ABSTRACT
A new class of PDF inhibitor with potent, broad spectrum antibacterial activity is described. Optimization of blood stability and potency provided compounds with improved pharmacokinetics that were suitable for in vivo experiments. Compound 5c, which has robust antibacterial activity, demonstrated efficacy in two respiratory tract infection models.
Subject(s)
Amides/chemical synthesis , Amidohydrolases/antagonists & inhibitors , Anti-Bacterial Agents/chemical synthesis , Bacterial Proteins/antagonists & inhibitors , Proline/analogs & derivatives , Proline/chemical synthesis , Respiratory Tract Infections/drug therapy , Administration, Oral , Amides/pharmacology , Amidohydrolases/metabolism , Animals , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Crystallography, X-Ray , Disease Models, Animal , Haemophilus influenzae/drug effects , Haemophilus influenzae/growth & development , Humans , Injections, Intravenous , Microbial Sensitivity Tests , Models, Molecular , Proline/pharmacology , Rats , Respiratory Tract Infections/microbiology , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/growth & development , Structure-Activity RelationshipABSTRACT
Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction of phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.
Subject(s)
Antineoplastic Agents/chemical synthesis , Indazoles/chemical synthesis , Morpholines/chemical synthesis , Piperidines/chemical synthesis , Protein Serine-Threonine Kinases/antagonists & inhibitors , Pyrimidines/chemical synthesis , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Crystallography, X-Ray , Drug Screening Assays, Antitumor , Indazoles/chemistry , Indazoles/pharmacology , Mice , Mice, SCID , Models, Molecular , Molecular Structure , Morpholines/chemistry , Morpholines/pharmacology , Neoplasm Transplantation , Phosphorylation , Piperidines/chemistry , Piperidines/pharmacology , Protein Binding , Pyrimidines/chemistry , Pyrimidines/pharmacology , Pyruvate Dehydrogenase Acetyl-Transferring Kinase , Stereoisomerism , Structure-Activity Relationship , Transplantation, HeterologousABSTRACT
Cyanide, a well-known toxic substance that could be used as a weapon of mass destruction, is likely responsible for a substantial percentage of smoke inhalation deaths. The vitamin B(12) precursor cobinamide binds cyanide with high affinity, changing color and, correspondingly, its spectrophotometric spectrum in the ultraviolet/visible light range. Based on these spectral changes, we developed a new facile method to measure cyanide in blood using cobinamide. The limit of detection was 0.25 nmol, while the limit of quantitation was approximately 0.5 nmol. The method was reliable, requires minimal equipment, and correlated well with a previously established method. Moreover, we adapted it for rapid qualitative assessment of cyanide concentration, which could be used in the field to identify cyanide-poisoned subjects for immediate treatment.
Subject(s)
Cobamides/chemistry , Cyanides/blood , Limit of Detection , Spectrophotometry , Vitamin B 12/chemistryABSTRACT
We describe the structure-activity relationship of the C1-group of pyrano[3,4-b]indole based inhibitors of HCV NS5B polymerase. Further exploration of the allosteric binding site led to the discovery of the significantly more potent compound 12.
Subject(s)
Antiviral Agents/chemistry , Enzyme Inhibitors/chemistry , Indoles/chemistry , Pyrans/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Binding Sites , Crystallography, X-Ray , Drug Discovery , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Indoles/chemical synthesis , Indoles/pharmacology , Pyrans/chemical synthesis , Pyrans/pharmacology , Structure-Activity Relationship , Viral Nonstructural Proteins/metabolismABSTRACT
Fragment screening of phosphoinositide-dependent kinase-1 (PDK1) in a biochemical kinase assay afforded hits that were characterized and prioritized based on ligand efficiency and binding interactions with PDK1 as determined by NMR. Subsequent crystallography and follow-up screening led to the discovery of aminoindazole 19, a potent leadlike PDK1 inhibitor with high ligand efficiency. Well-defined structure-activity relationships and protein crystallography provide a basis for further elaboration and optimization of 19 as a PDK1 inhibitor.
ABSTRACT
The synthesis of racemic nitrile (+/-)-9 was accomplished in four steps and 58% overall yield from the known pyrrolidinone 5. Nitrile (+/-)-9 was resolved via preparative chiral HPLC to afford optically pure nitriles (+)-9 and (-)-9, from which 3,3-dimethylprolines (+)-1 and (-)-1 and 3,3-dimethylprolinamides (+)-2 and (-)-2 could be accessed in nearly quantitative yield, without loss of optical purity. The absolute configurations of the resolved prolines and prolinamides were determined by correlation with an intermediate of known absolute stereochemistry.
Subject(s)
Proline/analogs & derivatives , Proline/chemical synthesis , Pyrrolidines/chemistry , Molecular Structure , Proline/chemistry , StereoisomerismABSTRACT
Gold islands, vapor deposited on silicon and quartz by microsphere lithography patterning, are used to nucleate arrays of ZnO nanorods. ZnO is grown on approximately 0.32 microm2 Au islands by carbothermal reduction in a tube furnace. Scanning electron microscopy (SEM) and energy dispersive atomic X-ray spectroscopy (EDS) confirm that the gold effectively controls the sites of nucleation of ZnO. Atomic force microscopy (AFM) shows that approximately 30 nm diameter nanorods grow horizontally, along the surface. Alloy droplets that are characteristic of the vapor-liquid-solid (VLS) mechanism are observed at the tips of the nanorods. The spatial growth direction of VLS catalyzed ZnO nanorods is along the substrate when they nucleate from gold islands on silicon and quartz. The energy of adhesion of the VLS droplet to the surface can account for the horizontal growth.
