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1.
Rehabilitación (Madr., Ed. impr.) ; 58(2): 1-4, abril-junio 2024. ilus
Artigo em Espanhol | IBECS | ID: ibc-232120

RESUMO

El síndrome de Parsonage-Turner o plexopatía braquial idiopática es una inflamación total o parcial del plexo braquial cuya presentación típica es una omalgia intensa y súbita, seguida de debilidad braquial y amiotrofia precoz. La etiología es desconocida, aunque se propone un mecanismo inmunomediado.El trasplante de progenitores hematopoyéticos es un tratamiento bien establecido de las neoplasias hematológicas y tiene un papel creciente en el tratamiento de enfermedades autoinmunes. Los efectos adversos neurológicos son probablemente infradiagnosticados.La asociación del síndrome de Parsonage-Turner y el trasplante de progenitores hematopoyéticos es muy poco conocida. Describimos dos casos clínicos de plexopatía braquial idiopática tras trasplante de células stem (progenitores) hematopoyéticas (TPH).La reconstitución del sistema inmune tras un trasplante de progenitores hematopoyéticos puede ser un desencadenante de plexopatía braquial, aunque se necesitan más estudios para entender la fisiopatología de esta entidad y establecer su relación causal con el trasplante. (AU)


Parsonage-Turner syndrome or idiopathic brachial neuritis is a total or partial inflammation of the brachial plexus, with a typical presentation as a sudden and very intense pain in the shoulder, followed by weakness and early amyotrophy. The etiology is still unknown, although an immune mediated mechanism is thought to be involved.Hematopoietic stem cell transplantation is a well-established treatment for hematological malignancies, but with a growing implication in the treatment of autoimmune diseases. The neurological side effects are probably underdiagnosed.The association of the Parsonage-Turner syndrome and the hematopoietic stem cell transplantation is scarce. We describe two clinical cases of idiopathic brachial plexopathy after hematopoietic stem cell transplantation.The reconstruction of the immune system after a transplant may be the trigger of a brachial plexopathy, but more studies are necessary for the etiology of this disease to be understood and to establish a cause-effect relation with the transplant. (AU)


Assuntos
Humanos , Masculino , Adulto , Transplante , Neuropatias do Plexo Braquial , Neurite do Plexo Braquial , Hematínicos , Sistema Imunitário , Plexo Braquial
2.
Rehabilitacion (Madr) ; 58(2): 100835, 2024.
Artigo em Espanhol | MEDLINE | ID: mdl-38141426

RESUMO

Parsonage-Turner syndrome or idiopathic brachial neuritis is a total or partial inflammation of the brachial plexus, with a typical presentation as a sudden and very intense pain in the shoulder, followed by weakness and early amyotrophy. The etiology is still unknown, although an immune mediated mechanism is thought to be involved. Hematopoietic stem cell transplantation is a well-established treatment for hematological malignancies, but with a growing implication in the treatment of autoimmune diseases. The neurological side effects are probably underdiagnosed. The association of the Parsonage-Turner syndrome and the hematopoietic stem cell transplantation is scarce. We describe two clinical cases of idiopathic brachial plexopathy after hematopoietic stem cell transplantation. The reconstruction of the immune system after a transplant may be the trigger of a brachial plexopathy, but more studies are necessary for the etiology of this disease to be understood and to establish a cause-effect relation with the transplant.


Assuntos
Neurite do Plexo Braquial , Transplante de Células-Tronco Hematopoéticas , Humanos , Neurite do Plexo Braquial/etiologia , Neurite do Plexo Braquial/terapia , Neurite do Plexo Braquial/diagnóstico , Dor , Atrofia Muscular/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos
8.
Clin Transl Oncol ; 22(3): 411-419, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31144211

