ABSTRACT
Preparative reactions that occur efficiently under dilute, buffered, aqueous conditions in the presence of biomolecules find application in ligation, peptide synthesis, and polynucleotide synthesis and sequencing. However, the identification of functional groups or reagents that are mutually reactive with one another, but unreactive with biopolymers and water, is challenging. Shown here are cobalt catalysts that react with alkenes under dilute, aqueous, buffered conditions and promote efficient cycloisomerization and formal Friedel-Crafts reactions. The constraining conditions of bioorthogonal chemistry are beneficial for reaction efficiency as superior conversion at low catalyst concentration is obtained and competent rates in dilute conditions are maintained. Efficiency at high dilution in the presence of buffer and nucleobases suggests that these reaction conditions may find broad application.
Subject(s)
Alkenes/chemistry , Water/chemistry , Catalysis , Cobalt/chemistry , Coordination Complexes/chemistry , Cyclization , Heterocyclic Compounds, 2-Ring/chemical synthesis , Heterocyclic Compounds, 3-Ring/chemical synthesis , IsomerismABSTRACT
The restricted expression pattern of B-cell maturation antigen (BCMA) makes it an ideal tumor-associated antigen (TAA) for the treatment of myeloma. BCMA has been targeted by both CD3 bispecific antibody and antibody-drug conjugate (ADC) modalities, but a true comparison of modalities has yet to be performed. Here we utilized a single BCMA antibody to develop and characterize both a CD3 bispecific and 2 ADC formats (cleavable and noncleavable) and compared activity both in vitro and in vivo with the aim of generating an optimal therapeutic. Antibody affinity, but not epitope was influential in drug activity and hence a high-affinity BCMA antibody was selected. Both the bispecific and ADCs were potent in vitro and in vivo, causing dose-dependent cell killing of myeloma cell lines and tumor regression in orthotopic myeloma xenograft models. Primary patient cells were effectively lysed by both CD3 bispecific and ADCs, with the bispecific demonstrating improved potency, maximal cell killing, and consistency across patients. Safety was evaluated in cynomolgus monkey toxicity studies and both modalities were active based on on-target elimination of B lineage cells. Distinct nonclinical toxicity profiles were seen for the bispecific and ADC modalities. When taken together, results from this comparison of BCMA CD3 bispecific and ADC modalities suggest better efficacy and an improved toxicity profile might be achieved with the bispecific modality. This led to the advancement of a bispecific candidate into phase I clinical trials.
Subject(s)
Antibodies, Bispecific/administration & dosage , B-Cell Maturation Antigen/metabolism , CD3 Complex/immunology , Immunoconjugates/administration & dosage , Multiple Myeloma/drug therapy , Animals , Antibodies, Bispecific/adverse effects , Antibodies, Bispecific/pharmacology , Antibody Affinity , B-Cell Maturation Antigen/antagonists & inhibitors , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Immunoconjugates/adverse effects , Immunoconjugates/pharmacology , Mice , Multiple Myeloma/metabolism , Signal Transduction/drug effects , Xenograft Model Antitumor AssaysABSTRACT
DNA-encoded libraries (DEL)-based discovery platforms have recently been widely adopted in the pharmaceutical industry, mainly due to their powerful diversity and incredible number of molecules. In the two decades since their disclosure, great strides have been made to expand the toolbox of reaction modes that are compatible with the idiosyncratic aqueous, dilute, and DNA-sensitive parameters of this system. However, construction of highly important C(sp3)-C(sp3) linkages on DNA through cross-coupling remains unexplored. In this article, we describe a systematic approach to translating standard organic reactions to a DEL setting through the tactical combination of kinetic analysis and empirical screening with information captured from data mining. To exemplify this model, implementation of the Giese addition to forge high value C-C bonds on DNA was studied, which represents a radical-based synthesis in DEL.
Subject(s)
DNA/chemistry , Gene Library , Models, Molecular , KineticsABSTRACT
Reported here are procedures for a one-pot oxidation and rearrangement of propargylamines to synthesize enaminones, with supporting mechanistic studies. Also reported are the extended one-pot syntheses of pyrazoles, including celecoxib and various heterocyclic compounds.
