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1.
Curr Med Res Opin ; 38(5): 777-784, 2022 05.
Article in English | MEDLINE | ID: mdl-35262430

ABSTRACT

OBJECTIVE: Network meta-analysis was used to derive estimates of the relative efficacy of inclisiran, evolocumab, alirocumab, bempedoic acid, and ezetimibe in patients with hypercholesterolemia and/or at increased cardiovascular risk due to elevated low-density lipoprotein cholesterol taking maximum tolerated dose statins. METHODS: Clinical trials published through February 2021 comparing percent change from baseline in low-density lipoprotein cholesterol were identified via a systematic review. Bayesian network meta-analyses were performed for patients with atherosclerotic cardiovascular disease and/or high cardiovascular risk on maximally tolerated statins in the base case, which included 23 trials. RESULTS: Results from the base-case analyses demonstrated that inclisiran, evolocumab, and alirocumab provide superior efficacy over placebo, bempedoic acid, and ezetimibe in terms of reduction in low-density lipoprotein cholesterol. Inclisiran was also comparable to alirocumab (mean difference: 0.78% [95% CrI: -8.35, 9.88]) and evolocumab (8.16%, [95% CrI: -1.82, 18.49]). Findings of a scenario which also included trials conducted in patients with heterozygous familial hypercholesterolemia were consistent with the base case. There was evidence of statistical heterogeneity across the included trials, roughly equivalent to variation of 5-10% change in low-density lipoprotein cholesterol, suggesting that any differences between treatments that were greater than 5-10% are generalizable. CONCLUSIONS: This study provides insight regarding the comparative efficacy of drugs for which no head-to-head trials exist and suggests that inclisiran, alirocumab, and evolocumab are expected to provide similar clinically meaningful improvements in low-density lipoprotein cholesterol in patients with hypercholesterolemia on maximally tolerated statins who are at increased cardiovascular risk.


Subject(s)
Anticholesteremic Agents , Cardiovascular Diseases , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Hypercholesterolemia , Hyperlipidemias , Anticholesteremic Agents/adverse effects , Anticholesteremic Agents/therapeutic use , Bayes Theorem , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control , Cholesterol , Cholesterol, LDL , Ezetimibe/therapeutic use , Heart Disease Risk Factors , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Hypercholesterolemia/complications , Hypercholesterolemia/drug therapy , Hyperlipidemias/drug therapy , Network Meta-Analysis , Risk Factors , Treatment Outcome
2.
Facial Plast Surg ; 32(2): 219-24, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27097144

ABSTRACT

The stigma of nasal deformity due to a congenital cleft lip-palate has an undeniable influence on the affected patient's life. It is therefore of interest to investigate if efforts to reduce esthetic and functional impairments by rhinoplasty (single or multiple) can result in an increased satisfaction with appearance and a self-perception similar to the noncleft population. Retrospective scoring before and after rhinoplasty using the validated Derriford Appearance Scale (DAS-59) and subsequent statistical evaluation and comparison to datasets available in the literature for further classification was used. Of the 61 patients who underwent at least one rhinoplasty, 26 responded to all questions. The mean age of responders was approximately 30 years of age and the male:female ratio was 1:1.2. The scale showed a significant overall improvement after surgery. The full scale and all subscale scores of the DAS-59 were significantly reduced after surgery demonstrating an improvement in the respective categories. Most importantly, if postoperative results were compared with a population concerned and unconcerned about appearance, no difference "facial self-consciousness" of appearance was apparent. Also postoperative subscores for "general self-consciousness" (GSC) and "social self-consciousness" of appearance (SSC) showed no difference from those obtained from the population concerned about appearance. The postoperative subscore for "sexual and bodily self-consciousness" of appearance (SBSC) indicated improvement beyond the level found in the concerned control population. Due to only a low improvement in the difference compared with the subscore representing a "negative self-concept," a statistically significant difference to the concerned population remained, possibly indicating that therapy beyond surgery is needed for improvement. After rhinoplasty, the investigated group of cleft lip-palate patients with nasal deformities showed an improvement in their self-conceived appearance as measured by the DAS-59. Their assessment of self-appearance was comparable to that of a group of noncleft persons with concern about their appearance. Taken together, rhinoplasties, primary and revision, add to the psychosocial well-being and an improved self-perception enhancing quality of life and enabling a more normal life. Further research is needed to clarify how the low reduction found in the "negative self-concept" may be addressed successfully.


