ABSTRACT
We review developments in fluorine chemistry contributing to the more precise use of fluorinated pyrimidines (FPs) to treat cancer. 5-Fluorouracil (5-FU) is the most widely used FP and is used to treat > 2 million cancer patients each year. We review methods for 5-FU synthesis, including the incorporation of radioactive and stable isotopes to study 5-FU metabolism and biodistribution. We also review methods for preparing RNA and DNA substituted with FPs for biophysical and mechanistic studies. New insights into how FPs perturb nucleic acid structure and dynamics has resulted from both computational and experimental studies, and we summarize recent results. Beyond the well-established role for inhibiting thymidylate synthase (TS) by the 5-FU metabolite 5-fluoro-2'-deoxyuridine-5'-O-monophosphate (FdUMP), recent studies have implicated new roles for RNA modifying enzymes that are inhibited by 5-FU substitution including tRNA methyltransferase 2 homolog A (TRMT2A) and pseudouridylate synthase in 5-FU cytotoxicity. Furthermore, enzymes not previously implicated in FP activity, including DNA topoisomerase 1 (Top1), were established as mediating FP anti-tumor activity. We review recent literature summarizing the mechanisms by which 5-FU inhibits RNA- and DNA-modifying enzymes and describe the use of polymeric FPs that may enable the more precise use of FPs for cancer treatment in the era of personalized medicine.
Subject(s)
Drug Development , Fluorine Compounds/chemistry , Fluorine Compounds/pharmacology , Precision Medicine , Pyrimidines/chemistry , Pyrimidines/pharmacology , Antimetabolites, Antineoplastic/chemistry , Antimetabolites, Antineoplastic/pharmacology , Antimetabolites, Antineoplastic/therapeutic use , Chemical Phenomena , DNA/drug effects , DNA/metabolism , Fluorine Compounds/chemical synthesis , Fluorine Compounds/therapeutic use , Fluorouracil/chemistry , Fluorouracil/pharmacology , Fluorouracil/therapeutic use , Humans , Pyrimidines/chemical synthesis , Pyrimidines/therapeutic use , RNA/drug effects , RNA/metabolism , Structure-Activity Relationship , Thymidylate Synthase/analysisABSTRACT
BACKGROUND: Cerebral edema after cardiac arrest (CA) is associated with increased mortality and unfavorable outcome in children and adults. Aquaporin-4 mediates cerebral water movement and its absence in models of ischemia improves outcome. We investigated early and selective pharmacologic inhibition of aquaporin-4 in a clinically relevant asphyxial CA model in immature rats in a threshold CA insult that produces primarily cytotoxic edema in the absence of blood-brain barrier permeability. METHODS: Postnatal day 16-18 Sprague-Dawley rats were studied in our established 9-min asphyxial CA model. Rats were randomized to aquaporin-4 inhibitor (AER-271) vs vehicle treatment, initiated at return of spontaneous circulation. Cerebral edema (% brain water) was the primary outcome with secondary assessments of the Neurologic Deficit Score (NDS), hippocampal neuronal death, and neuroinflammation. RESULTS: Treatment with AER-271 ameliorated early cerebral edema measured at 3 h after CA vs vehicle treated rats. This treatment also attenuated early NDS. In contrast to rats treated with vehicle after CA, rats treated with AER-271 did not develop significant neuronal death or neuroinflammation as compared to sham. CONCLUSION: Early post-resuscitation aquaporin-4 inhibition blocks the development of early cerebral edema, reduces early neurologic deficit, and blunts neuronal death and neuroinflammation post-CA.
