RESUMO
The development of a versatile platform for the synthesis of 1,2-difunctionalized bicyclo[1.1.1]pentanes to potentially mimic ortho/meta-substituted arenes is described. The syntheses of useful building blocks bearing alcohol, amine, and carboxylic acid functional handles have been achieved from a simple common intermediate. Several ortho- and meta-substituted benzene analogs, as well as simple molecular matched pairs, have also been prepared using this platform. The results of in-depth ADME (absorption, distribution, metabolism, and excretion) investigations of these systems are presented, as well as computational studies which validate the ortho- or meta-character of these bioisosteres.
Assuntos
Hidrocarbonetos Aromáticos/química , Pentanos/química , Bioensaio , Cristalografia por Raios X , Hepatócitos/metabolismo , Humanos , Concentração Inibidora 50 , Pentanos/síntese química , EstereoisomerismoRESUMO
First generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (gefitinib and erlotinib) demonstrate excellent clinical efficacy for NSCLC patients carrying EGFR oncogenic mutations (L858R, del exon 19 deletions between amino acids 746 and 750). Invariable, drug resistance occurs with around 60% of it driven by the EGFR-T790M gatekeeper mutation. To counter the T790M-dependent resistance, third generation covalent EGFR inhibitors have been developed with high potency toward T790M containing mutants and selectivity over WT EGFR. This review provides an overview of the third generation drugs currently in clinical trials and also encompasses novel methodologies developed to discover third generation covalent EGFR drugs.
Assuntos
Antineoplásicos/farmacologia , Receptores ErbB/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Inibidores de Proteínas Quinases/farmacologia , Animais , Antineoplásicos/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Inibidores de Proteínas Quinases/químicaRESUMO
Here, we report accessing small 3-fluoropyrrolidines and 3,3-difluoropyrrolidines through a 1,3-dipolar cycloaddition with a simple azomethine ylide and a variety of vinyl fluorides and vinyl difluorides. We demonstrate that vinyl fluorides within α,ß-unsaturated, styrenyl and even enol ether systems can participate in the cycloaddition reaction. The vinyl fluorides are relatively easy to synthesize through a variety of methods, making the 3-fluoropyrrolidines very accessible.
Assuntos
Compostos Azo/química , Pirrolidinas/síntese química , Tiossemicarbazonas/química , Reação de Cicloadição , Estrutura Molecular , Pirrolidinas/química , EstereoisomerismoRESUMO
Isoquinolone is one of the most common heterocyclic core structures in countless natural products and many bioactive compounds. Here, a highly efficient approach to synthesize isoquinolone scaffolds on DNA via rhodium(III)-catalyzed C-H activation has been described. This chemistry transformation is robust and has shown good compatibility with DNA, which is suitable for DNA-encoded library synthesis.
Assuntos
DNA , Ródio , Ródio/química , Catálise , Estrutura Molecular , DNA/química , Isoquinolinas/química , Isoquinolinas/síntese químicaRESUMO
N-(Pyridin-2-yl) arylsulfonamides 1 and 2 (PF-915275) were identified as potent inhibitors of 11ß-hydroxysteroid dehydrogenase type 1. A screen for bioactivation revealed that these compounds formed glutathione conjugates. This communication presents the results of a risk benefit analysis carried out to progress 2 (PF-915275) to a clinical study and the strategies used to eliminate reactive metabolites in this series of inhibitors. Based on the proposed mechanism of bioactivation and structure-activity relationships, design efforts led to N-(pyridin-2-yl) arylsulfonamides such as 18 and 20 that maintained potent 11ß-hydroxysteroid dehydrogenase type 1 activity, showed exquisite pharmacokinetic profiles, and were negative in the reactive metabolite assay.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Aminopiridinas/farmacocinética , Sulfonamidas/farmacocinética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Aminopiridinas/química , Aminopiridinas/farmacologia , Glutationa/farmacocinética , Células HEK293 , Humanos , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologiaRESUMO
Immune activating agents represent a valuable class of therapeutics for the treatment of cancer. An area of active research is expanding the types of these therapeutics that are available to patients via targeting new biological mechanisms. Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of immune signaling and a target of high interest for the treatment of cancer. Herein, we present the discovery and optimization of novel amino-6-aryl pyrrolopyrimidine inhibitors of HPK1 starting from hits identified via virtual screening. Key components of this discovery effort were structure-based drug design aided by analyses of normalized B-factors and optimization of lipophilic efficiency.
