Synthesis and in vitro antimicrobial property of o-carborane derivatives

Various o-carboranes and nido-type dicarbollide anions have been synthesized and tested for antimicrobial activity. Nearly all of the dicarbollide monoanions investigated were active in vitro against fungi such as Candida albicans, Aspergillus fumigatus, and Tricophyton asteroides, as well as against Gram-positive bacteria. From a consideration of the structure-activity relationships, it seems most reasonable to conclude that the introduction of lipophilic alkyl or o-carboranyl groups to the hydrophilic dicarbollide anions leads to the antimicrobial activity.