Subject(s)
Aquaporin 4/antagonists & inhibitors , Asphyxia/complications , Brain Edema/prevention & control , Fluorine Compounds/therapeutic use , Heart Arrest/physiopathology , Animals , CA1 Region, Hippocampal/pathology , Chlorophenols , Disease Models, Animal , Female , Fluorine Compounds/pharmacology , Heart Arrest/etiology , Humans , Male , Rats , Rats, Sprague-Dawley , Treatment OutcomeABSTRACT
Background and objectives: A considerable increase in the levels of adenoviral diseases among both adults and children necessitate the development of effective methods for its prevention and treatment. The synthesis of the new fluorinated 1,2,3-triazoles, and the study of the mechanisms of their action, are promising for the development of efficient antiviral drugs of our time. Materials and Methods: Antiviral activity and cell cytotoxic effect of 2-(3-chlorotetrahydrofuran-2-yl)-4-tosyl-5-(perfluoropropyl)-1,2,3-triazole (G29) were determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The influence of the compound on the infectivity of human adenovirus type 5 (HAdV-5) was carried out via the cytomorphology method. The influence of the compound on the cell cycle under a condition of adenovirus infection was studied using flow cytometric analysis of propidium iodide-stained cells. Results: It was found that G29 suppressed HAdV-5 reproduction by 50% in concentrations of 37 Āµg/mL. Furthermore, the compound reduced the titer of virus obtained de novo, and inhibited HAdV-5 inclusion bodies formation by 84Ć¢ĀĀ»90%. The use of fluorinated compounds under the conditions of adenovirus infection decreased the number of apoptotic cells by 11% and the number of cells in S phase by 21Ć¢ĀĀ»42% compared to the profile of infected cells. Conclusions: The fluorinated compound G29 showed moderate activity against HAdV-5 based on several mechanisms. It led to the normalization of the life cycle of cells infected with adenovirus to the level of non-infected cells and caused the obstruction of HAdV-5 reproduction, inducing the formation of non-infectious virus progeny.
Subject(s)
Adenoviruses, Human/drug effects , Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Fluorine Compounds/chemical synthesis , Fluorine Compounds/pharmacology , Triazoles/chemical synthesis , Triazoles/pharmacology , Adenovirus Infections, Human/drug therapy , Adenovirus Infections, Human/prevention & control , Animals , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , Casein Kinase II/antagonists & inhibitors , Cattle , Cell Cycle/drug effects , Cell Line , Cell Survival/drug effects , Fluorine Compounds/chemistry , Fluorine Compounds/therapeutic use , Microscopy, Fluorescence , Molecular Mimicry , Triazoles/chemistry , Triazoles/therapeutic use , Virus Replication/drug effectsABSTRACT
Thiosemicarbazone, a class of compounds with excellent biological activity, especially antitumor activity, have attracted wide attention. In this study, a novel fluorinated thiosemicarbazone derivative, 2-(3,4-difluorobenzylidene) hydrazinecarbothioamide (compound 1) was synthesized and its antitumor activities were further investigated on a non-small cell lung cancer cell line (A549) along with its underlying mechanisms. Compound 1 showed significant anti-proliferative activity on A549Ā cells, which was further proved by colony formation experiment. Compound 1 also inhibits the invasion of A549Ā cells in a trans-well culture system. Moreover, compound 1 markedly induced apoptosis on A549Ā cells, and the ratio of Bcl-2/Bax was decreased while the amount of p53, Cleaved-Caspase 3 and Cleaved-PARP expression were increased significantly. Compound 1 decreased the mitochondrial membrane potential, while the content of reactive oxygen was increased obviously. It is revealed that compound 1 mediated cell cycle arrest in G0/G1 phase by reducing G1 phase dependent proteins, CDK4 and Cyclin D1. As a result, it is indicated that compound 1 induced apoptosis on A549Ā cells was realized by regulating ROS-mediated mitochondria-dependent signaling pathway.
Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Proliferation/drug effects , Mitochondria/metabolism , Reactive Oxygen Species/metabolism , Thiosemicarbazones/chemical synthesis , A549 Cells , Antineoplastic Agents/chemistry , Dose-Response Relationship, Drug , Fluorine Compounds/chemical synthesis , Fluorine Compounds/pharmacology , Humans , Mitochondria/drug effects , Signal Transduction/drug effects , Thiosemicarbazones/pharmacologyABSTRACT
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most lethal and prevalent cancers in human population. The 6-fluoro-3-formylchromone (FCC) has been shown to have anti-tumor activity against various tumor cells. However, the effects of FCC on HCC cell lines have not yet been reported. This study aims to research the effects of FCC on HCC and advance the understanding of the molecular mechanism. METHODS: HCC cell line SMMC-7721 was treated with FCC at various concentrations (0, 2, 5, 10, and 20Ā Āµg/ml) for 24, 48 and 72Ā h, respectively. The proliferations of SMMC-7721 cells were measured by MTT assays. After cultured 24Ā hours, cell cycle distribution and apoptosis were determined by flow cytometry. However, the expression levels of PCNA, Bax and Bcl-2 were measured by western blotting after 48Ā hours. RESULTS: FCC displayed a dose- and time-dependent inhibition of the SMMC-7721 cell proliferations in vitro. It also induced apoptosis with 45.4% and caused cell accumulation in G0/G1 phase with 21.5%. PCNA and Bcl-2 expression was significantly suppressed by FCC in a dose-dependent manner (P < 0.05), while Bax expression was increased. CONCLUSIONS: FCC could significantly inhibit HCC cell growth in vitro through cell cycle arrest and inducing apoptosis by suppressing PCNA expression and modulating the Bax/Bcl-2 ratio.
