Ion mobility-mass spectrometry analysis of diarylquinoline diastereomers: Drugs used for tuberculosis treatment.

Mycobacterium tuberculosis infection results in more than two million deaths per year and is the leading cause of mortality in people infected with HIV. A new structural class of antimycobacterials, the diarylquinolines, has been synthesized and is being highly effective against both M. tuberculosis and multidrug-resistant tuberculosis. As diarylquinolines are biologically active only under their ( R,S) stereoisomeric form, it is essential to differentiate the stereoisomers ( R,S) and ( R,R). To achieve this, tandem mass spectrometry and ion mobility spectrometry-mass spectrometry have been performed with 10 diarylquinoline diastereomers couples. In this study, we investigated cationization with alkali metal cations and several ion mobility drift gases in order to obtain diastereomer differentiations. We have shown that diastereomers of the diarylquinolines family can be differentiated separately by tandem mass spectrometry and in mixture by ion mobility spectrometry-mass spectrometry. However, although the structure of each diastereomer is close, several behaviors could be observed concerning the cationization and the ion mobility spectrometry separation. The ion mobility spectrometry isomer separation efficiency is not easily predictable; it was however observed for all diastereomeric couples with a significant improvement of separation using alkali adducts compared to protonated molecules. With the use of drift gas with higher polarizability only an improvement of separation was obtained in a few cases. Finally, a good correlation of the experimental collision cross section (relative to three-dimensional structure of ions) and the theoretical collision cross section has been shown.

Minisci-Photoredox-Mediated α-Heteroarylation of N-Protected Secondary Amines: Remarkable Selectivity of Azetidines.

The development of a general, mild, and functional-group-tolerant direct functionalization of N-heteroarenes by C-H functionalization with N-protected amines, including azetidines under Minisci-mediated photoredox conditions, is reported. A broad scope of substituted azetidines, including spirocyclic derivatives, and heterocycles were explored. This reaction enables the production of sp3-rich complex druglike structures in one step from unactivated feedstock amines and heterocycles.

Synthesis and evaluation of analogues of the tuberculosis drug bedaquiline containing heterocyclic B-ring units.

Analogues of bedaquiline where the phenyl B-unit was replaced with monocyclic heterocycles of widely differing lipophilicity (thiophenes, furans, pyridines) were synthesised and evaluated. While there was an expected broad positive correlation between lipophilicity and anti-TB activity, the 4-pyridyl derivatives appeared to have an additional contribution to antibacterial potency. The majority of the compounds were (desirably) more polar and had higher rates of clearance than bedaquiline, and showed acceptable oral bioavailability, but there was only limited (and unpredictable) improvement in their hERG liability.

Identification of a series of substituted 2-piperazinyl-5-pyrimidylhydroxamic acids as potent histone deacetylase inhibitors.

Pursuing our efforts in designing 5-pyrimidylhydroxamic acid anti-cancer agents, we have identified a new series of potent histone deacetylase (HDAC) inhibitors. These compounds exhibit enzymatic HDAC inhibiting properties with IC(50) values in the nanomolar range and inhibit tumor cell proliferation at similar levels. Good solubility, moderate bioavailability, and promising in vivo activity in xenograft model made this series of compounds interesting starting points to design new potent HDAC inhibitors.

Synthesis and biological evaluation of C-5 methyl substituted 4-arylthio and 4-aryloxy-3-Iodopyridin-2(1H)-one type anti-HIV agents.

A series of C-5 methyl substituted 4-arylthio- and 4-aryloxy-3-iodopyridin-2(1H)-ones has been synthesized as new pyridinone analogues for their evaluation as anti-HIV inhibitors. The optimization at the 5-position was developed through an efficient use of the key intermediates 5-ethoxycarbonyl- and 5-cyano-pyridin-2(1H)-ones (14 and 15). Biological studies revealed that several compounds show potent HIV-1 reverse transcriptase inhibitory properties, for example, compounds 93 and 99 are active at 0.6-50 nM against wild type HIV-1 and a panel of major simple/double HIV mutant strains.

Selection of a respiratory syncytial virus fusion inhibitor clinical candidate. 2. Discovery of a morpholinopropylaminobenzimidazole derivative (TMC353121).

A preceding paper (Bonfanti et al. J. Med Chem. 2007, 50, 4572-4584) reported the optimization of the pharmacokinetic profile of substituted benzimidazoles by reducing their tissue retention. However, the modifications that were necessary to achieve this goal also led to a significant drop in anti-RSV activity. This paper describes a molecular modeling study followed by a lead optimization program that led to the recovery of the initial potent antiviral activity and the selection of TMC353121 as a clinical candidate.

Selection of a respiratory syncytial virus fusion inhibitor clinical candidate, part 1: improving the pharmacokinetic profile using the structure-property relationship.

We previously reported the discovery of substituted benzimidazole fusion inhibitors with nanomolar activity against respiratory syncytial virus (Andries, K.; et al. Antiviral Res. 2003, 60, 209-219). A lead compound of the series was selected for preclinical evaluation. This drug candidate, JNJ-2408068 (formerly R170591, 1), showed long tissue retention times in several species (rat, dog, and monkey), creating cause for concern. We herein describe the optimization program to develop compounds with improved properties in terms of tissue retention. We have identified the aminoethyl-piperidine moiety as being responsible for the long tissue retention time of 1. We have investigated the replacement or the modification of this group, and we suggest that the pKa of this part of the molecules influences both the antiviral activity and the pharmacokinetic profile. We were able to identify new respiratory syncytial virus inhibitors with shorter half-lives in lung tissue.

Synthesis of novel diarylpyrimidine analogues of TMC278 and their antiviral activity against HIV-1 wild-type and mutant strains.

Novel diarylpyrimidines (DAPY), which represent next generation of non-nucleoside reverse transcriptase inhibitors (NNRTIs), were synthesized and their activities against human immunodeficiency virus type I (HIV-1) assessed. Modulations at positions 2 and 6 of the left phenyl ring generated interesting derivatives of TMC278 displaying high potency against wild-type and mutant viruses compared to nevirapine and efavirenz. The pharmacokinetic profile of the best newly synthesized DAPY was evaluated and compared with TMC278 now in phase II clinical trials.

Discovery of pyrimidyl-5-hydroxamic acids as new potent histone deacetylase inhibitors.

A series of pyrimidyl-5-hydroxamic acids was prepared for evaluation as inhibitors of histone deacetylase (HDAC). Amino-2-pyrimidinyl can be used as a linker to provide HDAC inhibitors of good enzymatic potency.