Polymorphism of asymmetric catalysts based on amphiphilic lipopeptides in solution

Autor(es)

Pelin, Juliane N. B. D. ^{[1, 2]} ; Edwards-Gayle, Charlotte J. C. ^[2] ; Aguilar, Andrea M. ^[3] ; Kaur, Amanpreet ^[2] ; Hamley, Ian W. ^[2] ; Alves, Wendel A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre, SP - Brazil

^[2] Univ Reading, Dept Chem, Reading RG6 6AD, Berks - England

^[3] Univ Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SOFT MATTER; v. 16, n. 19, p. 4615-4624, MAY 21 2020.
• Citações Web of Science: 2

Resumo

The self-assembly of model {[}P]RWG lipopeptides (P: l-proline, R: l-arginine, W: l-tryptophan, G: l-glycine), containing one or two aliphatic octadecyl (C-18) chains in water and cyclohexanone/water solutions was examined. The self-assembly of mixtures of these RWG and PRWG lipopeptides was also investigated. These materials presented a similar critical aggregation concentration of similar to 4.0 x 10(-4) wt% and were characterized by unordered secondary structures with some beta-sheet content. TEM and cryo-TEM revealed the presence of mainly nanotape structures with micelles observed for systems rich in PRWG(C18H37). Analysis of detailed SAXS form factor measurements revealed the presence of bilayers 3-4 nm thick while the PRWG(C18H37) micelles have a core radius of approximately 3 nm, and a shell thickness of 2 nm. For the cyclohexanone/water systems polymorphs containing cluster aggregates (with radius of 0.25 nm to 0.50 nm) and some elongated structures (with radius of 5.7 nm to 26.1 nm) were seen. Longer structures were formed with the increase of the proline-containing lipopeptide content. The catalytic activity of these peptides was assessed using a model nitro-aldol reaction. The concentration of water in the reaction system influenced the conversion, higher content promoted better efficiency for the water systems, but the opposite was observed for the cyclohexanone/water samples. (AU)

• Processo FAPESP: 14/50867-3 - INCT 2014: Instituto Nacional de Ciência e Tecnologia de Bioanalítica
• Beneficiário: Marco Aurelio Zezzi Arruda
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 15/20446-9 - Estudo da auto-organização de estruturas hierárquicas de peptídeos em solução em presença de nanopartículas metálicas
• Beneficiário: Juliane Nogueira Batista Dias Pelin
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 18/12535-0 - Estudo da auto-organização de estruturas hierárquicas de peptídeos em solução em presença de nanopartículas metálicas
• Beneficiário: Juliane Nogueira Batista Dias Pelin
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto
• Processo FAPESP: 17/02317-2 - Interfaces em materiais: propriedades eletrônicas, magnéticas, estruturais e de transporte
• Beneficiário: Adalberto Fazzio
• Modalidade de apoio: Auxílio à Pesquisa - Temático