1
|
Design, synthesis and biological evaluation of Helicobacter pylori inosine 5′-monophosphate dehydrogenase (HpIMPDH) inhibitors. Further optimization of selectivity towards HpIMPDH over human IMPDH2. Bioorg Chem 2019; 87:753-764. [PMID: 30974298 DOI: 10.1016/j.bioorg.2019.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/20/2019] [Accepted: 04/01/2019] [Indexed: 02/05/2023]
|
2
|
Sahu NU, Purushothaman G, Thiruvenkatam V, Kharkar PS. Design, synthesis, and biological evaluation of Helicobacter pylori inosine 5'-monophosphate dehydrogenase (HpIMPDH) inhibitors. Drug Dev Res 2018; 80:125-132. [PMID: 30381846 DOI: 10.1002/ddr.21467] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/13/2018] [Accepted: 08/17/2018] [Indexed: 02/05/2023]
Abstract
Inosine 5'-monophosphate dehydrogenase (IMPDH) catalyzes a crucial step in the biosynthesis of guanine nucleotides. Being a validated target for immunosuppressive, antiviral, and anticancer drug development, lately it has been exploited as a promising target for antimicrobial therapy. Extending our previous work on Mycobacterium tuberculosis IMPDH, GuaB2, inhibitor development, we screened a set of 23 new chemical entities (NCEs) with substituted flavone (Series 1) and 1,2,3-triazole (Series 2) core structures for their in vitro Helicobacter pylori IMPDH (HpIMPDH) and human IMPDH2 (hIMPDH2) inhibitory activities. All the NCEs possessed acceptable molecular, physicochemical, and toxicity property profiles. The ranges for HpIMPDH and hIMPDH2 inhibition were 9-99.9% and 16-57%, respectively, at 10 μM concentration. The most potent HpIMPDH inhibitor, 25c, exhibited IC50 value of 1.27 μM with no hIMPDH2 inhibitory activity. The moderately potent, structurally novel hit molecule, 25c, may serve as a lead for further design and development of highly potent HpIMPDH inhibitors.
Collapse
Affiliation(s)
- Niteshkumar U Sahu
- Department of Pharmaceutical Chemistry, Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM's NMIMS, Mumbai, India
| | | | - Vijay Thiruvenkatam
- Biological Engineering, Indian Institute of Technology Gandhinagar, Gujarat, India.,Physics, Indian Institute of Technology Gandhinagar, Gujarat, India
| | - Prashant S Kharkar
- Department of Pharmaceutical Chemistry, Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM's NMIMS, Mumbai, India
| |
Collapse
|
3
|
Shah CP, Kharkar PS. Discovery of novel human inosine 5'-monophosphate dehydrogenase 2 (hIMPDH2) inhibitors as potential anticancer agents. Eur J Med Chem 2018; 158:286-301. [PMID: 30223117 DOI: 10.1016/j.ejmech.2018.09.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 08/13/2018] [Accepted: 09/05/2018] [Indexed: 02/08/2023]
Abstract
The enzyme inosine 5'-monophosphate dehydrogenase (IMPDH) catalyzes an essential step in the de novo biosynthesis of guanine nucleotides, and thus regulates the guanine nucleotide pool required for cell proliferation. Of the two isoforms, human IMPDH type 2 (hIMPDH2) is a validated molecular target for potential immunosuppressive, antiviral and anticancer chemotherapy. In search of newer hIMPDH2 inhibitors as potential anticancer agents, three novel series (A: 5-aminoisobenzofuran-1(3H)-one, B: 3,4-dimethoxyaniline and C: benzo[d]-[1,3]dioxol-5-ylmethanamine) were synthesized and evaluated for in vitro and cell-based activities. A total of 37 molecules (29-65) were screened for their in vitro hIMPDH2 inhibition, with particular emphasis on establishing their structure-activity relationship (SAR) trends. Eight compounds (hits, 30, 31, 33-35, 37, 41 and 43) demonstrated significant enzyme inhibition (>70% @ 10 μM); especially the A series molecules were more potent than B series (<70% inhibition @ 10 μM), while C series members were found to be inactive. The hIMPDH2 IC50 values for the hits ranged from 0.36 to 7.38 μM. The hits displaying >80% hIMPDH2 inhibition (30, 33, 35, 41 and 43) were further assessed for their cytotoxic activity against cancer cell lines such as MDA-MB-231 (breast adenocarcinoma), DU145 (prostate carcinoma), U87 MG (glioblastoma astrocytoma) and a normal cell line, NIH-3T3 (mouse embryonic fibroblast) using MTT assay. Most of the compounds exhibited higher cellular potency against cancer cell lines