Ultrasensitive small molecule fluorogenic probe for human heparanase

Heparanase (HPA) is a critical enzyme involved in the remodeling of the extracellular matrix (ECM), and its elevated expression has been linked with diseases such as various types of cancer and inflammation. The detection of heparanase enzymatic activity holds tremendous value in the study of the cellular microenvironment, and search of molecular therapeutics targeting heparanase, however, no structurally defined probes are available for the detection of heparanase activity. Here we present the development of the first ultrasensitive fluorogenic small-molecule probe for heparanase enzymatic activity via tuning the electronic effect of the substrate. The probe exhibits a 756-fold fluorescence turn-on response in the presence of human heparanase, allowing one-step detection of heparanase activity in real-time with a picomolar detection limit. The high sensitivity and robustness of the probe are exemplified in a high-throughput screening assay for heparanase inhibitors.

Heparanase, a critical enzyme involved in the remodeling of the extracellular matrix, activates a disaccharide probe HADP to give a strong fluorescence signal.     

Enantioseparation of Amino Acid Derivatives with a Cellulose-Based Chiral Stationary Phase

Five structurally related amino acid derivatives were enantioseparated by HPLC with a commercially available chiral stationary phase, Chiralcel OD-H. The chromatographic experiments were performed in the normal phase mode. n-Hexane/polar alcohol was used as mobile phase. Excellent baseline enantioseparations could be obtained for all these solutes. The effects of the concentration of polar alcohol and the column temperature on the retentions and enantioseparations were studied in detail. From the van't Hoff plots the corresponding apparent thermodynamic parameters were derived. Mechanism aspects of chiral recognition were discussed based on the relationship between the thermodynamic parameters and the structures of the solutes. It was found that the substituent of the phenyl group on the residual group of the amino acid derivatives was close relevant to thermodynamic origin of enantioseparation. Much better enthalpy–entropy compensation effect was obtained by plotting the differential, rather than the original, thermodynamic parameters.     

VIB金属蝎型配合物(Scorpionate)的研究进展

综述了VIB金属(Mo、W)多吡唑硼配合物近年来的研究进展。详细地叙述了第二代多吡唑硼配体的合成与表征。     

Ion-ion reactions for charge reduction of biopolymer at atmospheric pressure ambient

Extractive electrospray ionization source(EESI)was adapted for ion-ion reaction,which was demonstrated by using a linear quadrupole ion trap mass spectrometer for the first ion-ion reaction of biopolymers in the atmospheric pressure ambient.     

Strained aromatic oligoamide macrocycles as new molecular clips

Can one join both ends of a helix? A helical aromatic oligoamide was macrocyclized into a saddle-shaped bifunctional clip molecule that self-assembles into discrete circular dodecamers in the solid state and shows great potential for binding aromatic acid guests in solution. The cyclization step requires that the helix is only partly denatured in the reaction medium.     

SET8 suppression mediates high glucose-induced vascular endothelial inflammation via the upregulation of PTEN

Hyperglycemia-mediated endothelial inflammation participates in the pathogenesis of cardiovascular complications in subjects with diabetes. Previous studies reported that phosphatase and tensin homolog deleted on chromosome ten (PTEN) and SET8 participate in high glucose-mediated endothelial inflammation. In this study, we hypothesize that SET8 regulates PTEN expression, thus contributing to high glucose-mediated vascular endothelial inflammation. Our data indicated that plasma soluble intercellular adhesion molecule-1 (sICAM-1) and endothelial selectin (e-selectin) were increased in patients with diabetes and diabetic rats. PTEN expression was augmented in the peripheral blood mononuclear cells of patients with diabetes and in the aortic tissues of diabetic rats. Our in vitro study indicated that high glucose increased monocyte/endothelial adhesion, endothelial adhesion molecule expression and p65 phosphorylation in human umbilical vein endothelial cells (HUVECs). Moreover, high glucose led to endothelial inflammation via upregulation of PTEN. Furthermore, high glucose inhibited SET8 expression and histone H4 lysine 20 methylation (H4K20me1), a downstream target of SET8. SET8 overexpression reversed the effects of high-glucose treatment. shSET8-mediated endothelial inflammation was counteracted by siPTEN. Furthermore, SET8 was found to interact with FOXO1. siFOXO1 attenuated high glucose-mediated endothelial inflammation. FOXO1 overexpression-mediated endothelial inflammation was counteracted by siPTEN. H4K20me1 and FOXO1 were enriched in the PTEN promoter region. shSET8 increased PTEN promoter activity and augmented the positive effect of FOXO1 overexpression on PTEN promoter activity. Our in vivo study indicated that SET8 was downregulated and FOXO1 was upregulated in the peripheral blood mononuclear cells of patients with diabetes and the aortic tissues of diabetic rats. In conclusion, SET8 interacted with FOXO1 to modulate PTEN expression in vascular endothelial cells, thus contributing to hyperglycemia-mediated endothelial inflammation.Subject terms: Diabetes complications, Vascular diseases     

