# Chemical Constituents, Neuroprotective and Antioxidant Potential of _Klasea centauroides_ Leaves
## 3 Results  
### LC-MS Profiling of K. centauroides Leaf Extract  
Successful separation and identification of 41 compounds in _K. centauroides_ leaf extract were achieved after the polyamide solid phase extraction (SPE) procedure, followed by high-performance liquid chromatography with a photodiode and electrospray ionization triple quadrupole mass spectrometric detection. The application of SPE resulted in the isolation of the SPE-1 fraction enriched with non-absorbed compounds (e.g., phenols **(1-4)** and ecdysteroids **(5-22)**) and the SPE-2 fraction containing absorbed compounds such as caffeoylquinic acids **(23-25, 33-35)**, flavonol glucuronides **(26-32, 36-32, 36-38)**, and acylated flavonol glycosides **(39-41)** identified after comparing retention times, ultraviolet and mass spectra with the reference standard and literature data **(47-54)** (Figure 1, Table 1). Figure 1: High-performance liquid chromatography with photodiode array detection chromatogram of SPE-1 ((a); 254 nm) and SPE-2 ((b); 330 nm) fractions of _K. centauroides_ leaf extract. Compounds are numbered as listed in Table 1.  
\begin{table} \begin{tabular}{c c c c c c} \hline \hline
**No.** & **t, min** & **Negative Ionization, _m/z_** & **Positive Ionization, _m/z_** & **Compound [Ref.]** & **IL*** \\ \hline
**1** & 2.41 & \
\begin{tabular}{c} 271 [M-H]\({}^{*}\), \\ 109 [(M-H)-Glc]\({}^{*}\) \\ \end{tabular} & 295 [M+Na]\({}^{+}\), 273 [M+H]\({}^{+}\), 111 [(M+H)-Glc]\({}^{*}\) &
\begin{tabular}{c} Arbutin \\ (hydroquinone \\ \(O\)-glucose) [47] \\ \end{tabular} & 1 \\ \hline
**2** & 4.38 & \
\begin{tabular}{c} 285 [M-H]\({}^{*}\), \\ 123 [(M-H)-Glc]\({}^{*}\), \\ 109 [(M-H)-Glc-CH\({}_{2}\)]\({}^{*}\) \\ \end{tabular} & 309 [M+Na]\({}^{+}\), 287 [M+H]\({}^{+}\), 125 [(M+H)-Glc]\({}^{+}\), &
\begin{tabular}{c} Methyl arbutin \\ (hydroquinone methyl \\ \(O\)-glucose) [47] \\ \end{tabular} & 1 \\ \hline
**3** & 4.56 &
\begin{tabular}{c} 255 [M-H]\({}^{*}\), \\ 93 [(M-H)-Hex]\({}^{*}\) \\ \end{tabular} & 279 [M+Na]\({}^{+}\), 257 [M+H]\({}^{+}\), 95 [(M+H)-Hex]\({}^{*}\) & Phenol O-hexoside [48] & 2 \\ \hline
**4** & 5.02 & \
\begin{tabular}{c} 255 [M-H]\({}^{*}\), \\ 109 [(M-H)-dHex]\({}^{*}\) \\ \end{tabular} & 279 [M+Na]\({}^{+}\), 257 [M+H]\({}^{+}\), 111 [(M+H)-dHex]\({}^{*}\) &
\begin{tabular}{c} Hydroquinone \\ \(O\)-desoxyhexoside [48] \\ \end{tabular} & 2 \\ \hline
**5** & 6.01 &
\begin{tabular}{c} 681 [M+K]\({}^{*}\), 665 [M+Na]\({}^{*}\), 643 [M+H]\({}^{+}\), \\ 479 [(M-H)-Hex]\({}^{*}\) \\ \end{tabular} & 2 \\ \hline
**6** & 6.34 &
\begin{tabular}{c} 641 [M-H]\({}^{*}\), \\ 479 [(M-H)-Hex]\({}^{*}\) \\ \end{tabular} & 481 [(M+H)-Hex]\({}^{*}\), 463 [(M+H)-Hex-H2O]\({}^{+}\), & 20-Hydroxycedyne \\  & & 445 [(M+H)-Hex-2 \(\times\) H2O]\({}^{+}\), & 427 [(M+H)-Hex-3 \(\times\) H2O]\({}^{+}\), & 20-Hydroxycedyne \\  & & 409 [(M+H)-Hex-4 \(\times\) H2O]\({}^{+}\) & 3-O-glucose [49; 50; 51] & 1 \\ \hline
**7** & 7.22 &
\begin{tabular}{c} 621 [M+K]\({}^{*}\), 635 [M+Na]\({}^{*}\), 613 [M+H]\({}^{*}\), \\ 481 [(M+H)-Pent]\({}^{*}\), \\ 481 [(M+H)-Pent-4]\({}^{*}\) \\ \end{tabular} & 413 [(M+H)-Pent-4 \({}^{*}\), 463 [(M+H)-Pent-H2O]\({}^{+}\), \\ 20-Hydroxycedyne \\ O-pentoside [49; 50; 51] & 2 \\  & & 427 [(M+H)-Pent-4 \(\times\) H2O]\({}^{+}\), \\ \end{tabular}  & 2 \\ \hline
**8** & 7.47 & \begin{tabular}{c} 635 [M+K]\({}^{*}\), 519 [M+Na]\({}^{*}\), 497 [M+H]\({}^{*}\), \\ 479 [(M-H)-Pent]\({}^{*}\) \\ \end{tabular}  & 2 \\ \hline
**9** & 7.78 & \begin{tabular}{c} 495 [M-H]\({}^{*}\), \\ 495 [M-H]\({}^{*}\) \\ \end{tabular}  & 479 [(M+H)-H2O]\({}^{+}\), 461 [(M+H)-2 \(\times\) H2O]\({}^{+}\), 479 [(M+H)-H2O]\({}^{+}\), 461 [(M+H)-2 \(\times\) H2O]\({}^{+}\), \\ 443 [(M+H)-3 \(\times\) H2O]\({}^{+}\), 425 [(M+H)-4 \(\times\) H2O]\({}^{+}\) \\ \end{tabular} & 1 \\ \hline
**10** & 7.98 & \begin{tabular}{c} 495 [M-H]\({}^{*}\) \\ 495 [M-H]\({}^{*}\) \\ \end{tabular}