Subject(s)
Pargyline/analogs & derivatives , Propylamines/chemistry , Pyrazoles/chemical synthesis , Sulfonamides/chemical synthesis , Catalysis , Celecoxib , Combinatorial Chemistry Techniques , Molecular Structure , Oxidation-Reduction , Pargyline/chemistry , Pyrazoles/chemistry , Sulfonamides/chemistryABSTRACT
Antibody drug conjugates (ADCs) are a therapeutic class offering promise for cancer therapy. The attachment of cytotoxic drugs to antibodies can result in an effective therapy with better safety potential than nontargeted cytotoxics. To understand the role of conjugation site, we developed an enzymatic method for site-specific antibody drug conjugation using microbial transglutaminase. This allowed us to attach diverse compounds at multiple positions and investigate how the site influences stability, toxicity, and efficacy. We show that the conjugation site has significant impact on ADC stability and pharmacokinetics in a species-dependent manner. These differences can be directly attributed to the position of the linkage rather than the chemical instability, as was observed with a maleimide linkage. With this method, it is possible to produce homogeneous ADCs and tune their properties to maximize the therapeutic window.
Subject(s)
Antibodies/chemistry , Antineoplastic Agents/chemistry , Immunoconjugates/chemistry , Animals , Antibodies/immunology , Half-Life , Humans , Immunoconjugates/pharmacokinetics , Immunoconjugates/therapeutic use , Immunoglobulin Heavy Chains/chemistry , Immunoglobulin Heavy Chains/immunology , Immunoglobulin Light Chains/chemistry , Immunoglobulin Light Chains/immunology , Mice , Neoplasms/drug therapy , Rats , Transglutaminases/metabolism , Tubulin Modulators/chemistryABSTRACT
An extension of our previously reported series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. Addition of a second methyl group to the tether provided analogs that show increased potency in binding as well as cell-proliferation assays and, more importantly, are stable toward microsomes. We wish to disclose the discovery of a macrocycle which showed impressive biomarker activity 24-h post dosing and which demonstrated prolonged exposure in tumors. When studied in a lung cancer xenograft model, the compound demonstrated significant tumor size reduction.
Subject(s)
Antineoplastic Agents/chemistry , Benzamides/chemistry , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Lung Neoplasms/drug therapy , Macrocyclic Compounds/chemistry , Administration, Oral , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/therapeutic use , Benzamides/pharmacokinetics , Benzamides/therapeutic use , Binding Sites , Biomarkers/metabolism , Drug Evaluation, Preclinical , HSP90 Heat-Shock Proteins/metabolism , Humans , Mice , Mice, Nude , Microsomes, Liver/metabolism , Protein Structure, Tertiary , Rats , Transplantation, HeterologousABSTRACT
A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. In continuation of our research, heterocycle-containing tethers were explored with the intent to further improve potency and minimize hERG liabilities. This effort culminated in the discovery of compound 10, which efficiently suppressed proliferation of HCT116 and U87 cells. This compound showed prolonged Hsp90-inhibitory activity at least 24h post-administration consistent with elevated and prolonged exposure in the tumor. When studied in a xenograft model, the compound demonstrated significant suppression of tumor growth.
Subject(s)
Amines/chemical synthesis , Benzamides/chemical synthesis , Biomarkers, Tumor , Drug Discovery , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Macrocyclic Compounds/chemical synthesis , Macrocyclic Compounds/pharmacology , Amines/chemistry , Amines/pharmacology , Animals , Benzamides/chemistry , Benzamides/pharmacology , Benzoquinones/chemical synthesis , Benzoquinones/chemistry , Benzoquinones/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Inhibitory Concentration 50 , Lactams, Macrocyclic/chemical synthesis , Lactams, Macrocyclic/chemistry , Lactams, Macrocyclic/pharmacology , Macrocyclic Compounds/chemistry , Mice , Models, Molecular , Molecular Structure , Neoplasms/drug therapy , Xenograft Model Antitumor AssaysABSTRACT
A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. In continuation of our research in this area, macrocyclic amides and lactams were explored to reduce the risk of hERG liabilities. This effort culminated in the discovery of compound 38, which showed a favorable in vitro profile, and efficiently suppressed proliferation of several relevant cell lines. This compound showed prolonged Hsp90-inhibitory activity at least 24 h post-administration, consistent with elevated and prolonged exposure in the tumor.
Subject(s)
Antineoplastic Agents/pharmacology , Biomarkers/metabolism , Drug Design , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Lactams, Macrocyclic/chemical synthesis , Lactams, Macrocyclic/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/chemistry , Fluorescent Dyes/pharmacology , Humans , Inhibitory Concentration 50 , Lactams, Macrocyclic/chemistry , Models, Molecular , Molecular Structure , ortho-Aminobenzoates/chemical synthesis , ortho-Aminobenzoates/chemistry , ortho-Aminobenzoates/pharmacologyABSTRACT
A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. A basic nitrogen within the tether linking the aniline nitrogen atom to a tetrahydroindolone moiety allowed access to compounds with good physical properties. Important structure-activity relationship information was obtained from this series which led to the discovery of a soluble and stable compound which is potent in an Hsp90 binding and cell-proliferation assay.
