# Chemical Constituents, Neuroprotective and Antioxidant Potential of _Klasea centauroides_ Leaves
## 3 Results
### Quantification of K. centauroides Leaf Extract  
For the further characterization of _K. centauroides_ leaves, quantification of six extracts obtained by various solvent extractions was performed using SPE-HPLC-MS assay, and the levels of ten compounds, including arbutin, two ecdysteoroids (20-hydroxyecdysone, 2-deoxy-20-hydroxyecdysone), three caffeoylquinic acids (4-O-, 5-O-, 3,5-di-O-caffeoylquinic acid), and four flavonoids (luteolin 7-O-glucuronide, luteolin \(O\)-hexuronide-O-hexoside 26, apigenin 7-O-glucuronide, chrysoeriol 7-O-glucuronide) were determined (Table 2).  
Water and water-ethanol mixtures were chosen as solvents due to their good extraction power for the isolation of phytocomponents with various polarities found in the _Klasea species_[9; 19]. Finally, 40% ethanol extract showed the highest yield (32.1%) and total identified compound content (252.58 mg/g) with arbutin at 62.04 mg/g, ecdysteoroids at 36.81 mg/g, caffeoylquinic acid at 57.08 mg/g, and flavonoids at 96.65 mg/g. The dominant compounds were arbutin, 5-O-caffeoylquinic acid at 45.73 mg/g, luteolin 7-O-glucuronide at 39.01 mg/g, and 20-hydroxyecdysone at 30.08 mg/g. The 40% ethanol extract of _K. centauroides_ leaves showed a higher level of basic compounds than the extract of the _K. centauroides_ herb [19].  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Compound**} & \multicolumn{6}{c}{**Solvent**} \\ \cline{2-7}  & **Water** & **20\% EtOH** & **40\% EtOH** & **60\% EtOH** & **80\% EtOH** & **100\% EtOH** \\ \hline Yield \({}^{\text{a}}\) & 28.3 \(\pm\) 0.8 & 30.6 \(\pm\) 0.9 & 32.1 \(\pm\) 0.9 & 30.6 \(\pm\) 0.9 & 24.1 \(\pm\) 0.7 & 14.0 \(\pm\) 0.4 \\ Arbutin \({}^{\text{b}}\) & 52.06 \(\pm\) 1.01 & 58.11 \(\pm\) 1.16 & 62.04 \(\pm\) 1.24 & 54.73 \(\pm\) 1.09 & 42.17 \(\pm\) 0.84 & 26.11 \(\pm\) 0.52 \\
20-Hydroxyecdysone \({}^{\text{b}}\) & 24.17 \(\pm\) 0.48 & 26.57 \(\pm\) 0.52 & 30.08 \(\pm\) 0.60 & 27.06 \(\pm\) 0.54 & 25.29 \(\pm\) 0.50 & 14.22 \(\pm\) 0.28 \\
2-Deoxy-20-hydroxyecdysone \({}^{\text{b}}\) & 3.59 \(\pm\) 0.07 & 4.27 \(\pm\) 0.08 & 6.73 \(\pm\) 0.14 & 5.60 \(\pm\) 0.10 & 4.22 \(\pm\) 0.08 & 1.18 \(\pm\) 0.02 \\
4-O-Caffeoylquinic acid \({}^{\text{b}}\) & 3.04 \(\pm\) 0.06 & 4.79 \(\pm\) 0.09 & 5.34 \(\pm\) 0.11 & 5.33 \(\pm\) 0.11 & 5.26 \(\pm\) 0.10 & 3.29 \(\pm\) 0.06 \\
5-O-Caffeoylquinic acid \({}^{\text{b}}\) & 32.76 \(\pm\) 0.65 & 38.53 \(\pm\) 0.77 & 45.73 \(\pm\) 0.91 & 40.52 \(\pm\) 0.81 & 32.11 \(\pm\) 0.64 & 18.86 \(\pm\) 0.38 \\
3,5-Di-O-caffeoylquinic acid \({}^{\text{b}}\) & 3.02 \(\pm\) 0.06 & 4.82 \(\pm\) 0.08 & 6.01 \(\pm\) 0.11 & 6.00 \(\pm\) 0.11 & 5.43 \(\pm\) 0.10 & 3.76 \(\pm\) 0.07 \\ Luteolin 7-O-glucuronide \({}^{\text{b}}\) & 28.09 \(\pm\) 0.56 & 32.03 \(\pm\) 0.62 & 39.01 \(\pm\) 0.78 & 34.59 \(\pm\) 0.69 & 32.18 \(\pm\) 0.63 & 25.14 \(\pm\) 0.51 \\ Luteolin \(O\)-hexuronide-O-hexoside 26 \({}^{\text{b}}\) & 12.83 \(\pm\) 0.24 & 16.83 \(\pm\) 0.32 & 17.04 \(\pm\) 0.34 & 16.52 \(\pm\) 0.33 & 10.83 \(\pm\) 0.21 & 5.62 \(\pm\) 0.10 \\ Apigenin 7-O-glucuronide \({}^{\text{b}}\) & 7.26 \(\pm\) 0.14 & 15.83 \(\pm\) 0.31 & 22.03 \(\pm\) 0.44 & 18.31 \(\pm\) 0.37 & 14.29 \(\pm\) 0.28 & 9.52 \(\pm\) 0.19 \\ Chrysoeriol 7-O-glucuronide \({}^{\text{b}}\) & 4.82 \(\pm\) 0.08 & 11.86 \(\pm\) 0.21 & 18.57 \(\pm\) 0.37 & 16.98 \(\pm\) 0.36 & 15.83 \(\pm\) 0.35 & 10.35 \(\pm\) 0.21 \\ Total ecdysteroid content \({}^{\text{b}}\) & 27.76 & 30.84 & 36.81 & 32.66 & 29.51 & 15.40 \\ Total caffeoylquinic acid content \({}^{\text{b}}\) & 38.82 & 48.14 & 57.08 & 51.85 & 42.80 & 25.91 \\ Total flavonoid content \({}^{\text{b}}\) & 53.00 & 76.55 & 96.65 & 86.40 & 73.13 & 50.63 \\ Total phenolic content \({}^{\text{b}}\) & 143.88 & 182.80 & 215.77 & 192.98 & 158.10 & 102.65 \\ Total identified content \({}^{\text{b}}\) & 171.64 & 213.64 & 252.58 & 225.64 & 187.61 & 118.05 \\ \hline \hline \end{tabular} \({}^{\text{a}}\) % of dry plant weight. \({}^{\text{b}}\) mg/g of dry extract weight.  
\end{table}
Table 2: Yield and content of ten compounds in _K. centauroides_ leaf extracts.