used to qualitatively and quantitatively analyze the types and contents of flavonoids in the fruits of 20 sea buckthorn varieties(strains).Using mathematical analysis methods such as principal component analysis,factor analysis and cluster analysis,the resources of 20 sea buckthorn varieties(strains)were preliminarily evaluated from the perspective of the types and contents of flavonoids in sea buckthorn fruits.The research results were as follows:(1)The optimal process conditions for ultrasonic-assisted extraction of total flavonoids in sea buckthorn fruits were determined as follows: ethanol solution with a volume fraction of 95%,a material-to-liquid ratio of 1:26(g/m L),an extraction temperature of 80?,an extraction power of 200 W,and an extraction time of 35 min.(2)Qualitative analysis results showed that 34 flavonoids were detected in the fruits of 20 sea buckthorn varieties(strains),mainly in the form of glycosides such as glucoside,rhamnoside and rutinoside.There were five main types of flavonoids in sea buckthorn fruits,namely: flavan-3-ols,flavonols,flavanones,flavanonols and flavones,among which flavonol species were the most.Flavonols in sea buckthorn fruits were mainly quercetin,isorhamnetin and kaempferol.Most sea buckthorn varieties(strains)contained more than 20 flavonoids in their fruits.Among them,the number of flavonoids in the fruits of ‘Za 3-1' was the most abundant.12 kinds of flavonoids including quercetin-3-O-rutinoside,quercetin-3-O-glucoside,isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-glucoside substance were common flavonoids in the fruits of all sea buckthorn varieties(strains).Dihydroquercetin and laricitrin-3-O-glucoside might seem to be the unique flavonoid in the two strains ‘201318' and ‘HS-14',respectively.It showed that the types of flavonoids in sea buckthorn fruits were extremely rich,and the composition was extremely complicated.(3)Quantitative analysis results showed that the relative content of flavonols in sea buckthorn fruits was relatively high.Only from the perspective of the content of flavonols in sea buckthorn fruits,the relative contents of kaempferol,myricetin,syringetin and laricitrin were all at low levels,the relative contents of quercetin and isorhamnetin were at high levels.Quercetin and isorhamnetin were the two most important flavonoids in sea buckthorn fruits.(4)The results of principal component analysis showed that: flavone and flavanonol were the first principal component;flavanone and flavonol were the second principal component;flavan-3-ol was the third principal component.The results of factor analysis showed that the excellent strain ‘Za 3-1' had the highest comprehensive score.20 sea buckthorn varieties(strains)could be divided into two categories through cluster analysis.The first category had 17 varieties(strains)represented by ‘Wulan Gemu'.The second category mainly contained 3 varieties(strains)of ‘Shenqiu Hong',‘Fu Ou' and ‘You Sheng'.According to systematic analysis,the content of flavan-3-ols in the fruits of sea buckthorn varieties(strains)in the first category was relatively high,the content of flavan-3-ols in the fruits of sea buckthorn(strains)in the second category was relatively low.