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Two novel phloroglucinol-terpenoid adducts (1 and 2), featuring a rare 2,2,4-trimethyl-cinnamyl-β-triketone unit, were isolated from the buds of Cleistocalyx operculatus. Their structures with absolute configurations were established by spectroscopic analyses, single-crystal X-ray diffraction, and quantum chemical calculations. Structurally, compound 1 represents a new carbon skeleton possessing a densely functionalized tricyclo[11.3.1.03;8]heptadecane bridged ring system with an unusual bridgehead enol. Compounds 1 and 2 exhibited significant in vitro antiviral activities against respiratory syncytial virus (RSV).

Two novel phloroglucinol-terpenoid adducts (

Ethnopharmacological relevance For many years, Guangzhou University of Chinese Medicine has been successfully using the empirical Wenyang Huoxue Jiedu formula (WHJF) to treat coronary heart disease. Modern theories of acute coronary syndrome mainly focus on rupture of thin-cap fibroatheromas (TCFAs), which is closely related to the release of vascular endothelial growth factor and its receptor (VEGF/VEGFR). Aim of study We investigated the effects of WHJF on the formation of TCFA plaques and the potential mechanism (VEGF/VEGFR signaling pathway). Materials and methods For the in vivo experiments, WHJF was administered to ApoE-/- mice, as a model of TCFA plaque formation. Aortic sections of the mice were obtained, and the vulnerability index and new vessel density of plaques were calculated by the Movat staining assay and immunohistochemistry kit, respectively. Protein and mRNA expression levels of VEGF/VEGFR in aortas were assayed by capillary electrophoresis immunoassay and quantitative real-time polymerase chain reaction analyses. In vitro, WHJF serum was produced in rats on the fourth day 2 h after the first administration of different concentrations of WHJF. Proliferation, migration, and lumen formation ability of human umbilical vein endothelial cells (HUVECs) treated with sera from these rats were assayed by the CKK-8 kit, Transwell plates, and Matrigel assay, respectively. Protein and mRNA expression levels of signaling molecules in the VEGF/VEGFR pathways were also examined. Results In vivo, the vulnerability index and new vessel density of plaques in the WHJF group were lower than those values in the blank control group (P 0.05). In vitro, the proliferation, migration, and tube formation of HUVECs in the high-dose WHJF group were reduced compared to the control group (P 0.05). Conclusions WHJF inhibits TCFA formation by influencing the VEGF/VEGFR signaling pathway.

A new class of electrorheological (ER) material, rare earth (RE = Ce, Gd, Er and Y) complexes of phosphate cellulose, has been synthesized using microcrystalline cellulose, phosphoric acid, urea and RE(NO3)3 solutions as starting materials. The ER properties of suspensions of microcrystalline cellulose, phosphate cellulose [cellulose-P-ONH4] and the [cellulose(-P-O)3RE] complex particle materials in silicon oil have been investigated under DC electric field. The formation of rare earth complexes helps to decrease the shear stress and viscosity at zero electric field, and to enhance the ER effect of the materials. The shear stress (τE) of the ER fluid (20% weight fraction) of a typical yttrium complex [cellulose(-P-O)3Y], the yttrium content of which is 0.04 mol/100 g, is 2.3 kPa at 4.2 kV/mm and 300 s−1 with a τr value (τr = τE/τ0, where τ0 is the shear stress at no electric field and 300 s−1) of 34.3, which is 18 times higher than that of pure microcrystalline cellulose suspensions. The improvement of dielectric loss tangent of the material, due solely to the formation of rare earth complexes, resulted in an enhancement in the ER effect of the material. In addition, the cellulose(-P-O)3RE materials possess better thermal stability, and their suspensions are more stable in the anti-sedimentation than that of the cellulose-P-ONH4 material.

A phthalate-bridged copper(II) complex {[Cu(phth)(Phen)(H2O)] ⋅ H2O}n (H2phth: phthalic acid, Phen: 1,10-phenanthroline) has been synthesized by the reaction of CuCl2 and phthalic acid in the presence of 1,10-phenanthroline in aqueous solution. The crystal structure of the complex has been determined by X-ray diffraction analysis to be orthorhombic, with the centrosymmetric space group Pbcm, where a = 11.6652(3) A, b = 11.1709(3) A, c = 14.0532(4) A, V = 1831.28(9) A3, Z = 4. The L2− (the acid radical of H2phth) ion is coordinated to the Cu2+ ion as a monodentate ligand. Each L2− ion bridges two adjacent Cu2+ ions with its two oxygen atoms from two carboxylic groups to form a one-dimensional zigzag chain. The coordination water and uncoordinated carboxylic oxygen atoms from neighboring chains are linked through hydrogen bonds to form a two-dimensional structure. There is a weak interaction between the coordination water molecule and the Cu2+ ion in the neighboring chain.

A series of heptanuclear rare-earth-centered trigonal prism clusters [LnCu6(μ-OH)3(HL)2(L)4]·(ClO4)2·25H2O (Ln = La−Ho and Y; H2L = iminodiacetic acid) was synthesized and their crystal structures were determined by X-ray diffraction. The rare-earth center and the copper ions are bridged by three μ3-OH and six μ2-O moieties from the carboxyl groups of six different ligands. The rare earth ion is nine-coordinate and the coordination polyhedron is an unusual, highly symmetrical tricapped trigonal prism (C3h). The cluster has an interesting, highly symmetrical eclipsed structure (C3h) which utilizes the central rare earth cation as a template. The temperature-dependence of the magnetic susceptibility of the cluster series was investigated and was found to vary with the central rare-earth ions. The magnitude of the antiferromagnetic interaction constants J between Cu2+ ions in [LaCu6] and [YCu6] were compared and estimated to be −24 cm−1 and −7 cm−1, respectively, indicating a significant effect of the central diamagnetic ions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Radial gradient-index glass has been prepared by the sol-gel process using tetrabutoxytitanium as the source of index- modifying cation. Two systems have been studied. Wet gels were obtained by first partially hydrolyzing tetraethoxysilane (TEOS), then adding tetrabutoxytitanium alone or together with Y(NO 3 ) 3 into the mixture and using another part of water to hydrolyze the salts thoroughly and make it gel. The wet gels were then put into a H 2 SO 4 bath to partially leach out the index-modifying cations and form the concentration gradient. Through drying and sintering the gels were turned into transparent and colorless glass rods of about 4.5∼7.5 mm in diameter. The resulting refractive index profile of the glass has been measured and the maximum index change from the center to the perimeter was about 0.03.

Nanosized particle materials with different structures and grain sizes were prepared by doping TiO2 or ZrO2 with rare earth (RE) elements, and by changing the method of treatment. Their microstructures were confirmed by X-ray diffraction (XRD) analyses and measurements of the surface areas, pore volumes, and pore sizes of the particles. The electrorheological (ER) performance and dielectric properties of these materials, and the relationship between ER activity, microstructure, and grain size of these particle materials were investigated. The results have shown that RE doping can either increase or decrease the ER activity of a material, which is related to the pore volume in the grain. Body-centered tetragonal TiO2 and tetragonal ZrO2 possess higher ER activity than tetragonal TiO2 and monoclinic ZrO2, respectively. The effect of grain size on ER performance should not be neglected for different materials in a system with identical crystal structure and composition, and the co-action of both larger grain size and larger pore volume can play a very important role in nanosized particle materials. Optimal matching between appropriate RE-doping, microstructure and particle size, which can be achieved by fine-tuning the production process of a material, may provide a basis for producing an ER material with high activity.