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L→S Coordination Complexes Containing Benzothiazol-2-ylidene Ligand: Quantum Chemical Analysis and Synthesis. Chempluschem 2024:e202400150. [PMID: 38554142 DOI: 10.1002/cplu.202400150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 03/29/2024] [Accepted: 03/29/2024] [Indexed: 04/01/2024]
Abstract
(NHC)→E coordination interactions were known where NHC is an N-heterocyclic carbene, and E is a main group element (B, C, N, Si, P). Recently, it was suggested that compounds with (NHC)→S coordination chemistry are also possible. This work reports quantum chemical analysis and synthesis of (NHC)→S-R(+) complexes in which benzothiazol-2-ylidene acts as a ligand. A Density functional study established that (NHC)→S interaction can best be described as a coordination interaction. Synthetic efforts were made, initially, to generate divalent sulfur compounds containing benzothiazole substituents. N-alkylation of the heterocyclic ring in these sulfides using methyl triflate led to the generation of the desired products with (NHC)→S coordination chemistry, which involves the in situ generation of NHC ring ligands. The observed changes in the 13C NMR spectra, before and after methylation, confirmed the change in the electronic character of the C-S bond from a covalent character to a coordination character.
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Molecular Property Diagnostic Suite for COVID-19 (MPDS COVID-19): an open-source disease-specific drug discovery portal. GIGABYTE 2024; 2024:gigabyte114. [PMID: 38525218 PMCID: PMC10958779 DOI: 10.46471/gigabyte.114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 03/11/2024] [Indexed: 03/26/2024] Open
Abstract
Molecular Property Diagnostic Suite (MPDS) was conceived and developed as an open-source disease-specific web portal based on Galaxy. MPDSCOVID-19 was developed for COVID-19 as a one-stop solution for drug discovery research. Galaxy platforms enable the creation of customized workflows connecting various modules in the web server. The architecture of MPDSCOVID-19 effectively employs Galaxy v22.04 features, which are ported on CentOS 7.8 and Python 3.7. MPDSCOVID-19 provides significant updates and the addition of several new tools updated after six years. Tools developed by our group in Perl/Python and open-source tools are collated and integrated into MPDSCOVID-19 using XML scripts. Our MPDS suite aims to facilitate transparent and open innovation. This approach significantly helps bring inclusiveness in the community while promoting free access and participation in software development. Availability & Implementation The MPDSCOVID-19 portal can be accessed at https://mpds.neist.res.in:8085/.
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Identification of ethyl-6-bromo-2((phenylthio)methyl)imidazo[1,2-a]pyridine-3-carboxylate as a narrow spectrum inhibitor of Streptococcus pneumoniae and its FtsZ. Eur J Med Chem 2024; 267:116196. [PMID: 38350359 DOI: 10.1016/j.ejmech.2024.116196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/19/2024] [Accepted: 01/28/2024] [Indexed: 02/15/2024]
Abstract
Filamentous temperature-sensitive mutant Z (FtsZ) is a key cell-division protein recognized as an important target for anti-bacterial drug discovery, especially in the context of rising multi-drug resistance. A respiratory pathogen, Streptococcus pneumoniae, is rapidly evolving antibiotic resistance, thus posing a clinical risk in the developing world. Inhibiting the conserved protein FtsZ, leading to the arrest of cell division, is an attractive alternative strategy for inhibiting S. pneumoniae. Previously, Vitamin K3 was identified as an FtsZ-targeting agent against S. pneumoniae. In the present work, docking studies were used to identify potential anti-FtsZ agents that bind to the Vitamin K3-binding region of a homology model generated for S. pneumoniae FtsZ. Compounds with imidazo[1,2-a]pyridine-3-carboxylate core were synthesized and screened for their anti-proliferative activity against S. pneumoniae. Remarkably, the hit compound IP-01 showed anti-bacterial action against S. pneumoniae without any activity on other bacteria. In S. pneumoniae, IP-01 showed similar inhibitory action on FtsZ and cell division as Vitamin K3. Sequence alignment identified three unique residues within S. pneumoniae FtsZ that IP-01 binds to, providing a structural basis for the observed specificity. IP-01 is one of the first narrow-spectrum agents identified against S. pneumoniae that targets FtsZ, and we present it as a promising lead for the design of narrow-spectrum anti-FtsZ anti-pneumococcal compounds.
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Effect of Differential Surface Anisotropy on Dissolution Behavior of Fenofibrate Crystal Habits: Comparative Study using USP Type 2 and Type 4 Dissolution Apparatuses. J Pharm Sci 2024:S0022-3549(24)00044-3. [PMID: 38336008 DOI: 10.1016/j.xphs.2024.02.001] [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: 10/31/2023] [Revised: 02/01/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
The solid-state properties of active pharmaceutical ingredient (API) have significant impact on its dissolution performance. In the present study, two different crystal habits viz. rod and plate shape of form I of FEN were evaluated for dissolution profile using USP Type 2 and Type 4 apparatuses. Molecular basis of differential dissolution performance of different crystal habits was investigated. Rod (FEN-R) and plate (FEN-P) shaped crystal habits of Form I of FEN were generated using anti-solvent crystallization method. Despite the same polymorphic form and similar particle size distribution, FEN-P demonstrated higher dissolution performance than FEN-R. Crystal face indexation and electrostatic potential (ESP) map provided information on differential relative abundance of various facets and their molecular environment. In FEN-R, the dominant facet (001) is hydrophobic due to the exposure of chlorophenyl moiety. Whereas, in FEN-P the dominant facet (01-1) was hydrophilic due to the presence of chlorine and ester carbonyl groups. Deeper insight on the impact of different facets on dissolution behavior was obtained by energy framework analysis by unveiling strength of intermolecular interactions along various crystallographic facets. Moreover, type 4 apparatus provided higher discriminatory ability over USP Type 2 apparatus, in probing the crystal habit induced differential dissolution performance of FEN. The findings of this study emphasize that crystal habit should be considered as an important critical material attribute (CMA) during formulation development of FEN and due considerations should be given to the selection of the appropriate dissolution testing set-up for establishing in vitro-in vivo correlation.
