All spectrometric measurements were performed in multiplets (n = 3-6) in at least three independent experiments. Statistical analysis was performed using OriginPro 9.0.0 (OriginLab, USA). Statistical significance was analyzed after normality testing using one-way analysis of variance (ANOVA) followed by the Bonferroni posttest to compare the results with negative controls at significance level of p = 0.05. At the tested concentrations, no significant interference of tested compounds with any of the used assays was observed.