Synthesis of Molecularly Imprinted Polymer Particles by Suspension Polymerization in Silicon Oil

Molecular imprinting is a method to prepare polymers with recognition site of desired and predetermined selectivity1. Molecularly imprinted polymers (MIP) are prepared by copolymerizing functional and cross-linking monomers in the presence of a molecular …     

Novel Hydrogen‐bond Three Dimensional Networks Generated from the Reaction of Metal Nitrate Hydrate (M = Co,Ni) with Ammonium Thiocynate and Bidentate Ligand Piperazine

The reaction of Co(NO₃)₂·6H₂O with two equivalents of PPz (PPz = piperazine hexahydrate) and two equivalents of NH₄SCN in CH₃OH afforded the complex [Co(NCS)₂(PPz)₂(CH₃OH)₂]. The reaction of Ni(NO₃)₂·6H₂O with two equivalents of PPz and four equivalents of NH₄SCN in CH₃OH afforded the complex [Ni(NCS)₄(PPz)₂]. Their IR spectra have been recorded and the structures have been determined. Crystal data for 1 : space group P&1bar;, a = 6.7208(6) Å, b = 8.4310(8) Å, c = 8.5923(8) Å, a = 77.881(2)°, β = 76.342(2)°, γ = 83.936(2)°, V = 461.75(1) ų, Z = 1 with final residuals R1 = 0.0650 and wR2 = 0.1725. Crystal data for 2 : space group P2(1)/n, a = 7.4209(6) Å, b = 11.0231(9) Å, c = 12.317(1) Å, β = 96.642(9)°, V = 1000.9(2) ų, Z = 2 with final residuals R1 = 0.0378 and wR2 = 0.0809. Important NCS—H‐N and O‐H—N(PPz) hydrogen‐bonding interactions in compound 1 and NCS···H‐N hydrogen‐bonding interactions and NCS—SCN interactions in compound 2 play a significant role in aligning the polymer strands in crystalline solids.     

空间展布体系中由化学反应-扩散-热传导耦合导致的温度场对称破缺

分析了由于化学反应-扩散-热传导耦合而导致的非等温非均匀体系中温度场对称破缺.研究结果表明,在一定的边界条件下,甚至是单组分化学反应-扩散-热传导体系,温度场的这种自组织进程也不可避免.作为温度场结构的一个范例,进一步从解析解及计算机模拟两个方面研究了小展布非等温的Lindeman模型;结果表明,温度场出现时空自组织的阈值不仅与本征参数有关,而且与体系的边界条件及外控约束相关,揭示出了诱发或避免这种温度场时空自组织之途径.     

绿色合成氧化剂高铁酸盐

高铁酸盐是绿色、无污染、高选择性和高活性的强氧化剂，其氧化性能比KMn04、O3和Cl还强，可以氧化醇类、含氮化合物、甚至烃类等有机化合物，高铁酸盐在有机物氧化合成中的应用具有很好的发展前景。本文介绍了有关高铁酸盐的制备方法、性质及有机物氧化合成方面的研究进展。