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Synthesis of 3-sulfenylindole derivatives from 4-hydroxy-2H-chromene-2-thione and indole using oxidative cross-dehydrogenative coupling reaction and anti-proliferative activity study of some of their sulfone derivatives. Bioorg Chem 2023; 141:106900. [PMID: 37813073 DOI: 10.1016/j.bioorg.2023.106900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/11/2023]
Abstract
The synthesis of hitherto unreported 3-sulfenylindole derivatives is achieved from 4-hydroxy-2H-chromene-2-thione (1) and indole (2) by employing an oxidative cross-dehydrogenative coupling reaction using a combination of 10 mol% of molecular iodine and 1 equivalent of TBHP in DMSO at room temperature. Then, the 3-sulfenylindole derivatives 3a, 3b, 3d, 3f, 3 h, and 3 k were converted into their corresponding sulfone derivatives because of lead likeness properties. Subsequently, a target prediction and docking study of six sulfone derivatives (5a-f) was performed, and four sulfones, namely 5a, 5d, 5e, and 5f, were selected for further in-vitro studies. The four sulfones mentioned above exhibited prominent anti-proliferative activity on breast cancer (MCF7) cell lines. In addition, this reaction was exergonic through quantum chemical analysis of the mechanistic steps. The salient features of this reaction are mild reaction conditions, good yields, and broad substrate scope.
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Effect of Deep Eutectic System (DES) on Oral Bioavailability of Celecoxib: In Silico, In Vitro, and In Vivo Study. Pharmaceutics 2023; 15:2351. [PMID: 37765319 PMCID: PMC10534828 DOI: 10.3390/pharmaceutics15092351] [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: 08/08/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Different deep eutectic systems (DES) of choline chloride (CC)-urea (UA) (1:2), CC-glycerol (GLY) (1:2), CC-malonic acid (MA) (1:1), and CC-ascorbic acid (AA) (2:1) were generated and characterized by polarized light microscope (PLM) and Fourier transform infrared spectroscope (FTIR). The equilibrium solubility of celecoxib (CLX) in DES was compared to that in deionized water. The CC-MA (1:1) system provided ~10,000 times improvement in the solubility of CLX (13,114.75 µg/g) and was used for the generation of the CLX-DES system. The latter was characterized by PLM and FTIR to study the microstructure and intermolecular interaction between the CLX and CC-MA (1:1) DES. FTIR demonstrated the retention of the chemical structure of CLX. In vitro drug release studies in FaSSIF initially demonstrated high supersaturation, which decreased by ~2 fold after 2 h. Density functional theory (DFT)-based calculations provided a molecular-level understanding of enhanced solubility. Gibbs free energy calculations established the role of the strongest binding of CLX with CC and MA. A phase solubility study highlighted the role of hydrotropy-induced solubilization of the CLX-DES system. Animal pharmacokinetic studies established 2.76 times improvement in Cmax, 1.52 times reduction in tmax, and 1.81 times improvement in AUC0-∞. The overall results demonstrated the potential of developing a DES-based supersaturating drug-delivery system for pharmaceutical loading of drugs having solubility and dissolution rate-limited oral bioavailability.
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Bronsted Acid-Catalyzed Regioselective Carboxamidation of 2-Indolylmethanols with Isonitriles. J Org Chem 2023. [PMID: 37440673 DOI: 10.1021/acs.joc.2c02816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2023]
Abstract
A regioselective direct carboxamidation reaction of 2-indolylmethanols with readily available isocyanoesters/isocyanides has been reported in this work. The reaction was catalyzed by Bronsted acid such as p-TsOH to deliver the benzylic regioselective amides in 67-86% yield under mild conditions. The developed methodology provides alternative access to traditional metal-free carboxamidation via C-C and C-O bond formation with high atom economy. Furthermore, the developed approach was diversified to synthesize chiral indole-2-carboxamide derivatives with a moderate enantiomeric excess (61-73% ee) using an (R)-chiral phosphoric acid.
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Identification of CYP3A4 inhibitors as potential anti-cancer agents using pharmacoinformatics approach. J Mol Model 2023; 29:156. [PMID: 37097473 DOI: 10.1007/s00894-023-05538-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/30/2023] [Indexed: 04/26/2023]
Abstract
Biguanide derivatives exhibit a wide variety of therapeutic applications, including anti-cancer effects. Metformin is an effective anti-cancer agent against breast cancer, lung cancer, and prostate cancer. In the crystal structure (PDB ID: 5G5J), it was found that metformin is found in the active site of CYP3A4, and the associated anti-cancer effect was explored. Taking clues from this work, pharmacoinformatics research has been carried out on a series of known and virtual biguanide, guanylthiourea (GTU), and nitreone derivatives. This exercise led to the identification of more than 100 species that exhibit greater binding affinity toward CYP3A4 in comparison to that of metformin. Selected six molecules were subjected to molecular dynamics simulations, and the results are presented in this work.
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Copper (I) Catalysed Tandem C−C and C−N Bond Cleavage of N‐Fused Imidazoles towards the Synthesis of N‐pyridinylamides. ChemistrySelect 2023. [DOI: 10.1002/slct.202204845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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10
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Corrigendum to "Tuning of (E)-(4-fluorophenyl)-1, 1-diamino-2, 3-diazabuta-1, 3-diene nanostructures for the selective detection of imidacloprid" [Environ. Res. 216 (2023) 114494 Part 1]. ENVIRONMENTAL RESEARCH 2023; 221:115325. [PMID: 36669248 DOI: 10.1016/j.envres.2023.115325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
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11
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Iodocycloisomerization/Nucleophile Addition Cascade Transformations of 1,2-Alkynediones. J Org Chem 2023; 88:2377-2384. [PMID: 36730785 DOI: 10.1021/acs.joc.2c02790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A general electrophilic iodocyclization/nucleophile addition cascade transformation for 1,2-alkynediones for the synthesis of various oxygen heterocycles and access to regioselective alkyne hydroxylation is reported. Furan-tethered ynediones resulted in the construction of exo-enol ethers via carbonyl-alkyne cyclization-initiated heteroarene dearomatization, whereas other (hetero)arene-, alkenyl-, and alkyl-tethered ynediones resulted in the formation of highly functionalized 3(2H)-furanones. Importantly, the developed domino protocols involve the construction of important heterocyclic scaffolds and installation of two functional groups in a single operation. Moreover, the use of water as a nucleophile resulted in regioselective alkyne hydroxylation via furanone ring opening. The developed protocols are characterized by a wide substrate scope, and their utility has been demonstrated by a number of postsynthetic transformations.
