Toward an Optimal Joint Recognition of the S1‘ Subsites of Endothelin Converting Enzyme-1 (ECE-1), Angiotensin Converting Enzyme (ACE), and Neutral Endopeptidase (NEP)
摘要:
The formation of vasoconstrictors (e.g., angiotensin II and endothelin) and the inactivation of vasodilators (e.g., bradykinin and atrial natriuretic) by membrane-bound zinc metallopeptidases are key mechanisms in the control of blood pressure and fluid homeostasis. The way in which these peptides modulate physiological functions has been intensively studied. With the aim to develop compounds that can jointly block the three metallopeptidases-neutral endopeptidase (NEP, neprilysin), angiotensin-converting enzyme (ACE), and endothelin-converting enzyme (ECE-1)-we studied the common structural specificity of the S-1' subsites of these peptidases. Various mercaptoacyl amino acids of the general formula HS-CH2-CH(R-1')CO-Trp-OH, possessing more or less constrained R-1' side chains, were designed. The mercapto-acyl synthons contain one or two asymmetrical centers. The K-i values of the separated stereoisomers of the most efficient inhibitors were used to determine the stereochemical preference of each enzyme. A guideline for the joint inhibition of the three peptidases was obtained with the (2R,3R) isomer of compound 13b. Its K-i values on NEP, ACE, and ECE were 0.7, 43, and 26 nM, respectively.
Indium Chloride Catalyzed Alkylative Rearrangement of Propargylic Acetates Using Alkyl Chlorides, Alcohols, and Acetates: Facile Synthesis of α-Alkyl-α,β-Unsaturated Carbonyl Compounds
作者:Yoshiharu Onishi、Yoshihiro Nishimoto、Makoto Yasuda、Akio Baba
DOI:10.1021/ol500046e
日期:2014.2.21
Indium chloride catalyzed alkylative rearrangement of propargylic acetates into α-alkyl-α,β-unsaturated carbonyl compounds has been achieved. Propargylic acetates functioned as α-acylvinyl anion equivalents to react with carbocations generated from alkyl chlorides. Other alkyl electrophiles such as alcohols and acetates were also applicable.
AN INTERPRETATION OF THE SUBSTITUENT EFFECT IN THE BLAISE REARRANGEMENT IN TERMS OF PI-ORBITALS
作者:Yukio Abe、Tadashi Suehiro
DOI:10.1246/cl.1983.389
日期:1983.3.5
The migratory aptitude of the substituent groups in the Blaise rearrangement can be explained in terms of the pi-electronic properties of the groups in the highest occupied molecular orbitals. The rates of the rearrangement reaction with relation to the substituent groups were also rationally understood based on the energy levels of the molecular orbitals.
Blaise 重排中取代基的迁移能力可以用最高占据分子轨道中基团的 pi 电子特性来解释。基于分子轨道的能级,也可以合理地理解与取代基相关的重排反应速率。