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ABSTRACT: Novel substituted 2-methyl-3-indolylacetic derivatives were synthesized and evaluated for their activity in vitro and in vivo on COX-1 and COX-2. Active compounds were screened to determine their gastrointestinal tolerability in vivo in the rat. Results showed that 3 and 4 preferentially inhibited COX-1 in vitro and in vivo. MD simulations indicated an induced fit for COX-1 but not for COX-2, probably because of a lower plasticity of the latter.
Journal of Medicinal Chemistry 01/2007; 49(26):7774-80. · 5.25 Impact Factor
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Eleonora Distrutti,
Luca Sediari,
Andrea Mencarelli,
Barbara Renga,
Stefano Orlandi,
Giuseppe Russo,
Giuseppe Caliendo, Vincenzo Santagada,
Giuseppe Cirino,
John L Wallace,
Stefano Fiorucci
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ABSTRACT: H(2)S functions as a neuromodulator and exerts anti-inflammatory activities. Recent data indicate that irritable bowel syndrome (IBS) is linked to inflammation of the gastrointestinal tract. In this study, we have investigated the role of a novel H(2)S-releasing derivative of mesalamine (5-amino-2-hydroxybenzoic acid 4-(5-thioxo-5H-[1,2]dithiol-3yl)-phenyl ester, ATB-429) in modulating nociception to colorectal distension (CRD), a model that mimics some features of IBS, in healthy and postcolitic rats. Four graded (0.4-1.6 ml of water) CRDs were produced in conscious rats, and colorectal sensitivity and pain were assessed by measuring the abdominal withdrawal response and spinal c-Fos expression. In healthy rats, ATB-429 dose dependently (25, 50, or 100 mg/kg) attenuated CRD-induced hypersensitivity and significantly inhibited CRD-induced overexpression of spinal c-FOS mRNA, whereas mesalamine had no effect. ATB-429-induced antinociception was reversed by glibenclamide, a ATP-sensitive K(+) (K(ATP)) channel inhibitor. The antinociceptive effect of ATB-429 was maintained in a rodent model of postinflammatory hypersensitivity (4 weeks after colitis induction). At a dose of 100 mg/kg, ATB-429 reversed the allodynic response caused by CRD in postcolitic rats. Colonic cyclooxygenase-2 and interkeukin-1beta mRNA and spinal c-FOS mRNA expression were significantly down-regulated by ATB-429, but not by mesalamine. ATB-429, but not mesalamine, increased blood concentrations of H(2)S in both healthy and postcolitic rats. Taken together, these data suggest that ATB-429 inhibits hypersensitivity induced by CRD in both healthy and postcolitic, allodynic rats by a K(ATP) channel-mediated mechanism. This study provides evidence that H(2)S-releasing drugs might have beneficial effects in the treatment of painful intestinal disorders.
Journal of Pharmacology and Experimental Therapeutics 11/2006; 319(1):447-58. · 3.83 Impact Factor
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ABSTRACT: The factorial design (FD) strategy has been applied within the CoMFA framework to a set of 71 N-acyl-L-aminoacid esters undergoing hydrolysis by α-chymotripsin. The steric and electrostatic fields of the molecules aligned in their enzyme-bound conformations have been subjected to Principle Component Analysis (PCA) and three latent variables have been extracted to build up an FD scheme. Two different training sets of 12 compounds have been formed which satisfy the FD criteria. In addition to these two rationally designed series, 50 training sets of 12 structures have been defined through a random selection procedure.A CoMFA model has been derived from each training set by correlating the binding affinity to the enzyme with the ligands' steric and electrostatic fields. The efficiency of the FD approach versus a simple random selection of the structures has been finally assessed by comparing the performances of the different CoMFA models in predicting the binding affinity of 59 ligands not belonging to the training set under consideration. Our results show that in absence of a proper series design strategy the risk of deriving a poorly predictive CoMFA model cannot be neglected.
Quantitative Structure-Activity Relationships 09/2006; 13(3):249 - 261.
