1
|
Rahman M, Dannatt HRW, Blundell CD, Hughes LP, Blade H, Carson J, Tatman BP, Johnston ST, Brown SP. Polymorph Identification for Flexible Molecules: Linear Regression Analysis of Experimental and Calculated Solution- and Solid-State NMR Data. J Phys Chem A 2024; 128:1793-1816. [PMID: 38427685 PMCID: PMC10945485 DOI: 10.1021/acs.jpca.3c07732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 03/03/2024]
Abstract
The Δδ regression approach of Blade et al. [ J. Phys. Chem. A 2020, 124(43), 8959-8977] for accurately discriminating between solid forms using a combination of experimental solution- and solid-state NMR data with density functional theory (DFT) calculation is here extended to molecules with multiple conformational degrees of freedom, using furosemide polymorphs as an exemplar. As before, the differences in measured 1H and 13C chemical shifts between solution-state NMR and solid-state magic-angle spinning (MAS) NMR (Δδexperimental) are compared to those determined by gauge-including projector augmented wave (GIPAW) calculations (Δδcalculated) by regression analysis and a t-test, allowing the correct furosemide polymorph to be precisely identified. Monte Carlo random sampling is used to calculate solution-state NMR chemical shifts, reducing computation times by avoiding the need to systematically sample the multidimensional conformational landscape that furosemide occupies in solution. The solvent conditions should be chosen to match the molecule's charge state between the solution and solid states. The Δδ regression approach indicates whether or not correlations between Δδexperimental and Δδcalculated are statistically significant; the approach is differently sensitive to the popular root mean squared error (RMSE) method, being shown to exhibit a much greater dynamic range. An alternative method for estimating solution-state NMR chemical shifts by approximating the measured solution-state dynamic 3D behavior with an ensemble of 54 furosemide crystal structures (polymorphs and cocrystals) from the Cambridge Structural Database (CSD) was also successful in this case, suggesting new avenues for this method that may overcome its current dependency on the prior determination of solution dynamic 3D structures.
Collapse
Affiliation(s)
- Mohammed Rahman
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | | | | | - Leslie P. Hughes
- Oral
Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield SK10 2NA, U.K.
| | - Helen Blade
- Oral
Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield SK10 2NA, U.K.
| | - Jake Carson
- Mathematics
Institute at Warwick, University of Warwick, Coventry CV4 7AL, U.K.
| | - Ben P. Tatman
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | | | - Steven P. Brown
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
| |
Collapse
|
2
|
Szell PMJ, Rehman Z, Tatman BP, Hughes LP, Blade H, Brown SP. Exploring the Potential of Multinuclear Solid-State 1 H, 13 C, and 35 Cl Magnetic Resonance To Characterize Static and Dynamic Disorder in Pharmaceutical Hydrochlorides. Chemphyschem 2023; 24:e202200558. [PMID: 36195553 PMCID: PMC10099218 DOI: 10.1002/cphc.202200558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/30/2022] [Indexed: 02/04/2023]
Abstract
Crystallographic disorder, whether static or dynamic, can be detrimental to the physical and chemical stability, ease of crystallization and dissolution rate of an active pharmaceutical ingredient. Disorder can result in a loss of manufacturing control leading to batch-to-batch variability and can lengthen the process of structural characterization. The range of NMR active nuclei makes solid-state NMR a unique technique for gaining nucleus-specific information about crystallographic disorder. Here, we explore the use of high-field 35 Cl solid-state NMR at 23.5 T to characterize both static and dynamic crystallographic disorder: specifically, dynamic disorder occurring in duloxetine hydrochloride (1), static disorder in promethazine hydrochloride (2), and trifluoperazine dihydrochloride (3). In all structures, the presence of crystallographic disorder was confirmed by 13 C cross-polarization magic-angle spinning (CPMAS) NMR and supported by GIPAW-DFT calculations, and in the case of 3, 1 H solid-state NMR provided additional confirmation. Applying 35 Cl solid-state NMR to these compounds, we show that higher magnetic fields are beneficial for resolving the crystallographic disorder in 1 and 3, while broad spectral features were observed in 2 even at higher fields. Combining the data obtained from 1 H, 13 C, and 35 Cl NMR, we show that 3 exhibits a unique case of disorder involving the + N-H hydrogen positions of the piperazinium ring, driving the chloride anions to occupy three distinct sites.
Collapse
Affiliation(s)
| | - Zainab Rehman
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - Ben P Tatman
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - Leslie P Hughes
- Oral Product Development Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, SK10 2NA, UK
| | - Helen Blade
- Oral Product Development Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, SK10 2NA, UK
| | - Steven P Brown
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| |
Collapse
|
3
|
Khalaji M, Paluch P, Potrzebowski MJ, Dudek MK. Narrowing down the conformational space with solid-state NMR in crystal structure prediction of linezolid cocrystals. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2022; 121:101813. [PMID: 35964358 DOI: 10.1016/j.ssnmr.2022.101813] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 07/28/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
Many solids crystallize as microcrystalline powders, thus precluding the application of single crystal X-Ray diffraction in structural elucidation. In such cases, a joint use of high-resolution solid-state NMR and crystal structure prediction (CSP) calculations can be successful. However, for molecules showing significant conformational freedom, the CSP-NMR protocol can meet serious obstacles, including ambiguities in NMR signal assignment and too wide conformational search space to be covered by computational methods in reasonable time. Here, we demonstrate a possible way of avoiding these obstacles and making as much use of the two methods as possible in difficult circumstances. In a simple case, our experiments led to crystal structure elucidation of a cocrystal of linezolid (LIN), a wide-range antibiotic, with 2,3-dihydroxybenzoic acid, while a significantly more challenging case of a cocrystal of LIN with 2,4-dihydroxybenzoic acid led to the identification of the most probable conformations of LIN inside the crystal. Having four rotatable bonds, some of which can assume many discreet values, LIN molecule poses a challenge in establishing its conformation in a solid phase. In our work, a set of 27 conformations were used in CSP calculations to yield model crystal structures to be examined against experimental solid-state NMR data, leading to a reliable identification of the most probable molecular arrangements.