RESUMO

PURPOSE: We performed a cross-sectional study of neurocognitive function in non-brain cancer patients treated with long-term bevacizumab. METHODS/PATIENTS: From 2015 to 2017, we included patients with different types of cancer treated with bevacizumab with or without chemotherapy (BEV; N = 20) or only chemotherapy (ChT; N = 19) for at least 34 weeks, patients who received non-brain radiotherapy (RxT; N = 19), and healthy controls (HC; N = 19) were assessed once at week 34 of treatment (BEV and ChT) or at completion of radiotherapy. Neurocognition was evaluated with the Hopkins Verbal Learning Test-Revised (HVLT-R) total and delayed recall, the Trail Making Test A and B, and the Controlled Oral Word Association Test in the four groups. Non-parametric tests were used to assess differences between groups. RESULTS: The BEV, ChT, and RxT groups scored significantly lower than the HC group on all tests and especially on the HVLT-R total recall. In no case were the mean scores of the BEV group significantly lower than those of the ChT or RxT groups. CONCLUSIONS: Neurocognitive impairment was seen even in patients treated with local non-brain radiotherapy. Treatment with bevacizumab for a long period of time does not seem to worsen neurocognitive function to a greater extent than chemotherapy.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Bevacizumab/uso terapêutico , Neoplasias/tratamento farmacológico , Transtornos Neurocognitivos/diagnóstico , Antineoplásicos Imunológicos/efeitos adversos , Bevacizumab/efeitos adversos , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/radioterapia , Transtornos Neurocognitivos/etiologia , Testes Neuropsicológicos
9.
Eur J Neurol ; 18(6): 850-6, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21143338

RESUMO

BACKGROUND: Different factors may weight on time from stroke onset to hospital arrival, and patients' alert certainly contributes to it. We sought to identify clinical and sociodemographic factors associated with a delayed alert and to delineate the profile of the potential latecomer in Catalonia (Spain). METHODS: We used data from the Stroke Code (SC) registry that prospectively recruited consecutive patients with acute stroke, in whom SC was activated (SCA) or not (SCNA), admitted to all Catalan hospitals. Additionally, SCNA patients underwent a structured interview to explore additional beliefs and attitudes related to a delayed alert. We applied a 6-h cut-off to define alert delay according to the time limit for SC activation in Catalonia. We determined independent predictors of delay amongst clinical and sociodemographic data by multivariate logistic regression and applied sample weighting because of different study periods in the SCA and SCNA arms. RESULTS: Of the patients, 37.2% delayed alert beyond 6 h. Compared to non-delayers, latecomers were more likely diabetics, illiterates, belonged to an unfavored social class, and were living alone. Fewer had concomitant atrial fibrillation and alerted through emergency medical service (EMS)/112 whilst suffering a mild or moderate stroke. Amongst patients interviewed, being unaware of stroke's vascular nature and erroneously self-perceiving stroke as a reversible or irrelevant condition independently predicted a longer delay. CONCLUSIONS: Delaying alert after stroke shows a multifactorial background with implication of pre-stroke health status, socioeconomic factors, stroke-related features and patients' beliefs and attitudes toward the disease. In planning future educational campaigns, all these features should be considered.


Assuntos
Diagnóstico Tardio/tendências , Serviços Médicos de Emergência/tendências , Acesso aos Serviços de Saúde/tendências , Aceitação pelo Paciente de Cuidados de Saúde , Acidente Vascular Cerebral/epidemiologia , Idoso , Cuidadores , Escolaridade , Feminino , Humanos , Masculino , Aceitação pelo Paciente de Cuidados de Saúde/etnologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Educação de Pacientes como Assunto/tendências , Estudos Prospectivos , Sistema de Registros , Acidente Vascular Cerebral/psicologia
10.
Eur J Neurol ; 18(5): 686-94, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20840380