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Vincenzo Santagada,
Giuseppe Caliendo,
Beatrice Severino,
Antonio Lavecchia,
Elisa Perissutti,
Ferdinando Fiorino,
Angela Zampella,
Valentina Sepe,
Daniela Califano,
Giovanni Santelli,
Ettore Novellino
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ABSTRACT: Fifteen analogues of the C-terminal CA1A2X motif were synthesized and evaluated for their inhibition potency against farnesyltransferase (FTase). Replacement of the A2 residue by phenylalanine or tyrosine-derived analogues, in which a different number of methyl groups were introduced on the aromatic ring, resulted in compounds less active than the reference compound CVFM against FTase except for compounds I and VI (IC50=1 microM and 2.5 microM, respectively) that were comparable to CVFM and compound IV (IC50=0.1 microM), which was 6-fold more active than the reference compound. Because pseudopeptidic derivatives I-IX were inactive in the cellular assays, the N-formyl- and methyl-ester derivatives (compounds X-XV) were synthesized and tested on different cell lines, showing, in some cases, activity and appreciable selectivity against transformed cells. To rationalize the obtained results, molecular modeling experiments were carried out suggesting the molecular basis of FTase inhibition by these products.
Journal of Medicinal Chemistry 04/2006; 49(6):1882-90. · 5.25 Impact Factor
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ABSTRACT: The synthesis by microwave irradiation and the biological results of novel benzotriazinone and saccharine derivatives with potential antidiarrhoeal activity is described. Conventional and microwave heatings were compared for the reactions. Good yields and short reaction times are the main advantages of our synthetic route. Among the tested compounds, compound 12 inhibited motility both in in-vitro and in-vivo tests.
Archiv der Pharmazie 11/2005; 338(11):548 - 555. · 1.71 Impact Factor
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Ferdinando Fiorino,
Elisa Perissutti,
Beatrice Severino, Vincenzo Santagada,
Donatella Cirillo,
Sara Terracciano,
Paola Massarelli,
Giancarlo Bruni,
Elga Collavoli,
Christian Renner,
Giuseppe Caliendo
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ABSTRACT: New arylpiperazine derivatives were prepared to identify highly selective and potent ligands for the 5-hydroxytryptamine 1A (5-HT(1A)) receptor as potential pharmacological tools in studies of central nervous system (CNS) disorders. The combination of structural elements (heterocyclic nucleus, oxyalkyl chain, and arylpiperazine) known to introduce 5-HT(1A) receptor affinity and the proper selection of substituents led to compounds with higher receptor specificity and affinity. In binding studies, several molecules showed affinity in the nanomolar and subnanomolar ranges at 5-HT(1A) and moderate to no affinity for other relevant receptors (5-HT(2A), 5-HT(2C), D(1), D(2), alpha(1), and alpha(2)). The 4-[3-[4-(o-methoxyphenyl)piperazin-1-yl]propoxy]-4-aza-tricyclo[5.2.1.02,6]dec-8-ene-3,5-dione, with K(i) = 0.021 nM, was the most active and selective derivative for the 5-HT(1A) receptor with respect to other serotonin receptors, whereas the most selective derivative for dopaminergic and adrenergic receptors was a CF(3)-substituted arylpiperazine. As a general trend, compounds with a piperazinylpropoxy chain showed a preferential affinity for the 5-HT(1A) receptor, suggesting that the alkyl chain length represents a critical structural feature in determining 5-HT(1A) receptor affinity and selectivity, as confirmed by the molecular modeling invoked for explaining the differential binding affinities of the new arylpiperazines.
