## 3 Results
### Antimicrobial and Anticancer Activities of Pure Compounds  
The antimicrobial potential of five pure compounds was evaluated against tested pathogens at the concentration of 10 mM. Of note, four compounds, including methyl pyroglutamate, 2-(4-hydroxyphenyl) ethanol (tyrosol), macrolactin A, and macrolactin F, showed antimicrobial activity against at least one pathogenic strain, while no antimicrobial activity was observed for prunetin (Table 2). _E. coli_ ATCC 11105 and MRSA ATCC 33591 were inhibited by 2-(4-hydroxyphenyl) ethanol with inhibition zone sizes of 11.6 \(\pm\) 1.5 and 9.8 \(\pm\) 0.6, respectively. Macrolactin A and F showed similar antibacterial profiles expressed by strong inhibition against _E. coli_ ATCC 11105, _B. cereus_ ATCC 11778, and MRSA ATCC 33591 but not yeast _C. albicans_ ATCC 10231. In contrast, methyl pyroglutamate only suppressed _C. albicans_ ATCC 10231, with an inhibition zone size of 12.4 \(\pm\) 0.7 mm.  
In terms of anticancer activity, three out of five pure compounds, including macrolactin A, macrolactin F, and prunetin, caused cytotoxicity against A549 and MCF7 cell lines at moderate levels (Table 2). Macrolactin A and F moderately showed the inhibitory effect on A549 and MCF7 cell lines, with IC\({}_{50}\) values ranging from 82.4 \(\pm\) 2.9 to 92.0 \(\pm\) 8.8 \(\upmu\)M). At the lower level, prunetin inhibited A549 and MCF7, with IC\({}_{50}\) values of 98.9 \(\pm\) 7.3 \(\upmu\)M and 90.4 \(\pm\) 8.2 \(\upmu\)M, respectively.  
For antioxidant activity, five compounds exhibited remarkable antioxidant activity against DPPH and hydroxyl radicals, with the IC\({}_{50}\) values ranging from between 3.86-7.25 mM (Table 2). Specifically, prunetin was the most powerful antioxidant that scavenged DPPH and hydroxyl radicals, with the lowest IC\({}_{50}\) of 3.86 \(\pm\) 0.23 mM and 4.26 \(\pm\) 0.20 mM, respectively. Macrolactin A and F showed equivalent scavenging activ  
\begin{table}
\begin{tabular}{l c c c c c c c c} \hline \hline \multirow{2}{*}{**Compounds**} & \multicolumn{4}{c}{**Antibacterial Activity**} & \multicolumn{4}{c}{**Cytotoxicity**} & \multicolumn{2}{c}{**Antioxidant Activity**} \\  & **(Inhibition Diameter; mm)** & \multicolumn{4}{c}{**(IC\({}_{50}\); nM)**} & \multicolumn{2}{c}{**(IC\({}_{50}\); mM)**} \\ \cline{2-9}  & **_E. coli_** & **_B. cereus_** & **MRSA** & **C. albicans** & **C. albicans** & **ACC 110231** & **A549** & **MCF7** & **DPPH** & **Hydroxyl** \\ \hline Methyl pyroglutamate & nd & nd & nd & 12.4 \(\pm\) 0.7 & nd & nd & 5.01 \(\pm\) 0.49 & 7.25 \(\pm\) 0.16 \\ \hline
2-(4-hydroxyphenyl) ethanol & 11.6 \(\pm\) 1.5 & nd & 9.8 \(\pm\) 0.6 & nd & nd & nd & 5.24 \(\pm\) 0.37 & 4.01 \(\pm\) 0.15 \\ \hline Macrolactin A & 18.5 \(\pm\) 2.0 & 16.3 \(\pm\) 1.1 & 17.9 \(\pm\) 0.4 & nd & 82.4 \(\pm\) 2.9 & 87.7 \(\pm\) 8.5 & 4.16 \(\pm\) 0.19 & 5.60 \(\pm\) 0.30 \\ \hline Macrolactin F & 17.2 \(\pm\) 0.7 & 16.9 \(\pm\) 1.5 & 16.1 \(\pm\) 1.3 & nd & 92.0 \(\pm\) 8.8 & 86.5 \(\pm\) 7.6 & 4.14 \(\pm\) 0.20 & 5.31 \(\pm\) 0.40 \\ \hline Prunetin & nd & nd & nd & nd & 98.9 \(\pm\) 7.3 & 90.4 \(\pm\) 8.2 & 3.86 \(\pm\) 0.23 & 4.26 \(\pm\) 0.20 \\ \hline \hline \end{tabular} Notes: nd, not determined.  
\end{table}
Table 2: Antimicrobial and anticancer activities of 5 pure compounds.  
Figure 4: The chemical structure of 5 compounds from the _Xylaria_ sp. KET18 extract. (**1**)—methyl pyroglutamate, (**2**)—2-(4-hydroxyphenyl)ethanol, (**3**)—macrolactin A, (**4**)—macrolactin F, (**5**)—prunetin.  
ities to each radical. Methyl pyroglutamate had the lowest antioxidant activity against hydroxyls indicated by an IC\({}_{50}\) of 7.25 \(\pm\) 0.16 mM.