沉香籽萃取物的成份及抗氧化活性評估

Chemical Composition and Antioxidative Activity Evaluation of Aquilaria Sinensis (Lour.) Gilg Seed Extract

Aquilaria sinensis (Lour.) Gilg (A. sinensis)是一種原產於中國的熱帶常綠喬木，有許多文獻針對沉香木及沉香葉的萃取物進行研究，但針對沉香籽萃取物的研究卻非常少，因此本研究將對沉香籽的整顆種籽、種籽外皮以及種籽種仁之三種方法的萃取物評估其萃取產率、化學成分分析、抗氧化功效及總酚含量評估。結果發現使用熱迴流萃取的三種方法的產率在3.3~10.0%之間，以GC-MS分析發現整顆種籽及種籽外皮的三種主要之化合物皆為(Z)-octadec-11-enoic acid、(9Z, 12Z)-octadeca-9,12-dienoic acid、hexadecanoic acid，其中(Z)-octadec-11-enoic acid的含量更高達42.92~45.46%。而種籽種仁的主要成分相當不同，分別為propane-1,2,3-triol、2-(hydroxymethyl)-2-nitropropane-1,3-diol、methyl (9Z, 12Z, 15Z)-octadeca-9,12,15-trienoate，其中propane-1,2,3-triol的含量高達44.43%。在多種抗氧化活性分析都以種籽外皮的效果最好，其清除DPPH自由基、清除超氧陰離子及還原力的IC50分別為0.08、0.19及0.22 mg/mL，而在螯合亞鐵離子的效果較弱。總酚試驗以種籽外皮含量最高達200.46 mg GAE/g萃取物。本研究顯示沉香籽尤其是種籽外皮值得更進一步開發研究並應用於化妝品中。

Aquilaria sinensis (Lour.) Gilg (A. sinensis) is a tropical evergreen tree native trees in China. There are many studies on the stem and leaves extracts of A. sinensis, but very few studies on the seed extracts of A. sinensis. Therefore, this study will evaluate the extraction yield, chemical composition, antioxidative efficacy and total phenolic contents of the three extracts from the whole seed, seed husk and seed kernel of A. sinensis. The results showed the yields of the three samples using heat reflux extraction were between 3.3 and 10.0%. The three main compounds of the whole seed and seed husk were (Z)-octadec-11-enoic acid, (9Z, 12Z)-octadeca-9,12-dienoic acid, hexadecanoic acid, among which the content of (Z)-octadec-11-enoic acid was as high as 42.92~45.46%. The main components of the seeds kernels were quite different, namely propane-1,2,3-triol, 2-(hydroxymethyl)-2-nitropropane-1,3- diol, methyl (9Z, 12Z, 15Z)-octadeca-9,12, 15-trienoate, in which the content of propane-1,2,3-triol was as high as 44.43%. The seed husk exhibited the best effect in various antioxidant activities assays. The IC50 for scavenging DPPH free radicals, scavenging superoxide anion and reducing power were 0.08, 0.19 and 0.22 mg/mL respectively. The chelating ability of ferrous ions of three samples were weak. The highest total phenolic content of three samples was seed husk up to 200.46 mg GAE/g extract. This study demonstrates that A. sinensis seeds, especially the seed husks have potent antioxidative activities and, are worthy of further research and development and application in cosmetics.