Study On The Determination,Preparation And Antidiabetic Effect Of Main Functional Components In Angelica Keiskei

Angelica keiskei is a kind of perennial vegetable, introduced from Japan rencently. It has many active ingredients, including chalcones, coumarins, flavanones, natural organic germanium, which have been associated with the protection of human health. Nowadays, a variety of products have been developed from Angelica keiskei. 4-Hydroxyderricin(4-HD) and xanthoangelol(XAG) are the major functional components. Therefore, in order to better apply 4-HD, XAG or other related products to people’s daily life, it’s very necessary to intensively study 4-HD and XAG. The main conclusions in this paper are as follows.First, a quantitative method of 4-HD and XAG was established. Then the contents of 4-HD and XAG in different parts of Angelica keiskei were compared. RP-HPLC was used for determination. The column was Phenomenex C18(4.6 mm×l50 mm, 5 μm). The column temperature was 25°C. The mobile phase consisted of water-methanol(8:2, V/V) was run in isocratic mode, with the flow rate of 1 mL/min. And the detection wavelength was 368 nm and the injection volume was 10 μL. A fine linearity was obtained with correlation coefficient greater than 0.9990. The linearity ranged 11~176 μg/m L for 4-HD and 13~207 μg/m L for XAG. The limit of detection(LOD) and the limit of quantification(LOQ) for 4-HD was 1.53 μg/m L and 4.74 μg/mL, and for XAG was 1.81 μg/mL and 5.48 μg/m L. The recoveries of the two compounds were 100.05% and 100.37%, and relative standard deviation(RSD) were 1.37% and 1.49%. RSD for both intra-day and inter-day analysis, of the two compounds were between 1.01~3.09%. Results of content determination indicated that 4-HD and XAG mainly distributed in the roots. The contents of 4-HD were as follows: roots(1.83 mg/g)>stems(1.41 mg/g)>leaves(0.53 mg/g). The contents of XAG were as follows: roots(2.13 mg/g)>stems(1.92 mg/g)>leaves(0.87 mg/g).Second, the extraction and purification of 4-HD and XAG were studied. Single factor experiment and orthogonality test were developed to optimize the extraction process of 4-HD and XAG from the roots. The optimized extraction conditions were determined as follows: times of extraction as 3, extract solvent as 80% ethanol, extraction temperature as 55°C, extraction time as 60 min, ratio of solid to liquid as 1:10(g/m L). Under these optimized conditions, the extraction yield of 4-HD and XAG was 1.82 mg/g and 2.12 mg/g, respectively. Further, isolation and purification of 4-HD and XAG by silica gel column and semipreparative liquid chromatography was also described. The structures and purities were identified. Results showed that 4-HD at 99.08% purity and XAG at 98.92% purity were obtained.Last, mice model of type II diabetic established by high fat diet and injection of streptozotocin(STZ) was used for investigating the antidiabetic activity of the crude extraction from the roots of Angelica keiskei and the purified compounds(4-HD, XAG). The results showed that both of them could lower blood glucose, serum free fatty acids, serum total cholesterol, serum low density lipoprotein, atherogenic index, insulin resistance. And these functions between them had no significant difference(p>0.05) and both showed a dose response relationship. Furthermore, the crude extraction could also significantly decrease serum triglyceride and increase serum high density lipoprotein level(p<0.05) with a dosagedependent. Therefore, it can concluded that the crude extraction from the root of Angelica keiskei can improve glucose metabolism, lipid metabolism and islet function of type II diabetic mice and the main functional components are probably 4-HD and XAG.