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The importance of four-membered NHCs in stabilizing Breslow intermediates on benzoin condensation pathway. J Comput Chem 2023; 44:346-354. [PMID: 35652523 DOI: 10.1002/jcc.26935] [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: 02/23/2022] [Revised: 04/27/2022] [Accepted: 05/07/2022] [Indexed: 01/03/2023]
Abstract
N-heterocyclic carbenes (NHCs) have been established to be effective organocatalysts for facilitating the benzoin condensation and many other reactions. These reactions involve the formation of a Breslow intermediate (BI), which exhibits umpolung chemistry. To facilitate organocatalysis, several new cyclic carbenes are being introduced, four-membered NHCs are of special interest. Whether these NHCs can exhibit catalytic influence or not, can be evaluated by exploring the potential energy surface (PES) of the benzoin condensation reaction. Quantum chemical analysis has been carried out to compare the PES of these four-membered NHCs with that of standard five-membered NHCs to explore their catalytic ability. The barrier for the first step of the reaction for the formation of BI is comparable in all the cases. But the barrier for the second step of the reaction leading to the benzoin formation from BI is estimated to be very high for the four membered NHCs. These results indicate that the probability of identifying and isolating the BI is very high in comparison to the completion of benzoin condensation reaction in the case of the four-membered NHCs.
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Importance of tautomerism in drugs. Drug Discov Today 2023; 28:103494. [PMID: 36681235 DOI: 10.1016/j.drudis.2023.103494] [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: 06/13/2022] [Revised: 12/08/2022] [Accepted: 01/13/2023] [Indexed: 01/20/2023]
Abstract
Tautomerism is an important phenomenon exhibited by many drugs. As we discuss in this review, identifying the different tautomers of drugs and exploring their importance in the mechanisms of drug action are integral components of current drug discovery. Nuclear magnetic resonance (NMR), infrared (IR), ultraviolet (UV), Raman, and terahertz spectroscopic techniques, as well as X-ray diffraction, are useful for exploring drug tautomerism. Quantum chemical methods, in association with pharmacoinformatics tools, are being used to evaluate tautomeric preferences in terms of energy effects. Desmotropy (i.e., tautomeric polymorphism) of the drugs is particularly important in drug delivery studies.
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Metal-free synthesis of imidazoles and 2-aminoimidazoles. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2022.134092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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15
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Tuning of (E)-(4-fluorophenyl)-1,1-diamino-2,3-diazabuta-1,3-diene nanostructures for the selective detection of imidacloprid. ENVIRONMENTAL RESEARCH 2023; 216:114494. [PMID: 36209786 DOI: 10.1016/j.envres.2022.114494] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/27/2022] [Accepted: 10/01/2022] [Indexed: 06/16/2023]
Abstract
The present work demonstrates a facile route for synthesizing the organic nanoparticles (ONPs) and the blue fluorescent Quantum Dots (QDs) based on an organic molecule named (E)-(4-fluorophenyl)-1,1-diamino-2,3-diazabuta-1,3-diene. The synthesis process possesses advantages viz green synthesis, non-toxic degraded products, and amount of organic compound. Initially, the ONPs were prepared using the nanoprecipitation method and were screened for their recognition potential against various pesticides, however, no selectivity has been observed. This motivated us to tune the ONPs into QDs. The QDs were prepared using the hydrothermal method and a color change was observed in the QDs solution under daylight and under a UV lamp. The emission wavelength was observed at 400 nm (λexcitation = 278 nm). The synthesized QDs exhibited selective sensing potential towards imidacloprid via a quenching mechanism. A normalised decrement in the luminescence intensity of QDs was observed on raising the concentration of imidacloprid and a good linear response was noticed over a concentration varies from 1 μM to 100 μM with a regression coefficient of 0.99. The detection limit was estimated to be 4.53 nM and quantification limit was calculated to be and 13.72 nM.
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Mechanistic insights into granule-bound starch synthase I (GBSSI.L539P) allele in high amylose starch biosynthesis in wheat (Triticum aestivum L.). Funct Integr Genomics 2022; 23:20. [PMID: 36564499 DOI: 10.1007/s10142-022-00923-y] [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: 07/18/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022]
Abstract
Amylose fraction of grain starch is correlated with a type of resistant starch with better nutritional quality. Granule-bound starch synthase I (GBSSI) is the known starch synthase, responsible for elongation of linear amylose chains. GBSSI expression, activity, and binding to starch and other proteins are the key factors that can affect amylose content. Previously, a QTL, qhams7A.1 carrying GBSSI mutant allele, was identified through QTL mapping using F2 population of the high amylose mutant line, 'TAC 75'. This high amylose mutant line has >2-fold higher amylose content than wild variety 'C 306'. In this study, we characterized this novel mutant allele, GBSSI.L539P. In vitro starch synthase activity of GBSSI.L539P showed improved activity than the wild type (GBSSI-wt). When expressed in yeast glycogen synthase mutants (Δgsy1gsy2), GBSSI-wt and GBSSI.L539P partially complemented the glycogen synthase (gsy1gsy2) activity in yeast. Structural analysis by circular dichroism (CD) and homology modelling showed no significant structural distortion in the mutant enzyme. Molecular docking studies suggested that the residue Leu539 is distant from the catalytic active site (ADP binding pocket) and had no detectable conformational changes in active site. Both wild and mutant enzymes were assayed for starch binding in vitro, and demonstrating higher affinity of the GBSSI.L539P mutant for starch than the wild type. The present study indicated that distant residue (L539P) influenced GBSSI activity by affecting its starch-binding ability. Therefore, it may be a potential molecular target for enhanced amylose content in grain.