and notably lower toxicity towards NIH-3T3 cells compared to mycophenolic acid (MPA), a prototypical hIMPDH2 inhibitor. Two of the series A hits (30 and 35) were evaluated in human peripheral blood mononuclear cells (hPBMC) assay and found to be better tolerated than MPA. The calculated/predicted molecular and physicochemical properties were satisfactory with reference to drug-likeness. The molecular docking studies clearly demonstrated crucial interactions of the hits with the cofactor-binding site of hIMPDH2, further providing critical information for refining the design strategy. The present study reports the design and discovery of structurally novel hIMPDH2 inhibitors as potential anticancer agents and provides a guide for further research on the development of safe and effective anticancer agents, especially against glioblastoma.
Collapse
Affiliation(s)
- Chetan P Shah
- Department of Pharmaceutical Chemistry, Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM's NMIMS, V. L. Mehta Road, Vile Parle (West), Mumbai, 400 056, India
| | - Prashant S Kharkar
- Department of Pharmaceutical Chemistry, Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM's NMIMS, V. L. Mehta Road, Vile Parle (West), Mumbai, 400 056, India.
| |
Collapse
|
4
|
Shah CP, Kharkar PS. Newer human inosine 5'-monophosphate dehydrogenase 2 (hIMPDH2) inhibitors as potential anticancer agents. J Enzyme Inhib Med Chem 2018; 33:972-977. [PMID: 29792360 PMCID: PMC6009919 DOI: 10.1080/14756366.2018.1474211] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Human inosine 5′-monophosphate dehydrogenase 2 (hIMPDH2), being an age-old target, has attracted attention recently for anticancer drug development. Mycophenolic acid (MPA), a well-known immunosuppressant drug, was used a lead structure to design and develop modestly potent and selective analogues. The steep structure–activity relationship (SAR) requirements of the lead molecule left little scope to synthesise newer analogues. Here, newer MPA amides were designed, synthesised and evaluated for hIMPDH2 inhibition and cellular efficacy in breast, prostate and glioblastoma cell lines. Few title compounds exhibited cellular activity profile better than MPA itself. The observed differences in the overall biological profile could be attributed to improved structural and physicochemical properties of the analogues over MPA. This is the first report of the activity of MPA derivatives in glioblastoma, the most aggressive brain cancer.
Collapse
Affiliation(s)
- Chetan P Shah
- a Department of Pharmaceutical Chemistry , SPP School of Pharmacy and Technology Management, SVKM's NMIMS , Mumbai , India
| | - Prashant S Kharkar
- a Department of Pharmaceutical Chemistry , SPP School of Pharmacy and Technology Management, SVKM's NMIMS , Mumbai , India
| |
Collapse
|
5
|
Sahu NU, Singh V, Ferraris DM, Rizzi M, Kharkar PS. Hit discovery of Mycobacterium tuberculosis inosine 5'-monophosphate dehydrogenase, GuaB2, inhibitors. Bioorg Med Chem Lett 2018; 28:1714-1718. [PMID: 29699922 DOI: 10.1016/j.bmcl.2018.04.045] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 02/05/2023]
Abstract
Tuberculosis remains a global concern. There is an urgent need of newer antitubercular drugs due to the development of resistant forms of Mycobacterium tuberculosis (Mtb). Inosine 5'-monophosphate dehydrogenase (IMPDH), guaB2, of Mtb, required for guanine nucleotide biosynthesis, is an attractive target for drug development. In this study, we screened a focused library of 73 drug-like molecules with desirable calculated/predicted physicochemical properties, for growth inhibitory activity against drug-sensitive MtbH37Rv. The eight hits and mycophenolic acid, a prototype IMPDH inhibitor, were further evaluated for activity on purified Mtb-GuaB2 enzyme, target selectivity using a conditional knockdown mutant of guaB2 in Mtb, followed by cross-resistance to IMPDH inhibitor-resistant SRMV2.6 strain of Mtb, and activity on human IMPDH2 isoform. One of the hits, 13, a 5-amidophthalide derivative, has shown growth inhibitory potential and target specificity against the Mtb-GuaB2 enzyme. The hit, 13, is a promising molecule with potential for further development as an antitubercular agent.
