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Biomedical subjects

W D Zhang

Publications and source records attributed to W D Zhang.

At least 19 recordsLinked to original sources
PubMed2006

Two new iridoids from roots of Patrinia scabra Bunge.

Two new iridoids 1,3-dimethyloxy-7-hydroxymethyl-4-(3-methyl-butyryloxymethyl)-1-hydrocyclopenta-4,7-diene[c]pyran-6-one (1) and 1,3-dimethyloxy-7-hydroxymethyl-4-methyloxymethyl-1-hydrocyclopenta-4,7-diene[c]pyran-6-one (2) were isolated from the roots of Patrinia scabra Bunge. The structure elucidation of the isolated compounds was based primarily on HRESIMS, EIMS, IR, UV, 1D- and 2D-NMR analyses, including COSY, HMQC, HMBC and NOESY correlations, as well as X-ray crystallographic analysis.

Crystallography, X-Ray↗
PubMed2004

Inhibition of the proliferation of smooth muscle cells from human coronary bypass vessels by vasonatrin peptide.

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is known to be a key event in the development of atherosclerosis and restenosis. The present study examined the effect of a novel synthetic natriuretic peptide, vasonatrin peptide (VNP), on norepinephrine (NE)-induced proliferation of VSMCs from coronary bypass vessels. Human VSMCs were isolated from an internal mammary artery (IMA) and saphenous vein (SV) by explant culture and stimulated with NE. MTT assay and [3H] thymidine-incorporation were undertaken to analyze cell proliferation and radioimmunoassay was used to determine the level of intracellular cyclic 3',5'-guanosine monophosphate (cyclic GMP). NE (10(-8) - 10(-7) mol/l) had a mitogenic effect in human VSMCs from both SV and IMA. However, NE-stimulated proliferation of VSMCs from SV was greater than that from IMA. Furthermore, low concentration of NE (10(-10) mol/l) promoted cell growth in SV-derived cells but not in IMA-derived cells. VNP (10(-8) - 10(-6) mol/l) reduced NE-induced cell proliferation and increased intracellular cyclic GMP, which were abrogated by HS-142-1. In addition, the growth inhibition of VNP was mimicked by 8-bromo-cGMP. These results indicate that VNP has a significant inhibitory effect on NE-stimulated proliferation of human VSMCs from both IMA and SV, which is mediated by guanylate cyclase-linked receptors by increasing cyclic GMP.

Analysis of Variance↗
PubMed2001

[Studies on chemical constituents in root of Rumex patientia L].

OBJECTIVE: Investigating the chemical constituents in the root of Rumex patientia. METHOD: Compounds were separated by rechromatography on silica gel. Their structures were determined by spectral analysis and chemical evidence. RESULT: Eight compounds were isolated and identified as 5-methoxy-7-hydroxy-1 (3H)-benzofuranone (I), 5, 7-dihydroxy-1 (3H)-benzofuranone(II), nonadecanoic acid-2,3-dihydroxypropyl ester(III), torachrysone-8-O-beta-D-glucopyranoside(IV), gallic acid(V), beta-sitosterol(VI), beta-sitosterol-3-O-beta-D-glucopyranoside(VII) and catechin(VIII). CONCLUSION: Compound III is a new natural products, and compounds I and II were obtained from this plant for the first time.

Benzofurans↗
PubMed2001

VEGF induced hyperpermeability in bovine aortic endothelial cell and inhibitory effect of salvianolic acid B.

AIM: To examine the effect of recombinant human vascular endothelial growth factor (VEGF) on the low density lipoprotein (LDL) permeability of bovine aortic endothelial cells (BAEC) and the inhibitory effect of salvianolic acid B in vitro. METHODS: The confluence BAEC monolayers were cultured with normal medium and with medium containing VEGF or salvianolic acid B at various concentrations and for various time periods. The iodine labeled LDL flux across the monolayers was then performed, and radioactivity was measured by SN-695 automatic liquid scintillation counter. RESULTS: Addition of purified human recombinant VEGF to the BAEC monolayers could significantly increase the permeability of the monolayer to 125I-LDL (P < 0.01). The permeability-increasing activity of VEGF on the BAEC monolayers was both dose and time dependent. Salvianolic acid B could markedly inhibit the VEGF-induced hyperpermeability in BAECs (P < 0.01). CONCLUSION: VEGF plays a role in the formation and development of atherosclerosis, and salvianolic acid B has inhibitory effect on VEGF-induced hyperpermeability in BAEC.

Animals↗
PubMed2001

[Study on the structure and activity of new phenolic acid compounds from Erigeron breviscapus].

