| Scubellaria baicalensis from the family Scutellaria is one of the crude drugs in Traditional Chinese Medicine (TCM). The crude roots of S. baicalensis exhibit various therapeutic functions in the definition of TCM, such as the activities of the treatment of inflammation and the anticancer properties, among others. From the literature, about100compounds have been isolated from S. baicalensis in the field of phytochemistry which indicated that flavonoids are the major native chemical constituents. In the meantime, phenylpropanoid glycosides, diterpenoids, and styrenes, etc. have also been isolated from S. baicalensis. In order to find more active substance and functions of the natural medicine, this thesis studied the chemical constituents of the roots of S. baicalensis systematically.By using a variety of chromatographic techniques and spectroscopic methods,102compounds were isolated from the80%aq. ethanol of the roots of S. baicalensis, with95ones of which being identified in this dissertation. Names and structures of the purified compounds are listed in Table1and Figure1, respectively. Among them,18ones, i.e., compounds1*-13*and16*-20*, are new compounds, with compounds1*-7*being flavonoids; compounds8*-9*being novel biphenyls; compounds16*-19*being unusual8’,9’-dinoroxyneolignanes, compound14and20*being a7,9’:7’,9-diepoxylignane. Moreover, coumarins, stilbene, and lignans were isolated from S. baicalensis for the first time.The crude extracts of the roots of tested S. baicalensis and some isolated compounds were evaluated for their pharmacological effects according to the related literatures and their daily use.(1) The n-BuOH extract of S.baicalensis and compounds11and84showed significant osteoclast-inhibiting activities in vitro;(2) Twenty-nine compounds have been evaluated for acetylcholinesterase and butyrylcholinesterase inhibiting acitivites, but all of them have no significant activities;(3) Fifty-four compounds have been evaluated for anticancer activities, but all of them have no activities;(4) Sixty-one compounds are evaluated for their pharmacological effect by high-throughput screening and the result have not come out.The original determination of plant-derived subjects in the system of traditional herbal medicines is often complicated by the lack of morphological features in visual or microscopic inspection. Improved methods are urgently needed. In this paper, the profiles of proton nuclear magnetic resonance (1H NMR) and high performance liquid chromatography (HPLC) of fractionated non-polar and polar extracts from samples of Scutellaria baicalensis Georgi were recorded and analyzed by comparing them to each other and to those of the compounds of its own isolated in this work. The’H NMR spectra revealed not only the common features of chemical composition among collected samples of S. baicalensis, with the characteristic signals of their major constituents, flavonoids, being exhibited explicitly and reproducibly, but also the significantly signature features in the composition of signals when compared to other species. These features were further confirmed by HPLC and online HPLC/DAD/MS (mass spectrometry) analyses. Also, sixty-one flavonoids were isolated as pure monomers from the counterpart of the non-polar and polar extract of the roots of S. baicalensis. On the basis of chemical investigation, the signals and peaks in the profiles of1H NMR and HPLC were unambiguously assigned to their corresponding monomers. The general feature of1H NMR spectrum coupled with that of HPLC profile established for authentic sample explicitly provided the data of structures and composition for those particular compounds, which can be used as signature features for original authentication of S. baicalensis.Table1. Compounds isolated from Scutellaria baicalensis Georgi (*New compound)... |
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