Collapse
Affiliation(s)
- Niteshkumar U Sahu
- Department of Pharmaceutical Chemistry, SPP School of Pharmacy & Technology Management, SVKM's NMIMS, V.L. Mehta Road, Vile Parle (West), Mumbai 400 056, India
| | - Vinayak Singh
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch 7701, Cape Town, South Africa; South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
| | - Davide M Ferraris
- Dipartimento di Scienze del Farmaco, Università del Piemonte Orientale, Via Bovio 6, 28100 Novara, Italy
| | - Menico Rizzi
- Dipartimento di Scienze del Farmaco, Università del Piemonte Orientale, Via Bovio 6, 28100 Novara, Italy
| | - Prashant S Kharkar
- Department of Pharmaceutical Chemistry, SPP School of Pharmacy & Technology Management, SVKM's NMIMS, V.L. Mehta Road, Vile Parle (West), Mumbai 400 056, India.
| |
Collapse
|
6
|
Trapero A, Pacitto A, Singh V, Sabbah M, Coyne AG, Mizrahi V, Blundell TL, Ascher DB, Abell C. Fragment-Based Approach to Targeting Inosine-5'-monophosphate Dehydrogenase (IMPDH) from Mycobacterium tuberculosis. J Med Chem 2018; 61:2806-2822. [PMID: 29547284 PMCID: PMC5900554 DOI: 10.1021/acs.jmedchem.7b01622] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
Tuberculosis (TB)
remains a major cause of mortality worldwide,
and improved treatments are needed to combat emergence of drug resistance.
Inosine 5′-monophosphate dehydrogenase (IMPDH), a crucial enzyme
required for de novo synthesis of guanine nucleotides,
is an attractive TB drug target. Herein, we describe the identification
of potent IMPDH inhibitors using fragment-based screening and structure-based
design techniques. Screening of a fragment library for Mycobacterium
thermoresistible (Mth) IMPDH ΔCBS
inhibitors identified a low affinity phenylimidazole derivative. X-ray
crystallography of the Mth IMPDH ΔCBS–IMP–inhibitor
complex revealed that two molecules of the fragment were bound in
the NAD binding pocket of IMPDH. Linking the two molecules of the
fragment afforded compounds with more than 1000-fold improvement in
IMPDH affinity over the initial fragment hit.
