3025-96-5Relevant articles and documents
Apparent Molal Volumes of Amino Acids, N-Acetylamino Acids, and Peptides in Aqueous Solutions
Mishra, Awadhesh K.,Ahluwalia, Jagdish C.
, p. 86 - 92 (1984)
The apparent molal volumes of 24 α-amino acids, 6 N-acetylamino acids, and 9 peptides in aqueous solutions have been determined at 298.15 K from precise density measurements.Limiting partial molal volumes, , have been also evaluated from the apparent molal volumes at various solute concentrations.Group additivity relationships were examined from the data of these solutes as well as from those of several homologous series of compounds available in the literature.It has been shown that the presence of hydrophilic groups in close proximity in α-amino acids and N-acetylamino acids decreases the functional-group contribution as well as the contribution due to hydrophobic hydratoin toward relative to those observed in the monofunctional compounds.It is also found that the values of the peptides estimated from the values of the constituent amino acids, with a proper consideration of change in the electrostriction volume due to separation of the charged centers, agree with the experimental values.Concentration dependence of the apparent molal volumes of the solutes has been explained on the basis of combined effects of hydrophilic and hydrophobic solute-solute interactions mediated through the typical structure of water.
MUTUAL INFLUENCE OF ASCORBIC AND &γ-AMINOBUTYRIC ACIDS ON THEIR BIOLOGICAL PROPERTIES DURING COMPLEXATION
Fridman, Ya. D.,Kebets, N. M.,Nanaeva, M. T.,Zurdinov, A. Z.,Sabirova, T. S.,Atarskaya, L. I.
, p. 879 - 883 (1989)
-
Energetic contribution to both acidity and conformational stability in peptide models
Kubyshkin, Vladimir,Durkin, Patrick,Budisa, Nediljko
supporting information, p. 5209 - 5220 (2016/07/06)
The acidity of N-acyl amino acids is dependent upon the rotameric state of the amide bond. In this work we systematically investigated the acidity difference of the rotamers (ΔpKa) in the frames of various acetylated amino acids. Our results indicated a mutual interaction of two carbonyl groups of an attractive type. We observed conservative ΔpKas for acyclic amino acids (2.2-3.0 kJ mol-1), whereas in the case of alicyclic amino acids, the experimental values revealed a strong dependency on the structural context (1.5-4.4 kJ mol-1). In homologous amino acids (α-, β-, γ-, etc.), the strength of the attraction decays in an exponential fashion. Furthermore, the interaction can accumulate through a chain of amide bonds in a cascade fashion, as demonstrated by an Ac-Pro-Pro dipeptide. As a result, we demonstrate that ΔpKa is an experimental parameter to estimate increments in the carbonyl-carbonyl alignment, as determined by the amino acid or peptidyl context. This parameter is also important in understanding the roles of amino acids in both protein folding and translation in biological systems as well as their evolutionary appearance in the genetic code.
Direct C-H alkylation of naphthoquinones with amino acids through a revisited Kochi-Anderson radical decarboxylation: Trends in reactivity and applications
Naturale, Guillaume,Lamblin, Marc,Commandeur, Claude,Dessolin, Jean,Felpin, Francois-Xavier
supporting information, p. 5774 - 5788,15 (2020/09/15)
In our ongoing research program into the discovery of new anticancer drugs, we were interested in the preparation of naphthoquinone scaffolds bearing aminoalkyl side-chains. Following this aim, we revisited the Kochi-Anderson radical decarboxylation of amino acids in order to set up a versatile route to the direct functionalization of naphthoquinones. The best reaction conditions were applied to a selected series of compounds in a systematic methodological study which allowed us to establish important trends in reactivity. We found that α-substituted β-amino acids were the most suitable substrates for the radical addition. In contrast, α-amino acids gave modest results. The influence of the amine protecting groups on the reaction outcome has also been studied. This practical procedure allows the introduction of various unsymmetrical moieties, including orthogonally protected linear aminoalkyl chains or chiral dipeptidic chains, and opens the door to a wide scope of easily accessible chemical diversity.