Subject(s)
Cleft Lip/surgery , Cleft Palate/surgery , Nose/abnormalities , Nose/surgery , Rhinoplasty , Adult , Esthetics , Female , Follow-Up Studies , Humans , Male , Self Concept , Time Factors , Treatment Outcome
3.
J Med Chem ; 58(24): 9663-79, 2015 Dec 24.
Article in English | MEDLINE | ID: mdl-26551034

ABSTRACT

The HTS-based discovery and structure-guided optimization of a novel series of GKRP-selective GK-GKRP disrupters are revealed. Diarylmethanesulfonamide hit 6 (hGK-hGKRP IC50 = 1.2 µM) was optimized to lead compound 32 (AMG-0696; hGK-hGKRP IC50 = 0.0038 µM). A stabilizing interaction between a nitrogen atom lone pair and an aromatic sulfur system (nN → σ*S-X) in 32 was exploited to conformationally constrain a biaryl linkage and allow contact with key residues in GKRP. Lead compound 32 was shown to induce GK translocation from the nucleus to the cytoplasm in rats (IHC score = 0; 10 mg/kg po, 6 h) and blood glucose reduction in mice (POC = -45%; 100 mg/kg po, 3 h). X-ray analyses of 32 and several precursors bound to GKRP were also obtained. This novel disrupter of GK-GKRP binding enables further exploration of GKRP as a potential therapeutic target for type II diabetes and highlights the value of exploiting unconventional nonbonded interactions in drug design.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Glucokinase/metabolism , Hypoglycemic Agents/chemistry , Sulfonamides/chemistry , Thiophenes/chemistry , Active Transport, Cell Nucleus , Animals , Blood Glucose/metabolism , Cell Nucleus/metabolism , Crystallography, X-Ray , Cytoplasm/metabolism , Hypoglycemic Agents/pharmacokinetics , Hypoglycemic Agents/pharmacology , Male , Mice , Microsomes, Liver/metabolism , Models, Molecular , Molecular Conformation , Protein Binding , Rats, Sprague-Dawley , Stereoisomerism , Structure-Activity Relationship , Sulfonamides/pharmacokinetics , Sulfonamides/pharmacology , Thiophenes/pharmacokinetics , Thiophenes/pharmacology
4.
J Med Chem ; 58(1): 480-511, 2015 Jan 08.
Article in English | MEDLINE | ID: mdl-25469863

ABSTRACT

The development and optimization of a series of quinolinylpurines as potent and selective PI3Kδ kinase inhibitors with excellent physicochemical properties are described. This medicinal chemistry effort led to the identification of 1 (AMG319), a compound with an IC50 of 16 nM in a human whole blood assay (HWB), excellent selectivity over a large panel of protein kinases, and a high level of in vivo efficacy as measured by two rodent disease models of inflammation.


Subject(s)
Adenosine/pharmacology , Autoimmune Diseases/prevention & control , Class I Phosphatidylinositol 3-Kinases/antagonists & inhibitors , Inflammation/prevention & control , Protein Kinase Inhibitors/pharmacology , Quinolines/pharmacology , Adenosine/chemistry , Adenosine/metabolism , Animals , Cells, Cultured , Class I Phosphatidylinositol 3-Kinases/chemistry , Class I Phosphatidylinositol 3-Kinases/metabolism , Crystallography, X-Ray , Disease Models, Animal , Drug Discovery , Female , Humans , Mice, Inbred BALB C , Mice, Transgenic , Models, Chemical , Models, Molecular , Molecular Structure , Protein Binding , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/metabolism , Protein Structure, Tertiary , Quinolines/chemistry , Quinolines/metabolism , Rats, Inbred Lew , Sf9 Cells , Structure-Activity Relationship
5.
Front Psychol ; 5: 1390, 2014.
Article in English | MEDLINE | ID: mdl-25540629

