Amines That Transport Protons across Bilayer Membranes: Synthesis, Lysosomal Neutralization, and Two-Phase pKa Values by NMR
摘要:
It is desirable to be able to control the pH of lysosomes. A collection of lipophilic, nitrogenous bases, designed to act as membrane-active, catalytic proton transfer agents, were prepared and their effective pK(a)s measured in a vigorously stirred, two-phase system. One phase was a phosphate buffer whose pH was varied over the range ca, 1-11. The other was an immiscible, deuterated organic solvent in which the compounds preferentially resided even when protonated. When chemical shift changes versus the pH of the buffer were plotted, clear pK(a) curves were generated that are relevant to transmembrane proton transfer behavior. The two-phase pK(a)s increased with increasing counterion lipophilicity and with increasing organic solvent polarity, The compounds were also tested for their ability to neutralize the acidity of lysosomes, a model for other acidic vesicles involved in drug sorting. The most successful of these, imidazole 6a, has > 100 times the neutralizing power of ammonia, a standard lysosomotropic amine, causing a 1.7 unit rise in lysosomal pH of RAW cells at 0.1 mM, compared to a 0.2 and 1.4 unit rise for ammonium chloride at 0.1 and 10 mM, respectively.
[EN] ASPARAGINE DERIVATIVES AND METHODS OF USING SAME<br/>[FR] DÉRIVÉS D'ASPARAGINE ET LEURS PROCÉDÉS D'UTILISATION
申请人:SENDA BIOSCIENCES INC
公开号:WO2021252640A1
公开(公告)日:2021-12-16
The present disclosure relates to compounds of formulas (A) and (I), pharmaceutically acceptable salts thereof, and solvates of any of the foregoing, pharmaceutical compositions comprising the same, methods of preparing the same, intermediate compounds useful for preparing the same, and methods for treating or prophylaxis of diseases, in particular cancer, such as colorectal cancer, using the same.
On the use of 3-bromopropyne as a reagent for the introduction of the pyruvate moiety
作者:Chen Chen、David Crich
DOI:10.1039/c39910001289
日期:——
In the presence of metallic zinc 3-bromopropyne reacts with aldehydes to give homopropynylic alcohols which are converted to the corresponding bromohomopropynylic acetates by acetylation followed by reaction with N-bromosuccinimide and a catalytic quantity of silver acetate; these derivatives are then oxidized to γ-acetoxy-α-ketoesters with osmium tetroxide and tert-butyl hydroperoxide resulting in a convenient four step sequence for the introduction of the pyruvate moiety.
Three-component allylation and cyanation utilizing a ketone and an N-methoxyamine are reported. The high nucleophilicity of the N-methoxyamine and high electrophilicity of the corresponding iminium ion enable the concisesynthesis of α-trisubstitutedamines in a single step.
申请人:Unilever Home & Personal Care USA, Division of Conopco, Inc.
公开号:US20030044362A1
公开(公告)日:2003-03-06
A method and cosmetic product for lightening skin is provided, the method including wiping the skin with a cosmetic towelette. Impregnated on the towelette is an alpha-hydroxy carboxylic acid or salt thereof and a sunscreen agent.