Synthesis and Evaluation on the Fungicidal Activity of S-Alkyl Substituted Thioglycolurils.

A series of S-alkyl substituted thioglycolurils was prepared through the alkylation of corresponding thioglycolurils with halogenoalkanes and tested for their fungicidal activity against six phytopathogenic fungi from different taxonomic classes: Venturia inaequalis , Rhizoctonia solani , Fusarium oxysporum , Fusarium moniliforme , Bipolaris sorokiniana , and Sclerotinia sclerotiorum, and two pathogenic yeasts: Candida albicans and Cryptococcus neoformans var. grubii . A number of S-alkyl substituted thioglycolurils exhibited high activity against Venturia inaequalis and Rhizoctonia solani (85-100% mycelium growth inhibition), and moderate activity against other phytopathogens. S-Ethyl substituted thioglycolurils possessed a high activity against Candida albicans . Additionally, the hemolytic and cytotoxic properties of promising derivatives were determined using human red blood cells and human embryonic kidney cells, respectively. Two S-ethyl derivatives possessed both low cytotoxicity against normal human cells and high fungicidal activity against Candida albicans .