The Analytical Chemistry team has continued to perform the core responsibility of purifying samples with material in the range of milligrams to grams. Major and minor components (< 0.1 percent) have been isolated for additional testing and characterization. The teams automated sample processing protocol allows for dispensing into 1D barcoded vials, Matrix 2D barcoded tubes and/or 96-well plates for efficient tracking, storing and testing. The entire process from receiving the sample to final plating is completed within one week. While the group uses a variety of liquid chromatographs to determine identity and purity, single quadrupole liquid chromatography/mass spectrometry instrumentation is utilized for high-throughput automated analysis. Due to the wide variety of analytes tested, the teams range of analytical detectors includes ultraviolet (UV), mass spectrometry (MS; positive and negative mode), and evaporative light scattering detector and fluorescence (ELSD). Time-of-flight mass spectrometry (TOF/MS) is employed to achieve formula confirmation and identity determination of unknowns. The chemical and enantiomeric purity of chiral compounds is routinely determined within the groups full scale chiral laboratory. Methods development with the chiral chromatography screening protocol involves the utilization of various chiral stationary phases in conjunction with multiple mobile phase conditions. The use of an inline chiral detector allows for the determination of relative optical rotation. Sample purification on a scale of up to hundreds of milligrams is possible. We continued to expand our chiral column collection to meet the increasing demands of collaborators related to the type and quantity of compounds submitted for chiral separation. Furthermore, we are still working with the DPI Informatics group to incorporate vibrational circular dichroism (VCD) spectrometry into our routine workflow as a technique for determining the absolute configuration of isolated chiral compounds. The expansion of DPIs focus beyond small molecules to alternate therapeutic modalities has necessitated an increase in our NMR and MS analytical capabilities through the acquisition and incorporation of more advanced instrumentation and techniques in order to detect, identify, quantify, and validate these new chemical entities. For NMR spectroscopy, this has involved the use of Residual Dipolar Coupling (RDC) and Residual Chemical Shift Anisotropy (RCSA) analysis in the determination of structural configuration and conformation. Also, peptides are being explored as highly specific and potent enzyme inhibitors and we have begun NMR analysis of these more complex structures. For mass spectrometry, we have purchased state-of-the-art instrumentation that will aid in high-throughput MS sample analysis. The Orbitrap Fusion Lumos MS system will enable us to perform top-down proteomics including post-translational modification analysis. This will be of great use for TRNDs newly established antibody-drug conjugate (ADC) screening platform, as well as many other projects requiring intact protein analysis. The Rapiflex MALDI system, which involves a collaborative effort between Biology, Automation, and Analytical Chemistry is central to DPIs imaging mass spectrometry (IMS) initiative. Lastly, drug-drug interactions (DDIs) are a major concern in drug discovery research as most patients are taking several medications concurrently. Since it has been well established that cytochrome P450 inhibition can be a major cause for DDIs, knowing a drug candidates CYP450 inhibition potential is of great interest. As such, a collaboration with the DMPK group was started to develop a high-throughput RapidFire-MS/MS assay for cytochrome P450 inhibition studies in support of NCATS drug discovery research. The Sample Management and Resource Tracking (SMART) system, our proprietary LIMS, continues to be utilized at DPI for sample submission, compound purification, compound processing, sample registration, compound inventory, sample tracking, data retrieval, and data management. As SMART is constantly evolving based on changing workflows and scientist needs, we have add required functionality while also streamlining user interfaces and the underlying scripting, which has led to a more robust and efficient system. We have continued our efforts of migrating SMART to a unified platform. Working with NCATS OIT, we have redesigned the user interface to provide users with a streamlined dashboard for comprehensive access to all project related data. Additionally, the SMART Consumables, Acquisitions, and Reagent Tracker (SmartCART) has been successfully transitioned to the unified platform. The higher level of integration coupled with expanded functionality has allowed SmartCART to move closer to becoming NCATSs primary system for the requisition, organization, and management of scientific related orders. The upgraded ordering system has been rolled out to DPIs current users with intended expansion to all NCATS in 6 months.
| Liu, Li; Tang, Manshu; Walsh, Martin J et al. (2015) Structure activity relationships of human galactokinase inhibitors. Bioorg Med Chem Lett 25:721-7 |