Collapse
Affiliation(s)
- Ana Trapero
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom
| | - Angela Pacitto
- Department of Biochemistry , University of Cambridge , 80 Tennis Court Road , Cambridge CB2 1GA , United Kingdom
| | - Vinayak Singh
- MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Institute of Infectious Disease and Molecular Medicine and Division of Medical Microbiology, Faculty of Health Sciences , University of Cape Town , Rondebosch 7701 , Cape Town , South Africa
| | - Mohamad Sabbah
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom
| | - Anthony G Coyne
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom
| | - Valerie Mizrahi
- MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Institute of Infectious Disease and Molecular Medicine and Division of Medical Microbiology, Faculty of Health Sciences , University of Cape Town , Rondebosch 7701 , Cape Town , South Africa
| | - Tom L Blundell
- Department of Biochemistry , University of Cambridge , 80 Tennis Court Road , Cambridge CB2 1GA , United Kingdom
| | - David B Ascher
- Department of Biochemistry , University of Cambridge , 80 Tennis Court Road , Cambridge CB2 1GA , United Kingdom.,Department of Biochemistry and Molecular Biology, Bio21 Institute , University of Melbourne , 30 Flemington Road , Parkville , Victoria 3052 , Australia
| | - Chris Abell
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom
| |
Collapse
|
7
|
Zhu M, Fan W, Cha Y, Yang X, Lai Z, Li S, Wang X. Dynamic cell responses in Thermoanaerobacterium sp. under hyperosmotic stress. Sci Rep 2017; 7:10088. [PMID: 28855699 PMCID: PMC5577258 DOI: 10.1038/s41598-017-10514-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/09/2017] [Indexed: 12/17/2022] Open
Abstract
As a nongenetic engineering technique, adaptive evolution is an effective and easy-to-operate approach to strain improvement. In this work, a commercial Thermoanaerobacterium aotearoense SCUT27/Δldh-G58 was successfully isolated via sequential batch fermentation with step-increased carbon concentrations. Mutants were isolated under selective high osmotic pressures for 58 passages. The evolved isolate rapidly catabolized sugars at high concentrations and subsequently produced ethanol with good yield. A 1.6-fold improvement of ethanol production was achieved in a medium containing 120 g/L of carbon substrate using the evolved strain, compared to the start strain. The analysis of transcriptome and intracellular solute pools suggested that the adaptive evolution altered the synthesis of some compatible solutes and activated the DNA repair system in the two Thermoanaerobacterium sp. evolved strains. Overall, the results indicated the potential of adaptive evolution as a simple and effective tool for the modification and optimization of industrial microorganisms.
Collapse
Affiliation(s)
- Muzi Zhu
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Wudi Fan
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yaping Cha
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Xiaofeng Yang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Zhicheng Lai
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shuang Li
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.
| | - Xiaoning Wang
- State Key Laboratory of Kidney, the Institute of Life Sciences, Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
8
|
Highly selective inhibition of IMPDH2 provides the basis of antineuroinflammation therapy. Proc Natl Acad Sci U S A 2017; 114:E5986-E5994. [PMID: 28674004 DOI: 10.1073/pnas.1706778114] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Inosine monophosphate dehydrogenase (IMPDH) of human is an attractive target for immunosuppressive agents. Currently, small-molecule inhibitors do not show good selectivity for different IMPDH isoforms (IMPDH1 and IMPDH2), resulting in some adverse effects, which limit their use. Herein, we used a small-molecule probe specifically targeting IMPDH2 and identified Cysteine residue 140 (Cys140) as a selective druggable site. On covalently binding to Cys140, the probe exerts an allosteric regulation to block the catalytic pocket of IMPDH2 and further induces IMPDH2 inactivation, leading to an effective suppression of neuroinflammatory responses. However, the probe does not covalently bind to IMPDH1. Taken together, our study shows Cys140 as a druggable site for selectively inhibiting IMPDH2, which provides great potential for development of therapy agents for autoimmune and neuroinflammatory diseases with less unfavorable tolerability profile.
Collapse
|
9
|
Zhang YW, Guo YS, Bao XQ, Sun H, Zhang D. Bicyclol promotes toll-like 2 receptor recruiting inosine 5'-monophosphate dehydrogenase II to exert its anti-inflammatory effect. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2016; 18:475-485. [PMID: 26744808 DOI: 10.1080/10286020.2015.1131678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 12/10/2015] [Indexed: 06/05/2023]
Abstract
The aim was to investigate potential targets and anti-inflammatory mechanisms of bicyclol, which has been extensively used in clinic for decades in China. Tar-Fis-Dock, virtual molecular docking system, showed that inosine 5'-monophosphate dehydrogenase II (IMPDH II) has the highest probability of binding to bicyclol. To investigate the possible role of IMPDH II in mechanisms of bicyclol, recombinant enzyme models, mice splenic lymphocytes, and human lymphocytes were used. Bicyclol (1-5 μM) significantly inhibited the proliferation of mice splenic lymphocytes stimulated by concanavalin A (conA). However, bicyclol did not show inhibitory effects on proliferation of human peripheral blood mononuclear cells (hPBMC) induced by phytohemagglutinin (PHA). IMPDH II enzyme kinetic model showed that bicyclol only had a slight regulatory effect on IMPDH II enzyme activity. These results revealed that bicyclol may be not a conventional inhibitor of IMPDH II. Further studies showed that bicyclol could promote recruitment of IMPDH II by active toll-like 2 receptor (TLR2) complex. Such effects lead to the reduction of nuclear factor κB (NF-κB) expression, increase in I-κB expression, and decrease in cytokine release, including tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β). It may be a new mechanism of bicyclol for its anti-inflammatory effect.
