## 3 Results and Discussion
### Molecular Docking  
The binding energy values of each ligand against each enzyme target are given in Table 5. The representative bioactive compounds demonstrated binding potential to AChE, BChE, and amylase, with no/modest binding to tyrosinase. Rutin (quercetin 3-O-glucoside), kaempfer 3-O-rutinoside, and hyperoside bound well to AChE, BChE, and amylase. H-bonds are the major contributor, and several van der Waals interactions along with a couple of hydrophobic contacts added to the overall binding affinity. Rutin and kaempfer 3-O-rutinoside filled up the cavity of and formed H-bonds with polar amino acid residues of AChE and BChE via multiple hydroxyl groups (Figure 3A-C). Hyperoside bound strongly to amylase, mainly via H-bonds as well (Figure 3D). Shikimic acid fitted the narrow pocket of tyrosinase, forming 3 H-bonds and a couple of van der Waals interactions deep inside (Figure 3E), while the catalytic channel of amylase was bound by the quercetin via several H-bonds and a few van der Waals interactions.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Compound** & **AChE** & **BChE** & **Tyrosinase** & **Amylase** \\ \hline  & & & **Kcal/mol** & \\ \hline Shikimic acid & \(-8.25\) & \(-8.56\) & \(-4.26\) & \(-4.44\) \\
5-Caffeoylquinic acid & \(-9.76\) & \(-9.68\) & \(-4.99\) & \(-7.74\) \\
3-Caffeoylquinic acid & \(-11.30\) & \(-11.32\) & \(-4.08\) & \(-5.78\) \\ Vanillic acid & \(-7.44\) & \(-6.99\) & \(-5.20\) & \(-5.77\) \\ Caffeic acid & \(-8.85\) & \(-6.79\) & \(-3.37\) & \(-4.87\) \\ Syringic acid & \(-6.74\) & \(-6.52\) & \(-3.67\) & \(-5.78\) \\ P-Coumaric acid & \(-7.10\) & \(-6.58\) & \(-1.56\) & \(-4.70\) \\ Ferulic acid & \(-6.99\) & \(-6.99\) & \(-2.49\) & \(-4.33\) \\ Rutin & \(-13.89\) & \(-11.63\) & \(-6.23\) & \(-9.88\) \\ Hyperoside & \(-8.97\) & \(-8.32\) & \(-3.10\) & \(-9.95\) \\ Kaempfer-3-O-glucoside & \(-11.21\) & \(-11.92\) & \(-6.17\) & \(-9.95\) \\ Quercitrin & \(-8.68\) & \(-8.78\) & \(-3.34\) & \(-9.19\) \\ Quercetin & \(-6.89\) & \(-6.78\) & \(-4.67\) & \(-6.22\) \\ \hline \hline \end{tabular}
\end{table}
Table 5: Calculated binding energy values of bioactive compounds _Arnbis carduchorum_.  
Figure 2: PLS-DA scatter plot of _Arabis carduchorum_ extracts based on chemical components and biological activities (antioxidant and enzyme inhibitory abilities).  
ADMET properties of the dominant bioactive compounds in _A. carduchorum_ extracts were predicted using the SwissADME web server ([[http://www.swissadme.ch/](http://www.swissadme.ch/)]([http://www.swissadme.ch/](http://www.swissadme.ch/)), accessed on 1 April 2022). The predicted ADMET properties of each compound are shown in Table 6  
Figure 3: Protein–ligand interaction: (**A**) AChE and rutin (quercetin 3-O-glucoside), (**B**) AChE and kaempfer 3-O-glucose, (**C**) BChE and kaempfer-3-O-glucose, (**D**) amylase and hyperoside, (**E**) tyrosinase and shikimic acid, and (**F**) amylase and quercetin.  
and Figure 4. Vanillic acid, caffeic acid, syringe acid, p-Coumaric acid, and ferulic acid are predicted to have high gastrointestinal (GI) absorption and can cross the blood-brain barrier. While shikimic acid has high GI absorption, it cannot penetrate the blood-brain barrier. The rest of the compounds have low GI absorption and cannot pass the blood-brain barrier due to high polarity and violate some of [PERSON]'s \"rule of 5\" parameters because of their large size. Importantly, however, except for quercetin, all the compounds show no potential inhibition of liver metabolic CYP450 enzymes and are, therefore, considered non-toxic to the organ.  
Figure 4: ADMET plot: logarithm of octanol–water partition coefficient (LogP) versus topological polar surface area (PA), The 4 ellipses define areas of well-absorbed molecules: 95 and 99% of a molecule are expected to be in ellipses colored in red and green, respectively, and 95 and 99% of a molecule are within the ellipses colored in magenta and aqua, respectively, for blood–brain barrier permeability.