Biomedical subjects

Qin-Shi Zhao

Publications and source records attributed to Qin-Shi Zhao.

At least 19 recordsLinked to original sources

PubMed2007

Przewalskin B, a novel diterpenoid with an unprecedented skeleton from Salvia przewalskii maxim.

Przewalskin B (1), a novel diterpenoid possessing a unique skeleton, was isolated from a Chinese medicinal plant Salvia przewalskii. Its structure and relative stereochemistry were elucidated by extensive NMR analysis and a single-crystal X-ray study. A possible biosynthetic pathway for 1 was proposed. Compound 1 exhibited modest anti-HIV-1 activity with EC50 = 30 microg/mL. [structure: see text].

Anti-HIV Agents↗

PubMed2006

Synthesis and cytotoxicity of some new eriocalyxin B derivatives.

Eriocalyxin B (1) was regarded as the promising candidate for new anticancer agent because of its potent activity and novel mechanism of action. Systematic modifications of 1 were done, and nineteen derivatives were synthesized and their cytotoxicities against five tumor cell lines were evaluated. The structure-activity relationship (SAR) of 1 confirmed that the alpha,beta-unsaturated ketone moieties in ring A and D are the leading active sites; the 7,20-epoxy moiety, OH-6 and OH-7 play an important role in keeping the cytotoxicity. The 6,7-seco derivative 19 had remarkable activity while derivative 20 oxidized from 19 was completely inactive, which suggested that the carboxyl group could destroy the cytoxicity of 20 despite the presence of alpha,beta-unsaturated ketone moiety.

Antineoplastic Agents↗

PubMed2006

Przewalskin A: A new C23 terpenoid with a 6/6/7 carbon ring skeleton from Salvia przewalskii maxim.

Przewalskin A (1), a novel C23 terpenoid with a 6/6/7 carbon ring skeleton, was isolated from Salvia przewalskii. Its structure was determined by comprehensive 1D NMR, 2D NMR, and MS spectroscopic analysis and subsequently confirmed by a single-crystal X-ray diffraction study of its PDC oxidation derivative (2). Compounds 1 and 2 showed modest anti-HIV-1 activity with EC50 = 41 and 89 microg/mL, respectively.

Carbon↗

PubMed2006

Dichotomains A and B: two new highly oxygenated phenolic derivatives from Dicranopteris dichotoma.

[structure: see text] Dichotomains A (1) and B (2), two new highly oxygenated phenolic derivatives that feature a spirodilactone moiety in their structures, were isolated from the fronds of Dicranopteris dichotoma. Their structures were elucidated on the basis of NMR and MS spectroscopic data, and the stereochemistry of 1 was finally determined by single-crystal X-ray diffraction. Compound 2 showed weak anti-HIV-1 activity.

Anti-HIV Agents↗

PubMed2006

ent-Labdane diterpenoids from Andrographis paniculata.

Six new ent-labdane diterpenoids, 3-O-beta-D-glucopyranosyl-14,19-dideoxyandrographolide (1), 14-deoxy-17-hydroxyandrographolide (2), 19-O-[beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoyl]-3,14-dideoxyandrographolide (3), 3-O-beta-d-glucopyranosylandrographolide (4), 12S-hydroxyandrographolide (5), and andrographatoside (6), together with 17 known analogues, were isolated from the aerial parts of Andrographis paniculata. The structures of 1-6 were determined by spectroscopic data analysis. All compounds isolated were evaluated for their inhibitory activity against several bacterial and fungal strains.

Andrographis↗

PubMed2006

Taxoids from Taxus chinensis.

Two new taxoids, 13,15-epoxy-13-epi-taxayunnasin A (1) and taxchinin N (2), were isolated from the leaves and stems of Taxus chinensis. Compound 2 is the first taxoid to be reported with an alpha,beta-unsaturated lactone at C-4, C-5, C-20, and C-2. The structure of 1 was elucidated by spectroscopic analysis and confirmed by semisynthesis from taxayunnasin A, while 2 was determined structurally using spectroscopic methods and by single-crystal X-ray diffraction.

Crystallography, X-Ray↗

PubMed2006

Two new abietane diterpenoids from Salvia yunnanensis.