Collapse
Affiliation(s)
- You-Wen Zhang
- a State Key Laboratory of Bioactive Substance and Function of Natural Medicines , Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100050 , China
| | - Yan-Shen Guo
- a State Key Laboratory of Bioactive Substance and Function of Natural Medicines , Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100050 , China
| | - Xiu-Qi Bao
- a State Key Laboratory of Bioactive Substance and Function of Natural Medicines , Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100050 , China
| | - Hua Sun
- a State Key Laboratory of Bioactive Substance and Function of Natural Medicines , Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100050 , China
| | - Dan Zhang
- a State Key Laboratory of Bioactive Substance and Function of Natural Medicines , Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100050 , China
| |
Collapse
|
10
|
Inosine 5'-monophosphate dehydrogenase inhibitors as antimicrobial agents: recent progress and future perspectives. Future Med Chem 2016; 7:1415-29. [PMID: 26230881 DOI: 10.4155/fmc.15.72] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Inosine 5'-monophosphate dehydrogenase (IMPDH), a crucial enzyme required for de novo synthesis of guanine nucleotides, is an important target for cancer, bacterial, parasitic and viral infections and autoimmune disorders. Several classes of IMPDH inhibitors are known in the literature. The current review succinctly summarizes the progress made in the design and development of IMPDH inhibitors as antimicrobial agents in last five years or so. The focus is on the inhibitor and enzyme structural features responsible for imparting selectivity for the microbial over the host enzyme. Future perspectives clearly outline the inhibitor design opportunities available in this area to address the present challenges of drug resistance and re-emergence of newer and deadly strains of microbes, posing a serious threat to public.
Collapse
|
11
|
Myc-dependent purine biosynthesis affects nucleolar stress and therapy response in prostate cancer. Oncotarget 2016; 6:12587-602. [PMID: 25869206 PMCID: PMC4494960 DOI: 10.18632/oncotarget.3494] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 03/07/2015] [Indexed: 11/25/2022] Open
Abstract
The androgen receptor is a key transcription factor contributing to the development of all stages of prostate cancer (PCa). In addition, other transcription factors have been associated with poor prognosis in PCa, amongst which c-Myc (MYC) is a well-established oncogene in many other cancers. We have previously reported that the AR promotes glycolysis and anabolic metabolism; many of these metabolic pathways are also MYC-regulated in other cancers. In this study, we report that in PCa cells de novo purine biosynthesis and the subsequent conversion to XMP is tightly regulated by MYC and independent of AR activity. We characterized two enzymes, PAICS and IMPDH2, within the pathway as PCa biomarkers in tissue samples and report increased efficacy of established anti-androgens in combination with a clinically approved IMPDH inhibitor, mycophenolic acid (MPA). Treatment with MPA led to a significant reduction in cellular guanosine triphosphate (GTP) levels accompanied by nucleolar stress and p53 stabilization. In conclusion, targeting purine biosynthesis provides an opportunity to perturb PCa metabolism and enhance tumour suppressive stress responses.
