Studies For Stability Of Major Phenolic Constituents In Hawthorn And Their Extracts

Hawthorn (Crataegus) is a sort of important botanic resource in China. It has a long history of use in medicinal and edibles. According to present primary studies on procyanidins (PC) of hawthorn, it has many important pharmacological properties, such as decrease of blood pressure and cholesterol levels in serum, and the protective effect of against arrhythmia. These benefits are attributed to several active components, such as procyanidins, flavonoids, phenolic acids et al. Procyanidins are the important active component of hawthorn fruit, people have focused on it. The present paper established a suit of analysis methods for those active components by using a homemade high performane liquid chromatographic apparatus. By this method, the stability of PC and chlorogenic acid in hawthorn fruit was evaluated and studied.A suit of high performance liquid chromatographic (HPLC) method was established for analyzing the main active components of Hawthorn by homemade high performance liquid chromatographic apparatus. Column: Hypersil BDS C18 (4.6 mm id ×250 mm, 5 μm);mobile phase, A: 500 μg/mL formic acid;B: methanol / acetonitrile containing 500 μg/mL formic acid;the gradient elution condition (min/B%) was: 0/14, 8/14,15/18, 25/18, 28/50, 33/50, and 35/14;detection: UV at 280 nm;flow: 0.8 mL/min;temperature: 30℃;injection quantity: 10 μL. The external standard calibration curves ewere used in quantification. By this method, the main active components in hawthorn, epicatechin, procyanidin B2, procyanidin C₁, chlorogenic acid, were separated and determined well. RSD of these components were 1.16% 3.46%. The detection limit was 0.258⁰.941 ng. The linearity rang was 0.0687 0.975 μg/mL. The correlation coefficient (r) was 0.9998-0.9999. Analytic time of one sample was 32 minutes.The stability study of PC on storage temperature and matter concentration indicated that the contents' change of these main components conform to the law of first order reaction of chemical kinetics. Storage temperature and matter concentration had important effect on stability of PC. At -18 ℃, half life(T1/2) of every components in Hawthorn extract were 231—1505 days. At 20℃ T_1/2 were 73¹77days. In these active components, the chlorogenic acid had the best stability in storage processing. PC C-I has the best stability in several procyanidins , and the PC C₁ has the worst stability.At 20°C change trend of active components decomposition velocity constant is single apex in different matter concentration hawthorn extract and the constant arrived the apex at 50% matter concentration. At 50% matter concentration decomposition velocity constant were 2.76 X 10'3 1.34 X10'2.There were three desiccation quomodo using in experiment, vocuum freezing desiccation, oven desiccation in 60 °C , desiccation in room temperature. The experiment result showed the rate of active component losed in hawthorn is 24.68% at least. In three desiccation, the rate of active component losed in hawthorn is the least by vocuum freezing desiccation, the losing rate of active component were 50.59% 75.32% by vocuum freezing desiccation.The losing rate of the other desiccation quomodoes are sameness, there have no distinctness difference.Hawthorn fruits at 0°C storage showed the rate of the active components contents in storage comparing with hawthorn fruit were 78.65% 116.86%. The evaluative standards, such as good fruits percentage ,colour and Iu9tre so on, accorded normal range in 120 days. Comparing with hawthorn desiccation' result, the rate of active component losed in hawthorn at 0°C storage is lower.Therefore, the low temperature storage is one of choice fashion on solving short-term storage and supply of hawthorn materials. The method that the hawthorn fruit were dried and storaged in room temperature is suitable for solving long-term storage of hawthorn materials.