## 3 Results
### Microbiology  
In antibacterial activity screening, we used a panel of microorganisms (eight strains of Gram-positive bacteria, six strains of Gram-negative bacteria and six strains of yeasts belonging to _Candida_ spp.--Tables 4 and 5). \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \multirow{2}{*}{**Compound**} & \multicolumn{3}{c}{**Acetonitrile-Water**} & \multicolumn{3}{c}{**1,4-Dioxane-Water**} & \multicolumn{3}{c}{**Methanol-Water**} \\ \cline{2-11}  & \(\mathbf{R_{M0}}\) & \(S\) & \(r^{2}\) & \(\varphi\) & \(\mathbf{R_{M0}}\) & \(S\) & \(r^{2}\) & \(\varphi\) & \(\mathbf{R_{M0}}\) & \(S\) & \(r^{2}\) & \(\varphi\) \\ \hline
**13** & 2.5229 & \(-\)0.04 & 0.9916 & 63.57 & 2.9981 & \(-\)0.05 & 0.9932 & 59.95 & 3.5991 & \(-\)0.05 & 0.9902 & 79.83 \\ \hline
**14** & 2.1061 & \(-\)0.04 & 0.9838 & 59.31 & 2.4686 & \(-\)0.04 & 0.9988 & 58.77 & 3.1517 & \(-\)0.04 & 0.9891 & 76.62 \\ \hline
**15** & 0.8263 & \(-\)0.02 & 0.9903 & 40.06 & 1.0641 & \(-\)0.02 & 0.9882 & 45.35 & 2.4159 & \(-\)0.04 & 0.9783 & 65.56 \\ \hline
**16** & 1.2273 & \(-\)0.03 & 0.9732 & 43.00 & 1.0413 & \(-\)0.03 & 0.9948 & 45.60 & 1.7280 & \(-\)0.03 & 0.9809 & 63.13 \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._ \begin{table}
\begin{tabular}{c c c c} \hline \multicolumn{1}{c}{**Compound Number**} & \multicolumn{1}{c}{**LogP\({}_{\text{acetonitrile}}\)**} & \multicolumn{1}{c}{**LogP\({}_{\text{1.4-dioxane}}\)**} & \multicolumn{1}{c}{**LogP\({}_{\text{methanol}}\)**} \\ \hline
**2** & 3.73 & 3.63 & 3.81 \\ \hline
**3** & 4.30 & 4.46 & 4.65 \\ \hline
**4** & 3.14 & 3.77 & 3.71 \\ \hline
**5** & 3.84 & 4.60 & 4.50 \\ \hline
**6** & 4.07 & 4.73 & 4.50 \\ \hline
**7** & 4.37 & 4.80 & 4.64 \\ \hline
**8** & 4.76 & 4.74 & 4.78 \\ \hline
**9** & 2.48 & 2.81 & 2.93 \\ \hline
**10** & 2.67 & 3.05 & 3.28 \\ \hline
**11** & 2.72 & 2.79 & 3.10 \\ \hline
**12** & 2.92 & 3.11 & 3.09 \\ \hline
**13** & 3.28 & 3.47 & 3.37 \\ \hline
**14** & 2.56 & 2.80 & 2.93 \\ \hline
**15** & 0.33 & 1.02 & 2.20 \\ \hline
**16** & 1.03 & 0.99 & 1.52 \\ \hline \end{tabular}
\end{table} 
Table 3: The logP\({}_{\rm EXP}\) values of the synthesized hydrazide-hydrazones of phenylacetic acid **2–16**. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Species**} & \multicolumn{1}{c}{\multirow{2}{*}{**2**}} & \multicolumn{1}{c}{\multirow{2}{*}{**3**}} & \multicolumn{1}{c}{\multirow{2}{*}{**4**}} & \multicolumn{1}{c}{\multirow{2}{*}{**5**}} & \multicolumn{1}{c}{\multirow{2}{*}{**6**}} & \multicolumn{1}{c}{\multirow{2}{*}{**7**}} & \multicolumn{1}{c}{\multirow{2}{*}{**9**}} & \multicolumn{1}{c}{\multirow{2}{*}{**107**}} & \multicolumn{1}{c}{\multirow{2}{*}{**108**}} & \multicolumn{1}{c}{\multirow{2}{*}{**109**}} & \multicolumn{1}{c}{\multirow{2}{*}{**109**}} & \multicolumn{1}{c}{\multirow{2}{*}{**109**}} \\ \cline{3-3} \cline{8-12} \multicolumn{1}{c}{} & **2** & **3** & **4** & **5** &  
Our results show varied antimicrobial bioactivity of tested compounds **(2-16)**. Gram-positive bacteria, especially the strains belonging to _Staphylococcus_, were the most sensitive to these substances. Among them, compound **16** had the highest activity against all staphylococci with a very strong bactericidal effect (MIC = 1.95-7.81 \(\upmu\)g/mL, MBC = 1.95-31.25 \(\upmu\)g/mL and MBC/MIC = 1-4). Moreover, the next substance **13** indicated similar activity at MIC in the range from 1.95 to 15.62 \(\upmu\)g/mL and very strong or strong activity (but with bacteriostatic effect) towards these bacteria. Compound **11** was also noteworthy due to its strong bioactivity (MIC = 15.62 \(\upmu\)g/mL) against all _Staphylococcus aureus_ strains and good activity (MIC = 62.5 \(\upmu\)g/mL) towards _Staphylococcus epidermidis_ ATCC 12228. Its effect, similar to that of substance **13**, was bacteriostatic. The remaining Gram-positive bacteria (_Microoccus luteus_ ATCC 10240, _Enterococcus faecalis_ ATCC 29212 and _Bacillus_ spp.)