AIM: To isolate and identify the active constituents of Erigeron brevisapus (Vant.) Hand.-Mazz. METHODS: The chemical constituents were isolated by silica gel column chromatography and two new compounds were obtained. Their structures were elucidated by IR, MS, 1HNMR, 13CNMR, DEPT and 2DNMR. The injury of BCMEC (bovine cerebral microvascular endothelial cell) was determined by lactic dehydrogenase (LDH), the ability of the drugs anti-oxidation and scavenging oxidation of free radical was measured by colorimetric method. RESULTS: Two new compounds have been identified as 1-O-methyl-3, 5-O-dicaffeoyl quinic acid methyl ester (III) and 5-O-caffeoyl quinic acid butyl ester (IV). CONCLUSION: Compounds III and IV are new compounds. Compound III can protect BCMEC injury by LPC.

Animals↗
PubMed2001

[Studies on the chemical constituents of Zanthoxylum dimorphophyllum Hemsl. var spinifolium Rhed. et Wils].

AIM: To study the chemical components from the dried roots of Zanthoxylum dimorphophyllum Hemsl. var spinifolium Rhed. et Wils. METHODS: Modern chromatography was used to isolate chemical components and the compounds isolated from Zanthoxylum dimorphophyllum Hems1. var spinifolium Rhed. et Wils were identified by various spectral methods. RESULTS: Five compounds were isolated and identified as 6-(2',3'-dihydroxy-3'-methybutyl)-7-acetoxy-2H-1-benzopyran-2-one (I), 6-(2',3'-dihydroxy-3'-methybutyl)-7-(beta-D-glucopyranosyloxy)- 2H-1-benzopyran-2-one (II), hexacosanoci acid (III), aurepten (IV), 6-[6'-O-(-deoxy-alpha-L-mannopyranosyl)-beta-D-benzopyran-4-one (V). CONCLUSION: All of the above compounds were isolated from the plant for the first time, among them, I is a new compound.

Coumarins↗
PubMed2001

[Two new glycosides from Erigeron breviscapus (Vant.) Hand.-Mazz].

OBJECTIVE: To study the chemical constituents from the upground part of Erigeron breviscapus. METHOD: The compounds were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and 2D-NMR. RESULT: Two new compounds were isolated and identified as 5,4'-dihydroxy flavonod-7-O-beta-D-pyranglycuronate buthyl ester(VI) and 3,5-dimethoxy benzene carbonic acid-4-O-beta-D-pyranglucose(VII). CONCLUSION: Compounds VI and VII were new compounds.

Asteraceae↗
PubMed2001

[Studies on chemical constituents of Bletilla striata (Thunb) Reichb. f].

OBJECTIVE: To study the chemical constituents of Bletilla striata. METHOD: The constituents were separated and purified by column chromatography with silica gel, and identified by NMR, MS and physical data. RESULT: Three compounds were isolated and identified as hexacosanoic alcohol 3-(4-hydroxy-3-methoxybenzol)-trans-acryliceylenate(1), physcion(2) and cyclobalanol(3). CONCLUSION: Compound 1 was a new compound and compound 3 was isolated from this plant for the first time.

Acrylates↗
PubMed2000

New lanostanoids from Ganoderma lucidum that induce NAD(P)H:quinone oxidoreductase in cultured hepalcic7 murine hepatoma cells.

Two new lanostanoids were isolated from the basidiocarp of Ganoderma lucidum and were identified as 26,27-dihydroxy-5 alpha-lanosta-7,9(11),24-triene-3,22-dione (1) and 26-hydroxy-5 alpha-lanosta-7,9(11),24-triene-3,22-dione (2) by their respective spectral data. Crude extracts and the isolated compounds were tested for their potential to induce NAD(P)H:quinone oxidoreductase (QR), a phase 2 drug-metabolizing enzyme, as an approach to detect potential cancer chemopreventive activity. Compound 2 doubled the specific activity of QR at a concentration of 3.0 micrograms/ml, whereas compound 1 was significantly less active (1.7-fold induction at 20 micrograms/ml). In addition, both compounds weakly inhibited sheep vesicle cyclooxygenase 1 activity at a test concentration of 40 micrograms/ml.

Animals↗
PubMed2000

Two new caffeoyl conjugation from Erigeron breviscapus.

Two new constituents with a novel basic skeleton were isolated from Erigeron breviscapus. On the basis of chemical and spectroscopic evidences, the structures of the new compounds were elucidated as 1R,3R-dihydroxy-4S,5R-dicaffeoyloxy cyclohexane carboxylic acid methyl ester (V), 1,4-dihydroxy-3R,5R-dicaffeoyloxy cyclohexane carboxylic acid methyl ester (VI).

Caffeic Acids↗
PubMed2000

[A new fatty ketone of Radix Polygoni Multiflori Preparata].

OBJECTIVE: Investigating the chemical constituents of Radix Polygoni Multiflori Preparata. METHODS: Compounds were isolated from the CHCl3 extract with column chromatography on silica gel, and identified on the basis of spectral analysis(IR, EI-MS, 1H-NMR, 13C-NMR) and phytochemical properties. RESULTS: Two compounds were isolated and identified as 1,2-dihydroxynonadecone-3(I) and gallic acid(II). CONCLUSION: Compound I is a new compound.

