Biocompatible nanocomposites based on polyurethane-poly(2-hydroxyethyl methacrylate) matrix and filler modified by biologically active amino acid glycine: structure and thermodynamics of interactions

2016 ◽  
Vol 38 (3) ◽  
pp. 225-235 ◽  
Author(s):  
L.V. Karabanova ◽  
◽  
Yu.P. Gomza ◽  
S.D. Nesin ◽  
O.M. Bondaruk ◽  
...  
1979 ◽  
Vol 32 (1) ◽  
pp. 21 ◽  
Author(s):  
H Stunzi ◽  
DD Perrin ◽  
T Teitei ◽  
RLN Harris

Complex formation of the biologically active amino acid L-mimosine [α-amino-β-(3-hydroxy-4-oxo-1,4-dihydropyridin-1-yl)propanoic acid (1)], mimosinic acid (2), mimosine methyl ether (9) and 3-hydroxy-1-methylpyridin-4(1H)-one (4) with Cu2+, Zn2+, Cd2+ and Pb2+ was studied. Stability constants were determined by potentiometric titration in 0.15M KNOB3 as inert electrolyte at 37�. In the monomeric complexes formed by the mimosine derivatives, metal binding by the hydroxypyridone moiety was favoured relative to the amino acid group. With mimosine, dimeric complexes were major species. Under physiological conditions, mimosine binds copper and zinc ions more strongly than do simpler amino acids.


2019 ◽  
Vol 84 (10) ◽  
pp. 1083-1092 ◽  
Author(s):  
Farzaneh Mohamadpour

A highly versatile and convenient synthetic route for biologically active ?-amino acid, glutamic acid catalyzed facile and mild preparation of polyfunctionalized dihydro-2-oxypyrroles via one-pot, four condensation domino reaction between aromatic/aliphatic amines, dialkyl acetylenedicarboxylates and formaldehyde have been studied. The route includes green, biodegradable and inexpensive ?-amino acid catalyst, high atom-economy, simplicity of operation and work-up procedures, without chromatographic purification steps. The solid catalyst, non-toxic or hazardous, easily handled with mild reaction conditions and excellent yields are the notable benefits of the highly efficient and expedient synthesis of these products.


2021 ◽  
Vol 6 (22) ◽  
pp. 5614-5621
Author(s):  
Daria Szymaniak ◽  
Tomasz Kleiber ◽  
Marta Wojcieszak ◽  
Katarzyna Materna ◽  
Juliusz Pernak

2019 ◽  
Author(s):  
Andrea N. Bootsma ◽  
Analise C. Doney ◽  
Steven Wheeler

<p>Despite the ubiquity of stacking interactions between heterocycles and aromatic amino acids in biological systems, our ability to predict their strength, even qualitatively, is limited. Based on rigorous <i>ab initio</i> data, we have devised a simple predictive model of the strength of stacking interactions between heterocycles commonly found in biologically active molecules and the amino acid side chains Phe, Tyr, and Trp. This model provides rapid predictions of the stacking ability of a given heterocycle based on readily-computed heterocycle descriptors. We show that the values of these descriptors, and therefore the strength of stacking interactions with aromatic amino acid side chains, follow simple predictable trends and can be modulated by changing the number and distribution of heteroatoms within the heterocycle. This provides a simple conceptual model for understanding stacking interactions in protein binding sites and optimizing inhibitor binding in drug design.</p>


1991 ◽  
Vol 56 (9) ◽  
pp. 1963-1970 ◽  
Author(s):  
Jan Hlaváček ◽  
Václav Čeřovský ◽  
Jana Pírková ◽  
Pavel Majer ◽  
Lenka Maletínská ◽  
...  

In a series of analogues of the cholecystokinin octapeptide (CCK-8) the amino acid residues were gradually modified by substituting Gly by Pro in position 4, Trp by His in position 5, Met by Cle in position 6, or the Gly residue was inserted between Tyr and Met in positions 2 and 3 of the peptide chain, and in the case of the cholecystokinin heptapeptide (CCK-7) the Met residues were substituted by Nle or Aib. These peptides were investigated from the point of view of their biological potency in the peripheral and central region. From the results of the biological tests it follows that the modifications carried out in these analogues and in their Nα-Boc derivatives mean a suppression of the investigated biological activities by 2-3 orders of magnitude (at a maximum dose of the tested substance of 2 . 10-2 mg per animal).This means that a disturbance of the assumed biologically active conformation of CCK-8, connected with a considerable decrease of the biological potency of the molecule, takes place not only after introduction of the side chain into its centre (substitution of Gly4), but also after the modification of the side chains of the amino acids or by extension of the backbone in further positions around this central amino acid.


1961 ◽  
Vol 83 (21) ◽  
pp. 4449-4457 ◽  
Author(s):  
Choh Hao Li ◽  
Johannes Meienhofer ◽  
Eugen Schnabel ◽  
David Chung ◽  
Tung-Bin Lo ◽  
...  

2013 ◽  
Vol 72 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Muhammad Zia-Ul-Haq ◽  
Sanja Ćavar ◽  
Mughal Qayum ◽  
Inamullah Khan ◽  
Shakeel Ahmad

Abstract The aim of this study was to evaluate the compositional and nutritional potential of methanolic extracts of various parts of Acacia leucophloea Roxb. concerning the chemical composition and antioxidant potential of which limited information is available. Compositional studies indicated carbohydrates as major components in both seed and pods. Despite differences in mineral content among the leaves, pods and seeds, calcium was found in the highest amount and zinc in the lowest. The amino acid profile indicated aspartic acid as the major amino acid and proline as the minor. Among protein fractions, globulin was present in higher amounts than other fractions. Linoleic acid was the major fatty acid detected in the oil from both pods and seeds, while g-tocopherol was the major component of the tocopherol observed from same oil. Moreover, significant antioxidant potential was observed from the extracts of all three parts investigated. The results obtained in this study clearly indicate that A. leucophloea has a sufficient potential for use as a natural antioxidant agent. Further phytochemical studies will be performed for specification of the biologically active principles.


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