Subject(s)
Antineoplastic Agents/chemistry , Benzamides/chemistry , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Benzamides/chemical synthesis , Benzamides/pharmacology , Binding Sites , Cell Line, Tumor , Cell Proliferation , Computer Simulation , Crystallography, X-Ray , Drug Design , HSP90 Heat-Shock Proteins/metabolism , Humans , Protein Binding , Structure-Activity RelationshipABSTRACT
A series of 8,9-dimethoxy-5-(2-aminoalkoxy-pyridin-3-yl)-benzo[c][2,7]naphthyridin-4-ylamine-based inhibitors of 3-phosphoinositide-dependent kinase-1 (PDK-1) has been identified. Several examples appear to be potent and relatively selective inhibitors of PDK-1 over the related AGC kinases PKA, PKB/AKT, and p70S6K. The introduction of a stereochemical center beside the amino substituent on the aminoalkoxy-side chain had little effect upon the inhibitory activity against these enzymes, and X-ray crystallographic analyses of a representative pair of enantiomeric inhibitors bound to the active site of PDK-1 revealed comparable binding modes for each enantiomer.
Subject(s)
Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Pyridines/pharmacology , 3-Phosphoinositide-Dependent Protein Kinases , Crystallography, X-Ray , Hydrogen Bonding , Models, Molecular , Molecular Structure , Protein Kinase Inhibitors/chemistry , Pyridines/chemistry , Static Electricity , Structure-Activity RelationshipABSTRACT
A series of substituted benzo[c][2,7]-naphthyridines were prepared and showed good potency in inhibiting PDK-1. The synthesis and SAR of this series of compounds are presented as well as the X-ray crystal structure of one of these analogs in a complex with PDK-1.
Subject(s)
Antineoplastic Agents/chemistry , Naphthyridines/chemistry , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/antagonists & inhibitors , 3-Phosphoinositide-Dependent Protein Kinases , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Binding Sites , Crystallography, X-Ray , Humans , Molecular Conformation , Naphthyridines/chemical synthesis , Naphthyridines/pharmacology , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/metabolism , Structure-Activity RelationshipABSTRACT
A series of 4-indolylamino-5-phenyl-3-pyridinecarbonitrile inhibitors of PKCtheta were synthesized as potential anti-inflammatory agents. The effects of specific substitution on the 5-phenyl moiety and variations of the positional isomers of the 4-indolylamino substituent were explored. This study led to the discovery of compound 12d, which had an IC(50) value of 18nM for the inhibition of PKCtheta.
Subject(s)
Isoenzymes/antagonists & inhibitors , Protein Kinase C/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Pyridines/chemical synthesis , Adenosine Triphosphate/chemistry , Animals , Anti-Inflammatory Agents/pharmacology , Chemistry, Pharmaceutical/methods , Drug Design , Humans , Inhibitory Concentration 50 , Isoenzymes/chemistry , Mice , Models, Chemical , Molecular Structure , Protein Isoforms , Protein Kinase C/chemistry , Protein Kinase C-theta , Protein Kinase Inhibitors/pharmacology , Pyridines/pharmacology , Structure-Activity RelationshipABSTRACT
A series of 4-dimethylamino-but-2-enoic acid [4-(3,6-dioxo-cyclohexa-1,4-dienylamino)-7-ethoxy-quinazolin-6-yl]-amide derivatives were prepared. These compounds have two independent reactive centers and were designed to function as dual irreversible inhibitors of the kinase domains of both Epidermal Growth Factor Receptor (EGFR) and Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) where each reactive center targets a different, non-conserved, cysteine residue located in the ATP binding pocket of these enzymes. The compounds contain a 6-(4-(dimethylamino) crotonamide) Michael acceptor group that targets Cys-773 in EGFR and a 4-(amino-[1,4]benzoquinone) moiety that targets Cys-1045 in VEGFR-2. In vitro studies indicated that most of these compounds are relatively potent inhibitors of each enzyme. These inhibitors were compared with reference compounds that lack one or both of the reactive centers. The relative dependence of the IC(50) values on the concentration of ATP used in the assays suggests that these compounds appear to function as irreversible inhibitors of each kinase.
