| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 100 === Momordica charantia L. is a common vegetable in tropics and subtropics, which is rich in physiological functions. It has also been used in traditional medicine for treating diabetes in India. One of the antidiabetic bioactive compounds is charantin. For analyzing charantin, the standard is rare and expensive. In this experiment, charantin quantitation was carried out by analyzing the content of stigmasterol and sitosterol from Momordica charantia L.. A simple and sensitive analytical method by using derivatization was established in the experiment.
The charantin in bitter gourd was first extracted and hydrolyzed. It was then derivatized with 2-fluoro-1-methylpyridinium p-toluenesulfonate. The derivative was separated and quantitized with HPLC. The optimum conditions for hydrolysis, derivatization, and chromatography were also investigated. The recoveries of total amount of sitosterol and stigmasterol was 88.74-103.55%. The detection limit of stigmasterol derivative was 0.099 ppm. By applying the method to analyze three kinds of bitter gourd sold on the market, the results indicated that freeze-dried bitter gourd fruits contained more charantin than that in heat-dried ones, which were 1.74-2.49 folds to that in heat-dried powders. Bitter gourd seeds contained less charantin than fruits. The seed powders of white bitter gourd and wild bitter gourd contained 57.6 and 129.8 μg/g of charantin, respectively. No charantin was found in the seeds of green bitter gourd.
Most analytical methods for charantin relies on charantin standard, which is hard to obtain, to do the quantitation. In this experiment, charantin quantitation was carried out by analyzing the total content of stigmasterol and sitosterol from Momordica charantia L.. It is easier to perform. Furthermore, derivatization could lower the detection limit, reduce interference peaks, and shorten chromatographic time.
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