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Conformer equilibria of triostin A and its conformer‐specific interaction with nucleic acid bases
Author(s) -
Kyogoku Yoshimasa,
Higuchi Naoki,
Watanabe Mayumi,
Kawano Keiichi
Publication year - 1981
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1981.360200918
Subject(s) - conformational isomerism , chemistry , quinoxaline , hydrogen bond , stereochemistry , alkane stereochemistry , chirality (physics) , bicyclic molecule , crystallography , molecule , organic chemistry , crystal structure , nambu–jona lasinio model , chiral symmetry breaking , physics , quantum mechanics , quark
A quinoxaline antibiotic triostin A has a bicyclic octadepsipeptide structure. Proton and carbon‐13 nmr spectra showed the presence of two symmetrical conformations favoring polar and nonpolar solvents, respectively. They interconvert slowly on the nmr time scale, and this slow interconversion is due to the cooperative effects of the presence of the quinoxaline ring and the N‐methyl peptide bonds. Reversal of the chirality of the disulfide bond as the origin of the slow exchange was excluded by the presence of two conformers for S ‐benzyltriostin A. Conformer 2, which favors the polar solvent, can form hydrogen‐bonded complexes with purine nucleoside derivatives in organic solvents, but conformer 1 does not. The binding sites were elucidated and a mode of interaction with DNA proposed.