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Biomedical subjects

Biao Jiang

Publications and source records attributed to Biao Jiang.

At least 19 recordsLinked to original sources
PubMed2006

[Studies on chemical constituents of cytotoxic fraction from leaves of Elaeagnus pungens].

OBJECTIVE: To study the chemical constituents possessing cytotoxicity activity from Elaeagnus pungens. METHOD: The constituents were separated through repeated chromatographic methods and their structures were elucidated by spectral analysis. RESULT: Five compounds were isolated from the ethyl acetate ether extract of leaves of E. pungens. Their structures were elucidated as 4-hydroxybenzoic acid (1), 3, 3'-dimethoxyquercetin (2), caffeic acid methyl ester (3), methyl 3, 4-dihydroxybenzoate (4), spingic acid (5), 4-methoxylbenzoic acid (6), 3-methylkaempferol (7), kaempferol-3-O-beta-D-glucoside (8), dausosterol (9). CONCLUSION: Compounds 1-8 were isolated from this plant for the first time.

Caffeic Acids↗
PubMed2005

Six new sesquiterpenes from Cacalia ainsliaeflora.

Five new eremophilane sesquiterpenes, 3beta,6beta-diangeloyloxy-8beta,10beta-dihydroxyeremophilenolide (1); 6beta-acetoxy-3beta-angeloyloxy-8beta,10beta-dihydroxyeremophilenolide (2); 3beta-angeloyloxy-6beta-methoxyeremophil-7(11),9(10)-dien-8alpha,12-olide (3), 3beta-angeloyloxy-8-oxo-eremophil-6(7)-en-12-oic acid (4); 3beta-angeloyloxy-10beta-hydroxy-8-oxo-eremophil-6(7)-en-12-oic acid (5), and a novel nor-eremophilane derivative, 3beta-angeloyloxy-10beta-hydroxy-8-oxo-eremophil-6(7)-en (6), were isolated from the roots of Cacalia ainsliaeflora. Their structures were elucidated by spectroscopic methods, including 2DNMR. Compounds 1 and 2 were assayed against P388 and A549 Carcinoma cell lines. No positive activities were observed.

Antineoplastic Agents, Phytogenic↗
PubMed2004

[Magnetic resonance behavior of lipiodol--an experimental study].

OBJECTIVE: To describe the characteristics of magnetic resonance (MR) signals generated by lipiodol and to assess the influence on MR imaging of hepatoma nodule. METHODS: Pure lipiodol and lipiodol emulsions mixed with 76% urografin in different ratio were imaged by both CT and MR; quantitative T(1) and T(2) measurements of lipiodol were performed. Fourty-one SD rats with transplanted walker-256 sarcoma in liver were randomly divided into six groups: 0.4-0.6 ml lipiodol emulsion was infused via hepatic artery in experimental groups by means of laparotomy under celiac anesthesia. The changes in MRI signal of hepatoma nodule were observed. RESULT: In vitro, iodized oil demonstrated high signal on T(1)-weighted images when performed at 37 degree, but all could be suppressed by the fat saturation sequence, and showed very low signal on T(2)-weighted images. The characteristic of MR signal with ultra fluid lipiodol was different from that of iodized oil (P<0.01), showing short T(1) and long T(2) signal; the high signal on T(1)-weighted images was only partially suppressed by the fat saturation sequence. With descending ratio of lipiodol in emulsion, the signal behavior was gradually similar to urografin (r -0.958, P<0.01). When rats were transarterially infused with emulsion, the intensity of the signal on MRI was nearly the same as that in the control rats, but when lipiodol was injected out of the hepatic artery and accumulated in lymphadenopathy, it demonstrated a signal similar to fat; the high intensity signal was maintained on T(1)-weighted images and T(2)-weighted images. CONCLUSION: There are little changes in MR signal intensity when the lipiodol is accumulated in the tumor nodules. MR behavior of lipiodol is determined by its deposit area.

Animals↗
PubMed2004

[Histopathological changes in rat transplanted hepatoma after lipiodol transarterial embolization].

OBJECTIVE: To study the histopathological effect of hepatic arterial infusion of lipiodol on transplanted hepatoma in rats. METHODS: Fourty-one rats bearing Walker-256 transplanted hepatoma were randomly divided into embolization group (n = 35, divided in 5 subgroups, with 7 rats in each) and control group (n = 6). Lipiodol (0.5 ml/kg)emulsified with 0.2 - 0.3 ml of 76% urografin (v:v = 1:1) was infused via gastroduodenal artery into hepatic artery in embolization group. Rats in the control group were given via the same route urografin only. Histopathological changes of the treated tumors were examined by light and transmission electron microscopy. RESULTS: In the control rats treated with urografin alone, the average tumor size increased 2.8 fold on day 3, while that in the lipiodol treated rats increased 1.7 fold (P < 0.01). Compared with the control group, on day 3, 5, 10 after embolization treatment, tumor necrosis was more extensive (P < 0.01). In one of the treated rats, the tumor was completely necrotic on day 10. Inflammatory reaction was marked in the early post-embolic period, but it was replaced by fibrous tissue encapsulation. From day 1 on, in 17 of the 18 treated rats, apoptotic cells, identified by typical morphology under light and electronic microscopes, were observed, mainly in the tumor periphery. CONCLUSION: In addition to cellular necrosis, apoptosis may be another important mechanism leading to cell death in hepatoma treated with transarterial embolization.

Animals↗
PubMed2003

Enantioselective total syntheses of slagenins A-C and their antipodes.

Full details of the total syntheses of slagenins A-C (1a-c) and their antipodes (2a-c), novel bromopyrrole alkaloids with a unique tetrahydrofuro[2,3-d]imidazolidin-2-one moiety, are described in which their absolute stereochemistry was established. The key step in the syntheses involves the efficient condensation of dihydrofuran-3-one or glyoxal with urea to construct the slagenin bicycle core.

Alkaloids↗
PubMed2002

Enantioselective synthesis of slagenins A-C.

[formula: see text] An enantioselective synthesis of slagenins A-C (1a-c) is described in which their absolute stereochemistries were established. The key step in the synthesis involved the efficient condensation of 2-methoxy-dihydro-furan-3-one 9 and urea to construct the slagenin bicycle core.

Journal Article↗
PubMed2002

Highly enantioselective alkynylation of alpha-keto ester: an efficient method for constructing a chiral tertiary carbon center.

The asymmetric addition of terminal alkynes to alpha-keto ester was carried out using a catalytic amount of (1S,2S)-3-(tert-butyldimethylsilyloxyl)-2-N,N-(dimethylamino)-1-(p-nitrophenyl)-propane-1-ol in the presence of Zn(OTf)(2) to give the corresponding tertiary propargylic alcohols in high yields with up to 94% ee. N-Methylephedrine and Zn(OSO(2)CHF(2))(2) were also examined in this reaction. [reaction: see text]

Journal Article↗
PubMed2002

Zn(ODf)2: preparation and application in asymmetric alkynylation of aldehydes.

A new Lewis acid, Zn(ODf)2, was first prepared from commercially available 3,3,4,4-tetrafluoro[1,2]oxathietane 2,2-dioxide in four steps with 56% yields and also was applied to catalyze highly enantioselective alkynylation of aldehydes in the presence of ligand (1S,2S)-3-(tert-butyldimethylsilyloxyl)-2-N,N-dimethylamino-1- (p-nitrophenyl)-propane-1-ol or ligand (-)-N-methylephedrine to afford the corresponding propargylic alcohols in high yields with up to 99% ee.

Journal Article↗