Journal of Medicinal Chemistry 09/2005; 48(17):5495-503. · 5.25 Impact Factor
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Ferdinando Fiorino,
Elisa Perissutti,
Beatrice Severino, Vincenzo Santagada,
Donatella Cirillo,
Sara Terracciano,
Paola Massarelli,
Giancarlo Bruni,
Elga Collavoli,
Christian Renner,
Giuseppe Caliendo
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ABSTRACT: New arylpiperazine derivatives were prepared to identify highly selective and potent ligands for the 5-hydroxytryptamine 1A (5-HT1A) receptor as potential pharmacological tools in studies of central nervous system (CNS) disorders. The combination of structural elements (heterocyclic nucleus, oxyalkyl chain, and arylpiperazine) known to introduce 5-HT1A receptor affinity and the proper selection of substituents led to compounds with higher receptor specificity and affinity. In binding studies, several molecules showed affinity in the nanomolar and subnanomolar ranges at 5-HT1A and moderate to no affinity for other relevant receptors (5-HT2A, 5-HT2C, D1, D2, α1, and α2). The 4-[3-[4-(o-methoxyphenyl)piperazin-1-yl]propoxy]-4-aza-tricyclo[5.2.1.02,6]dec-8-ene-3,5-dione (3b), with Ki = 0.021 nM, was the most active and selective derivative for the 5-HT1A receptor with respect to other serotonin receptors, whereas the most selective derivative for dopaminergic and adrenergic receptors was a CF3-substituted arylpiperazine (2e). As a general trend, compounds with a piperazinylpropoxy chain (3b−g) showed a preferential affinity for the 5-HT1A receptor, suggesting that the alkyl chain length represents a critical structural feature in determining 5-HT1A receptor affinity and selectivity, as confirmed by the molecular modeling invoked for explaining the differential binding affinities of the new arylpiperazines.
08/2005;
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ABSTRACT: Methyleneamine is a reduced form of the amide bond. The CH2NH group may be a useful tool for delineating important hydrogen-bonding points and may also offer a general strategy for the production of enzyme resistance and potent competitive antagonists. This paper describes a facile synthesis of the CH2NH group by application of microwave energy. Moreover the importance of sterically hindered amino acids as well as the electronic effects of the side chain, in the synthesis of the hydroxamate and in the reductive alkylation steps, are evaluated. Room temperature, conventional heating and microwave irradiation of the reactions are compared. Synthesis by microwave irradiation gave the desired compound in higher yields and in shorter reaction times than those obtained at room temperature.
QSAR & Combinatorial Science 12/2004; 23(10):899 - 901. · 1.55 Impact Factor
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ABSTRACT: An efficient, facile, and practical parallel combinatorial synthesis of substituted-benzoxazines under microwave irradiation was described. The procedure involved the use of a microwave oven especially designed for organic synthesis suitable for parallel synthesis of solution libraries. A demonstration 19-membered library of substituted N,N-dimethyl- and N-methyl-benzoxazine amide derivatives, structurally related to the potassium channel opener cromakalim, was generated by both conventional and microwave procedures, achieving a reduction from 7 h to 30-36 min in library generation time for the microwave approach. All the synthesized compounds were tested using the in vitro models of rat aorta and guinea pig trachea rings pre-contracted with phenylephrine and carbachol, respectively. All N,N-dimethyl amide derivatives showed a relaxant activity higher on guinea pig trachea rings than on rat aorta rings.
European Journal of Medicinal Chemistry 11/2004; 39(10):815-26. · 3.35 Impact Factor
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ABSTRACT: One pot microwave-assisted synthesis of substituted 1,2,4-oxadiazoles in solvent and under solvent free condition was performed exploring the importance of some coupling reagents. Good yields and short reaction times were the main aspects of the methods.