Subject(s)
ErbB Receptors/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Quinazolines/chemistry , Quinazolines/pharmacology , Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors , Adenosine Triphosphate/chemistry , Adenosine Triphosphate/metabolism , Binding Sites , Biological Assay , Cells, Cultured , ErbB Receptors/chemistry , ErbB Receptors/metabolism , Humans , Inhibitory Concentration 50 , Models, Molecular , Molecular Structure , Protein Conformation/drug effects , Protein Kinase Inhibitors/chemical synthesis , Quinazolines/chemical synthesis , Vascular Endothelial Growth Factor Receptor-2/chemistry , Vascular Endothelial Growth Factor Receptor-2/metabolismABSTRACT
ZipA is a membrane anchored protein in Escherichia coli that interacts with FtsZ, a homolog of eukaryotic tubulins, forming a septal ring structure that mediates bacterial cell division. Thus, the ZipA/FtsZ protein-protein interaction is a potential target for an antibacterial agent. We report here an NMR-based fragment screening approach which identified several hits that bind to the C-terminal region of ZipA. The screen was performed by 1H-15N HSQC experiments on a library of 825 fragments that are small, lead-like, and highly soluble. Seven hits were identified, and the binding mode of the best one was revealed in the X-ray crystal structure. Similar to the ZipA/FtsZ contacts, the driving force in the binding of the small molecule ligands to ZipA is achieved through hydrophobic interactions. Analogs of this hit were also evaluated by NMR and X-ray crystal structures of these analogs with ZipA were obtained, providing structural information to help guide the medicinal chemistry efforts.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Carrier Proteins/antagonists & inhibitors , Cell Cycle Proteins/antagonists & inhibitors , Drug Evaluation, Preclinical/methods , Escherichia coli Proteins/antagonists & inhibitors , Magnetic Resonance Spectroscopy , Multiprotein Complexes/antagonists & inhibitors , Anti-Bacterial Agents/pharmacology , Carrier Proteins/metabolism , Cell Cycle Proteins/metabolism , Crystallography, X-Ray , Drug Design , Escherichia coli Proteins/metabolism , Hydrophobic and Hydrophilic Interactions , Ligands , Peptide Fragments/metabolism , Protein Binding , Structure-Activity RelationshipABSTRACT
A series of 2-(quinazolin-4-ylamino)-[1,4] benzoquinone derivatives that function as potent covalent-binding, irreversible inhibitors of the kinase domain of vascular endothelial growth factor receptor-2 (VEGFR-2) has been prepared by ceric ammonium nitrate oxidation of substituted (2,5-dimethoxyphenyl)(6,7-disubstituted-quinazolin-4-yl)amines and by displacement of the chlorine atom of substituted 2-chloro-5-(6,7-disubstituted-quinazolin-4-ylamino)-[1,4]benzoquinones with various amines, anilines, phenols, and alcohols. Enzyme studies were conducted in the absence and presence of glutathione and plasma. Several of the compounds inhibit VEGF-stimulated autophosphorylation in intact cells. Kinetic experiments were performed to study the reactivity of selected inhibitors toward glutathione. Reactivities correlated with LUMO energies calculated as averages of those of individual conformers weighted by the Boltzmann distribution. These results and molecular modeling were used to rationalize the biological observations. The compounds behave as non-ATP-competitive inhibitors. Unequivocal evidence, from mass spectral studies, indicates that these inhibitors form a covalent interaction with Cys-1045. One member of this series displays antitumor activity in an in vivo model.
Subject(s)
Angiogenesis Inhibitors/chemical synthesis , Benzoquinones/chemical synthesis , Quinazolines/chemical synthesis , Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors , Adenosine Triphosphate/metabolism , Angiogenesis Inhibitors/chemistry , Angiogenesis Inhibitors/pharmacology , Animals , Benzoquinones/chemistry , Benzoquinones/pharmacology , Binding Sites , Cell Line , Female , Glutathione/chemistry , Humans , Kinetics , Mice , Mice, Nude , Models, Molecular , Molecular Conformation , Phosphorylation , Protein Binding , Protein Structure, Tertiary , Quantum Theory , Quinazolines/chemistry , Quinazolines/pharmacology , Spectrometry, Mass, Electrospray Ionization , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Structure-Activity Relationship , Vascular Endothelial Growth Factor Receptor-2/chemistry , Vascular Endothelial Growth Factor Receptor-2/metabolism , Xenograft Model Antitumor AssaysABSTRACT
The effect of introducing hydrophobic groups onto the disaccharide portion of the mannopeptimycins has been examined. Under acid-catalyzed conditions dimethyl acetals and ketals react on the terminal mannose of the disaccharide moiety of mannopeptimycin-alpha and the cyclohexylalanyl analogue 2. The preferentially formed monofunctionalized 4,6-acetals and -ketals display potent antibacterial activities against Gram-positive microorganisms, including MRSA, PRSP, and VRE pathogens.
