Polymeric architectures of bismuth citrate based on dimeric building blocks.

Unlabelled: Four bismuth complexes, (HEn)[Bi(cit)(HO)]·(HO) (), (HEn)[Bi(cit)Cl]·(HO) (), (HPy)[Bi(cit)(HO)]·(HO) () and (HEn)[Bi(cit)](HO) () [cit = citrate; En = ethylenediamine; Py = pyridine] have been synthesized and crystallized. The crystal structures reveal that the basic building blocks in all of these complexes are bismuth citrate dimeric units which combine to form polymeric architectures. The embedded protonated ethylenediamine and pyridine moieties in the polymeric frameworks have been identified by X-ray crystallography and solid-state cross polarization/magic angle spinning (CP/MAS) C NMR.

1,4-Dibenzyl-piperazine.

In the title compound, C(18)H(22)N(2), which possesses non-crystallographic inversion symmetry, the central piperazine ring adopts a chair conformation. The phenyl rings are not exactly parallel and make a dihedral angle of 1.3 (1)°.

2-Amino-4-(4-hy-droxy-3,5-dimeth-oxy-phen-yl)-6-phenyl-nicotinonitrile.

In the title compound, C(20)H(17)N(3)O(3), the dihedral angles between the central pyridine ring and the two terminal rings are 15.07 (3) and 43.24 (3)°.

Investigation of the immunosuppressive activity of Physalin H on T lymphocytes.

Physalis angulata is an annual herb widely used in folk medicine. It is mainly used for treating rheumatoid arthritis (RA). Following bioactivity-guided isolation, a representative immunosuppressive compound, Physalin H was been identified from this herb medicine.

Anti-inflammatory function of Withangulatin A by targeted inhibiting COX-2 expression via MAPK and NF-kappaB pathways.

Withangulatin A (WA), an active component isolated from Physalis angulata L., has been reported to possess anti-tumor and trypanocidal activities in model systems via multiple biochemical mechanisms. The aim of this study is to investigate its anti-inflammatory potential and the possible underlying mechanisms.

Jatrophalactam, a novel diterpenoid lactam isolated from Jatropha curcas.

Jatrophalactam (1), a novel diterpenoid lactam possessing an unprecedented 5/13/3 tricyclic skeleton, was isolated from the roots of Jatropha curcas. The structure and relative configuration of jatrophalactam (1) were elucidated by extensive spectroscopic analysis and further determined by a single-crystal X-ray diffraction.

The natural product Aristolactam AIIIa as a new ligand targeting the polo-box domain of polo-like kinase 1 potently inhibits cancer cell proliferation.

Aim: To search for novel inhibitors of human polo-like kinase 1 (Plk1), which plays important roles in various aspects of mitotic progression and is believed as a promising anti-cancer drug target, and further investigate the potential inhibition mechanism of active compounds against Plk1, thus developing potent anti-tumor lead compounds.

Methods: Surface plasmon resonance (SPR) technology-based assay and enzymatic inhibition assay were used to screen Plk1 inhibitors. Sulphorhodamine B (SRB)-based assay, flow cytometry, confocal microscopy and Western blotting were used to further identify the potent Plk1 inhibitor.

Do quantum mechanical energies calculated for small models of protein-active sites converge?

A common approach for the computational modeling of enzyme reactions is to study a rather small model of the active site (20-200 atoms) with quantum mechanical (QM) methods, modeling the rest of the surroundings by a featureless continuum with a dielectric constant of approximately 4. In this paper, we discuss how the residues included in the QM model should be selected and how many residues need to be included before reaction energies converge. As a test case, we use a proton-transfer reaction between a first-sphere cysteine ligand and a second-sphere histidine group in the active site of [Ni,Fe] hydrogenase.

Dammarane-type glycosides and long chain sesquiterpene glycosides from Gynostemma yixingense.

A new dammarane-type glycoside and a new long chain sesquiterpene glycoside, along with nine known compounds 20(S)-ginsenoside Rh1 (3), 20(R)-ginsenoside Rh1 (4), ginsenoside F1 (4), amarantholidoside IV (6), ginsenoside Rc (7), 20(S)-ginsenoside Rg2 (8), 20(R)-ginsenoside Rg2 (9), ginsenoside Rd (10) and gypenoside XLVI (11) were isolated from Gynostemma yixingense. The structures of the new compounds were determined on the basis of spectroscopic analysis, including 1D-, 2D-NMR and ESI-MS techniques as well as by comparison of the spectral data with those of related compounds as 2 alpha,3beta,20(S)-trihydroxydammar-24-ene-3-O-[beta-D-glucopyranosyl((1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-xylopyranosyl((1-->6)-beta-D-glucopyranoside] (1) (2E,6E)-10-beta-D-glucopyranosyl-1,10,11-trihydroxy-3,7,11-trimethyldodeca-2,6-diene (2).

