Scheme 1. Reagents and conditions: (i) SOCl₂, pyridine, 50 °C, 30 min, then N-hydroxysuccinimide, 50 °C, 3 h; (ii) NaH, toluene, rt, 90 min; (iii) TFA, H₂O, rt, 30 min.

Scheme 2. 

Figure 1. Comparative photooxidation of DPBF (75 μM) in DMF/H₂O (9:1) with or without photosensitizer (1 μM); irradiation with white light filtered through a cut-off filter for wavelengths <540 nm (50 mW/cm²).

Figure 2. Photocytotoxicity profile of studied compounds in Vero cells. Each value represents mean ± standard deviation of three experiments, with three replicates each. Error bars represent standard deviations.

Figure 3. Virucidal effect of the target compounds (0.02 μM) on HSV-1, non-irradiated and irradiated for 5 or 15 min with white light (50 mW/cm²). The inhibition values (in %) were calculated in relation to the non-treated controls. Data are reported as means of three independent assays, each run in triplicate. Error bars represent standard deviations.

Photostability of the photosensitizers after irradiation with white light (50 mW/cm²) for different periods of time

The absorbance was measured at the corresponding Soret band wavelength. The results are presented in percentage calculated by the ratio of residual absorbance at different periods of time and the absorbance before irradiation.

Influence of the drug addition (0.02 μM) at different post-adsorption times on the inhibition of the virus yield

Each value represents mean ± standard deviation of two experiments, with three replicates each.