Drugs, Chinese Herbal↗
PubMed2000

[Studies on flavone constituents of Erigeron breviscapus (Vant.) Hand.-Mazz].

OBJECTIVE: To study the chemical constituents of Erigeron breviscapus. METHOD: The constituents were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and physical data. RESULT: Five compounds were isolated and identified as 3, 5, 6, 4'-tetrahydroxy-7-methoxy flavonoid(I); 5, 7, 4'-trihydroxy flavonoid(II); 3, 5, 6, 7, 4'-pentahydroxy flavonoid(III); scutellarein (IV) and 5, 7, 4'-trihydroxy flavanone(V). CONCLUSION: Compounds I, III and V were isolated from this plant for the first time.

Apigenin↗
PubMed2000

[Study of apoptosis in the male rat spermatogenic cells after vasostomy].

OBJECTIVE: To investigate the effect of vasostomy on apoptosis in the male rat spermatogenic cells after vasoligation. METHODS: Model of vasoligation and vasostomy in male rat was established, and then terminal deoxynucleotidyl transferase-mediated dUTP nick labelling technique to detect the apoptosis of spermatogenic cells at 4, 8, 12, 16 weeks after vasostomy. RESULTS: The number of apoptotic cells in vasostomy group was significantly lower than that of vasoligation group since 8 weeks after vasostomy(P < 0.05). The number of apoptotic cells in 8 and 12 weeks after vasostomy were significantly higher than that in prevasoligation(P < 0.05). 16 weeks after vasostomy, the number of apoptotic cells restored to the level same as that in prevasoligation stage. CONCLUSION: Vasostomy can reverse the apoptosis of spermatogenic cells due to vasoligation.

Animals↗
PubMed2000

[Structural elucidation of a new tetrahydroxystilbene of Radix Polygoni Multiflori Preparata and study on its cardiovascular activity].

AIM: To investigate the cardiovascular active constituents of Radix Polygoni multiflori Preparata. METHODS: Compounds were isolated from the water soluble extract with column chromatography of Sephadex, ODS and HPLC. The compounds were identified on the basis of spectral analysis (IR, EI-MS, FAB-MS, 1HNMR, 13CNMR, 2D-NMR) and phytochemical properties. Its inhibitory effect on the proliferation of bovine vascular smooth muscle cells were bioassayed in vitro. RESULTS: One compound was isolated and identified as: 2,3,5,4'-tetrahydroxystilbene-2-O-(6"-O-alpha-D- glucopyranosyl)-beta-D-glucopyranoside. CONCLUSION: Compound I is a new compound with cardiovascular activity.

Animals↗
PubMed1999

Association of smooth muscle cell phenotypic modulation with extracellular matrix alterations during neointima formation in rabbit vein grafts.

PURPOSE: To clarify the mechanisms of structural changes underlying vein graft stenosis that limits efficacy of bypass grafting operation, we examined the accumulation and distribution of various extracellular matrix (ECM) components during neointima formation in rabbit vein grafts and analyzed their correlation with proliferation and phenotypic modulation of smooth muscle cells (SMCs). METHODS AND RESULTS: An autologous external jugular vein graft was transplanted into the carotid artery in 25 rabbits. After the restoration of blood flow, the graft was markedly dilated. Medial SMCs in the graft appeared to be injured, and they began to proliferate at day 4 and subsequently migrated and formed the neointima at day 7. The neointima observed at days 7 and 14 contained ECM components, including type I collagen, heparan sulfate, and chondroitin sulfate, and the intimal SMCs were phenotypically modulated from the differentiated-type (SM2-positive and SM embryonic-negative) to the dedifferentiated-type (SM2-negative and SM embryonic-positive) as determined with immunostainings for myosin heavy chain isoforms. The intimal SMC proliferation was maximal at 2 weeks and then decreased rapidly. However, the neointima continued to thicken thereafter throughout the 6-month period of the experiment, and ECM accumulation, such as type I collagen and decorin, a small dermatan sulfate proteoglycan, was a prominent feature observed in the hypocellular region of the deep intima from 2 months after the transplantation. The phenotype of the intimal SMCs gradually returned to the differentiated-type from the deep intima after 2 months, but a small number of the intimal SMCs remained in the dedifferentiated phenotype even at 6 months after the operation. CONCLUSION: The neointima in the vein graft was formed initially by means of migration and proliferation of the phenotypically modulated, dedifferentiated-type SMCs and continued to thicken by means of sustained ECM accumulation, including type I collagen and decorin, in association with the prolonged presence of the dedifferentiated-type SMCs. These chronologic features in cell kinetics and ECM accumulation may contribute to the frequent occurrence of graft wall thickening that occurs in the vein grafts.

Animals↗