RESUMO

BACKGROUND: Randomized trials and meta-analyses indicate positive effects of stroke unit (SU) care on survival and dependency of patients with stroke. However, data on the advantages of SU in 'real-world' settings are limited. We prospectively assessed, in a large University Hospital, the effect of SU versus other conventional wards (OCW) care on all-cause mortality, death or dependency, death or institutionalization. METHODS: In a prospective observational study in the European Registers of Stroke Project, patients hospitalized for first-in-a-lifetime stroke were evaluated for demographics, risk factors, clinical presentation, resource use, 3-month and 1-year survival, and functional outcome. RESULTS: Overall, 355 patients (54.1% men, mean age 73.4 ± 14.5 years) were registered, 140 (39.4%) admitted to the SU, and 215 (60.6%) to OCW. OCW patients were older, whilst SU patients had more severe strokes according to NIHSS (P for trend = 0.025). SU patients were significantly more often treated by specialists in stroke medicine, stroke nurses, physiotherapists and speech therapists (all P < 0.001), psychologists (P = 0.025), dietitians (P < 0.001), and social workers (P = 0.003). MRI, carotid, and transcranial Doppler were significantly more often performed in SU patients (all P < 0.001). Intravenous fluids (P = 0.003) and intravenous anticoagulation (P < 0.001) were more often prescribed in SU. Controlling for case-mix, SU significantly reduced 1-year mortality (P = 0.020), death or dependency at 3 months (P = 0.006) and 1 year (P = 0.043), and death or institutionalization at 3 months (P = 0.001) and 1 year (P = 0.009). CONCLUSIONS: We confirmed the benefits of SU care in a clinical setting. Further analyses should define the contribution of individual components of care to stroke outcome.


Assuntos
Centros Médicos Acadêmicos/métodos , Unidades de Terapia Intensiva , Sistema de Registros , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/terapia , Idoso , Idoso de 80 Anos ou mais , Europa (Continente)/epidemiologia , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
11.
Amino Acids ; 35(2): 329-38, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18163179

RESUMO

New N-For-Met-Leu-Phe-OMe (fMLF-OMe) analogues incorporating three different gamma-delta-didehydro-alpha-aminoacid residues (namely: Alg = (S)-Allylglycine; Dag = Diallylglycine; Cpg = 1-Aminocyclopent-3-ene-1-carboxylic acid) replacing the native (S)-Leucine have been synthesized and their activity towards human neutrophils has been evaluated in comparison with that shown by the reference tripeptide fMLF-OMe. Chemotaxis, lysozyme release and superoxide anion production have been measured. (1)H NMR titration experiments and NOESY spectrum of the Cpg containing model 10 have been discussed in order to ascertain the preferred solution conformations. A fully extended (C(5)) conformation at position 2 and a folded conformation with two consecutive gamma-turns (C(7) structure) have been proposed for the Dag and Cpg containing tripeptides, respectively.


Assuntos
Compostos Alílicos/química , Alilglicina/química , Ácidos Carboxílicos/química , Fatores Quimiotáticos/farmacologia , Ciclopentanos/química , Glicina/análogos & derivados , N-Formilmetionina Leucil-Fenilalanina/análogos & derivados , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Fatores Quimiotáticos/síntese química , Fatores Quimiotáticos/química , Glicina/química , Humanos , Espectroscopia de Ressonância Magnética/métodos , Conformação Molecular , Muramidase/química , Muramidase/metabolismo , N-Formilmetionina Leucil-Fenilalanina/síntese química , Dobramento de Proteína , Superóxidos/química , Superóxidos/metabolismo
12.
Amino Acids ; 33(3): 477-87, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17021652

RESUMO

For-Met-betaAlapsi[CSNH]-Phe-OMe (3), For-Met-betaAlapsi[CH2NH]-Phe-OMe (5), For-Met-NH-pC6H4-SO(2-Phe-OMe 8a), For-Met-NH-mCH4-SO2-Phe-OMe (8b) and the corresponding N-Boc precursors (2, 4, 7a, b) have been synthesized and their activity towards human neutrophils has been evaluated in comparison with that shown by the reference tripeptide For-Met-Leu-Phe-OMe (fMLF-OMe). Chemotaxis, lysozyme release and superoxide anion production have been measured. (1)H NMR titration experiments and IR spectra have been discussed in order to ascertain the preferred solution conformation adopted by the tripeptide 3 with particular reference to the presence of a folded conformation centred at the centrally positioned thionated beta-residue.