Assuntos
Proteínas Serina-Treonina Quinases , Transdução de Sinais , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , Pirróis/farmacologiaRESUMO
Three photoaffinity labeled derivatives of epothilone D were prepared by total synthesis, using efficient novel asymmetric synthesis methods for the preparation of two important synthetic building blocks. The key step for the asymmetric synthesis of (S,E)-3-(tert-butyldimethylsilyloxy)-4-methyl-5-(2-methylthiazol-4-yl)pent-4-enal involved a ketone reduction with (R)-Me-CBS-oxazaborolidine. For the synthesis of (5S)-5,7-di[(tert-butyldimethylsilyl)oxy]-4,4-dimethylheptan-3-one an asymmetric Noyori reduction of a beta-ketoester was employed. The C26 hydroxyepothilone D derivative was constructed following a well-established total synthesis strategy and the photoaffinity labels were attached to the C26 hydroxyl group. The photoaffinity analogues were tested in a tubulin assembly assay and for cytotoxicity against MCF-7 and HCT-116 cancer cell lines. The 3- and 4-azidobenzoic acid analogues were found to be as active as epothilone B in a tubulin assembly assay, but demonstrated significantly reduced cellular cytotoxicity compared to epothilone B. The benzophenone analogue was inactive in both assays. Docking and scoring studies were conducted that suggested that the azide analogues can bind to the epothilone binding site, but that the benzophenone analogue undergoes a sterically driven ligand rearrangement that interrupts all hydrogen bonding and therefore protein binding. Photoaffinity labeling studies with the 3-azidobenzoic acid derivative did not identify any covalently labeled peptide fragments, suggesting that the phenylazido side chain was predominantly solvent-exposed in the bound conformation.
Assuntos
Epotilonas/síntese química , Sondas Moleculares/síntese química , Marcadores de Fotoafinidade/síntese química , Moduladores de Tubulina/síntese química , Tubulina (Proteína)/química , Epotilonas/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Marcadores de Fotoafinidade/química , Moduladores de Tubulina/químicaRESUMO
A series of C-2 pyrroloquinoline analogs designed to improve aqueous solubility were examined for herpesvirus polymerase and antiviral activity. Several analogs were identified that maintained the antiviral activity of the previous development candidate against HCMV, HSV-1 and VZV, but with significantly improved aqueous solubility.
Assuntos
Antivirais/química , Herpesviridae/enzimologia , Inibidores da Síntese de Ácido Nucleico , Pirróis/química , Quinolinas/química , Antivirais/síntese química , Antivirais/farmacologia , Citomegalovirus/efeitos dos fármacos , DNA Polimerase Dirigida por DNA/metabolismo , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 3/efeitos dos fármacos , Humanos , Pirróis/síntese química , Pirróis/farmacologia , Quinolinas/síntese química , Quinolinas/farmacologia , Solubilidade , Relação Estrutura-AtividadeRESUMO
The design and development of a series of highly selective pyrrolidine carboxamide 11beta-HSD1 inhibitors are described. These compounds including PF-877423 demonstrated potent in vitro activity against both human and mouse 11beta-HSD1 enzymes. In an in vivo assay, PF-877423 inhibited the conversion of cortisone to cortisol. Structure guided optimization effort yielded potent and stable 11beta-HSD1 selective inhibitor 42.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Adamantano/análogos & derivados , Amidas/química , Inibidores Enzimáticos/química , Hipoglicemiantes/química , Pirrolidinas/química , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Adamantano/síntese química , Adamantano/química , Adamantano/farmacologia , Amidas/síntese química , Amidas/farmacologia , Animais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Cobaias , Humanos , Hipoglicemiantes/síntese química , Hipoglicemiantes/farmacologia , Camundongos , Microssomos Hepáticos/metabolismo , Pirrolidinas/síntese química , Pirrolidinas/farmacologia , Relação Estrutura-AtividadeRESUMO
A unified synthetic strategy to access tertiary four-membered carbo/heterocyclic boronic esters is reported. Use of a Cu(I) catalyst in combination with a modified dppbz ligand enables regioselective hydroboration of various trisubstituted benzylidenecyclobutanes and carbo/heterocyclic analogs. The reaction conditions are mild, and the method tolerates a wide range of medicinally relevant heteroarenes. The protocol can be conveniently conducted on gram-scale, and the tertiary boronic ester products undergo facile diversification into valuable targets. Reaction kinetics and computational studies indicate that the migratory insertion step is turnover-limiting and accelerated by electron-withdrawing groups on the dppbz ligand. Energy decomposition analysis (EDA) calculations reveal that electron-deficient P-aryl groups on the dppbz ligand enhance the T-shaped π/π interactions with the substrate and stabilize the migratory insertion transition state.
