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1.
J Biomol Struct Dyn ; : 1-17, 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38511497

ABSTRACT

Type 2 Diabetes Mellitus (T2DM), as a significant health concern globally, particularly in India, underscoring the vital need for effective therapeutics. Current drug therapies for T2DM may have limitations, leading researchers to explore natural products as alternatives. In this study. We have investigated the anti-diabetic compounds from the Costus genus, known as the insulin plant, which is abundant in southern India. The bioinformatics tools and software used for in-silico analysis to identify potential therapeutic compounds and hub genes associated with T2DM in the Indian population that could cut short the in-vitro and in-vivo experimental approaches in near future. The systematic review and combinatorial in-silico analysis revealed IGF2BP2, INS and TCF as the key targets that are associated with T2DM. The compounds stigmasterol, cycloartenol, and diosgenone were explored to be potent among all the 38 phytocompounds from genus Costus with binding energies -8.48, -10.07, and -10.31 kcal/mol against IGF2BP2, INS and TCF. The molecular dynamics (MD) simulation studies of these complexes demonstrated stable and consistent dynamic behavior, particularly in the INS-cycloartenol, IGF2BP2-stigmasterol and TCF7L2-diosgenone complexes. The identified compounds and associated targets represent potential candidates for T2DM therapeutics in the Indian population. The pharmacoinformatics approach presented in the study could streamline the drug discovery process by prioritizing compounds for further experimental validation.Communicated by Ramaswamy H. Sarma.

2.
Biomed Chromatogr ; 38(3): e5813, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38148302

ABSTRACT

The US Food and Drug Administration and the European Medicines Agency approved alpelisib in 2019 for the treatment of metastatic breast cancer. A thorough literature review revealed that a stability-indicating analytical method (SIAM) is not available for the quantification of alpelisib and its degradation products (DPs). In this study, per the comprehensive stress study recommended by the International Council for Harmonisation (ICH), alpelisib was exposed to hydrolysis, oxidation, photolysis, and thermal stress. Degradation of the drug was observed under hydrolysis, oxidative, and photolysis conditions, whereas the drug was stable under thermal stress condition. We developed a SIAM for the separation of alpelisib and its major DPs that were formed under different stress conditions. The validation of the developed method was performed per ICH Q2(R1) guidelines. Five DPs were identified and characterized. Structure elucidation of all DPs was performed with the modern characterization tool of liquid chromatography-quadrupole time-of-flight mass spectrometer (LC-Q-TOF-MS/MS). The degradation pathway of the drug and its mechanisms were outlined, and in silico toxicity prediction was performed using the ProTox-II tool.


Subject(s)
Tandem Mass Spectrometry , Thiazoles , Tandem Mass Spectrometry/methods , Chromatography, High Pressure Liquid/methods , Drug Stability , Chromatography, Liquid/methods , Hydrolysis , Oxidation-Reduction , Photolysis
3.
Anal Methods ; 15(11): 1470-1477, 2023 03 16.
Article in English | MEDLINE | ID: mdl-36876453

ABSTRACT

Determining the purity of deuterium labelled compounds is important due to the increasing use of these compounds in mass spectrometry (MS) based quantitative analyses for targeting metabolic flux, reducing toxicity, confirming reaction mechanisms during synthesis, predicting enzyme mechanisms, and enhancing the efficacy of drugs, in quantitative proteomics, and also as internal standards. In the present study, a strategy using liquid chromatography electrospray ionization high resolution mass spectrometry (LC-ESI-HR-MS) and nuclear magnetic resonance (NMR) spectroscopy was proposed to determine the isotopic enrichment and structural integrity of deuterium labelled compounds. The proposed strategy involves recording full scan MS, extracting and integrating isotopic ions, and calculating the isotopic enrichment of the desired labelled compounds. NMR analysis confirms structural integrity or positions of labelled atoms and can provide insights into the relative percent isotopic purity. This strategy was used to evaluate the isotopic enrichment and structural integrity of in-house synthesized compounds as well as a series of commercially available deuterium labelled compounds. The % isotopic purity for labelled compounds of a benzofuranone derivative (BEN-d2), tamsulosin-d4 (TAM-d4), oxybutynin-d5 (OXY-d5), eplerenone-d3 (EPL-d3), and propafenone-d7 (PRO-d7) was calculated and found to be 94.7, 99.5, 98.8, 99.9, and 96.5, respectively. All the samples were run in triplicate and the results were observed to be reproducible.


