銀杏葉萃取物之品管分析須檢測黃酮醇配糖體   全文下載

Quality Control Analyses for Ginkgo Extracts Require Analysis of Intact Flavonol Glycosides

本研究分析十種市售宣稱標準化銀杏葉萃取物原料的黃酮醇配糖體（flavonol glycoside）和烯帖內酯（terpene lactone）含量。所有樣品均附有分析證明標示；其內容物為標準化的銀杏葉萃取物，並且至少含有24%的總銀杏黃酮醇配糖體和6%的烯帖內酯。總銀杏黃酮醇配糖體含量的分析是先將樣品酸水解成黃酮醇甘元（flavonol aglycone）後，再以配備有紫外線矩陣二極體吸收光譜儀的高效液相層析儀進行定量分析。完整未水解的銀杏黃酮醇配糖體和松烯內脂是以配備有紫外線矩陣二極體吸收光譜儀和電灑質譜儀的高效液相層析儀進行分析。十種樣品中，八種樣品的分析結果，層析圖和化學特徵參數符合銀杏葉萃取物；一個樣品的分析結果顯示有添加芸香甘（rutin）來冒充黃酮醇配糖體；另一個樣品則完全沒有有銀杏葉的成分。如果黃酮醇配糖體總量的分析方法是採用酸水解的方式，這樣添加芸香甘作假的行為，就不易被查獲，可是，如果分析方式是採用檢測特有完整未水解黃酮醇配糖體的量，添加物就容易被查驗出來。本研究顯示草藥產品須要有嚴謹的品管分析，而且檢測特有完整未水解成分的方法可有效辨別產品的真偽。

Ten commercial standardized Ginkgo biloba extracts were examined for flavonol glycoside and terpene lactone content. All samples arrived with certificates of analysis stating that the extracts were standardized Ginkgo biloba leaf extract and that they contained a minimum of 24% total flavonol glycosides and 6% terpene lactones. Samples were analyzed for total flavonol glycosides using a method involving acid hydrolysis and subsequent quantification of the flavonol aglycones by HPLC coupled with UV diode array absorbance detection. Analysis of intact flavonol glycosides and terpene lactones was accomplished using HPLC coupled with UV diode array detection and electrospray mass spectrometric detection. Of the ten standardized extracts eight samples provided chromatograms and chemical values characteristic of previously published analyses of ginkgo leaf extracts. One sample provided analyses that suggested that the extract had been adulterated with rutin in order to elevate total flavonol glycoside levels. Another sample indicated that it was not an extract of Ginkgo biloba leaf at all. Adulteration with rutin was not strongly evident when the acid hydrolysis method was used to analyze the sample for total flavonol glycosides. However, this particular adulteration was easily evident when analyzing the samples for characteristic intact flavonol glycosides. This work demonstrates the need for extensive quality control analyses for herbal products and that the analysis of intact characteristic compounds provides a reliable method for detecting adulteration. 本研究分析十種市售宣稱標準化銀杏葉萃取物原料的黃酮醇配糖體（flavonol glycoside）和烯帖內酯（terpene lactone）含量。所有樣品均附有分析證明標示；其內容物為標準化的銀杏葉萃取物，並且至少含有24%的總銀杏黃酮醇配糖體和6%的烯帖內酯。總銀杏黃酮醇配糖體含量的分析是先將樣品酸水解成黃酮醇甘元（flavonol aglycone）後，再以配備有紫外線矩陣二極體吸收光譜儀的高效液相層析儀進行定量分析。完整未水解的銀杏黃酮醇配糖體和松烯內脂是以配備有紫外線矩陣二極體吸收光譜儀和電灑質譜儀的高效液相層析儀進行分析。十種樣品中，八種樣品的分析結果，層析圖和化學特徵參數符合銀杏葉萃取物；一個樣品的分析結果顯示有添加芸香甘（rutin）來冒充黃酮醇配糖體；另一個樣品則完全沒有有銀杏葉的成分。如果黃酮醇配糖體總量的分析方法是採用酸水解的方式，這樣添加芸香甘作假的行為，就不易被查獲，可是，如果分析方式是採用檢測特有完整未水解黃酮醇配糖體的量，添加物就容易被查驗出來。本研究顯示草藥產品須要有嚴謹的品管分析，而且檢測特有完整未水解成分的方法可有效辨別產品的真偽。