Immunosuppressive withanolides from Withania coagulans.

Six new withanolides, withacoagulins A-F (1-6, resp.), together with ten known withanolides, 7-16, were isolated from the aerial parts of Withania coagulans. Their structures were determined by spectroscopic techniques including 1D- and 2D-NMR (1H, 13C, HMQC, and HMBC) and MS experiments.

Alternating and random copolymerization of isoprene and ethylene catalyzed by cationic half-sandwich scandium alkyls.

The acid-base reactions between the scandium trialkyl complex Sc(CH(2)SiMe(3))(3)(THF)(2) and 1 equiv of Cp'-H afforded straightforwardly the corresponding mono(cyclopentadienyl)scandium dialkyl complexes Cp'Sc(CH(2)SiMe(3))(2)(THF) (Cp' = C(5)H(5) (1), C(5)MeH(4) (2), C(5)Me(4)H (3), C(5)Me(5) (4), C(5)Me(4)SiMe(3) (5)) in 65-80% isolated yields. The analogous half-sandwich complexes having a heteroatom-containing side arm, (C(5)Me(4)R)Sc(CH(2)SiMe(3))(2) (R = CH(2)CH(2)PPh(2) (6), C(6)H(4)OMe-omicron (7)), were obtained by the one-pot metathetical reactions of ScCl(3)(THF)(3) with 1 equiv of the potassium salts of the ligands and 2 equiv of LiCH(2)SiMe(3). The similar reactions of ScCl(3)(THF)(3) with KC(5)Me(4)(C(6)H(4)NMe(2)-omicron) and LiCH(2)SiMe(3) gave a methylene-bridged binuclear complex [{C(5)Me(4)(omicron-C(6)H(4)N(Me)CH(2)-mu}Sc(CH(2)SiMe(3))](2) (8).

Antiplasmodial isoflavanones from the roots of Sophora mollis.

Six new prenylated isoflavanones named sophoronols A-F (1-6), together with eight phenolic constituents, were isolated from the roots of Sophora mollis. Their structures and stereochemistry were established by 1D and 2D NMR techniques, especially HMBC and NOESY as well as CD results. Componds 3 and 5 exhibited moderate anitplasmodial activity against the CQS D10 strain of Plasmodium falciparum, with IC(50) values of 12.

Synthesis and structure-activity relationship studies of cytotoxic anhydrovinblastine amide derivatives.

A series of 3-demethoxycarbonyl-3-amide methyl anhydrovinblastine derivatives (5b-24b) was designed, synthesized, and evaluated for their proliferation inhibition activities against two tumor cell lines (A549 and HeLa). Most of the amide anhydrovinblastine derivatives exhibited potent cytotoxicity, with the size of the introduced substituents being the foremost factor in determining the resultant cytotoxic activity. Test results in vivo against sarcoma 180 of three potent compounds (6b, 12b, and 24b) indicated that the introduction of an amide group at the 22-position of anhydrovinblastine (1e) improved both potency and toxicity.

[Drug discovery based on classic natural products].

We think the strategy of classic natural product-based drug discovery will be an effective way for us to develop new drugs with independent intellectual property. The strategy includes: to study the molecular mechanism of action of classic natural product with chemical genetics and chemical biology approaches firstly; then establish the proper in vitro bioassay or bioassay system based on its molecular mechanism for their pharmacodynamic evaluation; finally, study their structure-activity, structure-toxicity and structure-ADME properties with medicinal chemistry.

Terpenoids from roots of Chloranthus henryi.

Six new terpenoids, including three diterpenoids (1-3), one norditerpenoid (4) and two sesquiterpenoids (11 and 12), were isolated from the roots of Chloranthus henryi. The structures were elucidated mainly by 1D, and 2D NMR and MS experiments, and their relative configurations were determined by NOE techniques.

An approach to 3,6-disubstituted 2,5-dioxybenzoquinones via two sequential Suzuki couplings. three-step synthesis of leucomelone.

