| Semen Descurainiae and Semen Lepidii, or Tinglizi in Chinese, is a well-known Chinese medicine recorded first in the famous Shen Nong's Herbal as a lower grade drug. It has the effect of removing heat from the lung and relieving asthma, inducing diuresis and diminishing swelling, according to the theory of Traditional Chinese Medicine.The pharmacopoeia of P. R. China (2000 revision) specifies Tinglizi as the ripe dried seeds of Descurainia sophia (L.) Webb ex Prantl and Lepidium apetalum Willd. However, seeds of other plants from Cruciferae and even some fakes are also commercialized under the same name Tinglizi. Therefore, a quality control of this drug is in great demand, which is the aim of this dissertation.In the first part of the research, a herb market investigation was held. 26 crude drug samples collected from 16 provinces all over the country were carefully analyzed. The result shows that Descurainia sophia (L.) Webb ex Prantl is the main sources of Tinglizi at present.TLC and HPLC were tried to identify Semen Descuraininae. According to the results, it is found that different species of Tinglizi and fakes have their own significant features. Semen Descurainiae though from different provinces has its own stable characteristics, which can be used to distinguish from the other similar species rapidly and accurately.Chemical constituents of the 75% ethyl alcohol extract of Semen Descurainiae were investigated. 15 compounds were isolated by polyamide, silica gel, sephadex LH20 and reverse silica gel C18 column chromatography. The structures of 12 compounds were identified by means of mp., UV, NMR and MS, including 10 flavonoids and 2 organic acid derivatives. They are kaempferol-3-O-β-D-glucopyranosyl-7-O-[(2-O-trans-sinnapoyl)-β-D-glucopyranosyl(1â†'6)]-β-D-glucopyran -oside, quercetin-3-O-β-D-glucopyranosyl-7-O-β-gentiobioside, kaempferol-3-O-β-D-glucopyran -osyl-7-O-β-gentiobioside, isorhamnetin-3-O-β-D-glucopyranosyl-7-O-β-gentiobioside, quercetin -7-O-β-gentiobioside, kaempferol-7-O-β-gentiobioside, isorhamnetin-7-O-β-gentiobioside, quercetin-3,7-di-O-β-D-glucopyranoside, kaempferol-3,7-di-O-β-D-glucopyranoside, isorham -netin-3,7-di-O-β-D-glucopyranoside, sinapic acid ethyl ester, 4-methoxyl sinapic acid. Among them, there are some first reports such as : kaempferol-3-O-β-D-glucopyranosyl-7-O- [(2-O-trans-sinnapoyl)-β-D-glucopyranosyl(1â†'6)]-β-D- glucopyranoside and isorhamnetin-7-O-β-gentiobioside from natural plants, quercetin-7-O-β-gentiobioside, kaempferol-7-O-β-gentiobi -oside, quercetin-3,7-di-O-β-D-glucopyranoside, kaempferol-3,7-di-O-β-D-glucopyranoside and isorhamnetin-3,7-di-O-β-D-glucopyranoside from Cruciferae, quercetin-3-O-β-D-glucopyranosyl -7-O-β-gentiobioside, kaempferol-3-O-β-D-glucopyranosyl-7-O-β-gentiobioside and isorham -netin-3-O-β-D-glucopyranosyl-7-O-β-gentiobioside from genus Descurainiae, sinapic acid ethyl ester and 4-methoxyl sinapic acid from Descurainia sophia (L.) Webb ex Prantl. The linkage of glucoses in compounds quercetin-7-O-β-gentiobioside and kaempferol-7-O-β-gentiobioside were determined definitely by high resolving power NMR.Preliminary pharmacological experiments in vitro were designed and carried out according to theclinical effects of Tinglizi. It is suggested that total flavonoids existing in 75% EtOH extract of Semen Descurainiae has the anti-PAF activities. The above results can in a way be considered as the pharmacological mechanism of Tinglizi's relieving asthma to the body. Meanwhile, quercetin-3-O-β-D-glucopyranosyl-7-O-β-gentiobioside can be considered as one of the important active ingredients in Semen Descurainiae due to its great amount.The characteristic ingredient quercetin-3-O-β-D-glucopyranosyl-7-O-β-gentiobioside, which exists only in Semen Descurainiae, is chosen as the reference substance for qualitative and quantitative analysis of the drug, and 210mg is prepared with purity of no less than 98%. Furthermore, an economical, simple and reproducible preparation pr... |
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