Subject(s)
Magnetic Resonance Imaging , Spectrometry, Mass, Electrospray Ionization , Deuterium/chemistry , Magnetic Resonance Spectroscopy , Chromatography, Liquid/methods
4.
J Pharm Biomed Anal ; 212: 114675, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-35192992

ABSTRACT

Due to emergence of drug resistance and drug tolerability, there is urgent need for discovery of new chemical entity for the treatment of HIV infection. As a part of in-house small molecule drug discovery program for HIV infection, sodium-2-(tert-butoxy)- 2-(5-(2-(2-chloro-6-methylbenzyl)- 1,2,3,4-tetrahydroisoquinolin-6-yl)- 4-(4,4-dimethylpiperidin-1-yl)- 2,6-dimethylpyridin-3-yl) acetate (SCMTDDA) was prepared as an intermediate for the synthesis of an API, designed as a HIV-1 integrase inhibitor. Initially, the final compound was isolated as a mixture of rotamers. In the current study, we have developed a simple and efficient achiral, reversed phase (RP) HPLC method to separate the interconvertible rotamers of SCMTDDA. The effect of several parameters, including stationary phase, buffer, modifiers and column temperature, were optimized for the chromatographic separation and it was observed that best separation was achieved on a SunFire C18 column using TFA/acetonitrile (ACN) - methanol (MeOH) (1:1 v/v) as the mobile phase at 10 0C. The chromatographic observations were complemented with variable-temperature NMR and energy barrier calculations using density functional theory (DFT).


Subject(s)
Acetic Acid , HIV Infections , Chromatography, High Pressure Liquid/methods , Humans , Methanol/chemistry , Temperature
5.
Cancers (Basel) ; 13(24)2021 Dec 09.
Article in English | MEDLINE | ID: mdl-34944824

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy wherein a majority of patients present metastatic disease at diagnosis. Although the role of epithelial to mesenchymal transition (EMT), mediated by transforming growth factor beta (TGFß), in imparting an aggressive phenotype to PDAC is well documented, the underlying biochemical pathway perturbations driving this behaviour have not been elucidated. We used high-resolution mass spectrometry (HRMS) based molecular phenotyping approach in order to delineate metabolic changes concomitant to TGFß-induced EMT in pancreatic cancer cells. Strikingly, we observed robust changes in amino acid and energy metabolism that may contribute to tumor invasion and metastasis. Somewhat unexpectedly, TGFß treatment resulted in an increase in intracellular levels of retinoic acid (RA) that in turn resulted in increased levels of extracellular matrix (ECM) proteins including fibronectin (FN) and collagen (COL1). These findings were further validated in plasma samples obtained from patients with resectable pancreatic cancer. Taken together, these observations provide novel insights into small molecule dysregulation that triggers a molecular cascade resulting in increased EMT-like changes in pancreatic cancer cells, a paradigm that can be potentially targeted for better clinical outcomes.

