Studies On The Chemical Constituents,Quality And Changes Of Caragana Sinica

Caragana sinica (Buc'hoz) Rehd. (Fabaceae) is widely distributed in China. Its dried roots (Chinese name: Jinquegen) have been used in China as a folk medicine for the treatment of asthenia syndrome, vascular hypertension, leukorrhagia, bruises and contused wounds. In our previous study, we found that the EtOAc extract of the roots contained many oligostilbenes which had multi-faceted bioactivities. Pharmacological studies showed that stilbene oligomers promote the absorption of calcium, and therefore Caragana sinica was developed and marketed as a type of medicine for the treatment of osteoporosis for women after menopause.Pharmacological experiments indicated that the low polar parts of Caragana sinica could induce the death of lung cell. In order to find new active compounds, we made a systemmetric chemical research on the low polar parts of Caragana sinica under the instruction of the biologically active experiments, and obtained 30 compounds including: cerotic acid (1), isoliquiritigenin (2), dalbergioidin (3), resveratrol (4), 3,3'-Dimethoxyquercetin (5), capitatin (6), acacetin (7), (-) maackiain (8), odoratin (9), liquitirigenin (10), furo(2,3-f)-l,3-benzodioxole (11), 7,5'-dihydroxy-3'-methoxyisoflavone-7-O-P-D-glucoside (12), pinosylvin (13), caragagenin (14), 1-propanone (15), caraganoid (16), β-sitosterol (17), 7α-hydroxysitosterol (18), 7β-hydroxysitosterol (19), 5α-stigmastane -3β,6α-diol (20), (-)-ε-viniferin (21), caraphenol A (22), carasiphenol D (23), (+)-α-viniferin (24), (-)-ampelopsin F (25), kobophenol A (26), carasinol B(27), hypaphorine (28), arabinose (29), rhamnose (30). Compounds 14 and 16 are new compounds and compounds 2, 3, 5, 6, 10～15, 18～20 and 29～30 were first isolated from Caragana sinica. Activity experiments showed that compounds 2,3,10, 14 and 15 could inhibit the mycelia growth of P. oryzae by curling and swelling effect, and induced morphological changes of mycelia.As the constituents would change both in quality and in quantity during the growing process of plant, we determined the seasonal variations of the main compounds. TLC was developed to authenticate the kind of Caragana sinica, and then the various contents of carasinol B, kobophenol A and (+)-α-viniferin in Caragana sinica from different locations and season were determined by an improved HPLC method. The results indicated that no matter where did the samples come from, the contents of carasinol B, kobophenol A and (+)-α-viniferin in theroots were much higher than those in the tubers, and carasinol B and (+)-α-viniferin could not be detected in the leaves and none of the three could not be detected in the flowers of Caragana sinica in the detection ranges. The changing trends of carasinol B,kobophenol A were similar while that of (+)-α-viniferin was contrary to them. The contents of stilbene tetramers were maximal in winter while the contents of the stilbene trimer were maximal in summer. The changing trends of the contents were corresponded with growing stages. As far as the weather effect was concerned, lower temperature and sunlight, the higher contents of carasinol B and kobophenol A while lower contents of (+)-α-viniferin.As the constituents would change during the long deposition of EtOAc extract of Caragana sinica, we tested the stability of the three main constituents. The results showed that carasinol B and kobophenol A were stable during low temperature and weak acid condition while (+)-α-viniferin was not stable if long deposit in above condition, and it would transform into resveratrol. On the one hand, carasinol B was not stable in higher temperature and it would transform into other stilbene tetramers if heated for a long time. On the other hand, the transformation would be hastened if heated in a weak acid condition. Kobophenol A was also not stable in higher temperature, and it would transform into carasinol B if heated for 1 hour. In addition, the transformation between them would be hastened if heated in a weak acid condition. The results indicated that the configuration of carasinol B was more stable than that of kobophenol A. The change of (+)-α-viniferin was invisible in the condition of higher temperature and weak acid condition. All the experimental results were corresponded with the fact.The content of unsaturated fatty acid was 68.5% in Caragana sinica by using a GC/MS method.