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Three new phlorizin derivatives, 6"-O-vanilloylphlorizin (1), 6"-O-(4-hydroxybenzoyl)phlorizin (2), 6"-O-feruloylphlorizin (3), along with four known dihydrochalcones, phlorizin (4), 3-hydroxyphlorizin, trilobatin, and 6"-O-acetylphlorizin were isolated from the leaves of Lithocarpus litseifolius. Their structures were established by analysis of extensive spectroscopic data. The new compounds were shown to be non-cytotoxic when tested against A549, HeLa, HepG2, and MCF-7 cell lines. [ABSTRACT FROM AUTHOR]

Honokiol, a natural polyphenol, which was reported to have satisfactory influenza neuraminidase (NA) inhibitory activity, was structurally modified. Twenty-three compounds were synthesized and the ortho-effects in the epoxidation and hydrolyzation reactions were studied. The derivatives were evaluated for NA inhibitory activity and the benzoylhydrazone derivatives showed much better anti-NA activity than honokiol. Structure-activity relationship analysis suggested that the polyphenols exhibited better anti-NA activity than monophenols and biphenols. Furthermore, probable binding mode of drug with target revealed that the most active compound had much stronger interactions with the active site of NA than honokiol suggesting the potent anti-influenza virus activity. [ABSTRACT FROM AUTHOR]

Ginsenosides F4 and Rg6 (GF4 and GRg6), two main active components of steamed notoginseng or red ginseng, are dehydrated disaccharide saponins. In this work, biotransformation of ginsenosides F4 and Rg6 in zebrafish was investigated by qualitatively identifying their metabolites and then proposing their possible metabolic pathways. The prediction of possible metabolism of ginsenosides F4 and Rg6 using zebrafish model which can effectively simulate existing mammals model was early and quickly performed. Metabolites of ginsenosides F4 and Rg6 after exposing to zebrafish for 24 h were identified by Ultraperformance Liquid Chromatography/Quadrupole-Time-of-Flight Mass Spectrometry. A total of 8 and 6 metabolites of ginsenosides F4 and Rg6 were identified in zebrafish, respectively. Of these, 7 and 5, including M1, M3−M5, M7−M9 and N1 (N5), N2, N4 (N9), N7−N8 were reported for the first time as far as we know. The mechanisms of their biotransformation involved were further deduced to be desugarization, glucuronidation, sulfation, dehydroxylation, loss of C-17 and/or C-23 residue pathways. It was concluded that loss of rhamnose at position C-6 and glucuronidation at position C-3 in zebrafish were considered as the main physiologic and metabolic processes of ginsenosides F4 and ginsenosides Rg6, respectively. [ABSTRACT FROM AUTHOR]

Adiponectin, an adipokine with insulin-sensitizing effect, is secreted from adipocytes into circulation as high, medium, and low molecular weight (HMW, MMW, and LMW) forms. The HMW adiponectin is more metabolically active and the ratio of HMW adiponectin to total adiponectin directly correlates with insulin sensitivity. Evodiamine is an indole alkaloid found in the traditional Chinese medicinal plant Evodia rutaecarpa. In this study, evodiamine was found to activate AMP-activated protein kinase (AMPK) in both 3T3-L1 adipocytes and 293T cells. Activation of AMPK by evodiamine promoted the assembly of HMW adiponectin and increased the HMW/total ratio of adiponectin in 3T3-L1 adipocytes. The Ca2+-dependent PI3K/Akt/CaMKII-signaling pathway was demonstrated to be involved in evodiamine-induced AMPK activation. This study revealed a novel role of this Ca2+-mediated signaling pathway in promoting the multimerization of adiponectin. [ABSTRACT FROM AUTHOR]