RESUMO
Prostaglandins are widely used to lower intraocular pressure (IOP) as part of the treatment regimen for glaucoma. While FP and EP2 agonists are known to lower IOP, we investigated the ocular hypotensive activity and ocular drug distribution of PF-04475270, a novel EP4 agonist following topical administration in normotensive Beagle dogs. PF-04475270 is a prodrug of CP-734432, which stimulated cAMP formation in HEK293 cells expressing EP4 receptor and beta-lactamase activity in human EP4 expressing CHO cells transfected with a cAMP response element (CRE) with an EC(50) of 1 nM. Prodrug conversion and transcorneal permeability were assessed in rabbit corneal homogenates and a human corneal epithelial cell (cHCE) model. The compound underwent rapid hydrolysis to CP-734432 in corneal homogenates, and exhibited good permeability in the cHCE model. The descending order of ocular exposure to CP-734432 after topical dosing of PF-04475270 in dogs was as follows: cornea > aqueous humor >or= iris/ciliary body. When administered q.d., PF-04475270 lowered IOP effectively in the dog IOP model both after single and multiple days of dosing. A maximum decrease in IOP with PF-04475270 was between 30 and 45% at 24h post-dose relative to that observed with vehicle. In conclusion, PF-04475270 is a novel ocular hypotensive compound which is bioavailable following topical dosing, effectively lowering IOP in dogs. EP4 agonists could be considered as potential targets for lowering IOP for the treatment of glaucoma and ocular hypertension.
Assuntos
Olho/efeitos dos fármacos , Pressão Intraocular/efeitos dos fármacos , Pró-Fármacos/farmacocinética , Pirrolidinonas/farmacocinética , Receptores de Prostaglandina E/agonistas , Tiofenos/farmacocinética , Administração Tópica , Animais , Disponibilidade Biológica , Células CHO , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Cães , Relação Dose-Resposta a Droga , Olho/metabolismo , Olho/patologia , Humanos , Hidrólise , Hiperemia/induzido quimicamente , Modelos Animais , Soluções Oftálmicas , Permeabilidade , Pró-Fármacos/administração & dosagem , Pró-Fármacos/toxicidade , Pirrolidinonas/administração & dosagem , Pirrolidinonas/toxicidade , Coelhos , Receptores de Prostaglandina E/genética , Receptores de Prostaglandina E Subtipo EP4 , Tiofenos/administração & dosagem , Tiofenos/toxicidade , TransfecçãoRESUMO
N-(Pyridin-2-yl) arylsulfonamides are identified as inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1), an enzyme that catalyzes the reduction of the glucocorticoid cortisone to cortisol. Dysregulation of glucocorticoids has been implicated in the pathogenesis of diabetes and the metabolic syndrome. In this Letter, we present the development of an initial lead to an efficient ligand with improved physiochemical properties using a deletion strategy. This strategy allowed for further optimization of potency leading to the discovery of the clinical candidate PF-915275.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Aminopiridinas/síntese química , Inibidores Enzimáticos/síntese química , Sulfonamidas/síntese química , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Aminopiridinas/química , Aminopiridinas/farmacocinética , Animais , Linhagem Celular , Simulação por Computador , Cricetinae , Cristalografia por Raios X , Desenho de Fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Humanos , Ratos , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacocinéticaRESUMO
The total synthesis of 22-(3-azidobenzoyloxy)methyl epothilone C is described as a potential photoaffinity probe to elucidate the beta-tubulin binding site. A sequential Suzuki-aldol-Yamaguchi macrolactonization strategy was utilized employing a novel derivatized C1-C6 fragment. The C22-functionalized analog exhibited good activity in microtubule assembly assays, but cytotoxicity was significantly reduced. Molecular modeling simulations indicated that excessive steric bulk in the C22 position is accommodated by the large hydrophobic pocket of the binding site. Photoaffinity labeling studies were inconclusive suggesting non-specific labeling.
