## 2 Results and Discussion
### Bioactivities of the Absorbed Constituents Related to the Pharmacological Effects of AR  
Through HS-SPME-GC-MS and HPLC-APCI-IT-TOF-MS\({}^{\mathrm{n}}\), totally 47 absorbed constituents containing 14 monoterpenes, 10 phenylpropanoids, four benzene derivatives, two alkanes, nine _N_-alkylamides and eight lignans were identified in the rabbit plasma and CSF after intranasal administration of AR EtOAc extract. The numbers of identified absorbed constituents in different samples and by different methods are summarized in Table 4. It was found that these absorbed constituents were all the original constituents of AR and no metabolite was detected in the plasma and CSF. This may be because compounds avoid the gastrointestinal tract and first-pass metabolism through intranasal administration [24], indicating that these original constituents of AR might be the effective substances of AR when it is used in nasal therapy. Moreover, the molecular weight of these absorbed constituents were all less than 400 Da, and the number of the absorbed constituents having the molecular weight of less than 300 Da accounted for 83% of all the 47 absorbed constituents, which was consistent with the opinion that drugs with molecular weight lower than 300 Da are easy to be absorbed through intranasal administration [2]. AR powder comprised of lots of constituents with various polarities, and AR EtOAc extract was prepared from AR powder by extraction with EtOAc, a nonpolar solvent. Hence, AR EtOAc extract should be the less polar portion of AR powder. However, the absorbed constituents of AR powder are all found in the absorbed constituents of AR EtOAc extract. These findings suggested that the original constituents with small molecular weights and relatively low polarities might be the effective substances of AR when it is used in nasal therapy. To find whether the identified absorbed constituents might be the effective substances of AR, their bioactivities related to the pharmacological effects of AR were summarized based on the overall literature \begin{table}
\begin{tabular}{c c c c c} \hline  & **GC-MS** & **LC-MS** &
\begin{tabular}{c} **Same Constituents Identified by** \\ **GC-MS and LC-MS** \\ \end{tabular} & **Total No.** \\ \hline Plasma & 25 & 23 & 2 (**L6** = **G20**, **L7** = **G22**) & 46 \\ CSF & 25 & 5 & 2 (**L6** = **G20**, **L7** = **G22**) & 28 \\ Same constituents in & 24 (**G1**–**G13**, & 5 (**L6**, **L7**, & \\ plasma and CSF & **G15**, **G17**–**G26**) & **L15**–**L17**) & 2 (**L6** = **G20**, **L7** = **G22**) & 27 \\ Total No. & 26 & 23 & 2 & All: **47** \\ \hline \end{tabular}
\end{table} 
Table 4: The numbers of identified absorbed constituents in plasma and CSF of AR EtOAc extract group rabbits by HS-SPME-GC-MS and HPLC-APCI-IT-TOF-MS\({}^{\mathrm{n}}\). retrieval. As shown in Table 5, 33 of 47 absorbed constituents were reported to exhibit diverse bioactivities associated with the pharmacological actions of AR (detail information are listed in Supplemental Materials Table S1). We can see that one absorbed constituent can have several bioactivities (Table S1; Table 5). Namely, methyleugenol has eight bioactivities, limonene and eucalyptt have seven bioactivities; three constituents (camphor, l-borneol and \(\alpha\)-terpineol) have five bioactivities, six constituents have four bioactivities, three constituents have three bioactivities and six constituents have two bioactivities. These indicated that even one absorbed constituent could act on several targets simultaneously.