The Research Of Biochemical Characteristics Of Acer Truncatum Bunge's Leaves

This article firstly carry on a more systematic study on the biochemical characteristics of Acer truncatum Bunge's leaves.On the basis of detection of the biochemical components,this paper researched the extraction process and determination of its polyphenols,proved extraction process and purification methods of the functional and biological active ingredients,and further analysised the antioxiclant capacity of 70%ethanol extraction,purified flavonoids and chlorogenic acid;then compared the biochemical contents in different seasons and different blade Site,furthermore,detected the heavy metal content to analysis whether it enrichment of heavy metals,to comduct a preliminary evaluation of health and provide a theoretical basis for comprehensive development and utilization of Acer truncatum Bunge's leave.The results showed that:1.As to different blade site,the leaves had the highest content of active ingredients,followed by the entire leaf,and petiole the minimum.While the highest contents of the active ingredient were different in the development cycle of different seasons,the spring leaves had the highest content such as flee amino acids and water extraction.2.Acer truncatum Bunge's leave rich in the basical biochemical components.The total ash content was 5.3%to 8.0%,in which the acid-soluble and water-soluble ash had a high content,mineral elements can be used in a high content.Crude fiber content of leaves were much lower than the petiole,the lowest was 6.84%for the spring leaves.The highest content of water extraction was 39.99%in the spring leaves,with the maturing of spring leaves it slightly lower,in the summer it had risen to 39.89%,then became lower in the autumn.3.The highest content of amino acids about 1.5%in the spring tend leaves,following by matured leaves of spring.With the maturity of the leaves,free amino acid content become lower,to fall it almost completely decomposed.4.Using Folin reagent Colorimetry to detece the polyphenols content,the best conditions were as follows:the maximum absorptioh wavelength of polyphenols was at 700 nm±10nm;the ratio of Folin reagent and lye as 4:1(v:v),with the volume of 6smL and 1.5mL;reacted at 50℃with 15minute;polyphenols concentration from 0 to 14μg·mL^-1.The average recovery was from 92.2 %to 103.2%.Higher extraction rate was gained in acetone-water system than water;The dptimal extraction process were choosen as follows:50%acetone as solvent,50℃,extraction 2 times,each 120 minute.The polyphenols content was between 16.79%to 23.67%,the highest was in spring tend leaves. 5.Extraction and purification process of Acer truncatum Bunge's leaves flavonoids were as follows: 70%ethanol,70℃,condensation from returning 2 times,each time 2h→defat 3 times using chloroform→ethyl acetate extract 3 times→crude extract of flavonoids→vacuum decompression enrichment of ethyl acetate extract→column chromatography using polyamide resin.Better purification of column chromatography was:70%ethanol as eluting solvent,pH of extract from 4 to 5.The premilary pH of extract was between 4.5 to 5,at this pH resin absorption was higher. In general,Acer truncatum Bunge's leaves had high levels of flavonoids,the highest crude flavonoids up to 8.71%in the summer leaves;followed by autumn leaves,to 5.48%.Flavonoids in Leaves were much more than petiole of the same period,However,with the trend of seasonal change,the levels of flavonoids were higher in the spring immature samples than matured,then rose to the highest in summer,and slightly lower in autumn.Purified flavonoids in summer leaves up to 4.05%.Purification rate was between 42%to 77%.6.Extraction and purification process of Acer truncatum Bunge's leaves chlorogenic acid were as follows:70%e thanol,70℃,condensation from returning 2 times,each time 2h→defat 3 times using,chloroform→40%alkaline lead acetate as precipitation to isolate yellow-green precipitation→using 5%sulphuric acid change pH to 3,then filtering→extracted with ethyl acetate→vacuum decompression enrichment of water extract.Generally speaking,Acer truncatura Bunge's leaves had high levels of chlorogenic acid,the highest of which up to 2.46%in the summer leaves.With the trend of seasonal change,the levels of flavonoids were higher in the spring immature leaves than matured,then rose higher in summer, and then slight decline with the aging of leaves.It had a different changing trend in the petiole:the content reducted with mature of the petiole,but increased in fall,up tol.85%with 1.07%after purified.Purification rate was between 50%to 60%.7.Acer truncatum Bunge's leaves flavonoids have the strongest clear hydroxyl radical capacity,and larger than Vc,the strongest of which was spring matured leaves,up to 0.200mg/mL.This was followed by 70%ethanol extract,which was Stronger than Vc except the summer leaves;while the strongest was the autumn leaves,with IC₅₀was 0.571mg/mL,followed by spring matured leaves and summer petiole.But clear hydroxyl radical capacity of chlorogenic acid was relatively weak. At the same concentration,the higher the absorbance,the stronger the reducing power.Reducing power of 70%ethanol extract was the strongest,followed by purified flavonoids,chlorogenic acid was the weakest.8.Acer truncatum Bunge's leaves didn't accumulate heavy metals.This shows that Acer truncatum Bunge's leaves rich in and bio chemical components,such as mineral elements,water extraction,eapecially the polyphenols which has a larger proportion of flavonoids and chlorogenic acid than other plants.The active ingredients had a high rate of extraction and purification,there anti-oxidation function were also strong.As a result,leaves of Acer truncatum Bunge maybe a new type of polyphenols resources to be developed and utilized for its high polyphenols.