## 3 Results and Discussion
### Antioxidant Activity of TAEM and TAEE  
Comparing the two extraction methods, the yield of triterpenoids extracted by MAEM and ethanol hot reflux extraction method (EHRE) were \(1.82\pm 0.04\%\) and \(1.02\pm 0.13\%\) (Table 2), respectively. Besides, MAEM had a lower extraction temperature (50 \({}^{\circ}\)C), shorter extraction time (30 min) and avoided the extensive use of organic reagents. As for EHRE, long-term (120 min) extraction at a high temperature (90 \({}^{\circ}\)C) might be damaging to active components in AC. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Peak** & **Compound** & **Molecular** & **T\({}_{\text{R}}\) (min)** & **[M + H]\({}^{+}\)** & **[M - H]-** & **Molecular** & **Reference** \\ \hline
1 & 2, 4-dimethoxy-6- & & & & & & \\ methylbenzene-1,3-diol & & & & & & & \\
2 & Anticn K & & & & & & \\
3 & Anticn K & & & & & & \\
4 & Anticn C & & & & & & \\
5 & Anticn H & & & & & & \\
6 & Anticn A & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Chemical characterization of the main compounds detected in TAEM by LC-MS/MS. Figure 3: MS spectra of compounds extracted from _Antrolia camphorata_. (**a**) MS spectra of 2,4-dimethoxy-6-methylbenzene-1,3-diol, [M + H]\({}^{+}\)_m/z_ 185, (**b**) MS spectra of Antcin K [M + H]\({}^{+}\)_m/z_ 489, (**c**) MS spectra of Antcin K [M + H]\({}^{+}\)_m/z_ 489, (**d**) MS spectra of Antcin C [M + H]\({}^{+}\)_m/z_ 471, (**e**) MS spectra of Antcin H [M + H]\({}^{+}\)_m/z_ 487, (**f**) MS spectra of Antcin A [M - H]\({}^{-}\)_m/z_ 455. There have been many reports on the antioxidant activity of AC [22; 23; 24]. Four experiments related to antioxidant, scavenging ability on DPPH radicals, hydroxyl radicals, ABTS radicals and the reducing power of TAEM and TAEE were performed, and the results were shown in Figure 4. Both TAEM and TAEE exhibited strong scavenging capacity for DPPH free radicals (Figure 4a), with the EC\({}_{50}\) of 0.46 mg/mL and 0.73 mg/mL, respectively. When the concentration reached 1.6 mg/mL and 1.8 mg/mL, the scavenging effects were 94.31 \(\pm\) 3.01% and 93.17 \(\pm\) 2.87% while the positive control (ascorbic acid) was 97.53 \(\pm\) 2.11% at the same concentration. Similarly, scavenging capacity of TAEM and TAEE on ABTS radicals increased rapidly from 0 to 0.4 mg/mL, which was similar to ascorbic acid (Figure 4b). As Figure 4c showed, the scavenging capacity on hydroxyl radicals was stronger than that of ascorbic acid at a pretty low concentration (0-0.4 mg/mL). However, it slowly increased at a concentration of 0.4-2.0 mg/mL, and the scavenging ability was estimated to be 62.62 \(\pm\) 2.17%. At a concentration of 2.0 mg/mL, the scavenging ability was estimated to be 51.54 \(\pm\) 1.57%, while ascorbic acid showed a significant scavenging ability \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Method** & **Temperature (\({}^{\circ}\)C)** & **Solvent** & **Time (min)** & **Yield \({}^{\circ}\) (\%)** \\ \hline MAEM \({}^{\mathrm{a}}\) & 50 & Water & 30 & 1.82 \(\pm\) 0.04 \\ EHRE \({}^{\mathrm{b}}\) & 90 & Ethanol & 120 & 1.02 \(\pm\) 0.13 \\ \hline \hline \end{tabular} \({}^{\mathrm{a}}\) MAEM is ball mill assisted mechanochemical extraction method. \({}^{\mathrm{b}}\) EHRE is ethanol hot reflux extraction method. \({}^{\mathrm{c}}\) Extracted from dried fruiting bodies (10 g). Each value is expressed as mean \(\pm\) SD (\(n\) = 3).  
\end{table} 
Table 2: Comparison of mechanochemical-assisted extraction method (MAEM) and ethanol hot reflux extraction method (EHRE). Figure 4: Antioxidant activity of TAEM and TAEE. Scavenging activity of DPPH radicals (**a**), ABTS radicals (**b**) and hydroxyl radicals (**c**), and reducing powers (**d**). Data are expressed as mean \(\pm\) SD (\(n\) = 3). of 98.32 \(\pm\) 1.67% at 0.8 mg/mL. Reducing powers of the samples increased slowly at 0-1.2 mg/mL (Figure 4d), then the values rose in parallel at different levels of concentration until 2.0 mg/mL. The reducing powers hardly increased when the concentration was above 2.0 mg/mL.