Subject(s)
Apoptosis/drug effects , Carcinoma, Hepatocellular , Cell Proliferation/drug effects , Chromones/pharmacology , Fluorine Compounds/pharmacology , Formates/pharmacology , Liver Neoplasms , Cell Cycle/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Drug Screening Assays, Antitumor , Humans , Proliferating Cell Nuclear Antigen/drug effects , Proliferating Cell Nuclear Antigen/metabolism , Proto-Oncogene Proteins c-bcl-2/drug effects , Proto-Oncogene Proteins c-bcl-2/metabolism , bcl-2-Associated X Protein/drug effects , bcl-2-Associated X Protein/metabolismABSTRACT
With the aim of investigating the influence of fluorine, in particular on the A-ring, a new series of fluoro analogues (7a-l) of phenstatin (3) was synthesized and tested for interactions with tubulin polymerization and evaluated for cytotoxicity on an NCI-60 human cancer cell lines panel. We have shown that the replacement of 3,4,5-trimethoxyphenyl A-ring of phenstatin with 2,4,5-trifluoro-3-methoxyphenyl unit, results in the conservation of both antitubulin and cytotoxic effect. Fluoro isocombretastatin 7k was the most effective anticancer agent in the present study and demonstrated the highest antiproliferative potential on leukemia cell lines SR (GI50=15 nM) and HL-60(TB) (GI50=23 nM) and on melanoma cell line MDA-MB-435 (GI50=19 nM).
Subject(s)
Antimitotic Agents/chemical synthesis , Antineoplastic Agents/chemical synthesis , Benzophenones/chemical synthesis , Fluorine Compounds/chemical synthesis , Organophosphates/chemical synthesis , Prodrugs/chemical synthesis , Antimitotic Agents/pharmacology , Antineoplastic Agents/pharmacology , Benzophenones/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Fluorine Compounds/pharmacology , Halogenation , Humans , Inhibitory Concentration 50 , Mitosis/drug effects , Organophosphates/pharmacology , Prodrugs/pharmacologyABSTRACT
The development of safe and potent insecticides remains an integral part of a multifaceted strategy to effectively control human-disease-transmitting insect vectors. Incorporating fluorine can dramatically alter the physiochemical properties and bioavailability of insecticides. For example, 1,1,1-trichloro-2,2-bis(4-fluorophenyl)ethane (DFDT)Ć¢ĀĀa difluoro congener of trichloro-2,2-bis(4-chlorophenyl)ethane (DDT)Ć¢ĀĀwas demonstrated previously to be 10-fold less toxic to mosquitoes than DDT in terms of LD50 values, but it exhibited a 4-fold faster knockdown. Described herein is the discovery of fluorine-containing 1-aryl-2,2,2-trichloro-ethan-1-ols (FTEs, for fluorophenyl-trichloromethyl-ethanols). FTEs, particularly per-fluorophenyl-trichloromethyl-ethanol (PFTE), exhibited rapid knockdown not only against Drosophila melanogaster but also against susceptible and resistant Aedes aegypti mosquitoes, major vectors of Dengue, Zika, yellow fever, and Chikungunya viruses. The R enantiomer of any chiral FTE, synthesized enantioselectively, exhibited faster knockdown than its corresponding S enantiomer. PFTE does not prolong the opening of mosquito sodium channels that are characteristic of the action of DDT and pyrethroid insecticides. In addition, pyrethroid/DDT-resistant Ae. aegypti strains having enhanced P450-mediated detoxification and/or carrying sodium channel mutations that confer knockdown resistance were not cross-resistant to PFTE. These results indicate a mechanism of PFTE insecticidal action distinct from that of pyrethroids or DDT. Furthermore, PFTE elicited spatial repellency at concentrations as low as 10 ppm in a hand-in-cage assay. PFTE and MFTE were found to possess low mammalian toxicity. These results suggest the substantial potential of FTEs as a new class of compounds for controlling insect vectors, including pyrethroid/DDT-resistant mosquitoes. Further investigations of FTE insecticidal and repellency mechanisms could provide important insights into how incorporation of fluorine influences the rapid lethality and mosquito sensing.
