Extraction, Component Idendification And Antioxidant Ability Of Flavonoids From Fruits Of Chinese Dwarf Cherry (Cerasus Humilis(Bge)Sok)

Chinese dwarf cherry (Cerasus humilis(Bge)Sok) is a new cultivated shrub fruit tree which belongs to the genus Cerasus Yu. under the family Rosaceae Juss. It has a huge development prospect for its multpurpose of fresh edible fruit, good character for processing, ornamental and drugs value. The tree can aslo be used for conservation of water and soil in severe environment area. The cultivars and strains conservated by Shanxi agricultural university were used in this research for extraction, component idendification and antioxidant ability of flavonoids from the friut. Dynamics of the flavonoids during fruit development period were also studied. The results were as follows:1.When ethyl alcohol reflux were adopted for the extracting of flavonoids from the fruit the best conditions were:50% ethyl alcohol, time 1.5h, temperature 85℃, ratio of solid to liquid 1:40 from the peel; 60% ethyl alcohol, time 2.5h,temperature 85℃, ratio of solid to liquid 1:10 from the pulp; 90%ethyl alcohol,,time 2h,temperature 85℃ ratio of solid to liquid 1:30 from the seed kernel.2. The total flavonoid contents of 25 cultivars or strains in fruit peel, pulp and seed kernel were determined by using spectrophotometry. The contents of flavonoids in different organs of fruit are different and of the different cultivars or strains varied very much. The highest content of flavonoids in peel is ’nongda NO.9’with 72.80mg/g, and the lowest is’Y13-03’with 23.35mg/g. The highest content of flavonoids in pulp is’10-32’with 16.91mg/g and the lowest is’nongda NO.6’with 4.26mg/g.The highest content of flavonoids in seed kernel is’nongda NO.9’with16.91mg/g and the lowest is’wen fen li’with 8.13 mg/g.3.The flavonoid component of 20 cultivars or strains in fruits were anlaysed by using RP-HPLC The fruit contains mainly 14 kinds of flavonoids including 4 kinds of flavanol,3 kinds of dihydrochalcone, 6 kinds of flavonols and 1 kind of anthocyanins. Both flavanol and dihydrochalcones are the main component comprising 86% of the total flavonoids.The flavanols are mainly’procyanidin B1’. The dihydrogenchalcones are mainly’phloretin-3-O-2-glucosidase’.The flavonols are mainly ’quercetin-7-O-glucoside and acetyl quercetin-7-O-glucoside’. The Anthocyanins are mainly’cyanidin-3-0-glucoside1. These 8 kinds of flavonoids including’Catechin, epicatechin, procyanidin B1, procyanidins B2, phloretin-3-O-2-glucoside, quercetin, acetylquercetin-7-O-glucoside, quercetin-7-O-glucoside exist in all detected cultivars and strains.These chemical compounds reprensented the characteristics of friut flavoniods in Chinese dwarf cherry.4.The three cultivars were used for the research of dynamics of flavonoids during fruit development period. The content of total flavonoids in fruit is highest in young fruit period, minimum in maturation period.. Total flavonoids content in pulp decreased grandully, while trends of change in peel and seed kernel firstly decreased, then increased and finally decreased. All of dynamics of flavanols, flavonols and dihydrochalcones decreased grandully. Dynamics of anthocyanin accumulation in three cultivars are different. The’nongda NO.3’ firstly incresed,then decresed.andfinally increased. The’nongda NO.4’ is always lower values befor fruit enlargement, but incresed rapidly to the higthest values in fruit mature period. The’nongda NO.5’contains without anthocyanin.5.Antioxidant ability of flavonoids taken from fruit extracts of three cultivars was determined by means of DPPH with contrast BTH. When concentrations of flavonoid extracts from frruits of three cultivars were all 0.5mg/ml, radical scacenging rate of DPPH of’nongda N0.3’and’nongda N0.4’could reach 73.75% and 77.5% respectively which was close to the value(80%) of antioxidant synthetic agent BTH.The facts proved that flavonoids from fruit Chinese dwarf cherry have stronger antioxidant ability.