Assuntos
N-Formilmetionina Leucil-Fenilalanina/análogos & derivados , Quimiotaxia de Leucócito , Humanos , Estrutura Molecular , N-Formilmetionina Leucil-Fenilalanina/síntese química , N-Formilmetionina Leucil-Fenilalanina/química , N-Formilmetionina Leucil-Fenilalanina/metabolismo , Neutrófilos/metabolismo , Ressonância Magnética Nuclear Biomolecular , Peptídeos/química , Peptídeos/metabolismo , Solventes , Superóxidos/química , Superóxidos/metabolismo
13.
Amino Acids ; 30(4): 453-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16547648

RESUMO

The two fMLF-OMe analogues For-Met-beta(3)hAc(6)c-Phe-OMe (6) and For-Met-beta(2)hAc(6)c-Phe-OMe (12) and their corresponding N-Boc derivatives 5 and 11 have been synthesized and their biological activity towards human neutrophils evaluated. The N-formyl peptides 6 and 12 exhibit good activity as chemoattractans and 12 is highly active in superoxide anion production. The preferred solution conformation of the two N-formyl derivatives has been discussed.


Assuntos
Aminoácidos/química , N-Formilmetionina Leucil-Fenilalanina/química , Neutrófilos/efeitos dos fármacos , Peptídeos/síntese química , Peptídeos/farmacologia , Humanos , Ligantes , Estrutura Molecular , N-Formilmetionina Leucil-Fenilalanina/análogos & derivados , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Peptídeos/química , Estrutura Secundária de Proteína , Relação Estrutura-Atividade
14.
Amino Acids ; 28(1): 77-83, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15662563

RESUMO

Three novel carnosine analogues 7-9 containing the residue of L(+)2,3-diaminopropionic acid with different degree of N-acetylation instead of beta-alanine have been synthesized and characterized. Comparative analysis of hydrolysis by carnosinase revealed that the mono- and bis-acetylated compounds 8 and 9 are resistant to enzymatic hydrolysis and act as competitive inhibitors of this enzyme. The hydroxyl radical scavenging potential of the three analogues was evaluated by their ability to inhibit iron/H(2)O(2)-induced degradation of deoxyribose. The second-order rate constants of the reaction of compounds 7-9 with hydroxyl radical were almost identical to that of carnosine. These compounds were also found to act as protective agents against peroxynitrite-dependent damage as assessed by their ability to prevent nitration of free tyrosine induced by this species.


Assuntos
Carnosina/análogos & derivados , Carnosina/farmacologia , beta-Alanina/análogos & derivados , Acetilação , Antioxidantes/química , Antioxidantes/farmacologia , Bioquímica/métodos , Carnosina/química , Dipeptidases/antagonistas & inibidores , Dipeptidases/sangue , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Humanos , Hidrólise , Radical Hidroxila , Mimetismo Molecular , Ácido Peroxinitroso/química , Ácido Peroxinitroso/farmacologia , Relação Estrutura-Atividade , Tirosina/química , beta-Alanina/química
15.
Contraception ; 65(4): 317-20, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12020786

RESUMO

Research in male fertility is of interest in connection with both contraception and treatment of sterility. Several compounds have been shown to inhibit fertility by various mechanisms. The most significant of them are reviewed, including some recently described indazole carboxylic acids. Concerning sterility treatment, no effective treatment is so far available, with the exception of hormonal dysfunctions. The hypothesized role of an excess of free radicals in male sterility suggests a potential therapeutic value of free radicals scavengers. In this connection, indazole derivatives appear of special interest, as some of them display an anti-denaturant activity resulting in a peculiar scavenger-like activity. Some synthetic approaches are proposed, leading to new compounds of potential interest either as male contraceptives or in the treatment of male sterility.