6.
Rapid Commun Mass Spectrom ; 35(19): e9161, 2021 Oct 15.
Article in English | MEDLINE | ID: mdl-34240514

ABSTRACT

RATIONALE: Characterization of N,N'-substituted ureas was found to be challenging by nuclear magnetic resonance (NMR) spectroscopy, particularly N-di- and tri-alkylated ureas because of the absence of adjacent protons. In the present study, electrospray ionization tandem mass spectrometry has been used to differentiate positional isomeric pairs and to characterize a series of N,N'-substituted ureas, as these compounds have significant importance for drug discovery. Additionally, urea is an essential functionality in several bioactive compounds as well as a variety of clinically approved therapies. METHODS: High-resolution electrospray ionization tandem mass spectrometry (ESI-HR-MS/MS) has been used to characterize a series of N,N'-substituted urea derivatives and differentiate two pairs of positional isomers. The data was acquired by Xcaliber application in positive ionization mode. RESULTS: ESI-HR-MS/MS spectra of [M + H]+ ions of the positional isomeric urea derivatives 8a and 8b show distinct fragmentation patterns. For example, the MS/MS spectrum of the [M + H]+ ion of isomer 8a displays the abundant fragment ion at m/z 285.1595, which was totally absent in isomer 8b. This would be plausibly formed by the cleavage of the C-N bond of the urea group with the elimination of the isocyanate moiety. In contrast, the MS/MS spectrum of the [M + H]+ ion of isomer 8b shows an intense ion at m/z 311.1389 which is completely absent in isomer 8a which would be formed by the cleavage of the C-N bond attached to the ring nitrogen. Similarly, another pair of positional isomers, 8c and 8d, have been clearly distinguished by their fragmentation behaviour. In addition, a series of N,N'-substituted urea derivatives were studied to investigate the impact of different substitution on the fragmentation behaviour. CONCLUSIONS: The present study demonstrates that ESI-HR-MS/MS can be used to differentiate pairs of N,N'-substituted urea positional isomers and characterize a series of derivatives. It was observed that a characteristic fragment ion was formed by the C-N bond cleavage with the elimination of an isocyanate moiety. The proposed mechanism of fragmentation was supported by the change in the fragmentation pathway upon alkylation of the NH. In order to generalize this fragmentation pattern, a series of N-alkylated ureas was synthesized and studied by MS/MS.

7.
J Chromatogr A ; 1531: 122-130, 2018 Jan 05.
Article in English | MEDLINE | ID: mdl-29174572

ABSTRACT

Analysis and purification of boronic acid pinacol esters by RPLC is very challenging due to their degradation in aqueous and alcoholic solvents. These compounds are difficult to purify by SFC too as they are equally sensitive to traditional co-solvents like methanol, ethanol, and 2-propanol. 2,2,2 trifluoroethanol (TFE), which has been reported for the purification of a few alcohol sensitive compounds, was evaluated as a co-solvent in this study for the purification of chiral and achiral boronate esters by SFC. Examples of twelve compounds were presented in this paper where degradation of boronic acid pinacol esters was successfully controlled by replacing methanol with TFE as the co-solvent in SFC. A separate study showed that TFE can also control the epimerization of the enantiomers of 3 substituted 1,4 benzodiazepine analogues during the purification process. In addition to above benefits, 2,2,2trifloroethanol showed improved selectivity and resolution for most of the compounds. With its stronger solvent strength compared to other alcohols, TFE could also be used to reduce the co-solvent percentage needed for elution and to shorten retention time of highly polar samples which did not elute even in 50% of other co-solvents in SFC. A case study of compound B demonstrated that TFE provided a reduced co-solvent percentage and a shorter cycle time with much improved resolution as compared to methanol, thus resulting in higher loading and throughput with reduction of total solvent consumption.


Subject(s)
Boronic Acids/chemistry , Chromatography, Supercritical Fluid/methods , Esters/isolation & purification , Solvents/chemistry , Trifluoroethanol/chemistry , Esters/chemistry , Methanol/chemistry , Stereoisomerism
8.
Drug Metab Dispos ; 45(12): 1215-1224, 2017 12.
Article in English | MEDLINE | ID: mdl-28935657

ABSTRACT

Metabolites of new chemical entities can influence safety and efficacy of a molecule and often times need to be quantified in preclinical studies. However, synthetic standards of metabolites are very rarely available in early discovery. Alternate approaches such as biosynthesis need to be explored to generate these metabolites. Assessing the quantity and purity of these small amounts of metabolites with a nondestructive analytical procedure becomes crucial. Quantitative NMR becomes the method of choice for these samples. Recent advances in high-field NMR (>500 MHz) with the use of cryoprobe technology have helped to improve sensitivity for analysis of small microgram quantity of such samples. However, this type of NMR instrumentation is not routinely available in all laboratories. To analyze microgram quantities of metabolites on a routine basis with lower-resolution 400 MHz NMR instrument fitted with a broad band fluorine observe room temperature probe, a novel hybrid capillary tube setup was developed. To quantitate the metabolite in the sample, an artificial signal insertion for calculation of concentration observed (aSICCO) method that introduces an internally calibrated mathematical signal was used after acquiring the NMR spectrum. The linearity of aSICCO signal was established using ibuprofen as a model analyte. The limit of quantification of this procedure was 0.8 mM with 10 K scans that could be improved further with the increase in the number of scans. This procedure was used to quantify three metabolites-phenytoin from fosphenytoin, dextrophan from dextromethorphan, and 4-OH-diclofenac from diclofenac-and is suitable for minibiosynthesis of metabolites from in vitro systems.


