Study On The Resource Chemistry Of Ginkgo Biloba Root Barks

This dissertation was divided into four chapters.In the First Chapter,a detailed review,including origins,distribution,biological characteristics,chemical composition and pharmacological effects was given about the latest research progress of G.biloba.In the Second Chapter,the resource chemical constituents from G.biloba root barks were studied base on the ginkgo seeds comprehensive utilization and exploration.The compounds were isolated by a variety of column chromatography techniques.Their structures were elucidated as 4-(3,4-dimethoxyphenyl)-1.2-dimethoxybenzene(1),(+),sesamin(2),palmitic acid(3),stearic acid(4),behenic acid(5),lignoceric acid(6),heptacosanol(7),β-sitosterol(8),daucosterol(9),genkwanin(10),apigenin(11),bilobalide(12),ginkgolide A(13),ginkgolide B(14),ginkgolide C(15),sciadopitysin(16),ginkgetin(17),isoginkgetin(18),D-glucose(19)and sucrose(20).Among them,compound 1 and 7 were obtained from this plant for the first time.In Chapter 3,the resource chemistry evaluation on G.biloba were performed,and the results were summarized in four sections.Section 1,using UPLC-TQ-MS method simultaneously determine flavonoids,terpene lactones and ginkgolic acids in G.biloba.Terpene lactones and golides and ginkgolic acids were rich in different parts of G.biloba,but the different composition contents varied greatly among different parts.The results demonstrated that the distribution and determination of terpene lactone contents arranged in a decreasing order as:root>leaf>stem>branch,phloem>>xylem.The decreasing order of ginkgolide contents was leaf>branch>>roots>stems.Flavonoids,mainly concentrated in the leaves.Section 2,resources chemistry evaluation of the polysaccharides in different part of G.biloba.The ratio of neutral and acidic polysaccharides in different parts of G.biloba ranged from 4.87:1 to 2.12:1.The data indicated that neutral polysaccharide was the main part of total polysaccharides in different parts of G.biloba.The contents of neutral polysaccharide were higher than acidic polysaccharide in individual part of G.biloba.The contents of total polysaccharide were much higher in root barks than other parts.Section 3,resource chemistry evaluation of the free amino acids in G.biloba samples.The contents of 20 free amino acids were evaluated by hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry(HILIC-UPLC-TQ-MS/MS)in multiple-reaction monitoring(MRM)mode.It was shown that the total contents of amino acids variation range is 317.8～6397.18 μg·g-1,and the contents varied greatly among different parts.The contents of proline were extremely larger than any other amino acids in G.biloba.Section 4,resource chemistry evaluation of the inorganic elements in G.biloba samples.Inorganic elements were determined by ICP-AES using microwave digestion.The result showed that:the contents of Mg,K,Ca and Al,Fe,Si were more abundant.Mg have an impact on lipid peroxidation,protecting cell membranes,maintaining mitochondrial function and so on;K lays an important role in the maintenance of normal heart function and cellular metabolism.All the results will provide good basis for comprehensive utilization of G.biloba.In chapter 4,the material basement study of the efficacies in root barks of G.biloba.Section 1,acute toxicity test.By observing acute toxicity in the mice fed different doses of G.biloba root barks,dose helpful to provide reference for clinical drug safety and post-tests.Section 2,the effects of G.biloba root barks replication model for kidney stones glycol.Select Copy glycol rat model of kidney stones,G.biloba root barks medication and composition of different compatibility evaluation,serum calcium content and changes in blood flow,etc.as index,clinical studies on G.biloba root barks compatibility crystal sugar kidney stones affected.The results show that after the using of ethylene glycol copy of kidney stones model modeling,plasma viscosity rats have different degrees increase,given G.biloba root barks will return the plasma viscosity to normal levels.When used alone sugar,a corresponding increase in plasma viscosity.The material basis for their effectiveness needs to be further studied.Section 3,the cytotoxicities of the compound in G.biloba root barks was investigated in vitro against PC-12,MCF-7 and Hep3B tumor cells by MTT method.The results showed that 4-(3,4-dimethoxyphenyl)-1,2-dimethoxybenzene showed cytotoxic activities on MCF-7 cells.The result suggested that 4-(3,4-dimethoxyphenyl)-1,2-dimethoxybenzene can be used as an inhibitor of MCF-7 tumor cells,or lead compounds of anti-tumor drugs.