Synthesis,Biological Evaluation,and Docking Study of Ring-Opening Amide Analogs of Matrine as Antitumor Agents

In this article, we designed and synthesized two series of matrine analogs with ring-opening in the lactam portion of the molecule. Our in vitro cytotoxicity study showed that analog N-(3-bromophenyl)-4-[(1R,3aS,10aR,10bS)-decahydro-1H,4H-pyrido[3,2,1-ij][1,6]naphthyridin-1-yl]butanamide ( B11 ) with a meta-bromide on the phenyl ring displayed the best antiproliferative activity. Moreover, B11 induced cell cycle arrest in G1 phase and cell apoptosis in a dose-dependent manner in A549 cells. Molecular modeling revealed that B11 achieved a higher docking score compared to its precursor tert-butyl (1R,3aS,10aR,10bS)-1-[4-(3-bromoanilino)-4-oxobutyl]octahydro-1H,4H-pyrido[3,2,1-ij][1,6]naphthyridine-2(3H)-carboxylate ( A11 , an analog of B11 with a Boc group) and parent compound matrine, possibly because B11 formed a hydrogen bond with SER91 and a halogen bond with GLN320 on the binding site of annexin A2. Overall, we discovered the potential anticancer lead compound B11 , which can be used for further study both in vitro and in vivo.     

(Ni-Sn-M_xO_y)/Pb改性复合电极电解合成L-半胱氨酸的反应

在（Ｎｉ－Ｓｎ）／Ｐｂ合金修饰电极中添加某些金属氧化物进行改性，用于电解合成Ｌ－半胱氨酸反应。结果证明，添加ＷＯ３后电极反应活性大大加强，反应同期转化率有较大提高，选择性也有所提高，添加稀土金属氧化物能有效降低反应阴极过电位，使反应选择性有所提高，但是电极稳定性还有待改善。     

Conformationally altered aortic myosin light chains

Aorta smooth myosin contains two types of light chain, LC20 and LC17, which fold together with the N-terminal region of each heavy chain to form the globular head region of myosin. We demonstrate an altered conformation of LC20 after its separation from heavy chain by high concentrations of urea, on the basis of the following evidende: 1) A polyclonal antibody against LC20 was not able to recognize this conformationally altered form; 2) Myosin reconstituted from heavy chains and urea-dissociated light chains exhibited extremely low ATPase activity. Circular dichroism unfolding profiles showed that light chains dissociated from heavy chains by SDS appeared to be more stable than those generated by urea dissociation.     

An efficient, practical synthesis of 2-methoxyestradiol

An efficient and practical scheme to synthesize 2-methoxyestradiol has been developed. The key step was the copper-mediated methoxylation using ethyl acetate as a co-catalyst to introduce a methoxyl group. These synthetic procedures of four steps from 17β-estradiol as starting material gave 2-methoxyestradiol with a 61% overall yield.     

Molecular characterization of a mucin-type antigen associated with human pancreatic cancer. The DU-PAN-2 antigen

This work describes the molecular characterization of a human pancreatic cancer-associated antigen defined by a murine monoclonal antibody (DU-PAN-2). DU-PAN-2 antigen was isolated from a pancreatic adenocarcinoma cell line (HPAF) or patient's ascitic fluid, and the antigenic activity was monitored by competitive inhibition radioimmunoassay. Affinity chromatography and CsCl/guanidine HCl density gradient centrifugation were employed to remove other populations of mucin-type glycoproteins and noncovalently associated proteins, respectively. Three electrophoretically distinct components were detected by 1% agarose gel electrophoresis and were resolved by chromatography on Sepharose CL-4B. The major fraction (FII) was subjected to carbohydrate and amino acid analyses. The sum of threonine, serine, proline, glycine, and alanine comprised more than 50% of the amino acid residues. The saccharide units, O-glycosidically linked to the peptide via GalNAc, contained fucose, galactose, GlcNAc, GalNAc, and sialic acid. The total carbohydrate content of FI and FII was 80.8% and 77.4% by weight, respectively. The molecular weight of FII antigen showed two species of molecules of 1.45 X 10(6) and 4.59 X 10(6) by analytical sedimentation equilibrium. DU-PAN-2 antigen was susceptible to neuraminidase, pepsin, Pronase, and papain digestion. These results suggest that both protein components and sialic acid residues may play important roles in the binding of DU-PAN-2 antibody.     

墨红鲜花香气(头香)成分分析

利用 XAD-4憎水性吸附树脂采集墨红头香,以毛细管气相色谱双柱保留指数和 GC/MS/DS 联用方法鉴定头香的化学成份。共分离鉴定或初步鉴定了45种组份,其中含量较大的有乙酸芳樟酯(14.98%),柠檬烯(12.07%),甲基苯甲醚(9.88%),香茅醇(4.82%),乙酸巳酯(3.98%),β-石竹烯(4.55%),芳樟醇(3.18%),正巳醇(3.17%)等.