Bioorganic & Medicinal Chemistry Letters 10/2004; 14(17):4491-3. · 2.55 Impact Factor
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Giuseppe Pignataro,
Anna Tortiglione,
Antonella Scorziello,
Lucia Giaccio,
Agnese Secondo,
Beatrice Severino, Vincenzo Santagada,
Giuseppe Caliendo,
Salvatore Amoroso,
Gianfranco Di Renzo,
Lucio Annunziato
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ABSTRACT: In the present paper, the role played by Na+/Ca2+ exchanger (NCX) in focal cerebral ischemia was investigated. To this aim, permanent middle cerebral artery occlusion (pMCAO) was performed in male rats. The effects on the infarct volume of some inhibitors, such as tyrosine-6 glycosylated form of the exchanger inhibitory peptide (GLU-XIP), benzamil derivative (CB-DMB) and diarylaminopropylamine derivative (bepridil), and of the NCX activator, FeCl3, were examined. FeCl3, CB-DMB, bepridil and GLU-XIP, a modified peptide synthesized in our laboratory in order to facilitate its entrance into the cells through the glucose transporter, were intracerebroventricularly (i.c.v.) infused. FeCl3 (10 microg/kg) was able to reduce the extension of brain infarct volume. This effect was counteracted by the concomitant icv administration of CB-DMB (120 microg/kg). All NCX inhibitors, GLU-XIP, CB-DMB and bepridil, caused a worsening of the brain infarct lesion. These results suggest that a stimulation of NCX activity may help neurons and glial cells that are not irreversibly damaged in the penumbral zone to survive, whereas its pharmacological blockade can compromise their survival.
Neuropharmacology 04/2004; 46(3):439-48. · 4.81 Impact Factor
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ABSTRACT: In fibroblasts, thrombin induces collagen deposition through activation of a G-protein-coupled receptor, proteinase-activated receptor 1 (PAR(1)). In the current study, we examined whether PAR(1) antagonism inhibits hepatic stellate cell (HSC) activation in vitro and whether it protects against fibrosis development in a rodent model of cirrhosis. A rat HSC line was used for in vitro studies whereas cirrhosis was induced by bile duct ligation (BDL). The current results demonstrated that HSCs express PAR(1), as well as proteinase-activated receptors 2 (PAR(2)) and 4 (PAR(4)), and that all three PARs were up-regulated in response to exposure to growth factor in vitro. Exposure to thrombin and to SFLLRN-(SF)-NH(2), a PAR(1) agonist, and GYPGKF (GY)-NH(2), a PAR(4) agonist, triggered HSC proliferation and contraction, as well as monocyte chemotactic protein-1 (MCP-1) production and collagen I synthesis and release. These effects were inhibited by the PAR(1) antagonist. Administration of this antagonist, 1.5 mg/kg/d, to BDL rats reduced liver type I collagen messenger RNA (mRNA) expression and surface collagen by 63%, as measured by quantitative morphometric analysis. Similarly, hepatic and urinary excretion of hydroxyproline was reduced significantly by the PAR(1) antagonist. In conclusion, PAR(s) regulates HSC activity; development of PAR antagonists might be a feasible therapeutic strategy for protecting against fibrosis in patients with chronic liver diseases.
Hepatology 03/2004; 39(2):365-75. · 11.66 Impact Factor
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ABSTRACT: A rapid, sensitive and specific method to quantify bromazepam in human plasma using diazepam as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid-liquid extraction using diethyl ether-hexane (80 : 20, v/v). The extracts were analyzed by high-performance liquid chromatography (HPLC) coupled to electrospray tandem mass spectrometry (MS/MS). Chromatography was performed isocratically on a Genesis C(18) analytical column (100 x 2.1 mm i.d., film thickness 4 microm). The method had a chromatographic run time of 5.0 min and a linear calibration curve over the range 5.0-150 ng ml(-1) (r(2) > 0.9952). The limit of quantification was 5 ng ml(-1). This HPLC/MS/MS procedure was used to assess the bioequivalence of two bromazepam 6 mg tablet formulations (bromazepam from Medley SA Indústria Farmacêutica as the test formulation and Lexotan from Produtos Roche Químico e Farmacêutico SA as the reference formulation). A single 6 mg dose of each formulation was administered to 24 healthy volunteers (12 males and 12 females). The study was conducted using an open, randomized, two-period crossover design with a 3 week washout interval. Since the 90% CI for C(max), AUC(last), AUC(0-240 h) (linear) and AUC((0- infinity )) ratios were all inside the 80-125% interval proposed by the US Food and Drug Administration, it was concluded that the bromazepam formulation from Medley is bioequivalent to the Lexotan formulation for both the rate and the extent of absorption.