Two sequential Suzuki coupling reactions have been developed for efficient synthesis of synthetically and biologically important 3,6-disubstituted 2,5-dioxybenzoquinone architectures in a highly chemoselective controlled manner. The method serves as a key step in the total synthesis of leucomelone in three steps and in 61% overall yield.

Maleopimaric acid acetic acid solvate.

The title compound, C(24)H(32)O(5)·C(2)H(4)O(2), is a derivative of abietic acid. The two fused and unbridged cyclo-hexane rings have chair conformations and the anhydride ring is planar. Of the other three six-membered rings, two have boat conformations and one has a twist-boat conformation.

Anti-inflammatory effects of Z23 on LPS-induced inflammatory responses in RAW264.7 macrophages.

Aim Of The Study: Fissistigma oldhamii (Hemsl.) Merr, a traditional Chinese herb medicine, is used for treating rheumatoid arthritis in China. In our previous study, an effective compound, 7'-(3',4'-dihydroxyphenyl)-N-[(4-methoxyphenyl) ethyl] propenamide (Z23), from this herb has showed potent immunosuppressive effects both in vitro and in vivo.

WITHDRAWN: Eight new C21 steroidal glycosides from Cynanchum wilfordii.

This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).

Three flavonoids targeting the beta-hydroxyacyl-acyl carrier protein dehydratase from Helicobacter pylori: crystal structure characterization with enzymatic inhibition assay.

Flavonoids are the major functional components of many herbal and insect preparations and demonstrate varied pharmacological functions including antibacterial activity. Here by enzymatic assay and crystal structure analysis, we studied the inhibition of three flavonoids (quercetin, apigenin, and (S)-sakuranetin) against the beta-hydroxyacyl-acyl carrier protein dehydratase from Helicobacter pylori (HpFabZ). These three flavonoids are all competitive inhibitors against HpFabZ by either binding to the entrance of substrate tunnel B (binding model A) or plugging into the tunnel C near the catalytic residues (binding model B) mainly by hydrophobic interaction and hydrogen-bond pattern.

Oleanolic acid derivative NPLC441 potently stimulates glucose transport in 3T3-L1 adipocytes via a multi-target mechanism.

The natural product oleanolic acid (OA) has been discovered to exhibit varied pharmacological functions including anti-inflammation, anti-tumor and anti-diabetes, while appropriate synthetic oleanolic acid derivatives seem to possess more potent activities. Here we identified a new oleanolic acid derivative, 3-beta-(2-carboxybenzoyloxy)-oleanolic acid (NPLC441), which functioned as a competitive PTP1B inhibitor and enhanced insulin-stimulated phosphorylation of IR and AKT in HepG2 cells. As an RXRalpha antagonist, it could selectively activate LXRalpha:RXRalpha heterodimer and increase the promoter activities of ABCA1 and ABCG1 genes in transient transfection assays.

D-Alanine:D-alanine ligase as a new target for the flavonoids quercetin and apigenin.

Flavonoids are polyphenolic compounds that are ubiquitous in nature. They possess varied promising properties for medical use. Quercetin (3,3',4',5,7-pentahydroxyflavone) and apigenin (4',5,7-trihydroxyflavone) are two representative flavonoids, both of which have been reported to possess antibacterial activity by acting on multiple targets.

Synthesis and structure-activity relationship studies of cytotoxic ester and ether anhydrovinblastine derivatives.

Two new series of 3-demethoxycarbonyl-3-ester and 3-demethoxycarbonyl-3-ether methyl anhydrovinblastine derivatives were designed, synthesized, and evaluated for their inhibitory activities against human non-small-cell lung cancer (A549) and cervical epithelial adenocarcinoma (HeLa) cell lines. Ester anhydrovinblastine derivatives exhibited potent cytotoxicity, whereas the ether analogues were much less active. The size of the introduced substituents was the foremost factor in determining the resultant cytotoxic activity.

Oleanolic acid and its derivatives: new inhibitor of protein tyrosine phosphatase 1B with cellular activities.

Protein tyrosine phosphatase 1B is a key factor in the negative regulation of insulin pathway and a promising target for treatment of diabetes and obesity. Herein, a series of competitive inhibitors were optimized from oleanolic acid, a natural triterpenoid identified against PTP1B by screening libraries of traditional Chinese medicinal herbs. Modifying at 3 and 28 positions, we obtained compound 13 with a K(i) of 130 nM, which exhibited good selectivity between other phosphatases involved in insulin pathway except T-cell protein tyrosine phosphatase.