Phytochemical studies on Chinese medicinal plants: Hyoscyamus niger, Euptelea pleiospermum, and Rorippa montana.

摘要

In the present study, three medicinal plant species were studied for their organic constitution. The plant materials were extracted and purified by chromatographic separation using a combination of methods. Each compound isolated was fully characterized by spectroscopic and physical data. In particular, NMR results (1D and 2D) were carefully analyzed and compared with literature data. A number of new chemical structures were found.; The structure of each isolated compound was elucidated based on 1D, 2D-NMR (e.g. 1H-NMR, 13C-NMR, DEPT, 1H, 1H-COSY, 1H, 13C-COSY, COLOC, HMQC, HMBC, DIFNOE and NOESY), MS (e.g. EI-MS, CI-MS, DCI-MS, FAB-MS, ESI-MS, HRFAB-MS, MS/MS), IR, UV spectra, physical data as well as chemical reactions. In some cases, X-ray crystallography was sought to confirm the structures.; The investigation of an ethanol extract prepared from the seeds of Hyoscyamus niger (Solanaceae), a traditional Chinese medicine known as “Tian-Xian-Zi”, led to the isolation and identification of nineteen pure organic chemical compounds. These compounds included five lignanamides, two ferulic acid derivatives, three withanolides, five glycerol fatty acid esters, two steroids, one flavonoid glycoside (rutin) and one benzoic acid derivative (vanillic acid). Five of these isolates are new natural products, namely, hyoscyamiamide A, hyoscyamiamide B, hyoscyamiester (1,24-tetracosanediol diferulate), 16α-acetoxyhyoscyamilactol and 1-O-(9,12-octadecadienoyl)-3-O-nonadecanoyl glycerol. All isolated compounds were reported for the first time from Hyoscyamus species.; Seventeen pure organic chemical compounds were isolated and identified from an ethanol extract prepared from the small stem of Euptelea pleiospermum (Eupteleaceae), a medicinal plant in imminent danger. These compounds included three triterpenes, three saponins, two β-carboline-type gluco indole alkaloids, four iridoids, two chromones, one lignan [(−)-syringaresinol], one unsaturated alkane derivative (falcarindiol) and one phytosterol (β-sitosterol). Three of these compounds are newly reported structures, namely, euptelin A, euptelin B and euptelin C. All isolated compounds are reported for the first time from E. pleiospermum, while the β-carboline-type gluco indole alkaloids, iridoids, chromones, (−)-syringaresinol and falcarindiol are reported for the first time from the Euptelea genus.; The investigation of an ethanol extract prepared from the whole plant of Rorippa montana (Cruciferae), a herbal drug in China, led to the isolation and identification of six known organic compounds. These compounds were identified as rorifone, rorifamide, 1H-indole-3-carboxaldehyde and three flavonoid glycosides.; Bioassay results revealed that grossamide, cannabisin G, and cannabisin D are cytotoxic to LNCaP cells (IC₅₀ values were 33, 76, 81 μM respectively). 3α,5α-Tetrahydrodeoxycordifoline showed enhancing effect on the growth of PC12 cells. Rorifone and kaempferol-3-O-glucoside-7-O-rhamnoside increased the maximum force of contraction of the isolated rat heart (p 0.05), but were not effective on changing the heart rate. Rorifamide was strongly antiestrogenic (ED₅₀ 0.52 μg/ml).; In addition, quantitative analytical methods were established for the estimation of scopolamine and atropine in Tian-Xian-Zi by HPLC and HPCE methods, which will find application in the quality control of H. niger seeds as a crude drug.