In 2010,Zheng, Xiaowan; Pan, Yongmei; Acharya, Chayan; Swaan, Peter W.; Polli, James E. published 《Structural Requirements of the ASBT by 3D-QSAR Analysis Using Aminopyridine Conjugates of Chenodeoxycholic Acid》.Bioconjugate Chemistry published the findings.Category: pyridine-derivatives The information in the text is summarized as follows:
The human apical sodium-dependent bile acid transporter (ASBT) is a validated drug target and can be employed to increase oral bioavailability of various drug conjugates. The aim of the present study was to investigate the chem. space around the 24-position of bile acids that influences both inhibition and uptake by the transporter. A series of 27 aminopyridine and aminophenol conjugates of glutamyl-chenodeoxycholate were synthesized and their ASBT inhibition and transport kinetics (parametrized as Ki, Kt, and Jmax) measured using stably transfected ASBT-MDCK cells. All conjugates were potent ASBT inhibitors. Monoanionic conjugates exhibited higher inhibition potency than neutral conjugates. However, neutral conjugates and chloro-substituted monoanionic conjugates were not substrates, or at least not apparent substrates. Kinetic anal. of substrates indicated that similar values for Ki and Kt implicate substrate binding to ASBT as the rate-limiting step. Using 3D-QSAR, four inhibition models and one transport efficiency model were developed. Steric fields dominated in CoMFA models, whereas hydrophobic fields dominated CoMSIA models. The inhibition models showed that a hydrophobic or bulky substitute on the 2 or 6 position of a 3-aminopyridine ring enhanced activity, while a hydrophobic group on the 5 position was detrimental. Overall, steric and hydrophobic features around the 24 position of the sterol nucleus strongly influenced bile acid conjugate interaction with ASBT. The relative location of the pyridine nitrogen and substituent groups also modulated binding. In addition to this study using 6-Bromopyridin-3-amine, there are many other studies that have used 6-Bromopyridin-3-amine(cas: 13534-97-9Category: pyridine-derivatives) was used in this study.
6-Bromopyridin-3-amine(cas: 13534-97-9) belongs to anime. Hydrogen peroxide (H2O2) and peroxy acids generally add an oxygen atom to the nitrogen of amines. With primary amines, this step is normally followed by further oxidation, leading to nitroso compounds, RNO, or nitro compounds, RNO2. Secondary amines are converted to hydroxylamines, R2NOH, and tertiary amines to amine oxides, R3NO.Category: pyridine-derivatives