Studies of the Constituents and Biological Activities of Achytanthes Bidentata BL.
|School||Shenyang Pharmaceutical University|
|Course||Natural Medicinal Chemistry|
|Keywords||Achyranthes bidentata Bl. triterpene saponins phytosterones achyranthesterone A 25-R inokosterone 25-S inokosterone bioactivities anitumor improving the impairment of memory anti-inflammation|
Achyranthes bidentata Bl. is a traditional herb in China which belongs to family Amarathaceae and is widely distributed in He Nan, Shan Xi, Shan Dong, Jiang Su, An Hui, et al. It has the effects of dissipating blood stasis, subducing inflammation, nourishing the liver and kidney, strengthening the bones and muscles, et.al and is used for the treatment of osteodynia of lumbar and knees, spasm and flaccidity of limbs and so on.By various chromatographic methods, 39 compounds, which belong to phytosterones, triterpene saponins, flavonoids and so on, were isolated from A. bidentata. On the basis of physico-chemical characters and spectroscopic analysis such as UV, IR, NMR and MS, 34 compounds were identified as: achyranthesterone A (1), 25-R inokosterone (2), 25-5" inokosterone (3), rhapontisterone B (4), stachysterone D (5), ecdysterone (6), polypodine B (7), rubrosterone (8), ginsenoside Ro(9), zingibroside R1 (10), chikusetsusaponin IVa (11), deglucose chikusetsusaponin IVa (12), PJS-1(13), oleanolic acid (14), 28 - norolean - 17-en-3-ol (15), baicalin (16), wogonin (17), berberine (18), palmatine (19), coptisine (20), epiberberine (21), B-sitosterol (22), a -spinasterol(23), daucosterol (24), 3- O-B-D-glucopyranosyl - a -spinasterol (25), geniposide (26), cyclo-(-Pro-Leu) (27), cyclo-(-Leu-Ile) (28), nonanedioic acid (29), succinic acid (30), n-butyl- B -D-fructopyranoside (31), 5-hydromethyl furaldehyde (32), sucrose(33), glucose(34). Among them, compound 1 was a new compound; compound 2 and 3 were epimers which were firstly isolated from A. bidentata. Their absolute configurations were confirmed for the first time. Their 1H NMR,13C NMR data were summerised for the first time, too. Compounds 4, 5, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 21, 26, 27, 28, 29 and 32 were firstly isolated from A. bidentata.A review on the types of structures, pharmacological activities and the spectral characters of seco-glycosides was given on the basis of references.The bioactivities investigated in vitro by MTT method showed that the main components in A. bidentata, which had the activity of anitumor, were triterpene saponins. The SAR studies indicated that the glycosidation on the C3 of oleanolic acid could strengthen the anitumor effects. While, the glycosidation on the C28 would lower down their activities obviously. A further study on the phytosterones obtained in our laboratory found that the increase of double-bound and extension of conjugate system also promoted the antitumor effects.The pharmacological experiments showed that the general phytosterones in A. bidentata. had significant protective effects on the acquisition impairment of memory induced by scopolamine, the consolidation disruption of memory induced by cycloheximide employing the methods of step down test and step through test. It also protected mice against encepha-hypoxia significantly induced by KCN.The experiments in vitro showed that the general saponins of A. bidentata. had the obvious inhibitory activities on the synthesis and release of NO, which was induced by LPS in macrophage cells of mice abdominal cavity. They suppressed the synthesis and release of TNF-a in a certain degree. On the other hand, these inhibitory effects of the general phytosterones of A. bidentata were weak. Further pharmacological experiments in vivo showed that the general saponins from A. bidentata had the inhibiting effect on the xylene-induced ear edema in mice and on the hyperplasia of granulation tissue in mice. It also had the increased capillary permeability induced by acetic acid in mice. The experiments’ results in vitro and in vivo indicated that the triterpene saponins were the main constituents which had the anti-inflammatory effect in A. bidentata. This effect may have a relationship with the inhibitory activities on the synthesis and release of NO and TNF-?