Collapse
Affiliation(s)
- Mehrnaz Khalaji
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, Lodz, 90-363, Poland
| | - Piotr Paluch
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, Lodz, 90-363, Poland
| | - Marek J Potrzebowski
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, Lodz, 90-363, Poland
| | - Marta K Dudek
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, Lodz, 90-363, Poland.
| |
Collapse
|
4
|
Al-Ani A, Szell PMJ, Rehman Z, Blade H, Wheatcroft HP, Hughes LP, Brown SP, Wilson CC. Combining X-ray and NMR Crystallography to Explore the Crystallographic Disorder in Salbutamol Oxalate. CRYSTAL GROWTH & DESIGN 2022; 22:4696-4707. [PMID: 35971412 PMCID: PMC9374327 DOI: 10.1021/acs.cgd.1c01093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Salbutamol is an active pharmaceutical ingredient commonly used to treat respiratory distress and is listed by the World Health Organization as an essential medicine. Here, we establish the crystal structure of its oxalate form, salbutamol oxalate, and explore the nature of its crystallographic disorder by combined X-ray crystallography and 13C cross-polarization (CP) magic-angle spinning (MAS) solid-state NMR. The *C-OH chiral center of salbutamol (note that the crystal structures are a racemic mixture of the two enantiomers of salbutamol) is disordered over two positions, and the tert-butyl group is rotating rapidly, as revealed by 13C solid-state NMR. The impact of crystallization conditions on the disorder was investigated, finding variations in the occupancy ratio of the *C-OH chiral center between single crystals and a consistency across samples in the bulk powder. Overall, this work highlights the contrast between investigating crystallographic disorder by X-ray diffraction and solid-state NMR experiment, and gauge-including projector-augmented-wave (GIPAW) density functional theory (DFT) calculations, with their combined use, yielding an improved understanding of the nature of the crystallographic disorder between the local (i.e., as viewed by NMR) and longer-range periodic (i.e., as viewed by diffraction) scale.
Collapse
Affiliation(s)
- Aneesa
J. Al-Ani
- Centre
for Sustainable and Circular Technologies (CSCT), University of Bath, Claverton Down, Bath BA2
7AY, U.K.
| | | | - Zainab Rehman
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
| | - Helen Blade
- Oral
Product Development, Pharmaceutical Technology & Development,
Operations, AstraZeneca, Macclesfield SK10 2NA, U.K.
| | - Helen P. Wheatcroft
- Chemical
Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield SK10 2NA, U.K.
| | - Leslie P. Hughes
- Oral
Product Development, Pharmaceutical Technology & Development,
Operations, AstraZeneca, Macclesfield SK10 2NA, U.K.
| | - Steven P. Brown
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
| | - Chick C. Wilson
- Centre
for Sustainable and Circular Technologies (CSCT), University of Bath, Claverton Down, Bath BA2
7AY, U.K.
| |
Collapse
|
5
|
Tunable synthesis of furfurylamines or β-amino alcohols via Ru-catalyzed N–H functionalization using biomass-derived polyols. GREEN SYNTHESIS AND CATALYSIS 2022. [DOI: 10.1016/j.gresc.2022.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
6
|
Szell PMJ, Nilsson Lill SO, Blade H, Brown SP, Hughes LP. A toolbox for improving the workflow of NMR crystallography. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2021; 116:101761. [PMID: 34736104 DOI: 10.1016/j.ssnmr.2021.101761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 06/13/2023]
Abstract
NMR crystallography is a powerful tool with applications in structural characterization and crystal structure verification, to name two. However, applying this tool presents several challenges, especially for industrial users, in terms of consistency, workflow, time consumption, and the requirement for a high level of understanding of experimental solid-state NMR and GIPAW-DFT calculations. Here, we have developed a series of fully parameterized scripts for use in Materials Studio and TopSpin, based on the .magres file format, with a focus on organic molecules (e.g. pharmaceuticals), improving efficiency, robustness, and workflow. We separate these tools into three major categories: performing the DFT calculations, extracting & visualizing the results, and crystallographic modelling. These scripts will rapidly submit fully parameterized CASTEP jobs, extract data from the calculations, assist in visualizing the results, and expedite the process of structural modelling. Accompanied with these tools is a description on their functionality, documentation on how to get started and use the scripts, and links to video tutorials for guiding new users. Through the use of these tools, we hope to facilitate NMR crystallography and to harmonize the process across users.
Collapse
Affiliation(s)
| | - Sten O Nilsson Lill
- Early Product Development and Manufacturing, Pharmaceutical Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Helen Blade
- Oral Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, UK
| | - Steven P Brown
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK.
| | - Leslie P Hughes
- Oral Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, UK.
| |
Collapse
|