Two new abietane diterpenoids, yunnannin A and danshenol C, were isolated from Salvia yunnanensis together with ten known diterpenoids, danshenol A, przewalskin, tanshinone IIA, tanshinone I, crypotanshinone, 1,2-dihydrotanshinone, tanshinlactone, 5,6-dehydrosugiol, 12-hydroxy-6,7-seco-8,11,3-abietatriene-6,7-dial and phytol. Their structures were established based on spectroscopic data, chemical reactions and comparison with literature data. Compounds were tested for their antitumor activity in T-24, QGY, K562, Me180 and BIU87 cell lines. Compound showed inhibited growth of K562 (IC50=0.53 microg/mL), T-24 (IC50=7.94 microg/mL), QGY (IC50=4.65 microg/mL) and Me180 (IC50=6.89 microg/mL) cell lines while compound was inactive. Compound showed moderate inhibitory activity on QGY (IC50=16.75 microg/mL) and Me180 (IC50=5.84 microg/mL) cells.

Abietanes↗

PubMed2005

Kadlongilactones A and B, two novel triterpene dilactones from Kadsura longipedunculata possessing a unique skeleton.

[structure: see text] Two novel triterpene dilactones with an unprecedented rearranged hexacyclic skeleton, kadlongilactones A (1) and B (2), have been isolated from the leaves and stems of Kadsura longipedunculata Finet et Gagnep (Schisandraceae). Their structures were established by comprehensive 1D and 2D NMR spectroscopic analysis, coupled with single-crystal X-ray crystallographic diffraction. Compounds 1 and 2 exerted significant inhibitory effects against human tumor K562 cells with IC(50) = 1.40 and 1.71 microg/mL, respectively.

Cell Line, Tumor↗

PubMed2005

Structure and anti-HIV activity of micrandilactones B and C, new nortriterpenoids possessing a unique skeleton from Schisandra micrantha.

Two new highly oxygenated nortriterpenoids with a unique norcycloartane skeleton, micrandilactones B and C, were isolated from Schisandra micrantha; micrandilactone C exhibited an EC50 value of 7.71 microg/mL (SI > 25.94) against HIV-1 replication with minimal cytotoxicity, and the potent anti-HIV-1 activity and unique structural features of make it a promising lead for therapeutic development of a new generation of anti-HIV drug.

Animals↗

PubMed2005

Structure characterization and possible biogenesis of three new families of nortriterpenoids: schisanartane, schiartane, and 18-norschiartane.

Four new, highly oxygenated nortriterpenoids with unique schisanartane skeletons, micrandilactones D-G (1-4), have been isolated from the leaves and stems of Schisandra micrantha, and their structures have been elucidated on the basis of extensive spectral studies. The postulated biogenetic sequences of sixteen highly oxygenated nortriterpenoids and bisnortriterpenoids with new skeletons from three Schisandra species are discussed and have been compared from a chemotaxonomic standpoint.

Lactones↗

PubMed2005

Two new taxoids from Taxus chinensis.

Two new taxoids, 2,20-O-diacetyltaxumairol N (1) and 14beta-hydroxy-10-deacetyl-2-O-debenzoylbacatin III (2), were isolated from the needles and stems of Taxus chinensis. Their structures were determined on the basis of extensive 1D- and 2D-NMR-spectral analysis. Compound 1 showed weak cytotoxicity activity against T-24 (IC50 = 34 microg/ml) and QGY-7701 (IC50 = 22 microg/ml) cancer lines. Compound 2 showed no obvious cytotoxicity activity against T-24 (IC50 > 100 microg/ml) and QGY-7701 (IC50 > 100 microg/ml) cancer lines.

Antineoplastic Agents, Phytogenic↗

PubMed2005

ent-Kaurane Diterpenoids from Isodon albopilosus.

Nine new diterpenoids, albopilosins B-J (1-9), together with six known analogues, albopilosin A (10), macrocalyxin C (11), rabdokunmin C (12), excisanin (13), amethystonoic acid (14), and coetsanoic acid (15), were isolated from the aerial parts of Isodon albopilosus. The structures of 1-9 were established using spectroscopic methods including extensive 1D and 2D NMR analysis. The diterpenoids isolated were evaluated for their inhibitory activities against HepG2 (hepatoma) cells. Compounds 7 and 13 were the most active, with both having IC(50) values of <15 microM.

Antineoplastic Agents, Phytogenic↗

PubMed2005

Five new triterpene glycosides from Lysimachia foenum-graecum and evaluation of their effect on the arachidonic acid metabolizing enzyme.

