High-speed countercurrent chromatography isolation of flavans from Ixeris chinensis and their identification by NMR spectroscopy.

High-speed countercurrent chromatography, combined with macroporous resin chromatography were applied to the separation and purification of flavans from Ixeris chinensis. Four flavans, namely, 5-methoxy-7,4'-dihydroxyflavan-3-ol (1), 5,7-dimethoxy-4'-hydroxyflavan-3-ol (2), 5,7-dimethoxy-4'-hydroxyflavan (3), and 5,7-dimethoxy-8-methyl-4'-hydroxyflavan (4), were obtained from I. chinensis for the first time. Their chemical structural identification was carried out by spectroscopic methods, including 1D and 2D NMR spectroscopy. Amounts of 13.2 mg of compound 1, 6.4 mg of compound 2, 5.8 mg of compound 3, and 14.5 mg of compound 4 were separated from 120 mg 75% ethanol fraction. The purities of 1-4 were 99.1, 99.2, 97.3, and 98.6 %, respectively.

[Study on Chemical Constituents of Panzeria alaschanica].

OBJECTIVE: To study the chemical constituents of the ethyl acetate extract from Panzeria alaschanica. METHODS: The chemical constituents of ethyl acetate extract from Panzeria alaschanica were isolated and purified by silica gel. Their structures were i- dentified by means of spectra. RESULTS: Nine compounds were obtained and identified as 7-Methoxy coumarin (1), Isorhamnetin (2), Caf- feic acid (3), 5-Hydroxy-7,3',4'-trimethoxyflavone (4), 5-Hydroxy-7,4'-dimethoxyflavone (5),Kaempferol (6), Isorhamnetin-3-O-ß-D- glucoside (7) Kaempferol-3-O-ß-D-glucoside (8), and Isorhamnetin-7-O-ß-D-glucuronyl-(1-->6)-O-α-L-rhamnoside (9). CONCLUSION: Compounds 1-4,6,7 and 9 are isolated from this plant for the first time.

Lignans from Syringa pinnatifolia Hemsl. Var. alashanensis.

Two new lignans, syripinnalignans A and B (1 and 2), together with two known lignans, were isolated from the stem of Syringa pinnatifolia Hemsl. Var. alashanensis. The structures of 1 and 2 were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques.

[Study on chemical constituents of Ixeris chinensis].

OBJECTIVE: To study the chemical constituents of Ixeris chinensis. METHODS: The chemical constituents of Ixeris chinensia were isolated and purified by silica gel. LH-20 column chromatography and preparation HPLC etc. Their structures were identified b) means of spectra, in same cases by direct comparison with authentic samples. RESULTS: Ten compounds were obtained and identified as luteolin (1), luteolin-7-O-beta-D-glucopyranoside (2), apigenin-7-O-beta-D-glucopyrano side (3), luteolin-7-O-beta-D-glucopyranoside acatate (4), 3beta-(beta-D-glucopyranosyloxy) -8beta- (p-hydroxyphenylacetyloxy) -guaia-4 (15), 10 (14), 11 (13) -trien-1alpha, 5beta, 6beta, 7alphaH-12, 6-olide (5), beta- (beta-D-glucopyranosyloxy) -8beta- (2-hydroxy-3-methylbutanoyloxy) -guaia-4 (15),10 (14), 11 (13) -trien-1alpha, 5beta, 6beta,7alphaH-12,6-olide (6), 5, 3', 4'-trihydroxy-7-methoxyflavone (7), apigenin (8), 5-hydroxy-7,4'- dimethoxyflavone (9), 5, 7, 4'- trimethoxyflavone (10). CONCLUSION: Compounds (5, 6, 7, 9, 10) are isolated from this plant for the first time.

Two new flavonoid glycosides from Artemisia frigida Willd.

An investigation of the n-BuOH-soluble fraction from the aerial parts of Artemisia frigida has led to the isolation of two new flavonoid glycosides, named friginoside A and friginoside B. Their structures were characterized as 5,7-dihydroxy-3',4',5'-trimethoxy flavone 7-O-ß-d-glucuronide (1) and 5,7-dihydroxy-3',4',5'-trimethoxyflavone 7-O-ß-d-glucuronyl-(1 â†’ 2)O-ß-d-glucuronide (2) on the basis of 1D and 2D NMR spectral analysis.

Structure elucidation and antimicrobial activities of five compounds from Artemisia integrifolia L.

A new compound, integracid (1), together with four known compounds were isolated from the dichloromethane (CH2Cl2) extract from Artemisia integrifolia L. The structures of compounds (1-5) were elucidated by spectroscopic methods, including ultraviolet, infrared (IR), high resolution-electrospray ionization-mass spectrometry (HR-ESI-MS) and extensive one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) techniques, and by comparison with data reported in the references. Antibacterial activities of the compounds were evaluated against various bacteria.

Analgesic effects and structural elucidation of two new flavone C-glycosides from Artemisa sacrorum.

The present study was designed to isolate and characterize the analgesic compounds of Artemisa sacrorum Ledeb. The EtOAc crude extracts from the aerial parts of Artemisa sacrorum Ledeb were separated by chromatography and the structures of new compounds were elucidated based on spectral analyses. Analgesic activities of the isolated compounds were assessed in rats with hot plate test and paw pressure assay. Two new flavone C-glycosides, named as Sacroroside A and B (Compounds 1 and 2) were isolated from the EtOAc crude extract of the aerial parts ofArtemisa sacrorum Ledeb. They showed significant analgesic effects. In conclusion, Compounds 1 and 2 are new natural products, which show significant analgesic effects in a dose-dependent manner.

Two new xanthones from Lomatogonium carinthiacum.

AIM: To study the chemical constituents of Lomatogonium carinthiacum (Wulfen) Rchb. METHOD: The CHCl3-soluble fraction was separated by chromatography and the structures of the new compounds were elucidated by spectral experiments. RESULTS: Two new xanthones, 1, 8-dihydroxy-4, 5-dimethoxy-6, 7-methylenedioxyxanthone (1), 1, 4, 8-trimethoxyxanthone-6-O-ß-D-glucoronyl-(1→6)O-ß-D-glucoside (2) were isolated from the whole plant of Lomatogonium carinthiacum. CONCLUSION: Compounds 1 and 2 are new natural products.