Biomedical subjects

Gui-shan Tan

Publications and source records attributed to Gui-shan Tan.

7 recordsLinked to original sources

PubMed2006

[Studies on the chemical constituents from Asarum Chinese Franch. f. fargesii (Franch.) C. Y. Cheng (II)].

Three compounds were isolated from the roots and stems of Asarum chinese Franch. f. fargesii (Franch.) C. Y. Cheng with column chromatography methods. Their structures were identified as kakuol (I), 2-methoxy-4,5-methylenedioxypropiophenone (II) and pluviatilol (III) on the basis of physicochemical and spectroscopic analysis. The compound II and III were isolated from the genus of Asarum for the first time.

Asarum↗

PubMed2006

[Inhibitory effect of reinioside C on LOX-1 expression induced by ox-LDL].

OBJECTIVE: To investigate the effect of reinioside C (RC) on the expression of lectin-like oxidized low density lipoprotein receptor (LOX)-1 mRNA and LOX-1 protein induced by oxidized low density lipoprotein (ox-LDL) in cultured human umbilical vein endothelial cells (HUVEC). METHODS: HUVECs were cultured with ox-LDL (50 mg/L) for 24 h in the absence or presence of RC (1, 3, and 10 micromol/L). The expressions of LOX-1 mRNA and LOX-1 protein were examined by RT-PCR and Western-blot. RESULTS: Incubation with ox-LDL (50 mg/L) significantly raised the expression of LOX-1 mRNA and LOX-1 protein,which was concentration-dependent. CONCLUSION: RC can inhibit the increased expression of LOX-1 mRNA and LOX-1 protein induced by ox-LDL in HUVECs.

Cells, Cultured↗

PubMed2006

[Inhibition of 1,3,8-trihydroxy-5-methoxyxanthone on cytochrome P450s].

OBJECTIVE: To explore the inhibitive effects of 1,3,8-trihydroxy-5-methoxyxanthone (TMX) on cytochrome P450s (CYP450s) in human liver microsomes. METHODS: Probe drugs were incubated with and without adding TMX to determine the changes of enzyme activities. The concentration ratio of metabolites to probe drugs was used to present enzyme activities. Concentrations of the probe drugs and their metabolites in the incubated mixture were detected by high performance liquid chromatography. RESULTS: The variations (mean, 95%CI) of the activities of CYP1A2, CYP2C9, CYP2C19, CYP2E1 and CYP3A4 were 2.95 x 10(-3) (2.03 x 10(-3), 3.88 x 10(-3)), 3.14 x 10(-2) (1.87 x 10(-2), 4.42 x 10(-2)), 2.27 x 10(-3) (-1.4 x 10(-2),1.81 x 10(-2)), 7.72 x 10(-2) (-0.83 x 10(-2), 0.2374), and -0.2548 (-2.9802, 2.4707), respectively. The activities of CYP1A2 and CYP2C9 were significantly reduced in the present of TMX. CONCLUSION: TMX (10 micromol/L) has significant inhibitive effect on the activities of CYP1A2 and CYP2C9, but no significant inhibitive effect on the activities of CYP2C19, CYP2E1 and CYP3A4.

Cytochrome P-450 Enzyme System↗

PubMed2004

[Water-soluble chemical constituents of Swertia davidi Franch].

AIM: To study the active constituents of Swertia davidi Franch. METHODS: Column chromatographies on silica gel, Sephadex LH-20 and Diaion-201 et al. were used to isolate and purify the chemical components. Their structures were identified by UV, IR, MS, NMR and 2D-NMR. RESULTS: These compounds were elucidated as 8-O-beta-D-glucopyranosyl-1, 3, 5-trihydroxyxanthone (I), 5-O-beta-D-glucopyranosyl-1, 8-dihydroxy-3-methoxyxanthone (II), 5-O-beta-D-glucopyranosyl-1, 3, 8-trihydroxyxanthone (III) and swertamarin (IV). CONCLUSION: Compound III is a new xanthone glucoside. The other compounds were isolated from this plant for the first time.

Glucosides↗

PubMed2004

[A new xanthone from Polygala aureocauda Dunn].

AIM: To study the chemical constituents of Polygala aureocauda Dunn.. METHODS: Chemical compounds were isolated by column chromatography and their structures were determined mainly by spectroscopic means (UV, IR, MS, 1HNMR, 13CNMR, HMQC, HMBC). RESULTS: Three compounds were isolated and identified as 3-hydroxy-1,4-dimethoxyxanthone (I), 1, 7-dihydroxy-2, 3-methylendioxyxanthone (II), 7-hydroxy-1-methoxy-2, 3-methylendioxyxanthone (III). CONCLUSION: Compounds I-III were isolated from Polygala aureocauda Dunn. for the first time, whereas compound I is a new xanthone.

Molecular Conformation↗

PubMed2003

[Daviditin B from Swertia davidi Franch].

AIM: To study the active constituents of Swertia davidi Franch. METHODS: Chemical components were isolated by column chromatography and their structures were established mainly by spectroscopic means (UV, IR, NMR, 2D-NMR, MS). RESULTS: Three substances were identified as 2,5-dimethoxyl-1, 4-dicarboxyl benzene (VIII), 1,5,8-trihydroxyl-3,4-dimethoxyl xanthone (IX) and 1,8-dihydroxyl-3-(3'-hydroxyl-butoxy) xanthone (X). CONCLUSION: Compounds VIII and IX were isolated from Swertia davidi Franch, for the first time, whereas compound X is a new xanthone, named daviditin B with antioxygenated activity in vitro.

Antioxidants↗

PubMed2002

[Studies of the chemical constituents of Swertia davida Franch].

AIM: To study the active constituents of Swertia davidi Franch.. METHODS: Chromatography was used to isolate and purify the chemical components, their structures were identified by spectral analysis. RESULTS: Three compounds were identified as 1,7-dihydroxy-3,8-dimethoxyxanthone (gentiacaulein) (V), 1,8-dihydroxy-3,7-dimethoxyxanthone (methylswertianin) (VI) and 1,8-dihydroxy-3,4,7-trimethoxyxanthone (VII). CONCLUSION: Compound VII is a novel xanthone, named daviditin A, the others were isolated from Swertia davidi Franch. for the first time.

Molecular Structure↗