5-(4-Pentyl­phen­yl)-1,3,4-thia­diazol-2-amine

The title compound, C13H17N3S, was synthesized by the reaction of 4-pentyl­benzoic acid and thio­semicarbazide. The dihedral angle between the thia­diazole and phenyl rings is 29.9 (2)°. An intra­molecular C—H⋯S inter­action is observed. In the crystal, inter­molecular N—H⋯N hydrogen bonding links the mol­ecules into centrosymmetric dimers

Recent advances in polyoxometalate-based lanthanide–oxo clusters

Polyoxometalate (POM)-based lanthanide-oxo clusters (LnOCs) are a class of polynuclear lanthanide–oxygen complexes formed by polyoxometalate stabilization through oxygen bridges in which POMs can be viewed as multidentate inorganic ligands. POM-based LnOCs have received interest owing to their interesting structures and potential applications. In this paper, we summarize the classification, synthesis strategies, and properties of POM-based LnOCs. POM-based LnOCs are classified into three main categories according to their metal core element type and quantity: pure 4f clusters, 5d–4f clusters, and 3d–4f clusters. Their synthetic strategies are divided into four categories based on the source of the POM involved in the structural assembly: the lacunary POMs ligand-directed method, the in-situ transformation of lacunary POMs ligand-directed method, the in-situ generation of lacunary POMs ligand-directed method, and mixed synthesis strategies. In addition, the single-molecule magnets of POM-based LnOCs and their proton conduction properties are summarized

Bioactivities of berberine metabolites after transformation through CYP450 isoenzymes

<p>Abstract</p> <p>Background</p> <p>Berberine (BBR) is a drug with multiple effects on cellular energy metabolism. The present study explored answers to the question of which CYP450 (Cytochrome P450) isoenzymes execute the phase-I transformation for BBR, and what are the bioactivities of its metabolites on energy pathways.</p> <p>Methods</p> <p>BBR metabolites were detected using LC-MS/MS. Computer-assistant docking technology as well as bioassays with recombinant CYP450s were employed to identify CYP450 isoenzymes responsible for BBR phase-I transformation. Bioactivities of BBR metabolites in liver cells were examined with real time RT-PCR and kinase phosphorylation assay.</p> <p>Results</p> <p>In rat experiments, 4 major metabolites of BBR, berberrubine (M1), thalifendine (M2), demethyleneberberine (M3) and jatrorrhizine (M4) were identified in rat's livers using LC-MS/MS (liquid chromatography-tandem mass spectrometry). In the cell-free transformation reactions, M2 and M3 were detectable after incubating BBR with rCYP450s or human liver microsomes; however, M1 and M4 were below detective level. CYP2D6 and CYP1A2 played a major role in transforming BBR into M2; CYP2D6, CYP1A2 and CYP3A4 were for M3 production. The hepatocyte culture showed that BBR was active in enhancing the expression of insulin receptor (InsR) and low-density-lipoprotein receptor (LDLR) mRNA, as well as in activating AMP-activated protein kinase (AMPK). BBR's metabolites, M1-M4, remained to be active in up-regulating InsR expression with a potency reduced by 50-70%; LDLR mRNA was increased only by M1 or M2 (but not M3 and M4) with an activity level 35% or 26% of that of BBR, respectively. Similarly, AMPK-α phosphorylation was enhanced by M1 and M2 only, with a degree less than that of BBR.</p> <p>Conclusions</p> <p>Four major BBR metabolites (M1-M4) were identified after phase-I transformation in rat liver. Cell-free reactions showed that CYP2D6, CYP1A2 and CYP3A4 seemed to be the dominant CYP450 isoenzymes transforming BBR into its metabolites M2 and M3. BBR's metabolites remained to be active on BBR's targets (InsR, LDLR, and AMPK) but with reduced potency.</p

Structures, magnetic and catalytic properties of three sandwich-type silicotungstates containing tetranuclear copper(II) clusters

Three sandwich-type silicotungstates. formulated as [Cu-4(H2O)(2)(SiW9O34)(2)] 12NH(4) 22H(2)O (1), [Cu-4(H2O)(2)(SiW9O34)(2)] 12NH(4) 11H(2)P (2) and {[Cu(NH3)(4)](2)[Cu(H2O)(4)][Cu-4(H2O)(2)(SiW9O34)(2)]} 2[Cu(NH3)(4)(H2O)] 2NH(4) 6H(2)O (3), were synthesized by microwave irradiation and hydrothermal reaction Crystal structural analysis reveals that 1-3 possess the same dimeric polyoxoanions [Cu(2)StW(9)O(34) (H2O)(2)(12-) featuring tetranuclear copper(II) clusters Magnetic studies indicate that the Cu., clusters exhibit ferromagnetic coupling interactions Investigation on their catalytic activity for the oxidation of ethylbenzene suggests that catalytic activity of 1-3 is closely related to the acidity of complexes and the existence of unsaturated coordination sites in the complexNNSFC [20825103, 20721001, 90922031]; MSTC [200703815304]; Natural Science Foundation of Fujian Province of China [2008J0010