Novel 2′-hydroxylfurylchalcones: synthesis and biological activity

Twelve novel 2′-hydroxylfurylchalcones have been synthesized by Claisen-Schmidt condensation with galactosylisomaltol, a reagent prepared from lactose. The procedures are environmentally benign and economical. All the compounds are identified by IR, 1H NMR and 13C NMR spectroscopy and by mass spectrometry. Preliminary bioassays indicate that all the title compounds show moderately high herbicidal activities against the height and/or the fresh weight of the seedlings of cucumber, rape, amaranth, wheat, sorghum and Chinese sprangletop at 7.5 g of active ingredient per hm2. However, the compounds exhibit weak fungicidal activities against cucumber powdery mildew, and no activities against rice blast, cucumber grey mould and cucumber downy mildew. The structure-activity relationships are discussed. The present work demonstrates that 2′-hydroxylfurylchalcones could be used as potential lead compounds for further study of novel herbicides.