Assuntos
Epotilonas/síntese química , Marcadores de Fotoafinidade/química , Tubulina (Proteína)/química , Epotilonas/química , Humanos , Sondas Moleculares/síntese química , Moduladores de TubulinaRESUMO
The total synthesis of C25-benzyloxy epothilone C is described. A sequential Suzuki-Aldol-Yamaguchi macrolactonization strategy was utilized employing a novel derivatized C8-C12 fragment. The C25-benzyloxy analog exhibited significantly reduced biological activity in microtubule assembly and cytotoxicity assays. Molecular modeling simulations indicated that excessive steric bulk in the C25 position may reduce activity by disrupting key hydrogen bonds that are crucial for epothilone binding to beta-tubulin.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/toxicidade , Neoplasias da Mama/tratamento farmacológico , Epotilonas/síntese química , Epotilonas/toxicidade , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/toxicidade , Tubulina (Proteína)/biossíntese , Antineoplásicos/química , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Epotilonas/química , Humanos , Ligação de Hidrogênio/efeitos dos fármacos , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/químicaRESUMO
Mutant epidermal growth factor receptor (EGFR) is a major driver of non-small-cell lung cancer (NSCLC). Marketed first generation inhibitors, such as erlotinib, effect a transient beneficial response in EGFR mutant NSCLC patients before resistance mechanisms render these inhibitors ineffective. Secondary oncogenic EGFR mutations account for approximately 50% of relapses, the most common being the gatekeeper T790M substitution that renders existing therapies ineffective. The discovery of PF-06459988 (1), an irreversible pyrrolopyrimidine inhibitor of EGFR T790M mutants, was recently disclosed.1 Herein, we describe our continued efforts to achieve potency across EGFR oncogenic mutations and improved kinome selectivity, resulting in the discovery of clinical candidate PF-06747775 (21), which provides potent EGFR activity against the four common mutants (exon 19 deletion (Del), L858R, and double mutants T790M/L858R and T790M/Del), selectivity over wild-type EGFR, and desirable ADME properties. Compound 21 is currently being evaluated in phase-I clinical trials of mutant EGFR driven NSCLC.
Assuntos
Desenho de Fármacos , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirrolidinas/química , Pirrolidinas/farmacologia , Acrilamidas/química , Acrilamidas/farmacocinética , Acrilamidas/farmacologia , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Cães , Halogenação , Humanos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Camundongos , Modelos Moleculares , Simulação de Acoplamento Molecular , Mutação , Inibidores de Proteínas Quinases/farmacocinética , Pirrolidinas/farmacocinética , RatosRESUMO
First generation EGFR TKIs (gefitinib, erlotinib) provide significant clinical benefit for NSCLC cancer patients with oncogenic EGFR mutations. Ultimately, these patients' disease progresses, often driven by a second-site mutation in the EGFR kinase domain (T790M). Another liability of the first generation drugs is severe adverse events driven by inhibition of WT EGFR. As such, our goal was to develop a highly potent irreversible inhibitor with the largest selectivity ratio between the drug-resistant double mutants (L858R/T790M, Del/T790M) and WT EGFR. A unique approach to develop covalent inhibitors, optimization of reversible binding affinity, served as a cornerstone of this effort. PF-06459988 was discovered as a novel, third generation irreversible inhibitor, which demonstrates (i) high potency and specificity to the T790M-containing double mutant EGFRs, (ii) minimal intrinsic chemical reactivity of the electrophilic warhead, (iii) greatly reduced proteome reactivity relative to earlier irreversible EGFR inhibitors, and (iv) minimal activity against WT EGFR.
Assuntos
Descoberta de Drogas , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Proteínas Mutantes/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Pirróis/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Relação Dose-Resposta a Droga , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Modelos Moleculares , Estrutura Molecular , Mutação , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirimidinas/síntese química , Pirimidinas/química , Pirróis/síntese química , Pirróis/química , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Inhibition of the Smoothened (Smo) represents a promising therapeutic strategy for treating malignant tumors that are dependent on the Hedgehog (Hh) signaling pathway. PF-5274857 is a novel Smo antagonist that specifically binds to Smo with a K(i) of 4.6 ± 1.1 nmol/L and completely blocks the transcriptional activity of the downstream gene Gli1 with an IC(50) of 2.7 ± 1.4 nmol/L in cells. This Smo antagonist showed robust antitumor activity in a mouse model of medulloblastoma with an in vivo IC(50) of 8.9 ± 2.6 nmol/L. The downregulation of Gli1 is closely linked to the tumor growth inhibition in patched(+/-) medulloblastoma mice. Mathematical analysis of the relationship between the drug's pharmacokinetics and Gli1 pharmacodynamics in patched(+/-) medulloblastoma tumor models yielded similar tumor and skin Gli1 IC(50) values, suggesting that skin can be used as a surrogate tissue for the measurement of tumor Gli1 levels. In addition, PF-5274857 was found to effectively penetrate the blood-brain barrier and inhibit Smo activity in the brain of primary medulloblastoma mice, resulting in improved animal survival rates. The brain permeability of PF-5274857 was also confirmed and quantified in nontumor-bearing preclinical species with an intact blood-brain barrier. PF-5274857 was orally available and metabolically stable in vivo. These findings suggest that PF-5274857 is a potentially attractive clinical candidate for the treatment of tumor types including brain tumors and brain metastasis driven by an activated Hh pathway.