Journal of Mass Spectrometry 02/2004; 39(2):168-76. · 3.27 Impact Factor
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ABSTRACT: An alpha-toxin responsible for nitric oxide (NO) release in rabbit corpus cavernosum (RbCC) was isolated from Tityus serrulatus venom (TSV). The isolated peptide (molecular mass of 7427.66+/-0.15 Da) was identified as Ts3 after determination of Cys residues, N-terminal amino acid analysis, and proteolytic peptide mapping. Ts3 (30 nM) markedly relaxed the RbCC; this response was blocked by the NO synthesis inhibitor N(omega)-nitro-L-arginine methyl ester (100 microM) and the Na+ channel blocker tetrodotoxin (100 nM). Synthetic peptides based on either Ts3 (P1-16, P17-32, P33-48, P49-64, P9-24, P25-40, P41-56, YGLPDKVPTKT) or Bukatoxin (isolated from Buthus martensi Karsch scorpion venom) sequence (Buka11, Buka11-B, PDKVP, PDSEP) were assayed. These peptides slightly relaxed the RbCC, and such an effect was independent of Na+ channel activation or NO release. Our results indicate that Ts3 exerts nitrergic actions and contributes to the relaxing activity of TSV in RbCC, thus providing a valuable tool to investigate the mechanisms underlying nerve activation in erectile tissues, because NO released from nitrergic fibers plays a key role in the erectile process. Our findings revealed the key importance of the Ts3 structure three-dimensional conformation maintenance for biological activity, because linear peptide sequences neither presented substantial relaxations nor was this effect related to nitrergic activity.
The FASEB Journal 04/2003; 17(3):485-7. · 5.71 Impact Factor
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ABSTRACT: As part of a search for new potassium channel openers, the synthesis and vasorelaxant activity of new 1,4-benzoxazine derivatives derived from transformation of the benzopyran skeleton of cromakalim were described. Several new 1,4-benzoxazine derivatives were provided with significant vasorelaxant activity with an overall pharmacological behavior similar to CRK (1f, 1i, 2d, 2e, 2f and 2i).
Bioorganic & Medicinal Chemistry 09/2002; 10(8):2663-9. · 2.92 Impact Factor
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ABSTRACT: A series of novel 1,2,3-4-benzoyltriazole and saccharine derivatives were designed and synthesized by microwave heating. They were evaluated on a battery of receptors, including serotonin 5-HT(1A,) 5-HT(2A) and 5-HT(2C), and the most interesting compounds were further evaluated on dopaminergic D(1), D(2) and adrenergic alpha(1), alpha(2) receptors. Conventional and microwave heating of the reactions were compared. Synthesis by microwave heating gave the desired compounds in better yields than those obtained by conventional heating. The overall times for the syntheses were considerably reduced. All compounds displayed moderate affinity for 5-HT(1A) receptor. The most interesting compound 33 showed a high affinity (K(i)=93 nM) which was combined with no affinity on the other receptors considered.
European Journal of Pharmaceutical Sciences 08/2002; 16(1-2):15-28. · 3.21 Impact Factor
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ABSTRACT: Protease-activated receptor-2 (PAR-2) is a member of seven transmembrane domain G protein-coupled receptors activated by proteolytic cleavage. PAR-2 is involved in inflammatory events and cardiac ischemic reperfusion injury. The objective of this study was to investigate the effects of PAR-2 in experimental myocardial ischemic preconditioning. To monitor the effects of PAR-2, Langendorff-perfused rat hearts were used. These hearts were treated with PAR-2-activating peptide (PAR-2AP) in various protocols. Hemodynamic parameters (left ventricular developed pressure, left ventricular diastolic pressure, coronary flow rate, and heart rate), several indexes of oxidative injury, and neutrophil accumulation were evaluated. We show for the first time that enhanced PAR-2 activation improves efficiency of ischemic preconditioning and reduces cardiac inflammation in the rat heart. Indeed, after PAR-2AP infusion we found that hemodynamic parameters, oxidative injury, infarct size, and neutrophil accumulation were involved. These data support the concept that PAR-2-dependent cell trafficking may regulate signaling responses to cardiac ischemia and inflammation.