Tetranuclear zinc(II) citrates with N-heterocycle ligand, [Zn4(Hcit)2(phen)4(H2O)4]·2NO3·10H2O (1) and [Zn4(Hcit)2(bpy)4(H2O)6]·2NO3·12H2O (2) (H4cit?=?citric acid, phen?=?1,10-phenanthroline, bpy?=?2,2?-bipyridine), were synthesized from aqueous solution and characterized by Infrared, Powder X-ray diffraction, fluorescence spectra, and X-ray structural analyses. Complexes1and2are centrosymmetric tetranuclear species with two crystallographically independent Zn(II) ions, which display different coordination geometries, while the citrate ligand shows similar coordination modes and bridges three different Zn ions. In1, the Zn1 is five-coordinate by three oxygens from two citrates and two nitrogens from phen. There exist weak interactions between Zn1 and O4a atom of ?-carboxy group of citrate (Zn1?O4a?=?2.895?Å). Zn2 is six-coordinate by two oxygens from one citrate, two nitrogens from phen, and two water molecules. Zn1 and Zn2 are bridged by one citrate to form a dinuclear unit, which is further extended to a tetranuclear unit. In2, two citrates bridge two pairs of symmetry-related Zn(II) ions into a tetranuclear unit. The structural analyses of1and2indicate that different tetranuclear species are caused by arrangement of citrates with different steric hindrance of N-chelates.1H and13C NMR spectra indicate that2remains coordinated in D2O. Moreover, both1and2show strong fluorescent emission in dilute solution and solid state. Two tetranuclear zinc(II) citrates with N-heterocycle ligand, [Zn4(Hcit)2(phen)4(H2O)4]·2NO3·10H2O (1) and [Zn4(Hcit)2(bpy)4(H2O)6]·2NO3·12H2O (2) (H4cit?=?citric acid, phen?=?1,10-phenanthroline, bpy?=?2,2?-bipyridine), were synthesized from aqueous solution and characterized by Infrared, Powder X-ray diffraction, fluorescence spectra and X-ray structural analyses.1and2show strong fluorescent emission in dilute solution and solid state. [ABSTRACT FROM PUBLISHER]

Two new coumarins, clauexcavatins A (1) and B (2), along with seven known ones (3–9), were isolated from the roots of Clausena excavata Burm. f. (Rutaceae). Their structures were elucidated on the basis of spectral data. [ABSTRACT FROM AUTHOR]

Four new metabolites M-1 [1,2,18,19-tetradehydro-4-demethyl-3,17-epoxy-7,20(2H,19H)-cyclovobasan], M-2 [1,2,4,21,18,19-hexadehydro-4-demethyl-3,17-epoxy-7,20(2H,19H)-cyclovobasan], M-3 [1,2,18,19-tetradehydro-4-demethyl-4-formaldehyde-3,17-epoxy-7,20(2H,19H)-cyclovobasan], and M-4 [1,2,4,21,18,19-hexadehydro-4-demethyl-4-oxy-3,17-epoxy-7,20(2H,19H)-cyclovobasan] were isolated from the chloroform extract of koumine incubated with phenobarbital-treated rat liver microsomes. The structures of M-1, M-2, M-3, and M-4 were elucidated by spectroscopic methods including ESI-TOF-MS, 1D, and 2D NMR experiments. The metabolic pathway of koumine was proposed. The cytotoxic activities between koumine and its metabolites were also compared in the A549 cell line. [ABSTRACT FROM AUTHOR]

The 3D structure of the human β-defensin 28 (HBD-28) has been investigated via homology modelling and molecular dynamics (MD) approach. With known high-resolution structures of HBD-2 and -3, single- and multiple-template sequence alignments are applied to find highly probable candidates for HBD-28, which are in turn refined through MD simulations in pure water and 50% trifluoroethanol/water mixture. The models obtained from homology modelling were assessed by protein structure validation software suite, which includes Procheck, MolProbity, Verify-3D and various structure validation tools. We found that modelling quality is proportionally related to the sequence alignment accuracy. In comparison with circular dichroism experimental data as well as stabilities of β-sheets and α-helix, HBD-28 with a reliable 3D structure was found. [ABSTRACT FROM PUBLISHER]