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Microwave‐Induced Synthesis of Pyridine Based Schiff Bases and Their Applications as Efficient Antimicrobial Textile Dyeing Agents: Experimental and Theoretical Approach. ChemistrySelect 2022. [DOI: 10.1002/slct.202203109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Electronic Structure Analysis and Synthesis of Nitroso
N
‐Heterocyclic Imines. ChemistrySelect 2022. [DOI: 10.1002/slct.202203613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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19
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Metal-free methods for the generation of benzimidazoles and 2-aminobenzimidazoles. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.133143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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NIS mediated dehydrogenative-cyclocondensation in aqueous medium towards the synthesis of 2-arylimidazo[1,2-a]pyridines and their 3-formylated derivatives. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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21
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Understanding Poor Milling Behavior of Voriconazole from Crystal Structure and Intermolecular Interactions. Mol Pharm 2022; 19:985-997. [DOI: 10.1021/acs.molpharmaceut.1c00978] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Thiazetidin-2-ylidenes as four membered N-heterocyclic carbenes: theoretical studies and the generation of complexes with N + center. Phys Chem Chem Phys 2022; 24:629-633. [PMID: 34933326 DOI: 10.1039/d1cp04732a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Thiazetidin-2-ylidenes have been designed as four membered N-heterocyclic carbenes (NHCs) using quantum chemical studies. These species are smaller analogs of thiazol-2-ylidenes, possess high singlet stability (57 kcal mol-1) and large nucleophilicity (3.4 eV). The possible existence of these carbenes has been established by synthesizing and crystalizing compounds with NHC→N+←(thiazetidin-2-ylidene) coordination bonds.
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Remdesivir: Mechanism of Metabolic Conversion from Prodrug to Drug. Curr Drug Metab 2021; 23:73-81. [PMID: 34963432 DOI: 10.2174/1389200223666211228160314] [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: 09/29/2021] [Revised: 10/25/2021] [Accepted: 12/01/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Remdesivir (GS-5734) has emerged as a promising drug during the challenging times of COVID-19 pandemic. Being a prodrug, it undergoes several metabolic reactions before converting to its active triphosphate metabolite. It is important to establish the atomic level details and explore the energy profile of the prodrug to drug conversion process. METHODS In this work, Density Functional Theory (DFT) calculations were performed to explore the entire metabolic path. Further, the potential energy surface (PES) diagram for the conversion of prodrug remdesivir to its active metabolite was established. The role of catalytic triad of Hint1 phosphoramidase enzyme in P-N bond hydrolysis was also studied on a model system using combined molecular docking and quantum mechanics approach. RESULTS The overall energy of reaction is 11.47 kcal/mol exergonic and the reaction proceeds through many steps requiring high activation energies. In the absence of a catalyst, the P-N bond breaking step requires 41.78 kcal/mol, which is reduced to 14.26 kcal/mol in a catalytic environment. CONCLUSION The metabolic pathways of model system of remdesivir (MSR) were completely explored completely and potential energy surface diagrams at two levels of theory, B3LYP/6-311++G(d, p) and B3LYP/6-31+G(d), were established and compared. The results highlight the importance of an additional water molecule in the metabolic reaction. The P-N bond cleavage step of the metabolic process requires the presence of an enzymatic environment.
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1,1-Diaminoazines as organocatalysts in phospha-Michael addition reactions. Chem Commun (Camb) 2021; 57:11717-11720. [PMID: 34697617 DOI: 10.1039/d1cc04657h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
1,1-Diaminoazines can act as effective organocatalysts for the formation of phosphorus-carbon bonds between biphenylphosphine oxide and an activated alkene (Michael acceptor). These catalysts provide the P-C adducts at a faster rate and with relatively better yields in comparison to the organocatalysts employed earlier. The notable advantage is that 1,1-diaminoazines catalyse the reaction even in an aqueous medium with very good yields. Organocatalysis using 1,1-diaminoazines was also successfully carried out between dimethylphosphite and benzylidenemalononitrile under multicomponent conditions.
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Mesoionic and N-Heterocyclic Carbenes Coordinated N + Center: Experimental and Computational Analysis. Chempluschem 2021; 86:1416-1420. [PMID: 34636173 DOI: 10.1002/cplu.202100281] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/17/2021] [Indexed: 11/07/2022]
Abstract
N-Heterocyclic carbenes, carbocyclic carbenes, remote N-heterocyclic carbenes and N-heterocyclic silylenes are known to form L→N+ coordination bonds. However, mesoionic carbenes (MICs) are not reported to form coordination bonds with cationic nitrogen. Herein, synthesis and quantum chemical studies were performed on 1,2,3-triazol-5-ylidene stabilized N+ center. Six compounds with MIC→N+ ←NHC were synthesized. Density functional theory calculations and energy decomposition analysis were carried out to explore the bonding situation between MIC and N+ center. The C→N+ bond lengths were in the range of 1.295-1.342 Å and bond dissociation energies were <400 kcal/mol. Natural bond orbital analysis supported the presence of excess electron density (>3 electrons) at the N+ center. The computational and X-ray diffraction analysis results confirmed the presence of divalent NI character of center nitrogen and MIC→N+ ←NHC coordination interactions.
