## 4 Conclusions  
The current phytochemical research on wheat hull began with a shift in perception of wheat waste. Because wheat is one of the world's major crops, the quantity of by-products is also considerable. Therefore, studies reevaluating this common agricultural waste were considered as potential for research into new resources that have not yet been explored.  
The bioassay-guided investigation of the active ethyl acetate fraction of _T. aestivum_ hull afforded eight compounds, namely a typical cereal flavone, tricin (**1**), and seven flavonolignans (**2-8**). Flavonolignans **2-8** have not yet been isolated from _Triticum_ species. The presence of the flavonolignans in wheat is supported by previous studies reporting the use of tricin in grass lignification, but these findings serve as new chemotaxonomic information for _Triticum_ species.  
In addition, this is the first report on the evaluation of flavonolignans **2-4**, **7**, and **8** on NO production inhibitory activities in LPS-stimulated RAW 264.7 macrophage cells. Among tested compounds, **4** and **6** were demonstrated as effectively inhibiting LPS-induced NO production. Excess NO production has been reported to cause inflammatory diseases, and the evaluation of inhibitory effects on NO production has been developed as an in vitro research model to find lead compounds for potential anti-inflammatory agents. Thus, the present results provide experimental evidence for the medicinal benefit of _T. aestivum_ hull in the treatment of inflammatory diseases.  
The following are available online at [[http://www.mdpi.com/2076-3417/10/23/8656/s1](http://www.mdpi.com/2076-3417/10/23/8656/s1)]([http://www.mdpi.com/2076-3417/10/23/8656/s1](http://www.mdpi.com/2076-3417/10/23/8656/s1)), Table S1: Reported constituents of the aerial, hull, bran, and sprout part of _T. aestivum_, Figure S1: The chemical structures of reported constituents of the aerial, hull, bran, and sprout part of _T. aestivum_, Figures S2-S16: \({}^{1}\)H and \({}^{13}\)C NMR spectra of compounds **1-8**.  
**Author Contributions:** Conceptualization, A.-R.H., M.J.H., and C.H.J.; methodology, A.-R.H., M.J.H., C.H.J., and J.-W.N.J.; software, A.-R.H., Y.-S.K., and H.H.P.; validation, A.-R.H., C.H.J., and J.-W.N.; formal analysis, A.-R.H., Y.-S.K., and H.H.P.; investigation, A.-R.H., Y.-S.K., J.P., and H.H.P.; resources, M.J.H. and J.-B.K.; data curation, A.-R.H., Y.-S.K., and H.H.P.; writing-original draft preparation, A.-R.H. and Y.-S.K.; writing--review and editing, A.-R.H., Y.-S.K., J.P., and J.-W.N.; visualization, A.-R.H., Y.-S.K., and C.H.J.; supervision, J.-W.N.  
\begin{table}
\begin{tabular}{c c c} \hline
**Compounds** & **IC\({}_{50}\) (μM)** & **Cell Viability (\%) 1** \\ \hline
**1** & 46.41 & \(>\)100 \\
**2** & 58.95 & 99.7 \(\pm\) 2.1 \\
**3** & \(>\)100 & 99.3 \(\pm\) 2.3 \\
**4** & 24.14 & 85.7 \(\pm\) 4.0 \\
**5** & \(>\)100 & 98.8 \(\pm\) 3.2 \\
**6** & 37.52 & \(>\)100 \\
**7** & \(>\)100 & 99.8 \(\pm\) 10.8 \\
**8** & 45.67 & \(>\)100 \\ L-NMMA 2 & 51.01 & \(>\)100 \\ \hline \end{tabular} \({}^{1}\) The cell viability after treatment with 40 μM compounds. 2 L-NMMA was used as the positive control.  
\end{table}
Table 1: Inhibitory effects of the compounds **1-8** on the LPS-induced NO production in RAW 264.7 cells.  
and J.-B.K.; project administration, C.H.J. and J.-B.K.; funding acquisition, C.H.J. and J.-B.K. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the Radiation Technology R&D program (grant number 2017M2A2A6A05018541) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning.  
The authors thank the Core Research Support Center for Natural Products and Medical Materials (CRCNM), Gyeongsangbuk-do, Gyeongsan-si, Korea, for technical support for NMR and CD experiments.  
The authors declare no conflict of interest.