AJP Heart and Circulatory Physiology 07/2002; 282(6):H2004-10. · 3.71 Impact Factor
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ABSTRACT: We explored the unique substrate specificity of the primary S, subsite of human urinary kallikrein (hK1), which accepts both Phe or Arg synthesizing and assaying peptides derived from Phenylacetyl-Phe-Ser-Arg-EDDnp, a previously described inhibitor with analgesic and anti-inflammatory activities [Emim et al., Br. J. Pharmacol. 130 (2000), 1099-1107]. Phe was substituted by amino acids containing larger aliphatic or aromatic side chains as well as by non-natural basic amino acids, which were designed to combine a large hydrophobic and/or aromatic group with a positively-charged group at their side chains. In general, all peptides with basic amino acids represented better inhibitors than those with hydrophobic amino acids. Furthermore, the S1 subsite specificity proved to be much more selective than the mere distinction between Phe and Arg, for minor differences in the side chains of the non-natural amino acids resulted in major differences in the Ki values. Finally, we present a series of peptides that were assayed as competitive inhibitors for human tissue kallikrein that may lead to the development of novel peptides, which are both more potent and selective.
Biological Chemistry 06/2002; 383(5):853-7. · 2.96 Impact Factor
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ABSTRACT: A rapid, sensitive and specific method to quantify nevirapine in human plasma using dibenzepine as the internal standard (IS) was developed and validated. The method employed a liquid-liquid extraction. The analyte and the IS were chromatographed on a C(18) analytical column, (150 x 4.6 mm i.d. 4 microm) and analyzed by tandem mass spectrometry in the multiple reaction monitoring mode. The method had a chromatographic run time of 5.0 min and a linear calibration curve over the range 10-5000 ng ml(-1) (r(2) > 0.9970). The between-run precision, based on the relative standard deviation for replicate quality controls was 1.3% (30 ng ml(-1)), 2.8% (300 ng ml(-1)) and 3.6% (3000 ng ml(-1)). The between-run accuracy was 4.0, 7.0 and 6.2% for the above-mentioned concentrations, respectively. This method was employed in a bioequivalence study of two nevirapine tablet formulations (Nevirapina from Far-Manguinhos, Brazil, as a test formulation, and Viramune from Boehringer Ingelheim do Brasil Química e Farmacêutica, as a reference formulation) in 25 healthy volunteers of both sexes who received a single 200 mg dose of each formulation. The study was conducted using an open, randomized, two-period crossover design with a 3 week washout interval. The 90% confidence interval (CI) of the individual ratio geometric mean for Nevirapina/Viramune was 96.4-104.5% for AUC((0-last)), 91.4-105.1% for AUC((0-infinity)) and 95.3-111.6% for C(max) (AUC = area under the curve; C(max) = peak plasma concentration). Since both 90% CI for AUC((0-last)) and AUC((0-infinity)) and C(max) were included in the 80-125% interval proposed by the US Food and Drug Administration, Nevirapina was considered bioequivalent to Viramune according to both the rate and extent of absorption.
Journal of Mass Spectrometry 04/2002; 37(4):434-41. · 3.27 Impact Factor
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ABSTRACT: Protease-activated receptor 2 (PAR-2) is involved in inflammatory, gastrointestinal, and vascular diseases. The aim of the present work was to elucidate the minimal structural features for PAR-2 agonist activity in short peptides. Our study resulted in the discovery of dipeptide derivatives of N(alpha)-benzoyl-Arg(NO(2))-Leu-NH(2) displaying a potency comparable to that of the full-length rat PAR-2 activating peptide (Ser-Leu-Ile-Gly-Arg-Leu-NH(2)).
Bioorganic & Medicinal Chemistry Letters 02/2002; 12(1):21-4. · 2.55 Impact Factor