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Analytical developments of p-hydroxy prenylamine reference material for dope control research: Characterization and purity assessment. Drug Test Anal 2021; 14:224-232. [PMID: 34617411 DOI: 10.1002/dta.3171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/20/2021] [Accepted: 09/24/2021] [Indexed: 11/12/2022]
Abstract
Prenylamine was initially used for the treatment of angina pectoris and later on withdrawn from the market in 1988 due to cardiac arrhythmias concern. The major phase I metabolite of prenylamine is p-hydroxy prenylamine that has a chiral center in the structure. Even though p-hydroxy prenylamine was synthesized earlier, it lacked complete analytical developments for chiral high-performance liquid chromatography (HPLC) separation. However, p-hydroxy prenylamine reference material is not commercially available. The innovation of this manuscript is the development and validation of a chiral HPLC separation method and more extensive characterization of the reference material than previously reported method. Therefore, it was hypothesized to develop and validate normal phase HPLC method for p-hydroxy prenylamine reference material. p-Hydroxy prenylamine was synthesized in two batches and characterized successfully using 13 C NMR, 1 H NMR, high-resolution mass spectrometry (HRMS), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). A normal phase chiral HPLC method was developed to analyze the p-hydroxy prenylamine purity. Separation of the p-hydroxy prenylamine enantiomers were achieved using ultra-high-performance liquid chromatography (UHPLC) on a ChiralCel ODH column at wavelength of 220 nm. The developed method was validated in terms of its linearity, accuracy, precision, and robustness for purification, purity assessment, and stability studies. Proton and carbon peaks were confirmed by nuclear magnetic resonance (NMR) analysis. Functional groups were confirmed by FT-IR. Loss on drying was 0.3% and 0.6% for Batches 1 and 2, respectively. The purity of the developed reference material for Batches 1 and 2 was found to be 99.59% and 100%, respectively. Therefore, the synthesized batches of p-hydroxy prenylamine can be used in dope testing as reference material.
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F/G Region Rigidity is Inversely Correlated to Substrate Promiscuity of Human CYP Isoforms Involved in Metabolism. J Chem Inf Model 2021; 61:4023-4030. [PMID: 34370479 DOI: 10.1021/acs.jcim.1c00558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Of 57 human cytochrome P450 (CYP) enzymes, 12 metabolize 90% of xenobiotics. To our knowledge, no study has addressed the relation between enzyme dynamics and substrate promiscuity for more than three CYPs. Here, we show by constraint dilution simulations with the Constraint Network Analysis for the 12 isoforms that structural rigidity of the F/G region is significantly inversely correlated to the enzymes' substrate promiscuity. This highlights the functional importance of structural dynamics of the substrate tunnel.
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Compound with possible N → N coordination bond: Synthesis, crystal structure and electronic structure analysis. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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A novel copper-catalyzed, hydrazine-free synthesis of N-1 unsubstituted 1H-indazoles using stable guanylhydrazone salts as substrates. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132192] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Synthesis of 1,4-dihydropyrazolo[4,3-b]indoles via intramolecular C(sp 2)-N bond formation involving nitrene insertion, DFT study and their anticancer assessment. Bioorg Chem 2021; 114:105114. [PMID: 34243073 DOI: 10.1016/j.bioorg.2021.105114] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 11/19/2022]
Abstract
We herein report a new synthetic route for a series of unreported 1,4-dihydropyrazolo[4,3-b]indoles (6-8) via deoxygenation of o-nitrophenyl-substituted N-aryl pyrazoles and subsequent intramolecular (sp2)-N bond formation under microwave irradiation expedite modified Cadogan condition. This method allows access to NH-free as well as N-substituted fused indoles. DFT study and controlled experiments highlighted the role of nitrene insertion as one of the plausible reaction mechanisms. Furthermore, the target compounds exhibited cytotoxicity at low micromolar concentration against lung (A549), colon (HCT-116), and breast (MDA-MB-231, and MCF-7) cancer cell lines, induced the ROS generation and altered the mitochondrial membrane potential of highly aggressive MDA-MB-231 cells. Further investigations revealed that these compounds were selective Topo I (6h) or Topo II (7a, 7b) inhibitors.
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Role of surface molecular environment and amorphous content in moisture sorption behavior of milled Terbutaline Sulphate. Eur J Pharm Sci 2021; 161:105782. [PMID: 33675911 DOI: 10.1016/j.ejps.2021.105782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/12/2021] [Accepted: 02/24/2021] [Indexed: 11/26/2022]
Abstract
Milling may cause undesired changes in crystal topology, due to exposure of new facets, their corresponding functional groups and surface amorphization. This study investigated effect of milling induced surface amorphous content and chemical environment on moisture sorption behavior of a model hydrophilic drug, Terbutaline Sulphate (TBS). A Dynamic Vapor Sorption (DVS) based analytical method was developed to detect amorphous content, with LOD and LOQ of 0.41% and 1.24%w/w, respectively. The calibration curve gave a linear regression of 0.999 in a concentration range of 0-16.36%w/w amorphous content plotted against surface area normalized % weight change, due to moisture sorption. TBS was milled using air jet mill at 8 Bars for 3 cycles (D90- 3.46µm) and analyzed using the validated DVS method prior to and post conditioning. The moisture sorption was higher in case of milled unconditioned TBS. Molecular Dynamics Simulation (MDS) was performed to identify the cause for increased moisture sorption due to altered surface environment or amorphous content. The results implied that the new planes and functional groups exposed on milling had negligible contribution to moisture sorption and the higher moisture sorption in milled unconditioned TBS was due to surface amorphization. Conditioning under elevated humidity recrystallized the milling-induced surface amorphous content and led to decreased moisture sorption in milled conditioned TBS.
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Iodine Catalyzed Oxidative Coupling of Diaminoazines and Amines for the Synthesis of 3,5-Disubstituted-1,2,4-Triazoles. J Org Chem 2021; 86:7659-7671. [PMID: 34003643 DOI: 10.1021/acs.joc.1c00704] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A simple, convenient, transition metal-free one pot synthesis of 3,5-disubstituted-1,2,4-triazoles has been established. The innovation in this reaction is the use of easily available 1,1-diaminoazines as substrates. This method provides the products with wider substrate scope, at an expedited rate, and with relatively better yields in comparison to the reported methods. The reaction mechanism involves an initial intermolecular nucleophilic addition (facilitated by I2) followed by intramolecular nucleophilic cyclization.