Assuntos
Anticoncepcionais Masculinos , Fertilidade/efeitos dos fármacos , Infertilidade Masculina/tratamento farmacológico , Pesquisa , Antiespermatogênicos/síntese química , Desenho de Fármacos , Humanos , Masculino
16.
J Pept Res ; 59(6): 283-91, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12010519

RESUMO

In order to explore the properties of chemotactic N-formylpeptides containing isopeptide bonds within their backbones, a group of lysine-containing analogs of the prototypical chemotactic tripeptide N-formylmethionyl-leucyl-phenylalanine (fMLF) was synthesized. The new analogs were designed by adding to the HCO-Met or Boc-Met residue a dipeptide fragment made up of Lys and Phe residues joined through Lys N alpha or N epsilon bonds, in all possible combinations. Thus, the following six pairs of tripeptides were synthesized and examined for their bioactivity: RCO-Met-Lys(Z)-Phe-OMe (2a, b), RCO-Met-Lys(Z-Phe)-OMe (3a, b), Z-Lys(RCO-Met)-Phe-OMe (4a, b), Z-Phe-Lys(RCO-Met)-OMe (5a, b), RCO-Met-Phe-Lys(Z)-OMe (6a, b) and Z-Lys(RCO-Met-Phe)-OMe (7a, b), with R=OC(CH3)(3 )and R=H for compounds a and b, respectively. All the new models were characterized fully and their activity (chemotaxis, superoxide anion production and lysozyme release) on human neutrophils determined as agonists (compounds b) and antagonists (compounds a). All N-formyl derivatives 2b-7b are less potent than fMLF-OMe as chemoattractants, but compound 7b exhibits selective activity as superoxide anion producer. Derivatives 2a-7a do not show antagonistic activity towards fMLF induced chemotaxis and O(2)(-) production, however, all these compounds except 4a antagonize lysozyme release by 60%.


Assuntos
Lisina/química , N-Formilmetionina Leucil-Fenilalanina/análogos & derivados , N-Formilmetionina Leucil-Fenilalanina/síntese química , Oligopeptídeos/síntese química , Oligopeptídeos/farmacologia , Sequência de Aminoácidos , Quimiotaxia/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Muramidase/metabolismo , N-Formilmetionina Leucil-Fenilalanina/química , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Neutrófilos/metabolismo , Oligopeptídeos/antagonistas & inibidores , Oligopeptídeos/química , Relação Estrutura-Atividade , Superóxidos/metabolismo
17.
Cell Mol Life Sci ; 59(3): 546-51, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11964132

RESUMO

The naturally occurring dipeptides carnosine and anserine have been proposed to act as antioxidants in vivo. We investigated whether these compounds can act as protective agents able to counteract peroxynitrite-dependent reactions. The results showed that the dipeptides efficiently protect tyrosine against nitration, alpha1-antiproteinase against inactivation and human low-density lipoprotein against modification by peroxynitrite. Carnosine exerts its protective effect at concentrations similar to those found in human tissues. In addition, some synthetic pseudodipeptides, stucturally related to carnosine but stable to hydrolytic enzymes, possess protective properties against peroxynitrite-dependent damage similar to the natural dipeptides. These pseudodipeptides may represent stable mimics of the biologically active carnosine suitable for pharmacological applications.


Assuntos
Anserina/metabolismo , Carnosina/análogos & derivados , Carnosina/farmacologia , Ácido Peroxinitroso/metabolismo , Tirosina/análogos & derivados , Anserina/química , Antioxidantes/química , Antioxidantes/metabolismo , Carnosina/química , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Ágar , Ativação Enzimática , Humanos , Lipoproteínas LDL/metabolismo , Oxirredução , Ácido Peroxinitroso/antagonistas & inibidores , Tirosina/metabolismo , alfa 1-Antitripsina/metabolismo
18.
J Pept Res ; 58(1): 56-66, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11454170

RESUMO

In order to further examine the properties of pseudopeptides containing the 2-hydrazonoacyl fragment, two new series of analogs of the prototypical chemotactic N-formyl-tripeptide HCO-Met-Leu-Phe-OMe were designed and synthesized. The first group contains the new fragment as the N-terminal residue and is represented by the N-aryl derivatives p-Cl-C6H4-NH-N=C(R)-CO-Leu-Phe-OMe (2 and 3) and by the corresponding N-aroyl analogs p-CH3-C6H4-CO-NH-N=C(R)-CO-Leu-Phe-OMe (4). The second group contains the new fragment in place of the central Leu residue and is represented by compounds HCO-Xaa-NH-N=C(R)-CO-Phe-OMe (7a and 7b) where Xaa is Nle and Met, respectively. The conformational and biochemical properties of the new products were examined.


