Synthesis and antifungal activity of camphoric acid-based acylhydrazone compounds

Abstract
In the search of novel potent bioactive compounds, 18 novel camphoric acid-based acylhydrazone compounds 4a–4r were designed and synthesized by the condensation reaction of N-amino camphorimide (3) with substituted benzaldehyde based on camphoric acid as the starting material. The target compounds were characterized by means of Fourier transform infrared (FTIR), 1H nuclear magnetic resonance (NMR), 13C NMR, electrospray ionization-mass spectrometry (ESI-MS), and elemental analysis. The preliminary bioassay showed that the following camphoric acid-based compounds exhibited excellent antifungal activity with an inhibition ratio of 95% against Physalospora piricola at the concentration of 50 μg ml-1: o-bromophenyl acylhydrazone (4f), p-bromophenyl acylhydrazone (4g), p-methoxyphenyl acylhydrazone (4m), and p-hydroxyphenyl acylhydrazone (4p).