Transition-Metal Acetate-Promoted Intramolecular Nitrene Insertion to Vinylogous Carbonates for Divergent Synthesis of Azirinobenzoxazoles and Benzoxazines

Synthesis and isolation of highly unstable azirinobenzoxazole and benzoxazines in a chemodivergent fashion from aryl azido vinylogous carbonates by simple change in transition metal acetate is described. Thermal or rhodium(II) acetate-mediated decomposition of these azides gave dihydroazirino benzoxazole. Their nickel(II) acetate-promoted reaction gave 4-dihydro-2H-benzoxazines, whereas copper(II) acetate led to the corresponding oxidized imine derivatives. Benzaoxazine derivative could be kinetically resolved using a proline-catalyzed Mannich reaction. The benzoxazines were rapidly elaborated to angularly fused tetracyclic systems and coumarin-fused derivatives in a “one pot” fashion.     

一类推广的拟牛顿多进程异步并行方法

本文通过近似雅可比矩阵Bk代替雅可比矩阵F′(xk),运用多进程异步并行方法求解非线性方程组。该方法在保持解的精度的情况下,缩短了运行时间和迭代步数。文中给出了算法收敛性的证明及八个非线性方程组的数值测试结果,表明该算法是可行的和快速的。     

ICP-AES法测定人发中Cu、Zn、Fe、Mn和Ca

本文报导了用ＩＣＰ－ＡＥＳ测定人发中Ｃｕ、Ｚｎ、Ｆｅ、Ｍｎ和Ｃａ的方法。确定了仪器工作条件，并对酸度等的影响进行了探讨。人发标准物质的测定值与标准值很好地吻合。     

PyPLIF HIPPOS-Assisted Prediction of Molecular Determinants of Ligand Binding to Receptors

Identification of molecular determinants of receptor-ligand binding could significantly increase the quality of structure-based virtual screening protocols. In turn, drug design process, especially the fragment-based approaches, could benefit from the knowledge. Retrospective virtual screening campaigns by employing AutoDock Vina followed by protein-ligand interaction fingerprinting (PLIF) identification by using recently published PyPLIF HIPPOS were the main techniques used here. The ligands and decoys datasets from the enhanced version of the database of useful decoys (DUDE) targeting human G protein-coupled receptors (GPCRs) were employed in this research since the mutation data are available and could be used to retrospectively verify the prediction. The results show that the method presented in this article could pinpoint some retrospectively verified molecular determinants. The method is therefore suggested to be employed as a routine in drug design and discovery.