Naslov
Structural studies on monofluorinated derivatives of the phytohormone indole-3-acetic acid (auxin)

Autori
Antolić, Snježana ; Kojić-Prodić, Biserka ; Tomić, Sanja ; Nigović, Biljana ; Magnus, Volker ; Cohen, Jerry D.

Izvornik
Acta crystallographica. Section B, Structural science (0108-7681) 52 (1996), 4; 651-661

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
X-ray structure analysis ; lipophilicity ; bioassays ; auxins ; indole-3-acetic acid ; monofluorinated indole-3-acetic acids

Sažetak
As a part of molecular recognition studies on the phytohormone indole-3-acetic acid (IAA), a series of fluorinated IAAs was examined. Substitution at positions 4, 5, 6 and 7 of the phenyl ring resulted in four compounds, which were analyzed. Structure-activity considerations included the analysis of molecular conformation, based on the results of X-ray diffraction studies and computational chemistry, of lipophilicity and of UV absorbance, as well as bioactivity determinations in the Avena coleoptile and the Pisum sativum stem straight-growth tests. The conformations of monofluorinated IAAs and the unsubstituted parent compound are defined by rotation about two bonds: one determines the relative orientation of the side chain towards the indole plane and the second the orientation of the carboxylic group. The results of X-ray structure analysis revealed the folded shape of the molecules in all compounds studied. Molecular mechanics and dynamics located the folded shape as the local minimum, but failed to detect the planar conformation as one of the minima, which according to ab initio results on IAA and 4-Cl-IAA could also be possible.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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