ABSTRACT

This study explores the emergence of triadic interactions through the example of book sharing. As part of a naturalistic study, 10 infants were visited in their homes from 3-12 months. We report that (1) book sharing as a form of infant-caregiver-object interaction occurred from as early as 3 months. Using qualitative video analysis at a micro-level adapting methodologies from conversation and interaction analysis, we demonstrate that caregivers and infants practiced book sharing in a highly co-ordinated way, with caregivers carving out interaction units and shaping actions into action arcs and infants actively participating and co-ordinating their attention between mother and object from the beginning. We also (2) sketch a developmental trajectory of book sharing over the first year and show that the quality and dynamics of book sharing interactions underwent considerable change as the ecological situation was transformed in parallel with the infants' development of attention and motor skills. Social book sharing interactions reached an early peak at 6 months with the infants becoming more active in the coordination of attention between caregiver and book. From 7 to 9 months, the infants shifted their interest largely to solitary object exploration, in parallel with newly emerging postural and object manipulation skills, disrupting the social coordination and the cultural frame of book sharing. In the period from 9 to 12 months, social book interactions resurfaced, as infants began to effectively integrate manual object actions within the socially shared activity. In conclusion, to fully understand the development and qualities of triadic cultural activities such as book sharing, we need to look especially at the hitherto overlooked early period from 4 to 6 months, and investigate how shared spaces of meaning and action are structured together in and through interaction, creating the substrate for continuing cooperation and cultural learning.

6.
Bioorg Med Chem ; 22(23): 6570-6585, 2014 Dec 01.
Article in English | MEDLINE | ID: mdl-25456383

ABSTRACT

We report the discovery of a novel series of 2-(3-alkoxy-1-azetidinyl) quinolines as potent and selective PDE10A inhibitors. Structure-activity studies improved the solubility (pH 7.4) and maintained high PDE10A activity compared to initial lead compound 3, with select compounds demonstrating good oral bioavailability. X-ray crystallographic studies revealed two distinct binding modes to the catalytic site of the PDE10A enzyme. An ex vivo receptor occupancy assay in rats demonstrated that this series of compounds covered the target within the striatum.


Subject(s)
Phosphodiesterase Inhibitors/pharmacology , Phosphoric Diester Hydrolases/metabolism , Quinolines/pharmacology , Dose-Response Relationship, Drug , Humans , Models, Molecular , Molecular Structure , Phosphodiesterase Inhibitors/chemical synthesis , Phosphodiesterase Inhibitors/chemistry , Quinolines/chemical synthesis , Quinolines/chemistry , Solubility , Structure-Activity Relationship
7.
Eur J Med Chem ; 80: 364-82, 2014 Jun 10.
Article in English | MEDLINE | ID: mdl-24793884

ABSTRACT

The Cell division cycle 7 (Cdc7) protein kinase is essential for DNA replication and maintenance of genome stability. We systematically explored thiazole-based compounds as inhibitors of Cdc7 kinase activity in cancer cells. Our studies resulted in the identification of a potent, selective Cdc7 inhibitor that decreased phosphorylation of the direct substrate MCM2 in vitro and in vivo, and inhibited DNA synthesis and cell viability in vitro.


Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Thiazoles/chemical synthesis , Thiazoles/pharmacology , Animals , Catalytic Domain , Cell Cycle Proteins/chemistry , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Chemistry Techniques, Synthetic , Female , HCT116 Cells , Humans , Inhibitory Concentration 50 , Male , Mice , Minichromosome Maintenance Complex Component 2/metabolism , Molecular Docking Simulation , Phosphorylation/drug effects , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/metabolism , Protein Serine-Threonine Kinases/chemistry , Protein Serine-Threonine Kinases/metabolism , Rats , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/metabolism , Xenograft Model Antitumor Assays
8.
Bioorg Med Chem Lett ; 23(23): 6396-400, 2013 Dec 01.
Article in English | MEDLINE | ID: mdl-24120542

ABSTRACT

A series of aminooxadiazoles was optimized for inhibition of Cdc7. Early lead isoquinoline 1 suffered from modest cell potency (cellular IC50=0.71 µM measuring pMCM2), low selectivity against structurally related kinases, and high IV clearance in rats (CL=18 L/h/kg). Extensive optimization resulted in azaindole 26 (Cdc7 IC50=1.1 nM, pMCM2 IC50=32 nM) that demonstrated robust lowering of pMCM2 in a mouse pharmacodynamic (PD) model when dosed orally. Modifications to improve the pharmacokinetic profile of this series were guided by trapping experiments with glutathione in rat hepatocytes.


Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Oxadiazoles/chemistry , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Animals , Cell Cycle Proteins/chemistry , Cell Cycle Proteins/metabolism , Disease Models, Animal , Female , Mice , Mice, Nude , Molecular Structure , Oxadiazoles/chemical synthesis , Oxadiazoles/pharmacology , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/chemistry , Protein Serine-Threonine Kinases/metabolism , Rats , Structure-Activity Relationship , Xenograft Model Antitumor Assays
9.
Philos Trans R Soc Lond B Biol Sci ; 368(1628): 20130063, 2013 Oct 19.
Article in English | MEDLINE | ID: mdl-24018725

ABSTRACT

When watching an actor manipulate objects, observers, like the actor, naturally direct their gaze to each object as the hand approaches and typically maintain gaze on the object until the hand departs. Here, we probed the function of observers' eye movements, focusing on two possibilities: (i) that observers' gaze behaviour arises from processes involved in the prediction of the target object of the actor's reaching movement and (ii) that this gaze behaviour supports the evaluation of mechanical events that arise from interactions between the actor's hand and objects. Observers watched an actor reach for and lift one of two presented objects. The observers' task was either to predict the target object or judge its weight. Proactive gaze behaviour, similar to that seen in self-guided action-observation, was seen in the weight judgement task, which requires evaluating mechanical events associated with lifting, but not in the target prediction task. We submit that an important function of gaze behaviour in self-guided action observation is the evaluation of mechanical events associated with interactions between the hand and object. By comparing predicted and actual mechanical events, observers, like actors, can gain knowledge about the world, including information about objects they may subsequently act upon.


Subject(s)
Anticipation, Psychological/physiology , Attention/physiology , Eye Movements/physiology , Fixation, Ocular/physiology , Pattern Recognition, Visual/physiology , Adult , Analysis of Variance , Female , Hand , Humans , Male , Photic Stimulation , Reaction Time
10.
Exp Brain Res ; 228(2): 221-34, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23681295

ABSTRACT

The ability to predict accurately the weights of objects is essential for skilled and dexterous manipulation. A potentially important source of information about object weight is through the observation of other people lifting objects. Here, we tested the hypothesis that when watching an actor lift an object, people naturally learn the object's weight and use this information to scale forces when they subsequently lift the object themselves. Participants repeatedly lifted an object in turn with an actor. Object weight unpredictably changed between 2 and 7 N every 5th to 9th of the actor's lifts, and the weight lifted by the participant always matched that previously lifted by the actor. Even though the participants were uninformed about the structure of the experiment, they appropriately adapted their lifting force in the first trial after a weight change. Thus, participants updated their internal representation about the object's weight, for use in action, when watching a single lift performed by the actor. This ability presumably involves the comparison of predicted and actual sensory information related to actor's actions, a comparison process that is also fundamental in action.


Subject(s)
Adaptation, Physiological/physiology , Imitative Behavior/physiology , Lifting , Movement/physiology , Psychomotor Performance/physiology , Female , Humans , Male
11.
Bioorg Med Chem Lett ; 23(7): 2056-60, 2013 Apr 01.
Article in English | MEDLINE | ID: mdl-23481650

ABSTRACT

Cdc7 kinase is responsible for the initiation and regulation of DNA replication and has been proposed as a target for cancer therapy. We have identified a class of Cdc7 inhibitors based on a substituted indole core. Synthesis of focused indole and azaindole analogs yielded potent and selective 5-azaindole Cdc7 inhibitors with improved intrinsic metabolic stability (ie 36). In parallel, quantum mechanical conformational analysis helped to rationalize SAR observations, led to a proposal of the preferred binding conformation in the absence of co-crystallography data, and allowed the design of 7-azaindole 37 as a second lead in this series.


Subject(s)
Aza Compounds/pharmacology , Cell Cycle Proteins/antagonists & inhibitors , Indoles/pharmacology , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Animals , Aza Compounds/chemical synthesis , Aza Compounds/chemistry , Cell Cycle Proteins/metabolism , Dose-Response Relationship, Drug , Humans , Indoles/chemical synthesis , Indoles/chemistry , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/metabolism , Rats , Structure-Activity Relationship
13.
Org Lett ; 12(4): 792-5, 2010 Feb 19.
Article in English | MEDLINE | ID: mdl-20099864

ABSTRACT

An efficient and convenient method for the synthesis of [1,2,4]triazolo[4,3-a]pyridines was exemplified by the synthesis of 20 analogues bearing a variety of substituents at the 3-position. The methodology involves a palladium-catalyzed addition of hydrazides to 2-chloropyridine, which occurs chemoselectively at the terminal nitrogen atom of the hydrazide, followed by dehydration in acetic acid under microwave irradiation.