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Identification of selective LdDHFR inhibitors using quantum chemical and molecular modeling approach. J Biomol Struct Dyn 2021; 40:8687-8695. [PMID: 33904374 DOI: 10.1080/07391102.2021.1915182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Among the various known targets for the treatment of Leishmaniasis, dihydrofolate reductase (DHFR) is an essential target which plays an important role in the folate metabolic pathway. In the current study, pharmacoinformatics approaches including quantum chemistry methods, molecular docking and molecular dynamics simulations have been utilized to identify selective Leishmania donovani DHFR (LdDHFR) inhibitors. Initially, for the design of new LdDHFR inhibitors, a virtual combinatorial library was created by considering various head groups (scaffolds), linkers and tail groups. The scaffolds utilized in the library design were selected on the basis of their proton affinity (PA) estimated using quantum chemical methods, required to make a strong H-bond interaction with negatively charged LdDHFR active site. Later on, molecular docking-based virtual screening was performed to screen the designed library. Selectivity of the chosen hits toward the LdDHFR was established through re-docking in the human DHFR enzyme (HsDHFR). Best five hits were subjected to molecular dynamics (MD) simulations to validate their selectivity as well as stability in LdDHFR. Out of the five hits, four were found to be energetically more favorable and promising for selective binding toward LdDHFR in comparison to HsDHFR.Communicated by Ramaswamy H. Sarma.
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Reactive Metabolites from Thiazole-Containing Drugs: Quantum Chemical Insights into Biotransformation and Toxicity. Chem Res Toxicol 2021; 34:1503-1517. [PMID: 33900062 DOI: 10.1021/acs.chemrestox.0c00450] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Drugs containing thiazole and aminothiazole groups are known to generate reactive metabolites (RMs) catalyzed by cytochrome P450s (CYPs). These RMs can covalently modify essential cellular macromolecules and lead to toxicity and induce idiosyncratic adverse drug reactions. Molecular docking and quantum chemical hybrid DFT study were carried out to explore the molecular mechanisms involved in the biotransformation of thiazole (TZ) and aminothiazole (ATZ) groups leading to RM epoxide, S-oxide, N-oxide, and oxaziridine. The energy barrier required for the epoxidation is 13.63 kcal/mol, that is lower than that of S-oxidation, N-oxidation, and oxaziridine formation (14.56, 17.90, and 20.20, kcal/mol respectively). The presence of the amino group in ATZ further facilitates all the metabolic pathways, for example, the barrier for the epoxidation reaction is reduced by ∼2.5 kcal/mol. Some of the RMs/their isomers are highly electrophilic and tend to form covalent bonds with nucleophilic amino acids, finally leading to the formation of metabolic intermediate complexes (MICs). The energy profiles of these competitive pathways have also been explored.
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Biguanides: Species with versatile therapeutic applications. Eur J Med Chem 2021; 219:113378. [PMID: 33857729 DOI: 10.1016/j.ejmech.2021.113378] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 12/18/2022]
Abstract
Biguanides are compounds in which two guanidine moieties are fused to form a highly conjugated system. Biguanides are highly basic and hence they are available as salts mostly hydrochloride salts, these cationic species have been found to exhibit many therapeutic properties. This review covers the research and development carried out on biguanides and accounts the various therapeutic applications of drugs containing biguanide group-such as antimalarial, antidiabetic, antiviral, anticancer, antibacterial, antifungal, anti-tubercular, antifilarial, anti-HIV, as well as other biological activities. The aim of this review is to compile all the medicinal chemistry applications of this class of compounds so as to pave way for the accelerated efforts in finding the drug action mechanisms associated with this class of compounds. Importance has been given to the organic chemistry of these biguanide derivatives also.
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Molecular modeling studies on cytochrome P450 mediated drug metabolism. Curr Drug Metab 2021; 22:683-697. [PMID: 33605853 DOI: 10.2174/1389200222666210219122909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 11/22/2022]
Abstract
Drug metabolism studies play a critical role in the optimization of the therapeutic efficacy of newer drug candidates. Many drug candidates and drugs were withdrawn from the pre-clinical/clinical-stage or market due to the poor metabolic profiles. The poor metabolic profiles may make the clinical candidates/drugs inactive or toxic. Therefore, it is necessary to optimize the metabolic profiles at the initial phase of drug discovery and development processes. Recently, molecular modeling approaches were found to be useful in the optimization of metabolic profiles of clinical candidates. The molecular modeling approaches were employed in the identification of various metabolic profiles. In the present study, the current status of the research work on drug metabolism based on molecular modeling methodologies has been reviewed. The basics of drug metabolism and its importance in the physiological process of the human body have been described. Moreover, the involvement of molecular modeling approaches like pharmacophore-based modeling, QSAR, molecular docking, virtual screening, quantum chemical analysis, molecular dynamics, etc in predicting metabolic profiles of therapeutic agents is analyzed. The present review provides computational insights in the prediction of substrate specificity, metabolic activity, SOM, metabolites, toxicity, etc. on cytochrome P450 mediated drug metabolism. The study may help the researchers to design novel drug candidates for the various classes of therapeutic targets with efficient metabolic profiles.
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Abstract
We investigated a base-promoted protocol for the intermolecular anti-Markovnikov hydroamidation of vinyl arenes with arylamides to furnish the arylethylbenzamides with excellent chemo- and regioselectivity. The reaction tolerates an extensive variety of functional groups and has been successfully extended with electronically varied handles, aminobenzamides, electron-rich/electron-deficient heterocyclic amides, and vinyl arenes to afford the hydroamidated products. Excellent chemoselectivity was observed for the amide group over amine. The proposed mechanism and vital role of the solvent was well supported by deuterium labeling studies and control experiments.
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Visible light promoted tandem dehydrogenation-deaminative cyclocondensation under aerobic conditions for the synthesis of 2-aryl benzimidazoles/quinoxalines from ortho-phenylenediamines and arylmethyl/ethyl amines. NEW J CHEM 2021. [DOI: 10.1039/d0nj03002c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Visible light promoted tandem dehydrogenation-deaminative cyclocondensation of arylmethyl/ethyl amines with ortho-phenylenediamines under aerobic conditions is reported for the synthesis of 2-aryl benzimidazoles/quinoxalines.
