Regio- and Stereocontrol Elements in Rh(II)-Catalyzed Intramolecular C−H Insertion of α-Diazo-α-(phenylsulfonyl)acetamides
作者:Cheol Hwan Yoon、Michael J. Zaworotko、Brian Moulton、Kyung Woon Jung
DOI:10.1021/ol016647l
日期:2001.11.1
see text]. Intramolecular C-H insertion reaction of alpha-diazo-alpha-(phenylsulfonyl)acetamides proceeded with high regio- and stereoselectivities to afford highly functionalized gamma-lactams predominantly or exclusively. The high regioselectivity was attributed to the use of the phenylsulfonyl moiety, which altered electron density at the carbenoid center and exerted a steric effect during the insertion
antibacterial effect against clinical methicillin-resistantStaphylococcusaureus (MRSA) isolates (MICs: 1–2 μg/mL) but also had the advantages of rapid bactericidal properties, low toxicity, good plasma stability, and not readily inducing bacterial resistance. Mechanistic studies indicated that IV15 has good membrane-targeting ability and can bind to phosphatidylglycerol and cardiolipin in bacterial membranes
Methicillin-resistant (MRSA) is a widespread pathogen causing clinical infections and is multi-resistant to many antibiotics, making it urgent need to develop novelantibacterials to combat MRSA. Herein, we designed and prepared a series of novel osthole amphiphiles − by mimicking the structures and function of antimicrobial peptides (AMPs). Antibacterial assays showed that osthole amphiphile strongly
作者:Martin Winn、Thomas W. von Geldern、Terry J. Opgenorth、Hwan-Soo Jae、Andrew S. Tasker、Steven A. Boyd、Jeffrey A. Kester、Robert A. Mantei、Radhika Bal、Bryan K. Sorensen、Jinshyun R. Wu-Wong、William J. Chiou、Douglas B. Dixon、Eugene I. Novosad、Lisa Hernandez、Kennan C. Marsh
DOI:10.1021/jm9505369
日期:1996.1.1
We have discovered a novel class of endothelin (ET) receptor antagonists through pharmacophore analysis of the existing non-peptide ET antagonists. On the basis of this analysis, we determined that a pyrrolidine ring might replace the indan ring in SE 209670. The resultant compounds were readily prepared and amenable to extensive SAR studies. Thus a series of N-substituted trans,trans-2-(4-methoxyphenyl)-4-(1,3-benzodioxol-5-yl) pyrrolidine-3-carboxylic acids (8) have been synthesized and evaluated for binding at ET(A) and ET(B) receptors. Compounds with N-acyl and simple N-alkyl substituents had weak activity. Compounds with N-alkyl substituents containing ethers, sulfoxides, or sulfones showed increased activity. Much improved activity resulted from compounds where the N-substituents were acetamides. Compound 17u (A-127722) with the N,N-dibutylacetamide substituent is the best of the series. It has an IC50 = 0.36 nM for inhibition of ET-1 radioligand binding at the ETA(A) receptor, with a 1000-fold selectivity for the ET(A) vs the ET(B) receptor. It is also a potent inhibitor (IC50 = 0.16 nM) of phosphoinositol hydrolysis stimulated by ET-1, and it antagonized the ET-l-induced contraction of the rabbit aorta with a pA(2) = 9.20. The compound has 70% oral bioavailability in rats.