**4. Conclusions**

This study explored the chemical compositions and antioxidant activities of steam-distilled essential oil (SDEO) and glycosidically bound aglycone fraction (GBAF) extracts from fully ripe *M. triscuspidata* fruit. Thirteen carotenoid-derived compounds are being isolated for the first time in *M. triscuspidata* fruit. These compounds have been associated with a variety of organoleptic properties in other plants. A number of bioactive compounds were exclusively identified in the GBAF. It can be suggested that the relatively higher antioxidant activity observed in this particular fraction compared to the SDEO fraction is mainly associated with these exclusive compounds. Therefore, enzymatic treatments of fruits suh as *M. triscuspidata* can significantly enhance functional properties by releasing glycosidically bound bioactive components.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2304-8158/8/12/659/s1, Figure S1: Gas chromatograms of the volatile components detected in (A) steam distilled essential oil (SDEO); (B) glycosidically bound aglycone fraction (GBAF) isolated from Maclura triscuspidata.

**Author Contributions:** Conceptualization & Methodology, M.-K.K. and Y.-H.K.; Investigation & Resources, M.-K.K. and Y.-H.K.; Funding Acquisition, M.-K.K.; Formal analysis, G.-R.Y., D.-W.K., D.-H.K. and H.-A.H.; Writing—Original Draft Preparation, Y.-H.K.; Writing—Review and Editing, Y.A.G. All authors read and approved the final manuscript.

**Funding:** This work was carried out with the support of the Cooperative Research Program for Agricultural Science & Technology Development, gran<sup>t</sup> number PJ012588022019, National Academy of Agricultural Science, Rural Development Administration, Republic of Korea.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