Subject(s)
Aedes , Fluorine Compounds , Insecticides , Pyrethrins , Zika Virus Infection , Zika Virus , Animals , Humans , Insecticides/pharmacology , Fluorine/pharmacology , DDT/pharmacology , Fluorine Compounds/pharmacology , Drosophila melanogaster , Insecticide Resistance/genetics , Pyrethrins/pharmacology , MammalsABSTRACT
Menadione is the 2-methyl-1,4-naphthoquinone core used to design potent antimalarial redox-cyclers to affect the redox equilibrium of Plasmodium-infected red blood cells. Exploring the reactivity of fluoromethyl-1,4-naphthoquinones, in particular trifluoromenadione, under quasi-physiological conditions in NADPH-dependent glutathione reductase reactions, is discussed in terms of chemical synthesis, electrochemistry, enzyme kinetics, and antimalarial activities. Multitarget-directed drug discovery is an emerging approach to the design of new antimalarial drugs. Combining in one single 1,4-naphthoquinone molecule, the trifluoromenadione core with the alkyl chain at C-3 of the known antimalarial drug atovaquone, revealed a mechanism for CF(3) as a leaving group. The resulting trifluoromethyl derivative 5 showed a potent antimalarial activity per se against malarial parasites in culture.
Subject(s)
Antimalarials/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Fluorine Compounds/chemical synthesis , Glutathione Reductase/antagonists & inhibitors , Vitamin K 3/chemical synthesis , Antimalarials/pharmacology , Biocatalysis , Drug Design , Enzyme Inhibitors/pharmacology , Fluorine Compounds/pharmacology , Humans , Molecular Structure , Oxidation-Reduction , Plasmodium falciparum/drug effects , Plasmodium falciparum/enzymology , Structure-Activity Relationship , Vitamin K 3/pharmacologyABSTRACT
A simple protocol for the synthesis of N-perfluoroacylated and N-acylated glycals of neuraminic acid, with a secondary cyclic amine (morpholine or piperidine) at the 4α position, has been set-up, starting from peracetylated N-acetylneuraminic acid methyl ester that undergoes, sequentially to its direct N-transacylation followed by a C-4 amination, a Ć-elimination, and a selective hydrolysis of the ester functions, without affecting the sensitive perfluorinated amide.
Subject(s)
Amines/chemistry , Carbohydrates/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Ether/chemistry , Fluorine Compounds/chemical synthesis , Neuraminic Acids/chemistry , Neuraminidase/antagonists & inhibitors , Acylation , Carbohydrates/pharmacology , Cyclization , Enzyme Inhibitors/pharmacology , Fluorine Compounds/pharmacology , Molecular Structure , Structure-Activity Relationship , Vibrio cholerae/drug effects , Vibrio cholerae/enzymologyABSTRACT
The aim of this study is to compare the effects of new fluorinated taxanes SB-T-12851, SB-T-12852, SB-T-12853, and SB-T-12854 with those of the classical taxane paclitaxel and novel non-fluorinated taxane SB-T-1216 on cancer cells. Paclitaxel-sensitive MDA-MB-435 and paclitaxel-resistant NCI/ADR-RES human cancer cell lines were used. Cell growth and survival evaluation, colorimetric assessment of caspases activities, flow cytometric analyses of the cell cycle and the assessment of mitochondrial membrane potential, reactive oxygen species (ROS) and the release of cytochrome c from mitochondria were employed. Fluorinated taxanes have similar effects on cell growth and survival. For MDA-MB-435 cells, the C(50) of SB-T-12851, SB-T-12852, SB-T-12853 and SB-T-12854 was 3 nM, 4 nM, 3 nM and 5 nM, respectively. For NCI/ADR-RES cells, the C(50) of SB-T-12851, SB-T-12852, SB-T-12853, and SB-T-12854 was 20 nM, 20 nM, 10 nM and 10 nM, respectively. Selected fluorinated taxanes, SB-T-12853 and SB-T-12854, at the death-inducing concentrations (30 nM for MDA-MB-435 and 300 nM for NCI/ADR-RES) were shown to activate significantly caspase-3, caspase-9, caspase-2 and also slightly caspase-8. Cell death was associated with significant accumulation of cells in the G(2)/M phase. Cytochrome c was not released from mitochondria and other mitochondrial functions were not significantly impaired. The new fluorinated taxanes appear to use the same or similar mechanisms of cell death induction as compared with SB-T-1216 and paclitaxel. New fluorinated and non-fluorinated taxanes are more effective against drug-resistant cancer cells than paclitaxel. Therefore, new generation of taxanes, either non-fluorinated or fluorinated, are excellent candidates for further and detailed studies.