Assuntos
Fatores Quimiotáticos/química , Fatores Quimiotáticos/farmacologia , N-Formilmetionina Leucil-Fenilalanina/análogos & derivados , N-Formilmetionina Leucil-Fenilalanina/química , Oligopeptídeos/química , Bioquímica/métodos , Células Cultivadas , Quimiotaxia de Leucócito/efeitos dos fármacos , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Hidrazinas/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Oligopeptídeos/farmacologia , Relação Estrutura-Atividade , Superóxidos/metabolismo
19.
Farmaco ; 56(11): 851-8, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11765037

RESUMO

We report here the synthesis and activity of new analogs of the N-formyl and N-tert-butyloxycarbonyl (Boc) derivatives of the tripeptide Met-Leu-Phe-OMe containing an achiral omega-amino acid residue replacing the hydrophobic central leucine. The tripeptides HCO-Met-NH-(CH2)n-CO-Phe-OMe and Boc-Met-NH-(CH2)n-CO-Phe-OMe (n = 3-5) containing the central homomorphic residue of 5-aminopentanoic acid (delta-aminovaleric acid; delta-Ava; n = 4) and the two non-homomorphic residues of 4-aminobutanoic acid (gamma-aminobutyric acid; gamma-Abu; n = 3) and 6-aminohexanoic acid (epsilon-aminocaproic acid; epsilon-Aca; n = 5) have been examined. The activity as agonists and antagonists in chemotaxis, lysozyme release, and superoxide anion production of the new analogs has been determined. The N-Boc derivatives 2a and 2b, incorporating the gamma-Abu and the delta-Ava residues, show good and selective antagonist activity on superoxide anion production.


Assuntos
Fatores Quimiotáticos/síntese química , Fatores Quimiotáticos/farmacologia , N-Formilmetionina Leucil-Fenilalanina/análogos & derivados , Neutrófilos/efeitos dos fármacos , Sequência de Aminoácidos , Fatores Quimiotáticos/química , Quimiotaxia de Leucócito/efeitos dos fármacos , Humanos , Neutrófilos/fisiologia , Relação Estrutura-Atividade
20.
Biopolymers ; 54(6): 379-87, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10951324

RESUMO

The taurine (Tau) containing N-protected pseudotripeptide isopropylamide Z-Tau-Pro-D-Phe-NHiPr (1) has been specifically designed and synthesized as suitable model to test the ability of the sulfonamido group to participate as H-bond acceptor to a type II beta-turn and to get information on the preferred rotameric conformation around the S-N bond and the hybridization state of the nitrogen atom. The present structural investigation reveals that, although the sulfonamide junction is invariably folded in a gauche mode, the beta-turn structure, stabilized by the 4 --> 1 hydrogen bond, is not found in the crystal and the sulfonamido oxygen atoms are not involved in any intra- or intermolecular hydrogen-bond interaction. More than one conformer populates the CDCl(3) solution with only a minor contribution by the expected beta-turn. The Pro nitrogen is significantly pyramidalized and the nitrogen lone pair points in opposite direction to that of the Pro C(alpha)H bond thus adopting R chirality, in an arrangement practically identical to that found in the previously studied homochiral analogue Z-Tau-Pro-Phe-NHiPr.


Assuntos
Oligopeptídeos/química , Sulfonamidas/química , Cristalografia por Raios X , Desenho de Fármacos , Inibidores Enzimáticos/química , Ligação de Hidrogênio , Conformação Molecular , Mimetismo Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Solubilidade , Taurina/química
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