DERIVATIVES

Due to exceptional reactivity of -hydroxycoumarin, the synthesis of new coumarin deriva-tives of dimer and tetramer type has been carried out. Th e synthesis was carried out from -hydroxycoumarin and various aromatic aldehydes. In this way, compounds of the dimer ,’-(benzilidene)bis (-hydroxycoumarin) type, as well as of the tetramer ,’,’’,’’’-(,-dim-ethylenphenyl)tetra (-hydroxycoumarin) type were prepared. Th e newly synthesized derivatives contain diff erent functional groups, and as such they could exhibit microbiological activity. Th erefore, we tested the microbiological activity of these derivatives on various species of bacteria and fungi. Th e tested compounds have shown diff erent activity in terms of growth inhibition of microorganisms. Newly synthe-sized derivatives exhibit antibacterial activities, manifested as growth inhibition on Gram-positive bacteria types (Bacillus, Staphylococcus), while the activity against Candida was much weaker. Th e same compound did not show any antimicrobial activity against two Gram-negative bacteria types (Escherichia coli, Pseudomonas aeruginosa). Th e compound showed the best microbiological activity. Th e obtained results confi rmed its good antibac-terial and antimycotic activities against diff erent microorganisms