Synthesis and antifungal activity of dehydroabietic acid-based thiadiazole-phosphonates

In search of new potent bioactive compounds, a series of dehydroabietic acid-based thiadiazole-phosphonate compounds were designed and synthesized by the Mannich-type reaction. All target compounds were characterized by Fourier transform infrared, H-1 nuclear magnetic resonance (NMR), C-13 NMR, P-31 NMR, electrospray ionization-mass spectrometry, and UV-vis spectroscopy. The preliminary bioassay experiments showed that, at the concentration of 50 mu g ml(-1), some of the target compounds exhibited excellent antifungal activity against the five fungi tested, in which several compounds displayed even better antifungal effects than the commercial antifungal drug azoxystrobin, which served as the positive control in this study.