Preparation, characterization and biological activity of Schiff base compounds derived from 8-hydroxyquinoline-2-carboxaldehyde and Jeffamines ED®

Polyethers with 8-hydroxyquinolin-2-yl end groups (HOQCH=N-POE-N=CHQOH) were prepared by reaction between polyethers having amino end groups (Jeffamines ED(R)) and 8-hydroxyquinoline-2-carboxaldehyde. The HOQCH=N-POE-N=CHQOH polymers were characterized by size-exclusion chromatography, UV, IR, H-1 and C-13 NMR spectroscopy, and MALDI-TOF mass spectrometry. The complexation between HOQCH=N-POE-N= CHQOH and Fe3+ was studied by UV, IR spectroscopy and differential scanning calorimetry. The UV-irradiation of the complexes caused photodegradation of the polyether chains. It was shown that HOQCH=N-POE-N=CHQOH had high efficacy on remedying iron-deficient maize plants and exhibited very low-antibacterial activity towards nonpathogenic soil bacteria (B. subtilis). (C) 2002 Elsevier Science Ltd. All rights reserved.