Subject(s)
Capillary Tubing , Magnetic Resonance Spectroscopy/instrumentation , Anti-Inflammatory Agents, Non-Steroidal/analysis , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Calibration , Chromatography, High Pressure Liquid , Dextrorphan/analysis , Ibuprofen/analysis , Ibuprofen/pharmacokinetics , Magnetic Resonance Spectroscopy/methods , Phenytoin/analysis , Reference Standards , Solvents , Tandem Mass Spectrometry , Temperature
9.
J Proteome Res ; 16(10): 3805-3815, 2017 10 06.
Article in English | MEDLINE | ID: mdl-28825479

ABSTRACT

The potential for radiological accidents and nuclear terrorism has increased the need for the development of new rapid biodosimetry methods. In addition, in a clinical setting the issue of an individual's radiosensitivity should be taken into consideration during radiotherapy. We utilized metabolomics and lipidomics to investigate changes of metabolites in serum samples following exposure to total body ionizing radiation in humans. Serum was collected prior to irradiation, at 3-8 h after a single dose of 1.25-2 Gy, and at 24 h with a total delivered dose of 2-3.75 Gy. Metabolomics revealed perturbations in glycerophosphocholine, phenylalanine, ubiquinone Q2, and oxalic acid. Alterations were observed in circulating levels of lipids from monoacylglycerol, triacylglycerol, phosphatidylcholine, and phosphatidylglycerol lipid classes. Polyunsaturated fatty acids were some of the most dysregulated lipids, with increased levels linked to proinflammatory processes. A targeted metabolomics approach for eicosanoids was also employed. The results showed a rapid response for proinflammatory eicosanoids, with a dampening of the signal at the later time point. Sex differences were observed in the markers from the untargeted approach but not the targeted method. The ability to identify and quantify small molecules in blood can therefore be utilized to monitor radiation exposure in human populations.


Subject(s)
Inflammation/blood , Lipids/blood , Metabolome/genetics , Whole-Body Irradiation/adverse effects , Biomarkers/blood , Dose-Response Relationship, Radiation , Eicosanoids/blood , Eicosanoids/genetics , Female , Humans , Inflammation/etiology , Inflammation/genetics , Inflammation/pathology , Lipids/radiation effects , Male , Metabolome/radiation effects , Metabolomics/methods , Radiation Exposure/adverse effects
10.
Expert Opin Ther Pat ; 21(3): 399-416, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21342055

ABSTRACT

INTRODUCTION: The first US FDA approved HIV entry inhibitor drug Enfuvirdine belongs to the fusion inhibitor category. Earlier efforts in this area were focused on peptides and monoclonal antibodies; recently, the focus has shifted towards the development of small molecule HIV attachment and fusion inhibitors. They can be used for prophylactic purposes and also hold potential for the development of HIV microbicides. AREAS COVERED: In a previous paper ('Small molecule HIV entry inhibitors: Part I'), we reviewed patents and patent applications for small molecule chemokine receptor antagonists from major pharmaceutical companies. In this paper, the development of small molecule HIV attachment and fusion inhibitors is discussed in detail. It covers patents and patent applications for small molecule HIV attachment and fusion inhibitors published between 2004 and 2010 and related literature with a focus on recent developments based on lead generation and lead modification. EXPERT OPINION: To augment the potency of currently available antiretroviral drug combinations and to fight drug-resistant virus variants, more effective drugs which target additional steps in the viral replication cycle are urgently needed. HIV attachment and fusion processes are such targets. Inhibitors of these targets will provide additional options for the treatment of HIV drug-resistant strains. Small molecule HIV attachment inhibitors such as BMS-378806 and analogs from Bristol Myers Squibb, N-aryl piperidine derivatives from Propharmacon, and NBD-556 and NBD-557 from New York Blood Center may have potential as vaginal microbicidal agents and can be an economical alternative to monoclonal antibodies.


Subject(s)
HIV Fusion Inhibitors/pharmacology , Drug Discovery , Patents as Topic , Prodrugs/pharmacology , Time Factors
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