| Ginkgo biloba L., which was a traditional Chinese medicinal plant, has been recorded for several hundred years. And now it is approbated in the world for prevention and treatment of cardiovascular diseases. Bad-effect caused by extract of Ginkgo biloba leaves (EGb) have been reported. Ginkgolic acids are claimed to be allergenic compounds in Ginkgo biloba leaves, extrocarp and nut, but little reports were published on the safety of ginkgolic acids and the harmful compounds resulting in bad-effect in the usage of EGb. This paper is aimed to establish an efficient analytical method, probe its separation mechanism and find out the distribution and variation characteristic of ginkgolic acids by using modern chromatographic separation theory and identification technique. On the other hand, the bad-effect caused by ginkgolic acids and its early-hint were also studied systematically at animals level, cell level and molecular level. Emphases were put to reveal the allergenicity and immune sensitization mechanism of ginkgolic acids anaphylactogen. Anti-allergic mechanism of OPC, which was effective in preventing allergy caused by ginkgolic acids, was also discussed. Main research results:1 Separation of ginkgolic acids by second chemical equilibrium-high performance liquid chromatography (HPLC) and its mechanismAccording to the difference of ginkgolic acids in structure and character, separation mechanism of reversed-phase argentatin high performance liquid chromatography (RP-AHPLC) analytical method, which has been developed to separate ginkgolic acids in our laboratory, was studied utilizing basic theory and method of complexation chemistry in second chemical equilibrium. Ginkgolic acids homologues were separated efficiently by RP-AHPLC. Separation factor and resolution were up to 1.3 and 1.6 respectively. The results of chromatographic thermodynamics and kinetics showed that the partition model of complexation compound was the main retention mechanism of reversed-phase argentatin high performance liquid chromatographic behavior; the thermodynamic parameters of solute in physical partition equilibrium were changed markedly duo to the participation of second chemical equilibrium, which was the mechanism that the separation selectivity of ginkgolic acids homologues was increased by RP-AHPLC. The results revealed that second chemical equilibrium was a perfect method for the separation of homologues and isomers in HPLC. This method was also applied to separation of fatty acids homologues successfully.2 Distribution and contents variation characteristics of ginkgolic acidsThe kinds, composition, form, content distribution, variation rule and affecting factors of ginkgolic acids from different parts of Ginkgo biloba were studied by LC/(-)ESI/MS, FTICR-SIMS, RP-AHPLC and GC. The results showed that five kinds of ginkgolic acids C13: 0, C13: 1, C15:0, C17: 2 and C17:1 were present in Ginkgo biloba leaves, extrocarp and nuts, together with long chain phenols, the homophylic derivatives of ginkgolic acids. The contents and proportions of ginkgolic acids homologues were different evidently. The main ginkgolic acids in Ginkgo biloba were C15: 1, C17:1,which has unsaturated side chain, and C13: 0, which has saturated chain, and were up to 95% in sum. The variety, areas, age and growth period has different effect on the contents and proportions of ginkgolic acids. The pertinence between ginkgolic acids and fatty acids confirmed further the hypothesis that fatty acids were precursors of alkyl chain of anacardic acids.3 Purification of ginkgolic acids and conformation characteristic of ginkgolic acids complete antigen (GA-BSA)Ginkgolic acids were extracted by moderate polarity solvents containing phase-regulators, and separated on different resins, then purified by re-crystalization. LC/(-) ESI/MS was applied to identify the samples. Four ginkgolic acids Ci3,o, Cis, i, C^, o, and Cn, i from Ginkgo biloba leaves and extrocarp were confirmed. The contents of ginkgolic acids from Ginkgo biloba leaves and ext...
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