5‐Ethynyl‐2′‐deoxycytidine: a DNA building block with a `clickable' side chain

The title compound [systematic name: 4‐amino‐1‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐5‐ethynylpyrimidin‐2(1H)‐one], C₁₁H₁₃N₃O₄, shows two conformations in the crystalline state. The N‐glycosylic bonds of both conformers adopt similar conformations, with χ = −149.2 (1)° for conformer (I‐1) and −151.4 (1)° for conformer (I‐2), both in the anti range. The sugar residue of (I‐1) shows a C2′‐endo envelope conformation (²E, S‐type), with P = 164.7 (1)° and τ_m = 36.9 (1)°, while (I‐2) shows a major C3′‐exo sugar pucker (C3′‐exo‐C2′‐endo, ₃T², S‐type), with P = 189.2 (1)° and τ_m = 33.3 (1)°. Both conformers participate in the formation of a layered three‐dimensional crystal structure with a chain‐like arrangement of the conformers. The ethynyl groups do not participate in hydrogen bonding, but are arranged in proximal positions.     

A graphene-cobalt oxide based needle electrode for non-enzymatic glucose detection in micro-droplets

A novel graphene-cobalt oxide hybrid needle-like electrode was fabricated for non-enzymatic glucose detection. Taking advantage of its small size, the needle electrode can probe glucose in a micro-droplet with high sensitivity.     

Pillar[5]arene-based polymeric architectures constructed by orthogonal supramolecular interactions

Ureidopyrimidinone functionalized pillar[5]arene (UPyP5) was synthesized and employed to complex with a bisparaquat derivative (G) to form supramolecular polymers at relatively high concentration. The orthogonal binding interactions including quadruple hydrogen bonding and host-guest interaction should play vital roles in the construction of this linear assembly.     

Quinoline-3-carboxamide derivatives as potential cholesteryl ester transfer protein inhibitors

A series of novel quinoline-3-carboxamide derivatives 10-17 and 23-27 were designed and synthesized as cholesteryl ester transfer protein (CETP) inhibitors. All of them exhibited activity against CETP. Particularly, compounds 24 and 26 displayed the best activity against CETP with the same inhibitory rate of 80.1%.     

p-Cymene protects mice against lipopolysaccharide-induced acute lung injury by inhibiting inflammatory cell activation

The objective of this study was to test the hypothesis that p-cymene can attenuate acute lung injury induced by lipopolysaccharide (LPS) in vivo. In the mouse model of LPS-induced acute lung injury, intraperitoneal preconditioning with p-cymene resulted in a significant reduction of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), lung water gain, inflammatory cell infiltration, lung tissue myeloperoxidase activity. In addition, p-cymene blocked the phosphorylation of IκBα protein and mitogen-activated protein kinases (MAPK) signaling pathway activation. Histopathologic examination of lung tissue indicated that p-cymene treatment markedly decreased focal thickening, congestion, pulmonary edema, and inflammatory cells infiltration. The results showed that p-cymene had a protective effect on LPS-induced ALI in mice.     

Cytotoxicity and inhibition of lipid peroxidation activity of resveratrol/cyclodextrin inclusion complexes

Resveratrol (Res) is a plant-based polyphenol compound and is known to inhibit the growth of a variety of cancer cells and protect lipoproteins against oxidative damage. However the poor solubility and labile property may constitute a serious problem for its bioavailability. The problem could be overcome by the formation of inclusion complexes with cyclodextrins (CDs). The aim of this work is to include Res by β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-CD) to form the Res/β-CD and Res/HP-CD inclusion complexes and evaluate their cytotoxicity on cancer cells and inhibition of lipid peroxidation activity. The complexes are characterized by powder X-ray diffraction, fourier transform infrared spectroscopy and scanning electron microscopy. The cytotoxicity of the two complexes has been evaluated by methylthiazoletetrazolium reduction assay on two cancer cell lines (cervical carcinoma cells HeLa and hepatocellular liver cancer cells Hep3B) and one normal cell line (umbililical vein endothelial cell HUVEC). The results showed that the two complexes exhibit high cytotoxicity on two cancer cells, especially for Hep3B, and show no significant effect on normal cells. The Res/HP-CD complex shows higher cytotoxicity on the two cancer cells than that of the Res/β-CD complex. The inhibition of lipid peroxidation induced by Fe²⁺/ascorbate of the two inclusion complexes has been determined by thiobarbituric acid assay. The inhibition rate shows a linear increase with the increase of CDs concentration, and the Res/HP-CD complex shows stronger inhibition activity than that of the Res/β-CD complex. The results of this work indicate a potential for using the Res/CD complexes to inhibit human cancer growth and lipoproteins peroxidation.     

One‐Step Synthesis of SnO2 and TiO2 Hollow Nanostructures with Various Shapes and Their Enhanced Lithium Storage Properties

A versatile one‐step method for the general synthesis of metal oxide hollow nanostructures is demonstrated. This method involves the controlled deposition of metal oxides on shaped α‐Fe₂O₃ crystals which are simultaneously dissolved. A variety of uniform SnO₂ hollow nanostructures, such as nanococoons, nanoboxes, hollow nanorings, and nanospheres, can be readily generated. The method is also applicable to the synthesis of shaped TiO₂ hollow nanostructures. As a demonstration of the potential applications of these hollow nanostructures, the lithium storage capability of SnO₂ hollow structures is investigated. The results show that such derived SnO₂ hollow structures exhibit stable capacity retention of 600–700 mAh g^?1 for 50 cycles at a 0.2 C rate and good rate capability at 0.5–1 C, perhaps benefiting from the unique structural characteristics.     

Electrochemical detection of in situ DNA damage induced by enzyme-catalyzed Fenton reaction. Part I: in phosphate buffer solution

We report on a biosensor for the electrochemical detection of the damage of DNA and of antioxidant protecting DNA. The biosensor was constructed by co-immobilization of DNA and glucose oxidase (GOx) on a glassy carbon electrode. Under aerobic conditions, GOx catalyzes the oxidation of glucose, and the hydrogen peroxide produced reacts with ferrous ions in a Fenton-type reaction to generate hydroxy radical. This was validated by UV–vis spectroscopy. The hydroxy radical can cause serious oxidative damage to DNA, and this can be detected by square wave voltammetry of the electroactive indicator Co(bpy) ₃ ³⁺ . The effects of pH value, incubation time, and the concentration of glucose and ferrous ion were optimized. The effects of the antioxidants ascorbic acid and aloe emodin on DNA damage were also investigated within the concentration range from 0.05 to 200?μM. This work provides an in-vitro model system to mimic the processes in oxidative DNA damage by a simple electrochemical approach.