Subject(s)
Drug Resistance, Neoplasm/drug effects , Fluorine Compounds/pharmacology , Taxoids/pharmacology , Caspases/metabolism , Cell Cycle/drug effects , Cell Death/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cytochromes c/metabolism , DNA, Neoplasm/metabolism , Drug Screening Assays, Antitumor , Fluorine Compounds/chemistry , Humans , Mitochondria/drug effects , Mitochondria/metabolism , Paclitaxel/chemistry , Paclitaxel/pharmacology , Reactive Oxygen Species/metabolism , Taxoids/chemistryABSTRACT
BACKGROUND: Hydrofluoric acid (HF) is a small and partially dissociated acid (pK(a) 3.2), able to deeply penetrate into human skin in addition to the corrosiveness of the hydrogen ion (H(+)) and the toxicity of the fluoride ion (F(-)). However, there has been a lack of experimental studies to objectively characterize the results of human HF skin exposure decontamination. METHODOLOGY/PRINCIPAL FINDINGS: A previously established experimental method using a human skin explants ex vivo model (Part 1. Experimental 70% hydrofluoric acid (HF) burns: Histological observations in an established human skin explants ex vivo model) described the lesions that appeared following 70% HF penetration. Within 5 min, 70% HF penetrates to the dermis. Using the same experimental conditions, a comparison study of two different washing protocols was performed: water + topical calcium gluconate (CaG) versus Hexafluorine(Ā®). In these conditions, washing for 15 min with running tap water followed by topical CaG ointment only delayed burn onset, while severe tissue damage appeared later. In contrast, after washing with Hexafluorine(Ā®) over 10 min, no histological lesions developed. These results are in accordance with the results of accidental human industrial case reports. CONCLUSION/SIGNIFICANCE: Amphoteric and hypertonic Hexafluorine(Ā®) can deactivate H(+) and chelate F(-) ions. Based on these results, it should be considered as a promising first-aid decontamination solution to prevent or minimize significant local and systemic consequences of concentrated HF skin exposures.
Subject(s)
Burns, Chemical/therapy , Calcium Gluconate/pharmacology , Emergency Treatment , Fluorine Compounds/pharmacology , Hydrofluoric Acid/toxicity , Water , Adult , Burns, Chemical/pathology , Decontamination , Female , Humans , Models, Biological , Tissue Culture TechniquesABSTRACT
This study compared the topography of different titanium surface structures (TiO2 nanotube and grain) with similar elemental compositions (TiO2 and fluorine [F]) on the Ti surface. High magnification indicated that the surfaces of the control and etching groups were similar to each other in a flat, smooth form. The group anodized for 1Ā h was observed with TiO2 nanotubes organized very neatly and regularly. In the group anodized for 30 min after etching, uneven wave and nanopore structures were observed. In addition, MTT assay showed that the F of the surface did not adversely affect cell viability, and the initial cell adhesion was increased in the 2.8% F-incorporated TiO2 nanograin. At the edge of adherent cells, filopodia were observed in spreading form on the surfaces of the anodizing and two-step processing groups, and they were observed in a branch shape in the control and etching groups. Moreover, cell adhesion molecule and osteogenesis marker expression was increased at the F-incorporated TiO2 nanostructure. In addition, it was found that the expression of p-extracellular signal-regulated kinase (ERK) and p-cAMP response element-binding protein (CREB) increased in the TiO2 nanograin with the nanopore surface compared to the micro rough and nanotube surfaces relative to the osteogenic-related gene expression patterns. As a result, this study confirmed that the topographic structure of the surface is more affected by osteogenic differentiation than the pore size and that differentiation by specific surface composition components is by CREB. Thus, the synergy effect of osteogenic differentiation was confirmed by the simultaneous activation of CREB/ERK.
