ABSTRACT
To clarify the chemical basis of the total alkaloids of Uncaria rhynchophylla, HPLC-VWD chromatogram of total alkaloids was established. Under its guidance, modern chromatographic and spectroscopic techniques were used to track, isolate and identify the representative principal components. As a result, one new monoterpenoid indole alkaloid, 3S,15S-N4-methoxymethyl-geissoschizine methyl ether (1), together with 20 known alkaloids (2-21), and 5 other known compounds (22-26) were obtained. Meanwhile, sixteen characteristic peaks were identified from the total alkaloids using HPLC analysis. Then, the anti-neuroinflammatory effect of compounds 1-21 was assessed through inhibiting nitric ---oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Among them, compounds 1, 3, 7, 8, 11, 12, 19 and 21 showed potent inhibitory activities with IC50 values of 5.87-76.78 µM.
Subject(s)
Alkaloids , Anti-Inflammatory Agents , Indole Alkaloids , Lipopolysaccharides , Microglia , Nitric Oxide , Uncaria , Uncaria/chemistry , Molecular Structure , Alkaloids/pharmacology , Alkaloids/chemistry , Nitric Oxide/antagonists & inhibitors , Nitric Oxide/biosynthesis , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/chemistry , Lipopolysaccharides/pharmacology , Microglia/drug effects , Animals , Mice , Chromatography, High Pressure Liquid , Secologanin Tryptamine Alkaloids/pharmacology , Secologanin Tryptamine Alkaloids/chemistryABSTRACT
Menispermi Rhizoma is the dried rhizome of Menispermum dauricum DC. (Menispermaceae), which commonly used to treat sore throat, enteritis, and dysentery in traditional Chinese medicine. To clarify the chemical basis of the total alkaloids of M. Rhizoma, HPLC was used to analyze total alkaloids, and then representative chemical constituents were separated by tracking. Nineteen compounds, including two new alkaloids (1R-methymenidaurine A-α-N-oxide (1) and 1R-7'-hydroxymethyl-menidaurine A (2)), thirteen known alkaloids, and four known flavonoids were isolated and identified using spectroscopic methods. Meanwhile, seven characteristic peaks were identified from the total alkaloids using HPLC analysis. Furthermore, compounds 1-18 were screened in vitro for their inhibitory effect against nitric oxide production in BV-2 microglia cells stimulated by lipopolysaccharide. Among them, six compounds showed weak inhibition, and the IC50 values of compounds 1 and 2 were 56.87 ± 1.61 and 53.67 ± 1.52 mM, respectively.
ABSTRACT
Rhododendron Molle G. Don belongs to Ericaceae family. As a toxic traditional Chinese medicine, its roots, flowers, and fruit are often mixed and substituted arbitrarily to treat rheumatoid arthritis in clinic. To clarify the main chemical basis of each medicinal part, and provide sufficient scientific basis for clinical application, analysis using HPLC-ELSD of the roots, flowers, and fruit from R. molle was established, and characteristic chemical constituents of them were separated by tracking. The structures were determined by NMR methods. Finally, 16, 21, and 18 compounds were obtained from the roots, flowers, and fruit, respectively. Overall, 49 compounds were obtained, of which 25 were identified for the first time in R. molle. Meanwhile, among the obtained compounds, 12, 11, and 6 characteristic peaks were identified from the roots, flowers, and fruit, respectively. Thus, the basic chemical substances of the medicinal parts of R. molle were determined initially.
