Synthesis, antibacterial and antifungal activity of 4-hydroxycoumarin derivatives, analogues of novobiocin.

3-Acylamino-, -arylsulfonylamino-, -(N'-arylureido)-, -arylideneamino- and -arylcarbamoyl-4-hydroxycoumarins have been synthesized and tested for antibacterial and antifungal activity. 3-Arylcarbamoyl-4-hydroxycoumarins have been shown to possess significant activity against Gram-positive bacteria; 3-acylamino-4-hydroxycoumarins have moderate antibacterial and antifungal effects whereas the additional compounds are inactive.