Subject(s)
Biocompatible Materials/pharmacology , Cell Adhesion/drug effects , Fluorine Compounds/pharmacology , Mesenchymal Stem Cells/cytology , Titanium/pharmacology , Biocompatible Materials/chemistry , Cell Differentiation/drug effects , Cell Line , Cyclic AMP Response Element-Binding Protein/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Fluorine Compounds/chemistry , Humans , Mesenchymal Stem Cells/drug effects , Nanotubes/chemistry , Osteogenesis/drug effects , Signal Transduction , Titanium/chemistryABSTRACT
Experimental determination of the free energy (DeltaG) stabilizing the structure of membrane proteins (MPs) in their native environment has been hampered by the aggregation and precipitation of MPs outside the lipid bilayer. We recently demonstrated that the latter process can be prevented by the use of fluorinated surfactants, FTACs, that act as chaperones for MP insertion without partitioning in the membrane themselves. Here we combine the advantages of the chaperone-like ability of FTACs with the sensitivity of fluorescence correlation spectroscopy measurements to determine DeltaG of bilayer insertion of model MPs. First, we calibrate our approach by examining the effects of chaperoned insertion on DeltaG of transmembrane insertion of Annexin B12. We find that a shorter-chained surfactant, FTAC-C6, for which the working concentration range of 0.05-0.2 mM falls below CMC = 0.33 mM, has a mild effect on an apparent DeltaG. In contrast, additions of a longer-chained FTAC-C8 (CMC = 0.03 mM) result in a steep and nonlinear concentration dependence of DeltaG. We then apply the same methodology to the pH-triggered insertion of diphtheria toxin T-domain, which is known to be affected by nonproductive aggregation in solution. We find that the correction of the DeltaG value needed to compensate for unchaperoned insertion of the T-domain exceeds 3 kcal/mole. A relatively shallow and linear dependence of the DeltaG for Annexin B12 and T-domain insertion on FTAC-C6 concentration is encouraging for future applications of this surfactant in thermodynamic studies of the stability of other MPs.
Subject(s)
Annexins/metabolism , Fluorine Compounds/pharmacology , Lipid Bilayers/metabolism , Membrane Proteins/metabolism , Surface-Active Agents/pharmacology , Lipids/chemistry , Spectrometry, Fluorescence , Thermodynamics , TitrimetryABSTRACT
Glycoside hydrolases are important enzymes in a number of essential biological processes. Irreversible inhibitors of this class of enzyme have attracted interest as probes of both structure and function. In this review we discuss some of the compounds used to covalently modify glycosidases, their use in residue identification, structural and mechanistic investigations, and finally their applications, both in vitro and in vivo, to complex biological systems.
