*3.7. Effect on the Cell Wall Integrity of B. cinerea*

The effect of compounds **3a–j** on cell wall integrity was evaluated using the method described by Mendoza et al. [27]. Compounds **3a–j** were tested at 0.16 mM. To measure the effect of these compounds on the cell wall, fluorescence intensity was quantified using ImageJ (v1.80), an outline was drawn around each hypha, and mean fluorescence was measured, along with several adjacent background readings. Mean fluorescence was compared to the negative control (maximum fluorescence).

#### **4. Conclusions**

Ten compounds were synthetized; two of them (compounds **3a** and **3f**) have been previously described. All the products showed higher antifungal activity than the substrates. Chloro-substituted compounds showed the highest antifungal effect against *B. cinerea* being the 3,5-dichlorinated product **3h** the most active. Synthesis using syringic acid or syringaldehyde with *p*-chloroaniline yield the same main product (compound **3a**). Finally, regarding the inhibition mechanism of these compounds, the results suggest that these compounds damage the cell wall.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/1420-3049/24/4/706/s1, Figures S1–S30: 1H-, 13C-NMR and Mass spectra of compounds **3a–j**, Figures S31–S40: IR spectra of compounds **3a–j**. Table S1: Retention Index.

**Author Contributions:** Methodology, P.C., P.C.P., K.L., and R.S.; Investigation, P.C.; Formal Analysis, L.M., M.C., F.N. and P.C.; Writing-Original Draft P.C.; Writing-Review and Editing, L.M., M.C., F.N., P.C.P., and P.C.; Project Administration C.V.

**Funding:** This research was funded by FONDECYT, grant number 3170478, and by Universidad de Santiago de Chile DICYT 021640VG\_POSTDOC.
