## 2 Materials and Methods
### Component Identification of Zanthoxylum bungeanum Essential Oil  
The components of the _Zanthoxylum bungeanum_ essential oil were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC7890A-MSD5975C, Agilent Technologies, Santa Clara, CA, USA). The chromatographic column was an HP-5 MS ultra insert (30 m \(\times\) 250 \(\mu\)m \(\times\) 0.25 \(\mu\)m), and the injection volume was 1 \(\mu\)L. The programmed temperature parameters were as follows: the initial temperature was 60 \({}^{\circ}\)C, held for 2 min and then increased to 280 \({}^{\circ}\)C at a rate of 10 \({}^{\circ}\)C/min within 5 min. The temperatures of the injection port, auxiliary heater, and ion source were 220, 280, and 230 \({}^{\circ}\)C, respectively. The carrier gas was high-purity helium, and the flow rate was 1.0 mL/min (split ratio was 50:1). The ionization mode was EI, and the scanning quality range was \(m/z\): 35-900. The identification of the components was based on retrieval and matching by the mass spectrometry database of the GC-MS instrument, combined with literature reports and CAS (American Chemical Society, Washington, DC, USA) data. The relative content of each component was calculated according to the peak area normalization method.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Group** & **PBS** & **Sample** & **Enzyme** & **PNPG** & **Na2 CO3** \\ \hline Blank & 80 & 0 & 10 & 10 & 100 \\ Background & 80 & 10 & 0 & 10 & 100 \\ Acarbose & 70 & 10 & 10 & 10 & 100 \\ Sample & 70 & 10 & 10 & 10 & 100 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Sample solution addition (\(\mu\)L) of each group.  
Molecular Docking between the Main Components of Zanthoxylum bungeanum Essential Oil and \(\alpha\)-Glucosidase  
According to Section 2.5, the main components of the _Zanthoxylum bungeanum_ essential oil were ligands, which were used to build the model using the Rdkit program. The lowest energy conformations of the molecules were obtained by energy minimization modules of the program. As ligands, the molecules were added as atomic charges and allocated atomic types. All flexible bonds were rotatable by default.  
The \(\alpha\)-glucosidase molecule was the receptor of this docking. The crystal structure of the \(\alpha\)-glucosidase (PDB ID: 3 wy1) was obtained from the protein database ([[http://www.rcsb.org/pdb](http://www.rcsb.org/pdb)]([http://www.rcsb.org/pdb](http://www.rcsb.org/pdb)), accessed on 15 January 2020). All water molecules and original ligands in the \(\alpha\)-glucosidase molecule were deleted, polar hydrogen atoms were added, and Gasteiger charges were calculated by Autodock tools 1.5.6 software (Center for Computational Structural Biology, La Jolla, CA, USA).  
The active sites of the molecular docking and protein active pocket were determined according to the coordinates of the original ligand in the crystal protein complex, and molecular docking were carried out by Autodock Vina 1.1.2. The ligand was set to be flexible, and the receptor was set to be rigid. The gridbox location of the active center was set to \(x=-9.088\), \(y=-16.231\), \(z=21.156\). The size was set to 6.0 and the spaces were set to 1. The search accuracy was set to 32, num modes were 5, and other parameters were default values.