Assuntos
2,2'-Dipiridil/análogos & derivados , Proteínas Hedgehog/antagonistas & inibidores , Proteínas Hedgehog/metabolismo , Meduloblastoma/tratamento farmacológico , Piperazinas/farmacologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , 2,2'-Dipiridil/farmacologia , Animais , Antineoplásicos , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Linhagem Celular Tumoral , Células HEK293 , Humanos , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Meduloblastoma/patologia , Camundongos , Camundongos SCID , Camundongos Transgênicos , Receptores Patched , Ratos , Ratos Wistar , Receptores de Superfície Celular/genética , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor Smoothened , Proteína GLI1 em Dedos de ZincoRESUMO
N-acyl-urea derivatives of carbamazepine (CBZ) were synthesized through the reactions of iminostilbene with acyl-isocyanates to form N-glycyl-carbamazepine (N-Gly-CBZ, after a deprotection step) or N-acetyl-carbamazepine (N-acetyl-CBZ). N-Gly-CBZ was isolated as its water-soluble HCl salt and was designed to act as a prodrug and convert to CBZ and glycine in vivo by enzymatic cleavage of the acyl-urea bond. The stability pH-rate profiles for N-Gly-CBZ and N-acetyl-CBZ were determined. The stability of N-Gly-CBZ was found to range over four orders of magnitude with its greatest stability at pH 3-4 and a t(90) value of 5.9 day at pH 4 at 25 degrees C. From the fit of the pH rate profile two pK(a) values were estimated to be 7.2 (terminal amine) and 10.0 (imide), which were independently verified using UV-visible spectroscopic analysis. The solubility of N-Gly-CBZ in aqueous solution was determined in the range of pH 5.5-7.5. The intrinsic solubility of the neutral form of the prodrug was found to be 4.4 mg/mL, and the solubility of the prodrug increased exponentially (log linear) as pH was decreased below its pK(a1) value. N-Gly-CBZ was found to have an aqueous solubility in excess of 50 mg/mL at pH 4. The presence of N-Gly-CBZ was found to increase the aqueous solubility of CBZ, a degradation product. CBZ showed an 8.6-fold greater solubility in an aqueous solution containing 23 mg/mL of N-Gly-CBZ than in water alone. The solubilization of CBZ by N-Gly-CBZ was investigated by examining the diffusion coefficients of the predominant species in D(2)O and was found to be more consistent with stacking complex formation than micelle formation. The stability of N-Gly-CBZ makes a ready-to-use parenteral formulation impractical, but a freeze-dried preparation for reconstitution appears to be feasible.
Assuntos
Carbamazepina/química , Glicina/química , Pró-Fármacos/química , Carbamazepina/síntese química , Difusão , Estabilidade de Medicamentos , Glicina/síntese química , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Pró-Fármacos/síntese química , Solubilidade , Temperatura , Água/químicaRESUMO
A novel series of 2-aryl-2-hydroxyethylamine substituted 4-oxo-4,7-dihydrothieno[2,3-b]pyridine-5-carboxamides have been identified as potent antivirals against human herpesviruses. These compounds demonstrate broad-spectrum inhibition of the herpesvirus polymerases HCMV, HSV-1, EBV, and VZV with high specificity compared to human DNA polymerases.
Assuntos
Antivirais/farmacologia , Citomegalovirus/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Etilaminas/farmacologia , Exodesoxirribonucleases/antagonistas & inibidores , Herpesviridae/efeitos dos fármacos , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 4/efeitos dos fármacos , Inibidores da Síntese de Ácido Nucleico , Piridinas/farmacologia , Proteínas Virais/antagonistas & inibidores , Antivirais/síntese química , Antivirais/uso terapêutico , Ligação Competitiva , DNA Polimerase Dirigida por DNA , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/uso terapêutico , Etilaminas/síntese química , Herpes Zoster/tratamento farmacológico , Herpesviridae/enzimologia , Humanos , Modelos Químicos , Piridinas/síntese química , Relação Estrutura-AtividadeRESUMO
An efficient and concise approach to the synthesis of the macrolide core of the cryptophycins has been developed. A novel macrolactonization utilizing a reactive acyl-beta-lactam intermediate incorporates the beta-amino acid moiety within the 16-membered macrolide core. This modular approach, involving a cyanide-initiated acyl-beta-lactam ring opening followed by cyclization, was successfully applied to the total synthesis of cryptophycin-24. The strategy was also used in an efficient synthesis of the 6,6-dimethyl-substituted dechlorocryptophycin-52. In this case, the cyanide-initiated ring opening of the bis-substituted 2-azetidinone followed by macrolactonization was achieved through a catalytic process.