Subject(s)
Enzyme Inhibitors/pharmacology , Glycoside Hydrolases/antagonists & inhibitors , Glycoside Hydrolases/metabolism , Animals , Biochemistry , Biology , Fluorine Compounds/chemistry , Fluorine Compounds/pharmacology , Glycoside Hydrolases/classification , Humans , Protein BindingABSTRACT
The function of gamma-aminobutyric acid type A receptors (GABA(A) receptors) is enhanced by various clinically important drugs including benzodiazepines that act on an allosteric site formed at the interface between the alpha and gamma subunits. In contrast to classical benzodiazepines, the novel pyrazolopyrimidine indiplon (N-methyl-N-{3-[7-(thiophene-2-carbonyl)-1,5,9-triazabicyclo[4.3.0]nona-2,4,6,8-tetraen-2-yl]phenyl}acetamide; N-methyl-N-{3-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidine-7-yl]phenyl}-acetamide) demonstrates relative binding selectivity for the alpha1 subunit containing receptor subtypes, which are the most frequently expressed in the mammalian central nervous system. To investigate the pharmacological properties at GABA(A) receptors and to promote the development of alpha1 subunit selective radiotracers for positron emission tomography imaging, we have started with the evaluation of various fluorinated indiplon derivatives. Binding affinities were determined in homogenates from newborn and adult rats suggesting an alpha1 preference of the reference compounds indiplon, zaleplon as well as for all newly synthesized indiplon derivatives. In homogenated cerebellar tissue obtained from adult rat brain, known to primarily express alpha1 containing GABA(A) receptors, the high affinity of the basic indiplon structure was only slightly affected by an elongation of the alkyl substituent of the amide N from methyl (indiplon; K(i) 3.1 nM) via ethyl (2a, N-(2-fluoro-ethyl)-N-{3-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidine-7-yl]phenyl}-acetamide; K(i) 5.4 nM) to propyl (2b, N-(3-fluoro-propyl)-N-{3-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidine-7-yl]phenyl}-acetamide; K(i) 2.4 nM). Whole cell patch-clamp recordings at neuronal and recombinant GABA(A) receptors indicated that the fluorinated derivatives 2a and 2b have a high potency at alpha1beta3gamma2L isoforms comparable to indiplon (EC(50): 105, 158, and 81 nM, respectively), with 2b displaying the most pronounced efficacy at alpha3beta3gamma2L subtypes. In conclusion, the affinity profiles and functional properties of the newly synthesised fluorinated indiplon derivatives make compounds 2a and 2b suitable for the development of [(18)F]-labelled ligands at GABA(A) receptors containing the alpha1 subunit.
Subject(s)
Benzodiazepines/pharmacology , Fluorine Compounds/pharmacology , Hypnotics and Sedatives/pharmacology , Receptors, GABA-A/drug effects , Thiophenes/pharmacology , Animals , Animals, Newborn , Benzodiazepines/agonists , Benzodiazepines/chemical synthesis , Binding Sites , Electrophysiology , Fluorine Compounds/chemical synthesis , Fluorine Radioisotopes , Humans , Hypnotics and Sedatives/chemical synthesis , Ligands , Patch-Clamp Techniques , Positron-Emission Tomography/methods , Radioligand Assay , Rats , Receptors, GABA-A/metabolism , Structure-Activity Relationship , Thiophenes/agonists , Thiophenes/chemical synthesisABSTRACT
We have synthesized and evaluated a series of triaryl sulfonamide-based PTP1B inhibitors in which a difluoro-methylenephosphonate group of a potent lead has been replaced by potential bioisosteric replacements. Several mono- or di-charged compounds (8a, 8b, and 15a) were shown exhibit inhibitory activity in the low micromolar range, demonstrating the feasibility of using this approach in identifying non-phosphonate pTyr mimetics in a small molecular scaffold. These results also provide a useful indication of the relative effectiveness of these pTyr mimetics.
Subject(s)
Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Fluorine Compounds/chemical synthesis , Organophosphorus Compounds/chemical synthesis , Organophosphorus Compounds/pharmacology , Protein Tyrosine Phosphatase, Non-Receptor Type 1/antagonists & inhibitors , Sulfonamides/chemistry , Enzyme Inhibitors/chemistry , Fluorine Compounds/chemistry , Fluorine Compounds/pharmacology , Molecular Structure , Organophosphorus Compounds/chemistry , Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism , Structure-Activity RelationshipABSTRACT
Dipeptidyl peptidase IV (DPP-IV) inhibitors are promising antidiabetic drugs, and several drugs are in the developmental stage. We previously reported that the introduction of fluorine to the 4-position of 2-cyanopyrrolidine enhanced the DPP-IV inhibitory effect. In the present report, we examined the structure-activity relationship (SAR) of 2-cyano-4-fluoropyrrolidine with N-substituted glycine at the 1-position. We report the identification of a potent and stable DPP-IV inhibitor (TS-021) with a long-term persistent plasma drug concentration and a potent antihyperglycemic activity.
