Role of functional groups in determining interactions in ternary aqueous solutions of enantiomeric α-amino acids: a calorimetric study at 298 K

1999 ◽  
Vol 1 (24) ◽  
pp. 5653-5657 ◽  
Author(s):  
Giuseppina Castronuovo ◽  
Vittorio Elia ◽  
Marcella Niccoli ◽  
Daniela Strollo ◽  
Filomena Velleca
Keyword(s):  
Amino Acids ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Calorimetric Study

Chiral recognition in aqueous solutions at 25 °C. A calorimetric study of the interaction between enantiomeric α-amino acids of different alkyl chain length

1991 ◽  
Vol 69 (5) ◽  
pp. 794-797 ◽  
Author(s):  
Giuseppina Castronuovo ◽  
Vittorio Elia ◽  
Michela Magliulo
Keyword(s):  
Amino Acids ◽  
Aqueous Solutions ◽  
Chiral Recognition ◽  
Excess Enthalpy ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Calorimetric Study ◽  
Experimental Uncertainty ◽  
Enthalpies Of Dilution

Cross-homo- and cross-heterotactic enthalpic coefficients, [Formula: see text] respectively, were determined at 25 °C, measuring the enthalpies of dilution of ternary aqueous solutions containing two different α-amino acids of the same or different chirality. Differences of about 200–300 J mol−2 kg between cross-homo- and cross-heterotactic coefficients were found, well beyond the experimental uncertainty. The role of the zwitterionic interaction, already proposed to explain the nature of chiral recognition, was strengthened. Key words: α-amino acids, excess enthalpy, chiral recognition.

scholarly journals Natural Products Containing ‘Rare’ Organophosphorus Functional Groups

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 866 ◽  
Author(s):  
Janusz Petkowski ◽  
William Bains ◽  
Sara Seager
Keyword(s):  
Amino Acids ◽  
Natural Products ◽  
Functional Groups ◽  
Functional Group ◽  
Organophosphorus Compounds ◽  
Living Cells ◽  
Unusual Amino Acids ◽  
Biological Source ◽  
Technological Limitations

Phosphorous-containing molecules are essential constituents of all living cells. While the phosphate functional group is very common in small molecule natural products, nucleic acids, and as chemical modification in protein and peptides, phosphorous can form P–N (phosphoramidate), P–S (phosphorothioate), and P–C (e.g., phosphonate and phosphinate) linkages. While rare, these moieties play critical roles in many processes and in all forms of life. In this review we thoroughly categorize P–N, P–S, and P–C natural organophosphorus compounds. Information on biological source, biological activity, and biosynthesis is included, if known. This review also summarizes the role of phosphorylation on unusual amino acids in proteins (N- and S-phosphorylation) and reviews the natural phosphorothioate (P–S) and phosphoramidate (P–N) modifications of DNA and nucleotides with an emphasis on their role in the metabolism of the cell. We challenge the commonly held notion that nonphosphate organophosphorus functional groups are an oddity of biochemistry, with no central role in the metabolism of the cell. We postulate that the extent of utilization of some phosphorus groups by life, especially those containing P–N bonds, is likely severely underestimated and has been largely overlooked, mainly due to the technological limitations in their detection and analysis.

Thermodynamics of the interaction of cyclodextrins with aromatic and α, ω-amino acids in aqueous solutions: a calorimetric study at 25°C

1995 ◽  
Vol 272 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Giuseppina Castronuovo ◽  
Vittorio Elia ◽  
Dimitrios Fessas ◽  
Antonio Giordano ◽  
Filomena Velleca
Keyword(s):  
Amino Acids ◽  
Aqueous Solutions ◽  
Calorimetric Study

Role of the functional group in the formation of the complexes between α-cyclodextrin and alkanols or monocarboxylic acids in aqueous solutions. A calorimetric study at 25 °C

1998 ◽  
Vol 306 (1-2) ◽  
pp. 147-155 ◽  
Author(s):  
Giuseppina Castronuovo ◽  
Vittorio Elia ◽  
Marcella Niccoli ◽  
Filomena Velleca ◽  
Giuseppe Viscardi
Keyword(s):  
Aqueous Solutions ◽  
Functional Group ◽  
Calorimetric Study ◽  
Monocarboxylic Acids

Chiral recognition in aqueous solutions: On the role of urea in hydrophilic and hydrophobic interactions of unsubstituted ?-amino acids

1996 ◽  
Vol 25 (9) ◽  
pp. 837-848 ◽  
Author(s):  
Salvatore Andini ◽  
Giuseppina Castronuovo ◽  
Vittorio Elia ◽  
Amelia Pignone ◽  
Filomena Velleca
Keyword(s):  
Amino Acids ◽  
Aqueous Solutions ◽  
Chiral Recognition ◽  
Hydrophobic Interactions

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.

Sign in / Sign up

Export Citation Format

Share Document