N-Phenyl and N-phenylalkyl-maleimides acting against Candida spp.: Time-to-kill, stability, interaction with maleamic acids

N-Phenyl and N-phenylalkyl maleimides (alkyl chain = (CH2)n; n = 0–4) and their respective open derivatives (maleamic acids) were evaluated against Candida spp. with the microbroth dilution method following the guidelines of CLSI (formely NCCLS). MIC values of maleimides without pre-incubation and submitted to different pre-incubation times into the growth media, time-to-kill studies as well as a time-dependent UV-spectroscopy study of the maleimides in water, led to determine that maleimides display antifungal activities with their intact maleimide ring, being in addition their activities not dependent on the length of the alkyl chain. They are not only fungistatic but fungicidal with very low MICs and MFCs, displaying strong fungicide activities not only against standardized but also clinical isolates of Candida albicans and non-albicans Candida spp.

N-Phenyl and N-phenylalkylmaleimides of the general structure A with n = 0–4 showed potent fungistatic and fungicide activities against a standardized strain as well as clinical isolates of Candida albicans and non-albicans Candida spp. Stability studies using biological and spectrophotometric methods showed that all maleimides tested maintain intact their maleimide ring during the time required for killing fungi. Antifungal properties of their open derivatives along with the type of interaction between maleimides and maleamic acids are reported too.Figure optionsDownload as PowerPoint slide