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491.
Suresh Chander Suri Angelica C. Cabrera Edward J. Wucherer Stephen L. Rodgers 《合成通讯》2013,43(5):841-851
A mixture of 1-methyl- and 2-methyl-1,4,4a,8a,-tetrahydro-endo-1,4-methano-naphthalene-5,8-diones ( 2 & 3 ) was chemically transformed into separable methyl substituted tricyclo[5.2.1.02,6]decadienones 7 , 8 & 9 . The structure of 8 & 9 were elucidated via Cope rearrangement of their corresponding allylic alcohols ( 10 & 11 ) to furnish 12 & 13 respectively. 相似文献
492.
Ixone Esnal Dr. Ismael Valois‐Escamilla César F. A. Gómez‐Durán Arlette Urías‐Benavides María L. Betancourt‐Mendiola Prof. Iñigo López‐Arbeloa Dr. Jorge Bañuelos Prof. Inmaculada García‐Moreno Prof. Angel Costela Prof. Eduardo Peña‐Cabrera 《Chemphyschem》2013,14(18):4134-4142
A series of meso‐substituted boron‐bipyrromethene (BODIPY) dyes are synthesized and their laser and photophysical properties systematically studied. Laser emission covering a wide visible spectral region (from blue to orange) is obtained by just changing the electron donor character of the heteroatom at position 8. The additional presence of methyl groups at positions 3 and 5 results in dyes with a photostability similar to that of the unsubstituted dye but with much improved efficiency. Correlation of the lasing properties of the different dyes to their photophysical properties provides inklings to define synthetic strategies of new BODIPY dyes with enhanced efficiency and modulated wavelength emission over the visible spectral region. 相似文献
493.
Cabrera MP Alvares DS Leite NB de Souza BM Palma MS Riske KA Neto JR 《Langmuir : the ACS journal of surfaces and colloids》2011,27(17):10805-10813
Antimicrobial peptides of the mastoparans family exert their bactericidal activity by binding to lipid membranes, inducing pores or defects and leaking the internal contents of vesicles and cells. However, this does not seem to be the only mechanism at play, and they might be important in the search for improved peptides with lower undesirable side effects. This work deals with three mastoparans peptides, Polybia-MP-1(MP-1), N2-Polybia-MP-1 (N-MP-1), and Mastoparan X (MPX), which exhibit high sequence homology. They all have three lysine residues and amidated C termini, but because of the presence of two, one, and no aspartic acid residues, respectively, they have +2, +3, and +4 net charges at physiological pH. Here we focus on the effects of these mastoparans peptides on anionic model membranes made of palmitoleyoilphosphatidylcholine (POPC) and palmitoleyoilphosphatidylglycerol (POPG) at 1:1 and 3:1 molar ratios in the presence and in the absence of saline buffer. Zeta potential experiments were carried out to measure the extent of the peptides' binding and accumulation at the vesicle surface, and CD spectra were acquired to quantify the helical structuring of the peptides upon binding. Giant unilamellar vesicles were observed under phase contrast and fluorescence microscopy. We found that the three peptides induced the leakage of GUVs at a gradual rate with many characteristics of the graded mode. This process was faster in the absence of saline buffer. Additionally, we observed that the peptides induced the formation of dense regions of phospholipids and peptides on the GUV surface. This phenomenon was easily observable for the more charged peptides (MPX > N-MP-1 > MP-1) and in the absence of added salt. Our data suggest that these mastoparans accumulate on the bilayer surface and induce a transient interruption to its barrier properties, leaking the vesicle contents. Next, the bilayer recovers its continuity, but this happens in an inhomogeneous way, forming a kind of ply with peptides sandwiched between two juxtaposed membranes. Eventually, a peptide-lipid aggregate forming a lump is formed at high peptide-to-lipid ratios. 相似文献
494.
Cabrera ÁC Gil-Redondo R Perona A Gago F Morreale A 《Journal of computer-aided molecular design》2011,25(9):813-824
A graphical user interface (GUI) for our previously published virtual screening (VS) and data management platform VSDMIP (Gil-Redondo
et al. J Comput Aided Mol Design, 23:171–184, 2009) that has been developed as a plugin for the popular molecular visualization program PyMOL is presented. In addition, a ligand-based
VS module (LBVS) has been implemented that complements the already existing structure-based VS (SBVS) module and can be used
in those cases where the receptor’s 3D structure is not known or for pre-filtering purposes. This updated version of VSDMIP
is placed in the context of similar available software and its LBVS and SBVS capabilities are tested here on a reduced set
of the Directory of Useful Decoys database. Comparison of results from both approaches confirms the trend found in previous
studies that LBVS outperforms SBVS. We also show that by combining LBVS and SBVS, and using a cluster of ~100 modern processors,
it is possible to perform complete VS studies of several million molecules in less than a month. As the main processes in
VSDMIP are 100% scalable, more powerful processors and larger clusters would notably decrease this time span. The plugin is
distributed under an academic license upon request from the authors. 相似文献