Subject(s)
Combinatorial Chemistry Techniques , Hydrazines/chemistry , Palladium/chemistry , Pyridines/chemistry , Pyridines/chemical synthesis , Triazoles/chemical synthesis , Acetic Acid/chemistry , Catalysis , Cyclization , Microwaves , Molecular Structure , Triazoles/chemistry
14.
J Med Chem ; 52(22): 7044-53, 2009 Nov 26.
Article in English | MEDLINE | ID: mdl-19856920

ABSTRACT

Tumor protein 53 (p53) is a critical regulator of cell cycle and apoptosis that is frequently disabled in human tumors. In many tumor types, p53 is deleted or mutated, but in others p53 is inactivated by overexpression or amplification of its negative regulator mouse double minute 2 (MDM2). A high-throughput screening effort identified 6,7-bis(4-bromophenyl)-7,12-dihydro-6H-chromeno[4,3-d][1,2,4]triazolo[1,5-a]pyrimidine as a potent inhibitor of the MDM2-p53 protein-protein interaction. This screening hit was found to be chemically unstable and difficult to handle due to poor DMSO solubility. Co-crystallization with the target protein helped to direct further optimization and provided a tractable lead series of novel MDM2-p53 inhibitors. In cellular assays, these compounds were shown to upregulate p53 protein levels and p53 signaling and to cause p53-dependent inhibition of proliferation and apoptosis.


Subject(s)
Drug Discovery , Proto-Oncogene Proteins c-mdm2/metabolism , Pyrimidines/chemistry , Pyrimidines/pharmacology , Tumor Suppressor Protein p53/metabolism , Apoptosis/drug effects , Cell Proliferation/drug effects , HCT116 Cells , Humans , Inhibitory Concentration 50 , Models, Molecular , Molecular Conformation , Protein Binding/drug effects , Stereoisomerism , Structure-Activity Relationship
15.
J Am Chem Soc ; 131(11): 3840-1, 2009 Mar 25.
Article in English | MEDLINE | ID: mdl-19249829

ABSTRACT

A convergent synthesis of the marine natural product (+)-peloruside has been reported. This target has been assembled through the successive application of two methyl ketone boron aldol addition reactions to the latent C(7)-C(11) dialdehyde synthon. This approach afforded a 22-step synthesis of this natural product. The influence of resident stereocenters on aldol reaction diastereoselection has been examined in detail.


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic/chemical synthesis , Lactones/chemical synthesis , Alcohols , Aldehydes , Animals , Biological Products/chemical synthesis , Porifera/chemistry , Stereoisomerism , Tubulin Modulators/chemical synthesis
16.
J Med Chem ; 51(20): 6271-9, 2008 Oct 23.
Article in English | MEDLINE | ID: mdl-18817365

ABSTRACT

Investigations into the structure-activity relationships (SAR) of a series of phthalazine-based inhibitors of p38 are described. These efforts originated from quinazoline 1 and through rational design led to the development of a series of orally bioavailable, potent, and selective inhibitors. Kinase selectivity was achieved by exploiting a collection of interactions with p38alpha including close contact to Ala157, occupation of the hydrophobic gatekeeper pocket, and a residue flip with Gly110. Substitutions on the phthalazine influenced the pharmacokinetic properties, of which compound 16 displayed the most desirable profile. Oral dosing (0.03 mg/kg) of 16 in rats 1 h prior to LPS challenge gave a >50% decrease in TNFalpha production.


Subject(s)
Mitogen-Activated Protein Kinase 14/antagonists & inhibitors , Phthalazines/chemistry , Phthalazines/pharmacology , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Animals , Cells, Cultured , Crystallography, X-Ray , Drug Evaluation, Preclinical , Humans , Mitogen-Activated Protein Kinase 14/chemistry , Mitogen-Activated Protein Kinase 14/metabolism , Models, Molecular , Molecular Structure , Phthalazines/chemical synthesis , Protein Kinase Inhibitors/chemical synthesis , Quinolines/chemical synthesis , Quinolines/chemistry , Quinolines/pharmacology , Rats , Sensitivity and Specificity , Structure-Activity Relationship
17.
Perception ; 36(7): 1066-83, 2007.
Article in English | MEDLINE | ID: mdl-17844972

ABSTRACT

In a series of exploratory experiments we investigated interrelations between structure and shape of architectural indoor spaces on the one hand, and affective experience and navigation behaviour on the other hand. For this, isovist-based descriptions of 16 virtual indoor scenes were correlated with behavioural data from the experimental tasks. For all tasks-two active navigation tasks and an introspective appraisal of experiential qualities--strong correlations between subjects' behaviour and a small set of quantitative measurands derived from the isovists were found. The outcomes suggest that isovist analysis captures behaviourally relevant properties of space and is therefore a promising general means for predicting central experiential qualities of architecture and navigation behaviour.