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3D QSAR studies on amphiphilic indoles for antimycobacterial activity. J Biochem Mol Toxicol 2020; 35:e22675. [PMID: 33347664 DOI: 10.1002/jbt.22675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/02/2020] [Accepted: 12/03/2020] [Indexed: 01/06/2023]
Abstract
A persistent infection prolongs treatment duration and also enhances the chance of resistance development against antibiotics. Recently, a class of amphiphilic indole derivatives was discovered exhibiting bactericidal activity against both growing and nongrowing Mycobacterium bovis BCG (M. bovis BCG). These antibacterials are suggested to disturb the integrity and functioning of the cell membrane, a property that can help eradicate persistent organisms. This study article describes field-based three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of 79 amphiphilic indole derivatives. The aim of this QSAR study is to optimize this class of compounds for the development of more potent antimycobacterial agents. The results obtained indicate that steric interactions are crucial for antimycobacterial activity, while hydrogen bond donor groups participate negligibly in activity. The derived 3D-QSAR models showed acceptable r2 (0.91) and q2 (0.91) with a root mean squared error (RMSE) of 0.08. The models were cross-validated using the leave-one-out method. Applying the same QSAR model to another congeneric series of amphiphilic indoles externally validated the QSAR model. The model could appreciably predict the activity (pMIC50 ) of this congeneric series of amphiphilic indoles, with an RMSE of 0.49, indicating the robustness of the model and its efficiency in predicting the potentially active compounds.
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Abstract
C-N bond formation is a particularly important step in the generation of many
biologically relevant heterocyclic molecules. Several methods have been reported for this
purpose over the past few decades. Well-known named reactions like Ullmann-Goldberg
coupling, Buchwald-Hartwig coupling and Chan-Lam coupling are associated with the C-N
bond formation reactions. Several reviews covering this topic have already been published.
However, no comprehensive review covering the synthesis of drugs/ lead compounds using
the C-N bond formation reactions was reported. In this review, we cover many modern
methods of the C-N bond formation reactions, with special emphasis on metal-free and
green chemistry methods. We also report specific strategies adopted for the synthesis of
drugs, which involve the C-N bond formation reactions. Examples include anti-cancer,
antidepressant, anti-inflammatory, anti-atherosclerotic, anti-histaminic, antibiotics, antibacterial, anti-rheumatic,
antiepileptic and anti-diabetic agents. Many recently developed lead compounds generated using the C-N bond
formation reactions are also covered in this review. Examples include MAP kinase inhibitors, TRKs inhibitors,
Polo-like Kinase inhibitors and MPS1 inhibitors.
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Molecular docking and molecular dynamics to identify collagenase inhibitors as lead compounds to address osteoarthritis. J Biomol Struct Dyn 2020; 40:2339-2351. [PMID: 33103592 DOI: 10.1080/07391102.2020.1838326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Osteoarthritis (OA) is a degenerative disease which affects a large number of individuals. Collagenases, which belong to a class of metalloproteases (MMPs), are responsible for the degradation of cartilage manifested in OA. Inhibition of the catalytic domains of these MMPs is one of the important therapeutic strategies proposed for the prevention of OA. The main objective of this work is to evaluate the binding of curcumin and its metabolites with the active sites of collagenases in comparison to standard inhibitors on the basis of our hypothesis that curcumin/metabolites could exhibit an inhibitory effect on MMPs. Here, we report the molecular docking analysis of curcumin and its metabolites with collagenases (MMP-1, MMP-8, MMP-13). Among the molecules tested, curcumin monoglucuronide (CMG) demonstrated the best binding affinity with MMP-13, which is specifically implicated in OA. The CMG-MMP-complexes were further subjected to molecular dynamic simulations to explore the stability of the complexes and to estimate the free binding energies. The results indicated that CMG preferentially bind to MMP-13 in comparison to that of MMP-1 and MMP-8 with binding free energies (ΔGbind) of (-60.55), (-27.02) and (-46.91) kcal/mol, respectively. This is the first study which suggests that curcumin monoglucuronide can be considered as an effective lead compound to prevent the progression of OA.Communicated by Ramaswamy H. Sarma.
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Abstract
C-N bond formation is a particularly important step in the generation of many
biologically relevant heterocyclic molecules. Several methods have been reported for this
purpose over the past few decades. Well-known named reactions like Ullmann-Goldberg
coupling, Buchwald-Hartwig coupling and Chan-Lam coupling are associated with the C-N
bond formation reactions. Several reviews covering this topic have already been published.
However, no comprehensive review covering the synthesis of drugs/ lead compounds using
the C-N bond formation reactions was reported. In this review, we cover many modern
methods of the C-N bond formation reactions, with special emphasis on metal-free and
green chemistry methods. We also report specific strategies adopted for the synthesis of
drugs, which involve the C-N bond formation reactions. Examples include anti-cancer,
antidepressant, anti-inflammatory, anti-atherosclerotic, anti-histaminic, antibiotics, antibacterial, anti-rheumatic,
antiepileptic and anti-diabetic agents. Many recently developed lead compounds generated using the C-N bond
formation reactions are also covered in this review. Examples include MAP kinase inhibitors, TRKs inhibitors,
Polo-like Kinase inhibitors and MPS1 inhibitors.
