Molecular Recognition of Malto-oligosaccharides by Free and Metal Tetrakis(4-sulfonatophenyl)porphyrins in Basic Aqueous Solutions

2001 ◽  
Vol 1 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Sanyo Hamai
Keyword(s):  
Molecular Recognition ◽  
Aqueous Solutions

scholarly journals Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

2017 ◽  
Vol 13 ◽  
pp. 1572-1582 ◽  
Author(s):  
Spyros D Chatziefthimiou ◽  
Mario Inclán ◽  
Petros Giastas ◽  
Athanasios Papakyriakou ◽  
Konstantina Yannakopoulou ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Molecular Recognition ◽  
Aqueous Solutions ◽  
Crystalline State ◽  
Dimeric Complex ◽  
Nmr Studies ◽  
Guest Molecules ◽  
Crystallographic Order

The enantioselectivity of β-cyclodextrin (β-CD) towards L- and D-N-acetyltryptophan (NAcTrp) has been studied in aqueous solution and the crystalline state. NMR studies in solution show that β-CD forms complexes of very similar but not identical geometry with both L- and D-NAcTrp and exhibits stronger binding with L-NAcTrp. In the crystalline state, only β-CD–L-NAcTrp crystallizes readily from aqueous solutions as a dimeric complex (two hosts enclosing two guest molecules). In contrast, crystals of the complex β-CD–D-NAcTrp were never obtained, although numerous conditions were tried. In aqueous solution, the orientation of the guest in both complexes is different than in the β-CD–L-NAcTrp complex in the crystal. Overall, the study shows that subtle differences observed between the β-CD–L,D-NAcTrp complexes in aqueous solution are magnified at the onset of crystallization, as a consequence of accumulation of many soft host–guest interactions and of the imposed crystallographic order, thus resulting in very dissimilar propensity of each enantiomer to produce crystals with β-CD.

Molecular recognition of crown ethers by β-lactose in aqueous solutions

2006 ◽  
Vol 16 (1) ◽  
pp. 45-46
Author(s):  
Nadezhda L. Volkova ◽  
Elena V. Parfenyuk
Keyword(s):  
Molecular Recognition ◽  
Aqueous Solutions ◽  
Crown Ethers

Surfactant-induced chirality on reluctant aggregates of a chiral amphiphilic cationic (l)-proline–Zn(ii)porphyrin conjugate in water

RSC Advances ◽  
2014 ◽  
Vol 4 (98) ◽  
pp. 55362-55366 ◽  
Author(s):  
Edoardo Simoncini ◽  
Fabrizio Caroleo ◽  
Francesca Ceccacci ◽  
Giovanna Mancini ◽  
Manuela Stefanelli ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Aqueous Solutions ◽  
Porphyrin Derivative ◽  
Chiral Surfactants

The aggregation of an amphiphilic chiral Zn(ii)porphyrin derivative occurs in aqueous solutions of chiral surfactants with highly specific molecular recognition.

Ultrathin frozen sections of yeast without aldehyde prefixation

1978 ◽  
Vol 36 (2) ◽  
pp. 58-59
Author(s):  
K. J. Böhm ◽  
a. E. Unger
Keyword(s):  
Aqueous Solutions ◽  
Biological Material ◽  
Yeast Cells ◽  
Frozen Sections ◽  
Good Preservation ◽  
Ultrathin Frozen Sections

During the last years it was shown that also by means of cryo-ultra-microtomy a good preservation of substructural details of biological material was possible. However the specimen generally was prefixed in these cases with aldehydes.Preparing ultrathin frozen sections of chemically non-prefixed material commonly was linked up to considerable technical and manual expense and the results were not always satisfying. Furthermore, it seems to be impossible to carry out cytochemical investigations by means of treating sections of unfixed biological material with aqueous solutions.We therefore tried to overcome these difficulties by preparing yeast cells (S. cerevisiae) in the following manner:

Imaging polymers, proteins and dna in aqueous solutions with the atomic force microscope

1989 ◽  
Vol 47 ◽  
pp. 32-33
Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Sequencing ◽  
Aqueous Solutions ◽  
Atomic Force Microscope ◽  
Piezoelectric Crystal ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Optical Lever

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.

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