Subject(s)
Cyanides/chemistry , Dipeptidyl Peptidase 4/metabolism , Dipeptidyl-Peptidase IV Inhibitors , Protease Inhibitors/chemical synthesis , Protease Inhibitors/pharmacology , Pyrrolidines/chemical synthesis , Pyrrolidines/pharmacology , Animals , Blood Glucose/metabolism , Fluorine Compounds/blood , Fluorine Compounds/chemical synthesis , Fluorine Compounds/chemistry , Fluorine Compounds/pharmacology , Insulin/blood , Male , Models, Molecular , Molecular Structure , Protease Inhibitors/blood , Protease Inhibitors/chemistry , Pyrrolidines/blood , Pyrrolidines/chemistry , Rats , Structure-Activity RelationshipABSTRACT
Synthesis and antiviral activity of the title fluoromethylenecyclopropane analogues 15a, 15b, 16a, and 16b is described. Methylenecyclopropane carboxylate was first transformed to 2,2-bis-hydroxymethylmethylenecyclopropane. Selective monoacetylation followed by introduction of fluorine gave 2-acetoxymethyl-2-fluoromethylmethylenecyclopropane as the key intermediate. The synthesis of analogues 15a, 15b, 16a, and 16b then followed alkylation-elimination procedure as described previously for other methylenecyclopropane analogues [corrected] Compounds 15a, 15b, 16a and 16b were not active against Epstein-Barr virus (EBV) [corrected] Analogue 15a inhibited hepatitis C virus by virtue of its cytotoxicity and it moderately inhibited replication of the Towne strain of human cytomegalovirus (HCMV). The E-isomer 16a was a substrate for adenosine deaminase, whereas the Z-isomer 15a was not deaminated.
Subject(s)
Adenine/chemical synthesis , Adenine/pharmacology , Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Cyclopropanes/chemistry , Guanine/chemical synthesis , Guanine/pharmacology , Adenine/chemistry , Antiviral Agents/chemistry , Cell Line , Fluorine Compounds/chemical synthesis , Fluorine Compounds/chemistry , Fluorine Compounds/pharmacology , Guanine/chemistry , Hepacivirus/drug effects , Hydroxylation , Isomerism , Magnetic Resonance Spectroscopy , Methylation , Molecular Structure , Nucleosides/chemistryABSTRACT
A series of trifluoromethyl ketones as SARS-CoV 3CL protease inhibitors was developed. The inhibitors were synthesized in four steps from commercially available compounds. Three different amino acids were explored in the P1-position and in the P2-P4 positions varying amino acids and long alkyl chain were incorporated. All inhibitors were evaluated in an in vitro assay using purified enzyme and fluorogenic substrate peptide. One of the inhibitors showed a time-dependent inhibition, with a K(i) value of 0.3 microM after 4h incubation.
Subject(s)
Cysteine Endopeptidases/metabolism , Ketones/chemical synthesis , Ketones/pharmacology , Protease Inhibitors/chemical synthesis , Protease Inhibitors/pharmacology , Severe acute respiratory syndrome-related coronavirus/enzymology , Viral Proteins/antagonists & inhibitors , Viral Proteins/metabolism , Coronavirus 3C Proteases , Cysteine Endopeptidases/chemistry , Drug Design , Fluorine Compounds/chemical synthesis , Fluorine Compounds/chemistry , Fluorine Compounds/pharmacology , Hydrogen Bonding , Ketones/chemistry , Methylation , Models, Molecular , Molecular Structure , Protease Inhibitors/chemistry , Viral Proteins/chemistryABSTRACT
Thirty-four newer 1-cyclopropyl-1,4-dihydro-6-fluoro-7-(substituted secondary amino)-8-methoxy-5-(sub)-4-oxoquinoline-3-carboxylic acids were synthesized from 1,2,3,4-tetrafluoro benzene and evaluated for in vitro and in vivo antimycobacterial activities against Mycobacterium tuberculosis H37Rv (MTB), multi-drug resistant M. tuberculosis (MDR-TB) and Mycobacterium smegmatis (MC(2)) and also tested for the ability to inhibit the supercoiling activity of DNA gyrase. Among the synthesized compounds, 7-(1-(4-methoxybenzyl)-3,4,5,6,7,8-hexahydroisoquinolin-2(1H)-yl)-1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-5-nitro-4-oxoquinoline-3-carboxylic acid (13n) was found to be the most active compound in vitro with MIC of 0.16 and 0.33 microM against MTB and MDR-TB, respectively. In the in vivo animal model 13n decreased the bacterial load in lung and spleen tissues with 2.54 and 2.92-log10 protections, respectively, at the dose of 50mg/kg body weight. Compound 13n also inhibited the supercoiling activity of mycobacterial DNA gyrase with IC(50) of 30.0 microg/ml.