Five new oleanane-type triterpene saponins, named foenumosides A ( 1), B ( 2), C ( 3), D ( 4) and E ( 5), were isolated from the aerial parts of Lysimachia foenum-graecum Hance. Their structures were identified on the basis of 1D and 2D NMR techniques, including H-H COSY, HMQC, HMBC, HMQC-TOCSY, ROESY experiments as well as chemical methods. We have evaluated the cytotoxity of 1 - 5 against rat and human polymorphonuclear leukocytes and the effect of 5 on the arachidonic acid metabolizing enzyme. All compounds showed a high degree of toxicity except for compound 5, while 5 notably reduced the production of leukotriene B (4) (LTB (4)) from rat peritoneal leukocytes with an IC (50) value of 74 microM without inhibiting human elastase. Compound 5 also reduced the production of 12-HHTrE and 12-HETE by 14 % and 50 % as a measurement for cyclooxygenase-1 and 12-lipoxygenase inhibition at 100 microM.

Animals↗

PubMed2005

Three new compounds from Isodon melissoides.

Reinvestigation of the aerial parts of Isodon melissoides has afforded two new ent-diterpenoids, melissoidesins V (1) and W (2), together with five known ones, glabcensin W (3), melissoidesin C (4), melissoidesin A (5), melissoidesin B (6) and melissoidesin D (7), one new ionone derivative 3alpha,4alpha-isopropyliden-beta-ionol (8), as well as three analogues, 3-hydroxy-4-oxo-beta-ionol (9), megastigma-7-en-3,5,6,9-tetraol (10) and blumenol A (11), and three phenolic compounds salicylic acid (12), syringic acid (13) and cirsiliol (14). The new structures were elucidated on the basis of spectroscopic techniques, especially the 2D-NMR spectral analysis.

Chromatography, Gel↗

PubMed2005

Two new icetexane diterpenoids from Salvia przewalskii.

Two new icetexane diterpenoids, przewalskin C, D (1, 2), together with sixteen known diterpenoids, were isolated from Salvia przewalskii. Eight of known ones (compounds 3, 12-18) were reported firstly from this plant. To the best of our knowledge, it's the first report of icetexane diterpenoids from this plant. The identification and structural elucidation of these compounds were based on 1D- and 2D-NMR spectral data analysis.

Diterpenes↗

PubMed2004

Coriatone and corianlactone, two novel sesquiterpenes from Coriaria nepalensis.

Both coriatone (1). a novel highly oxygenated picrotoxane-type sesquiterpene, and corianlactone (2). with an unprecedented sesquiterpene basic skeleton, named coriane, were isolated from Coriaria nepalensis Wall. The structures of 1 and 2 were determined by analysis of their two-dimensional NMR data, and the structure of 2 was confirmed by X-ray analysis. Compounds 1 and 2 showed no remarkable inhibitory activity toward K(562) cells. They are cytotoxic with IC(50) > 50 microg/mL (cis-platinim: IC(50) = 0.49 microg/mL).

Crystallography, X-Ray↗

PubMed2004

Cytotoxic isoprenylated xanthones from Cudrania tricuspidata.

Eight new isoprenylated xanthones, cudratricusxanthones A-H (1-8), were isolated from the roots of Cudrania tricuspidata, together with ten known compounds, cudraxanthones H (9) and M (10), xanthone V(1a) (11), toxyloxanthone C (12), macluraxanthone B (13), 1-hydroxy-3, 6, 7-trimethoxyxanthone (14), cycloartocarpesin (15), artocarpesin (16), cudraflavone B (17), and kaempferol (18). Their structures were characterized by spectroscopic methods. Xanthones 5, 7, 10, and 12 showed inhibitory effects on four kinds of human digestive apparatus tumor cell lines (HCT-116, SMMC-7721, SGC-7901, and BGC-823) with IC(50) values of 1.6-11.8 microg/mL. Xanthones 2, 4, and 11 displayed significant cytotoxicity against HCT-116, SMMC-7721, and SGC-7901 (IC(50)=1.3-9.8 microg/mL). Flavonoids 15-17 were almost inactive.

Antineoplastic Agents↗

PubMed2004

ent-Kaurene diterpenoids from Isodon oresbius.

Three new ent-kaurene diterpenoids, oreskaurins A-C (1-3), together with ten known ent-kaurene diterpenoids, enmenin monoacetate (4), effusanin E (5), adenolin B (6), maoecrystal G (7), enmelol (8), trichokaurin (9), sodoponin (10), trichorabdal A (11), nodosin (12), enmein (13), and a flavonoid, vitexin (14), were isolated from Isodon oresbius. Their structures were determined by spectroscopic means. Compound 12 showed inhibitory activity toward K562 cells with IC(50)=1.43 microg/ml.

Diterpenes, Kaurane↗