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Synthesis and Conformational Analysis of Aminopyrazolonyl Amino Acid (APA)/Peptides
Author(s) -
Bollu Amarnath,
Sharma Nagendra K.
Publication year - 2019
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201801640
Subject(s) - chemistry , amino acid , hydrogen bond , supramolecular chemistry , intramolecular force , stereochemistry , peptide , molecule , macromolecule , pyrazole , covalent bond , chemical ligation , amide , photo reactive amino acid analog , residue (chemistry) , combinatorial chemistry , organic chemistry , biochemistry , protein catabolism
Pyrazole, pyrazolone, and aminopyrazolone derived molecules are bioactive molecules and considered as potential therapeutic drug candidates because of their unique structural properties. These molecules have abilities to interact with several bio‐macromolecules via non‐covalent interactions such as hydrogen bonding and π–π interactions. In structural organization of dipeptides, pyrazole containing aromatic amino acid/dipeptides have been explored and considered as potential amino acid residue. In repertoire of unnatural aromatic amino acids, this report describes the synthesis of 4‐aminopyrazolonyl containing amino acids and their crystal structures. The incorporation of 4‐aminopyrazolonyl at N‐terminal of native amino acid/dipeptides influences the conformational changes of respective peptide which induces the formation of distinctive supramolecular self‐assembly structures such as β‐sheet and α‐helices in their solid‐state crystal. The structural conformation of those peptides, here, are also demonstrated in solution phase by 1 H‐NMR (1D/2D) and [D 6 ]DMSO titration methods which support the formation of inter‐/intramolecular hydrogen bonding in solution. Hence, these unnatural amino acid analogues can tune the secondary structure of natural amino acid/peptides by introducing at N ‐terminal via amide bond.