- Design, synthesis and biological evaluation of Helicobacter pylori inosine 5′-monophosphate dehydrogenase (HpIMPDH) inhibitors. Further optimization of selectivity towards HpIMPDH over human IMPDH2
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Inosine 5′-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205) catalyzes a crucial step in guanine nucleotide biosynthesis, thereby governing cell proliferation. In contrast to mammalian IMPDHs, microbial IMPDHs are relatively less explored as potential tar
- Shah, Chetan P.,Purushothaman, Gayathri,Thiruvenkatam, Vijay,Kirubakaran, Sivapriya,Juvale, Kapil,Kharkar, Prashant S.
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- Novel chalcone and flavone derivatives as selective and dual inhibitors of the transport proteins ABCB1 and ABCG2
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During cancer chemotherapy, certain cancers may become cross-resistant to structurally diverse antineoplastic agents. This so-called multidrug resistance (MDR) is highly associated with the overexpression of ATP-binding cassette (ABC) transport proteins. These membrane-bound efflux pumps export a broad range of structurally diverse endo- and xenobiotics, including chemically unrelated anticancer agents. This translocation of drugs from the inside to the outside of cancer cells is mediated at the expense of ATP. In the last 40 years, three ABC transporters – ABCB1 (P-gp), ABCC1 (MRP1), and ABCG2 (BCRP) – have mainly been attributed to the occurrence of MDR in cancer cells. One of the strategies to overcome MDR is to inhibit the efflux transporter function by small-molecule inhibitors. In this work, we investigated new chalcone- and flavone-based compounds for selective as well as broad-spectrum inhibition of the stated transport proteins. These include substituted chalcones with variations at rings A and B, and flavones with acetamido linker at position 3. The synthesized molecules were evaluated for their inhibitory potential against ABCB1, ABCC1, and ABCG2 in calcein AM and pheophorbide A assays. In further investigations with the most promising candidates from each class, we proved that ABCB1- and ABCG2-mediated MDR could be reversed by the compounds. Moreover, their intrinsic toxicity was found to be negligible in most cases. Altogether, our findings contribute to the understanding of ABC transport proteins and reveal new compounds for ongoing evaluation in the field of ABC transporter-mediated MDR.
- Silbermann, Katja,Shah, Chetan P.,Sahu, Niteshkumar U.,Juvale, Kapil,Stefan, Sven Marcel,Kharkar, Prashant S.,Wiese, Michael
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p. 193 - 213
(2019/01/03)
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- Design, synthesis, and biological evaluation of Helicobacter pylori inosine 5′-monophosphate dehydrogenase (HpIMPDH) inhibitors
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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.
- Sahu, Niteshkumar U.,Purushothaman, Gayathri,Thiruvenkatam, Vijay,Kharkar, Prashant S.
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p. 125 - 132
(2018/11/06)
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- Discovery of novel human inosine 5′-monophosphate dehydrogenase 2 (hIMPDH2) inhibitors as potential anticancer agents
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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 (50 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.
- Shah, Chetan P.,Kharkar, Prashant S.
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p. 286 - 301
(2018/09/18)
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- (3Z)-3-(2,3-dihydro-1H-inden-1-ylidene)-1,3-dihydro-2H-indol-2-ones as kinase inhibitors
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The present invention relates to organic molecules capable of modulating tyrosine kinase signal transduction in order to regulate, modulate and/or inhibit abnormal cell proliferation.
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