Novel bicyclic .beta.-lactams and intermediates useful in their preparation are disclosed. In particular, 7.beta.-acyl-amino- and 7.beta.-amino-8-oxo-4-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acids are prepared. The acylated compounds are antibacterial agents.
Methods and intermediates for preparing cis-4-oxoazetidine intermediates
申请人:SmithKline Corporation
公开号:US04166816A1
公开(公告)日:1979-09-04
The stereospecific cycloaddition of nitrogen containing acetic acid halides or anhydrides with Schiff bases having a carbalkoxy group substituted on the methine carbon atom offers new intermediates and methods for preparing synthetic cephalosporin congeners having antibacterial activity.
Oxidative damage of proline residues by nitrate radicals (NO<sub>3</sub>˙): a kinetic and product study
作者:Joses G. Nathanael、Jonathan M. White、Annika Richter、Madison R. Nuske、Uta Wille
DOI:10.1039/d0ob01337d
日期:——
indicating that NO3˙-induced oxidation of amide bonds proceeds through initial formation of a charge transfer complex. Furthermore, the rate of oxidative damage of proline and N-methyl glycine is significantly influenced by its position in a peptide. Thus, neighbouring peptide bonds, particularly in the N-direction, reduce the electron density at the tertiary amide, which slows down the rate of ET by up
叔酰胺,例如N-酰化脯氨酸或N-甲基甘氨酸残基,与硝酸根 (NO 3 ˙) 快速反应,在乙腈中的绝对速率系数范围为 4-7 × 10 8 M -1 s -1 。主要途径通过氮处的氧化电子转移 (ET) 进行,而在这些条件下,夺氢只是次要因素。然而,酰胺的空间位阻,例如α-碳上的烷基侧链,使速率系数降低高达 75%,表明 NO 3˙ 诱导的酰胺键氧化通过电荷转移复合物的初始形成进行。此外,脯氨酸和N-甲基甘氨酸的氧化损伤率显着受其在肽中的位置的影响。因此,相邻的肽键,特别是在N方向上,会降低叔酰胺的电子密度,从而将 ET 的速率降低多达一个数量级。这些模型研究的结果表明,与单一氨基酸相比,肽中脯氨酸残基对自由基诱导的氧化损伤的敏感性应大大降低。
Energetic contribution to both acidity and conformational stability in peptide models
The acidity difference of the amide rotamers has been revised for a large set ofN-acetyl amino acids.
酰胺构象异构体的酸度差异已经针对大量的N-乙酰氨基酸进行了修订。
[EN] PRODRUGS OF KETAMINE, COMPOSITIONS AND USES THEREOF<br/>[FR] PROMÉDICAMENTS À BASE DE KÉTAMINE, COMPOSITIONS ET UTILISATIONS DE CEUX-CI
申请人:XW LAB INC
公开号:WO2019137381A1
公开(公告)日:2019-07-18
Provided are prodrugs of (S) -or (R) -ketamine, including isotopically labeled ketamine,composition and uses thereof. Compounds having formula (Ia) or (Ib) as the prodrugs of (S) -or (R) -ketamine, including isotopically labeled ketamine, and pharmaceutical compositions comprising the compounds provided herein are used for treating or preventing a CNS disease.More particularly, the related diseases include depression and pain. (Ia) (Ib)