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Transition metal-free diastereospecific synthesis of (Z)-2-arylidene-2,3-dihydrobenzo[b][1,4]dioxines by reaction of (Z)-1,2-dibromo-3-aryl-2-propenes with catechols. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.131482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Divalent N I Compounds: Identifying new Carbocyclic Carbenes to Design Nitreones using Quantum Chemical Methods. J Comput Chem 2020; 41:2624-2633. [PMID: 32964506 DOI: 10.1002/jcc.26417] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/23/2020] [Accepted: 08/24/2020] [Indexed: 11/05/2022]
Abstract
Nitreones are compounds with oxidation state 1 at the nitrogen, these compounds carry formal positive charge as well as two lone pairs of electrons at nitrogen center. These compounds are also known as divalent NI compounds and can be represented with the general formula L → N+ ← L, where L is an electron donating ligand. In the recent past, several divalent NI compounds have been reported with L = N-heterocyclic carbene (NHC), remote N-heterocyclic carbene (rNHC), carbocyclic carbene (CCC) and diaminocarbene. Recently, our group reported that a novel six-membered CCC (cyclohexa-2,5-diene-4-[diaminomethynyl]-1-ylidene) can stabilize N+ center in nitreones. As an independent carbene, this species is very unstable. In this work, modulation of this CCC using (a) annulation, (b) heterocyclic ring modification, (c) substitutions adjacent to the carbenic carbon, (d) exocyclic double bond insertion and (e) ring contraction, has been reported. These modulations and quantum chemical analyses helped in the identification of five new six-membered CCCs which carry improved donation and stability properties. Further, these CCCs were employed in the design of new divalent NI compounds (nitreones) which carry coordination bonds between ligands and N+ center. The molecular and electronic structure properties, and the donor→acceptor coordination interactions present in the resultant low oxidation state divalent NI compounds have been explored.
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Novel Furan-2-yl-1 H-pyrazoles Possess Inhibitory Activity against α-Synuclein Aggregation. ACS Chem Neurosci 2020; 11:2303-2315. [PMID: 32551538 DOI: 10.1021/acschemneuro.0c00252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A series of novel furan-2-yl-1H-pyrazoles and their chemical precursors were synthesized and evaluated for their effectiveness at disrupting α-synuclein (α-syn) aggregation in vitro. The compounds were found to inhibit α-syn aggregation with efficacy comparable to the promising drug candidate anle138b. The results of this study indicate that compounds 8b, 8l, and 9f may qualify as secondary leads for the structure-activity relationship studies aimed to identify the suitable compounds for improving the modulatory activity targeted at α-syn self-assembly related to Parkinson's disease.
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Mechanistic studies on the drug metabolism and toxicity originating from cytochromes P450. Drug Metab Rev 2020; 52:366-394. [DOI: 10.1080/03602532.2020.1765792] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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47
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Cu(II)-catalyzed sulfonylation of 7-azaindoles using DABSO as SO2-Source and its mechanistic study. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.131337] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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48
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Synthesis of N-substituted indole derivatives as potential antimicrobial and antileishmanial agents. Bioorg Chem 2020; 99:103787. [DOI: 10.1016/j.bioorg.2020.103787] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/24/2020] [Accepted: 03/21/2020] [Indexed: 11/16/2022]
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Identification of Selective Inhibitors of LdDHFR Enzyme Using Pharmacoinformatic Methods. J Comput Biol 2020; 28:43-59. [PMID: 32207987 DOI: 10.1089/cmb.2019.0332] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dihydrofolate reductase (DHFR) is a well-known enzyme of the folate metabolic pathway and it is a validated drug target for leishmaniasis. However, only a few leads are reported against Leishmania donovani DHFR (LdDHFR), and thus, there is a need to identify new inhibitors. In this article, pharmacoinformatic tools such as molecular docking, virtual screening, absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling, and molecular dynamics (MD) simulations were utilized to identify potential LdDHFR inhibitors. Initially, a natural DHFR substrate (dihydrofolate), a classical DHFR inhibitor (methotrexate), and a potent LdDHFR inhibitor, that is, "5-(3-(octyloxy)benzyl)pyrimidine-2,4-diamine" (LEAD) were docked in the active site of the LdDHFR and MD simulated to understand the binding mode characteristics of the substrates/inhibitors in the LdDHFR. The shape of the LEAD molecule was used as a query for shape-based virtual screening, while the three-dimensional structure of LdDHFR was utilized for docking-based virtual screening. In silico ADMET factors were also considered during virtual screening. These two screening processes yielded 25 suitable hits, which were further validated for their selectivity toward LdDHFR using molecular docking and prime molecular mechanics/generalized born surface area analysis in the human DHFR (HsDHFR). Best six hits, which were selective and energetically favorable for the LdDHFR, were chosen for MD simulations. The MD analysis showed that four of the hits exhibited very good binding affinity for LdDHFR with respect to HsDHFR, and two hits were found to be more selective than the reported potent LdDHFR inhibitor. The present study thus identifies hits that can be further designed and modified as potent LdDHFR inhibitors.
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Characterization of Photodegradation Products of Bepotastine Besilate and In Silico Evaluation of Their Physicochemical, Absorption, Distribution, Metabolism, Excretion and Toxicity Properties. J Pharm Sci 2020; 109:1883-1895. [PMID: 32173321 DOI: 10.1016/j.xphs.2020.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 02/13/2020] [Accepted: 03/06/2020] [Indexed: 12/21/2022]
Abstract
Bepotastine (BPT) is a H1-receptor antagonist. It is used as a besilate salt in ophthalmic solution for allergic conjunctivitis and orally for the treatment of allergic rhinitis and urticaria/pruritus. Its systematic forced degradation study is unreported. The same was carried out in different conditions prescribed by International Conference on Harmonisation. The stressed solutions were subjected to reversed phase liquid chromatographic analysis, and BPT was observed to be labile under photobasic condition only, yielding 5 photodegradation products. The structures of the latter were elucidated from data generated by liquid chromatography-high-resolution mass spectrometry and multistage mass spectrometry. Of the 5, 4 products were further isolated and subjected to nuclear magnetic resonance spectroscopy to justify the proposed structures. Two of them, with similar accurate mass, were additionally and unambiguously characterized from their heteronuclear multiple bond correlation data, hydrogen deuterium exchange mass data, and quantum chemical analysis using density functional theory calculations. One degradation product had a structure that could only be explained by unusual rearrangement involving conversions of N-oxide into hydroxylamine, similar to Meisenheimer rearrangement. The physicochemical, as well as absorption, distribution, metabolism, excretion, and toxicity properties of BPT and its characterized photodegradation products were evaluated in silico by ADMET Predictor™ software.
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