| A method for the extraction and isolation of alkylphenols in ginkgo biloba leaves was introduced , through the TLC and HPLC preparation , Six monomers were acquired. By UV,IR,MS,1H-NMR and 13C-NMR spectral analysis , the structures of the compounds were identifited as:1. 3-(8- pentadecenyl (phenol2. 3-(4(z),7(z)-heptadecadienyl( phenol3. 3-(10-heptadecenyl( phenol4. 6-(8- pentadecenyl (salicylic acid5. 6-(10-heptadecenyl ( salicylic acid6. 5-(8- pentadecenyl (resorcinol The structure of compound 1 , 3 , 4 , 5 , 6 were confirmed by comparison with those of literature data .The position of the double bonds in compound 2 was determined from the GC-MS spectrum of its oxide and methylated products.The compound 6 was the first time found in ginkgo biloba leaves. And the compound 2 was determined as a new natural compound by search in Infochem Spresi Structural ( Reaction Database in INTERNET. A simple HPLC analysis method for quantitative determination of the alkylphenol , including ginkgolic acids and ginkgols ,in the Ginkgo biloba leaves ,extracts and preparations was estsblished. The RSD of the method is 3.57% (n=5) ,and the rate of recovery is 98.83%.In order to decrease the content of ginkgolic acids in the commercial GBE products, a method of extracting the alkylphenols from the GBE was studied. A suitable solvent system A was development to obtain the Ginkgo biloba extracts with the content of Flavonoids 24%, Terpene Lacton 6% , and less than 10ppm ginkgolic acids.{{END-END }} Key word :ginkgo biloba leaves,alkylphenol,HPLC,ginkgolic acid,ginkgol,bilobol... |
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