Systematic optimization of targeted and multiplexed MS-based screening workflows for protein biomarkers.

The capability of targeted MS-based methods to simultaneously measure multiple analytes with high selectivity and sensitivity greatly facilitates the discovery and quantitation of novel biomarkers. However, the complexity of biological samples is a major bottleneck that requires extensive sample preparation. This paper reports a generic workflow to optimize surrogate peptide-based protein biomarker screening for seven human proteins in a multiplexed manner without the need for any specific affinity reagents.

Intact mAb LC-MS for drug concentration from pre-clinical studies: bioanalytical method performance and in-life samples.

Antibody biotherapeutic measurement from pharmacokinetic studies has not been traditionally based on intact molecular mass as is the case for small molecules. However, recent advancements in protein capture and mass spectrometer technology have enabled intact mass detection and quantitation for dosed biotherapeutics. A bioanalytical method validation is part of the regulatory requirement for sample analysis to determine drug concentration from in-life study samples.

Microflow UPLC and high-resolution MS as a sensitive and robust platform for quantitation of intact peptide hormones.

Recent advances in microflow ultra performance liquid chromatography (UPLC) systems offer higher sensitivity with robustness to meet the routine bioanalytical demands. Modern high-resolution mass spectrometers (HRMS) enable the development of highly selective methods with broad dynamic range. The quantitative performances of tandem quadrupole MS and HRMS were comprehensively compared using seven intact peptide hormones up to 9.

An HS-MRM Assay for the Quantification of Host-cell Proteins in Protein Biopharmaceuticals by Liquid Chromatography Ion Mobility QTOF Mass Spectrometry.

The analysis of low-level (1-100 ppm) protein impurities (e.g., host-cell proteins (HCPs)) in protein biotherapeutics is a challenging assay requiring high sensitivity and a wide dynamic range.

Enantioselective Synthesis and Profiling of Two Novel Diazabicyclooctanone β-Lactamase Inhibitors.

The enantioselective synthesis of two novel cyclopropane-fused diazabicyclooctanones is reported here. Starting from butadiene monoxide, the key enone intermediate 7 was prepared in six steps. Subsequent stereoselective introduction of the cyclopropane group and further transformation led to compounds 1a and 1b as their corresponding sodium salt.

Experimental solubility profiling of marketed CNS drugs, exploring solubility limit of CNS discovery candidate.

We determined the experimental solubility of CNS marketed drugs. Of the 98 drugs measured, greater than 90% had solubility >10 μM in pH 7.4 buffer.

A high throughput dried DMSO LogD lipophilicity measurement based on 96-well shake-flask and atmospheric pressure photoionization mass spectrometry detection.

A rapid throughput octanol-water lipophilicity measurement based on 96-well shake-flask and LC/UV/APPI/MS is described. The method utilizes central liquid storage where compounds are stored as 10 mM solutions in dimethyl sulfoxide (DMSO). The DMSO is subsequently removed to generate solid like material used for LogD measurement.

Application of a Dried-DMSO rapid throughput 24-h equilibrium solubility in advancing discovery candidates.

A rapid throughput equilibrium solubility measurement is described. The method utilizes central liquid storage where compounds are stored as 10mM solution in dimethyl sulfoxide (DMSO). The DMSO is subsequently removed to generate solid like material used for solubility measurement.

Scores of extended connectivity fingerprint as descriptors in QSPR study of melting point and aqueous solubility.

QSPR studies, using scores of SciTegic's extended connectivity fingerprint as raw descriptors, were extended to the prediction of melting points and aqueous solubility of organic compounds. Robust partial least-squares models were developed that perform as well as the best published QSPR models for structurally diverse organic compounds. Satisfactory performance of the QSPR models indicates that the scores of extended connectivity fingerprint are high performance molecular descriptors for QSAR/QSPR studies.

Structural analysis and optimization of NK(1) receptor antagonists through modulation of atropisomer interconversion properties.

We have previously described a series of antagonists that showed high potency and selectivity for the NK(1) receptor. However, these compounds also had the undesirable property of existing as a mixture of interconverting rotational isomers. Here we show that alteration of the 2-naphthyl substituent can modulate the rate of isomer exchange.