Subject(s)
Acetals/chemical synthesis , Anti-Bacterial Agents/chemical synthesis , Glycopeptides , Gram-Positive Bacteria/drug effects , Acetals/chemistry , Acetals/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Hydrophobic and Hydrophilic Interactions , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Spectrometry, Mass, Electrospray Ionization , Structure-Activity RelationshipABSTRACT
A series of highly potent thiourea inhibitors of cytomegalovirus (CMV) with improved stability properties was prepared and evaluated. Compound 29 inhibited the virus in cultured HFF cells with IC50 of 0.2 nM.
Subject(s)
Antiviral Agents/chemical synthesis , Cytomegalovirus/drug effects , Herpesviridae/drug effects , Thiourea/analogs & derivatives , Antiviral Agents/pharmacology , Cells, Cultured , Drug Resistance, Microbial , Humans , Inhibitory Concentration 50 , Structure-Activity Relationship , Thiourea/pharmacologyABSTRACT
AC98-6446 is a novel semisynthetic cyclic glycopeptide antibiotic related to the natural product mannopeptimycin alpha (AC98-1). In the present study the activity of AC98-6446 was evaluated against a variety of recent clinical gram-positive pathogens including multiply resistant strains. AC98-6446 demonstrated similar potent activities against methicillin-susceptible and methicillin-resistant staphylococci and glycopeptide-intermediate staphylococcal isolates (MICs at which 90% of isolates are inhibited [MIC(90)s], 0.03 to 0.06 microg/ml). AC98-6446 also demonstrated good activities against both vancomycin-resistant and -susceptible strains of enterococci (MIC(90)s, 0.12 and 0.25 microg/ml, respectively) as well as against streptococcal strains (MIC(90)s,
Subject(s)
Anti-Bacterial Agents/pharmacology , Glycopeptides/pharmacology , Gram-Positive Bacteria/drug effects , Gram-Positive Bacterial Infections/microbiology , Enterococcus faecalis/drug effects , Enterococcus faecium/drug effects , Humans , Kinetics , Microbial Sensitivity Tests , Staphylococcus aureus/drug effects , Streptococcus pneumoniae/drug effects , Vancomycin/pharmacologyABSTRACT
The naturally occurring mannopeptimycins (formerly AC98-1 through AC98-5) are a novel class of glycopeptide antibiotics that are active against a wide variety of gram-positive bacteria. The structures of the mannopeptimycins suggested that they might act by targeting cell wall biosynthesis, similar to other known glycopeptide antibiotics; but the fact that the mannopeptimycins retain activity against vancomycin-resistant organisms suggested that they might have a unique mode of action. By using a radioactive mannopeptimycin derivative bearing a photoactivation ligand, it was shown that mannopeptimycins interact with the membrane-bound cell wall precursor lipid II [C(55)-MurNAc-(peptide)-GlcNAc] and that this interaction is different from the binding of other lipid II-binding antibiotics such as vancomycin and mersacidin. The antimicrobial activities of several mannopeptimycin derivatives correlated with their affinities toward lipid II, suggesting that the inhibition of cell wall biosynthesis was primarily through lipid II binding. In addition, it was shown that mannopeptimycins bind to lipoteichoic acid in a rather nonspecific interaction, which might facilitate the accumulation of antibiotic on the bacterial cell surface.
Subject(s)
Anti-Bacterial Agents/pharmacology , Gram-Positive Bacteria/drug effects , Vancomycin Resistance , Affinity Labels , Anti-Bacterial Agents/metabolism , Bacterial Outer Membrane Proteins , Bacterial Proteins/metabolism , Binding, Competitive/drug effects , Carrier Proteins/metabolism , Cell Membrane/drug effects , Cell Membrane/metabolism , Chromatography, Thin Layer , Culture Media , Escherichia coli/drug effects , Escherichia coli Proteins , Glycopeptides , Gram-Positive Bacteria/metabolism , Hexosyltransferases/metabolism , Muramoylpentapeptide Carboxypeptidase/metabolism , Penicillin-Binding Proteins , Peptidoglycan/biosynthesis , Peptidyl Transferases/metabolism , Protein Binding , Receptors, Virus , Staphylococcus aureus/drug effects , Staphylococcus epidermidis/drug effectsABSTRACT
A series of ester and carbonate derivatives of the glycopeptide mannopeptimycin alpha (1) with potent activity against G+ bacteria, including the methicillin-resistant staphylococci and vancomycin-resistant enterococci, was synthesized. The SAR data obtained from natural and semisynthetic compounds demonstrated the importance of a hydrophobic group in the terminal mannosyl moiety for antibacterial activity.