Subject(s)
Locomotion , Space Perception , Adult , Emotions , Environment Design , Female , Humans , Male , Orientation , Psychomotor Performance , Reaction Time , Sensation , Sex Factors , Spatial Behavior , User-Computer Interface
18.
Acc Chem Res ; 39(7): 433-42, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16846207

ABSTRACT

Small peptides exhibit a wide range of biological activities, but although there are some notable exceptions, they are not generally useful as drugs. This has spurred widespread interest in designing peptidomimetics and introducing them as replacements of portions of native peptides to enhance their biological properties. Special attention has been focused upon rigid replacements because of their potential to preorganize the resulting pseudopeptide in a conformation corresponding to its bound structure. Toward this goal, we invented trisubstituted cyclopropanes as novel peptidomimetics, anticipating that the cyclopropane ring would locally orient the backbone and the corresponding amino acid side chain in the biologically active conformation. Selected aspects of the syntheses and applications of these cyclopropane-derived peptidomimetics are presented in this Account.


Subject(s)
Cyclopropanes/chemistry , Molecular Mimicry , Peptides/chemical synthesis , Matrix Metalloproteinase Inhibitors , Models, Molecular , Peptides/chemistry , Protease Inhibitors/chemical synthesis , Protease Inhibitors/chemistry
19.
J Org Chem ; 67(12): 4062-75, 2002 Jun 14.
Article in English | MEDLINE | ID: mdl-12054939

ABSTRACT

We have previously used trisubstituted cyclopropanes as peptide replacements to induce conformational constraints in known pseudopeptide inhibitors of a number of important enzymes. Cyclopropane-derived peptide mimics are novel in that they are among the few replacements that locally orient the peptide backbone and the amino acid side chain in a predefined manner. Although these dipeptide isosteres have been employed to orient amino acid side chains mimicking the gauche(-) conformation of chi(1)-space, their ability to project the side chains into an anti orientation has not been evaluated. As a first step toward this goal, the conformationally constrained pseudopeptides 8 and 10 and their corresponding flexible analogues 9 and 11 were prepared and tested as inhibitors of matrix metalloproteinases (MMPs). These compounds are analogues of 4 and 5, which were known to be potent MMP inhibitors. The anti orientations of the isopropyl side chain in 8 and the aromatic ring in 10 relative to the peptide backbone substituents on the cyclopropane were predicted to correspond to the known orientations of the P1' and P2' side chains of 5 when bound to MMPs. Hence, 8 and 10 were designed explicitly to probe topological features of the S1' or the S2' binding pockets of the MMPs. They were also designed to explore the importance of the P1'-P2' amide group, which is known to form highly conserved hydrogen bonds in several MMP-inhibitor complexes, and the viability of introducing a retro amide linkage between P2' and P3'. Pseudopeptides 8 and 9 were found to be weak competitive inhibitors of a series of MMPs. Any entropically favorable conformational constraints that were induced by the cyclopropane in 8 were thus overwhelmed by the loss of the hydrogen bonding capability associated with the P1'-P2' amide group. On the other hand, compounds 10 and 11, which contain a P2'-P3' retro amide group, were modest competitive inhibitors of a series of MMPs. The results obtained for 10 and 11 suggest that there may be a loss of hydrogen bonding capability associated with introducing the P2'-P3' retro amide group. However, because the conformationally constrained pseudopeptide 10 was significantly more potent than its flexible analogue 11, trisubstituted cyclopropanes related to 3 may serve as useful rigid dipeptide replacements in some biologically active pseudopeptides.


Subject(s)
Cyclopropanes/chemistry , Drug Design , Matrix Metalloproteinase Inhibitors , Molecular Mimicry , Peptides , Protease Inhibitors/chemical synthesis , Amino Acid Sequence , Binding Sites , Combinatorial Chemistry Techniques , Drug Evaluation, Preclinical , Inhibitory Concentration 50 , Models, Molecular , Molecular Structure , Oxidation-Reduction , Peptides/chemical synthesis , Peptides/chemistry , Peptides/pharmacology , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , Spectrum Analysis , Structure-Activity Relationship , Substrate Specificity
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