Collapse
|
12
|
Effects of unbound mycophenolic acid on inosine monophosphate dehydrogenase inhibition in pediatric kidney transplant patients. Ther Drug Monit 2015; 36:716-23. [PMID: 24739663 DOI: 10.1097/ftd.0000000000000081] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mycophenolic acid (MPA) is a key immunosuppressive drug that acts through inhibition of inosine monophosphate dehydrogenase (IMPDH). MPA is commonly measured, as part of therapeutic drug monitoring, as the total concentration in plasma. However, it has been postulated that the free (unbound) fraction of MPA (fMPA) is responsible for the immunosuppressive effects. In this study, a sensitive low volume high-performance liquid chromatography (HPLC) assay was developed to measure fMPA concentrations to explore the relationship between fMPA and IMPDH activity. METHODS To obtain fMPA concentrations, plasma samples were filtrated using Centrifree ultrafiltration devices. The ultrafiltrate was analyzed by HPLC using a Kinetex C18 column (2.6 μm, 3.0 × 75 mm). fMPA concentrations were compared with the total MPA concentrations available in 28 pediatric kidney transplant patients at 3 consecutive occasions after transplantation. The relationship between fMPA and IMPDH activity was analyzed using an Emax model. RESULTS The HPLC assay, using 25 μL of the ultrafiltrates, was validated over a range from 2.5 to 1000 μL with good accuracy, precision, and reproducibility. Total and free MPA concentrations were well correlated (R = 0.85, P < 0.0001), although large intraindividual and interindividual variability in the bound MPA fractions was observed. The overall relationship between fMPA concentrations and IMPDH inhibition using the Emax model was comparable with that of total MPA, as previously reported. The model estimated EC50 value (164.5 μL) is in good agreement with reported in vitro EC50 values. CONCLUSIONS This study provides a simple HPLC method for the measurement of fMPA and a pharmacologically reasonable EC50 estimate. The good correlation between the total and free MPA concentrations suggests that routine measurement of fMPA to characterize mycophenolate pharmacokinetic and pharmacodynamic does not seem warranted, although the large variability in the bound fractions of MPA warrants further study.
Collapse
|
13
|
Sugaya N. Ligand efficiency-based support vector regression models for predicting bioactivities of ligands to drug target proteins. J Chem Inf Model 2014; 54:2751-63. [PMID: 25220713 DOI: 10.1021/ci5003262] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The concept of ligand efficiency (LE) indices is widely accepted throughout the drug design community and is frequently used in a retrospective manner in the process of drug development. For example, LE indices are used to investigate LE optimization processes of already-approved drugs and to re-evaluate hit compounds obtained from structure-based virtual screening methods and/or high-throughput experimental assays. However, LE indices could also be applied in a prospective manner to explore drug candidates. Here, we describe the construction of machine learning-based regression models in which LE indices are adopted as an end point and show that LE-based regression models can outperform regression models based on pIC50 values. In addition to pIC50 values traditionally used in machine learning studies based on chemogenomics data, three representative LE indices (ligand lipophilicity efficiency (LLE), binding efficiency index (BEI), and surface efficiency index (SEI)) were adopted, then used to create four types of training data. We constructed regression models by applying a support vector regression (SVR) method to the training data. In cross-validation tests of the SVR models, the LE-based SVR models showed higher correlations between the observed and predicted values than the pIC50-based models. Application tests to new data displayed that, generally, the predictive performance of SVR models follows the order SEI > BEI > LLE > pIC50. Close examination of the distributions of the activity values (pIC50, LLE, BEI, and SEI) in the training and validation data implied that the performance order of the SVR models may be ascribed to the much higher diversity of the LE-based training and validation data. In the application tests, the LE-based SVR models can offer better predictive performance of compound-protein pairs with a wider range of ligand potencies than the pIC50-based models. This finding strongly suggests that LE-based SVR models are better than pIC50-based models at predicting bioactivities of compounds that could exhibit a much higher (or lower) potency.
Collapse
Affiliation(s)
- Nobuyoshi Sugaya
- Drug Discovery Department, Research & Development Division, PharmaDesign, Inc. , Hatchobori 2-19-8, Chuo-ku, Tokyo 104-0032, Japan
| |
Collapse
|
14
|
Cholewiński G, Iwaszkiewicz-Grześ D, Prejs M, Głowacka A, Dzierzbicka K. Synthesis of the inosine 5′-monophosphate dehydrogenase (IMPDH) inhibitors. J Enzyme Inhib Med Chem 2014; 30:550-63. [DOI: 10.3109/14756366.2014.951349] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|