investigating the effectiveness of spirocyclopropane-oxindole derivatives on clinical isolates of candida albicans

Objectives: given the spread of azole resistance in candida albicans (c. albicans), searching for new potent compounds, such as spirocyclopropane-oxindole derivatives is important. this study evaluates the antifungal susceptibility of spirocyclopropane-oxindole derivatives on clinical isolates of c. albicans. methods: antifungal susceptibility of 50 clinical isolates of c. albicans to spirocyclopropane-oxindole derivatives (4a, 4b, and 4c), nystatin, and fluconazole were evaluated according to clinical laboratory standards institute (m27-s4) guidelines. the medicinal dilution range of the compounds, fluconazole, and nystatin was 0.256 to 128, 0.128 to 64, and 0.032 to 16 μg/ml, respectively. the minimum inhibitory concentration (mic) was defined as the concentration that caused at least 50% growth inhibition compared to the positive control. statistical analysis was performed using the spss software, version 20. the significance level was set at p≤0.05.results: there was a significant difference between the mic values of spirocyclopropane-oxindole derivatives (4a, 4b, and 4c), nystatin, and fluconazole against c. albicans. the comparison of the mics of the spirocyclopropane-oxindole derivatives (4a, 4b, and 4c) against c. albicans showed that derivative 4a had a lower mic50 (8 μg/ml), mic90 (16 μg/ml), and geometric (g) mean (10.126) than derivatives 4b (mic50=64, mic90=128, g mean=76.638), and 4c (mic50=64, mic90=128, g mean=60.547).discussion: antifungal effects of spirocyclopropane-oxindole derivatives (4a, 4b, and 4c) on c. albicans isolates were significantly less than nystatin and fluconazole. therefore, with structural changes, the antifungal effects of these compounds will increase.