**4. Conclusions**

In this work, a microextraction procedure was developed and applied for the establishment of the multicomponent phenolic pattern of aerial parts from *G. verum*, *G. album*, *G. rivale*, *G. pseudoaristatum*, and *G. purpureum*. The DLLME procedure in NADES solvent medium could provide high extraction efficiency within a short extraction time and with good correspondence with the MAE procedure. The biological results showed that *G. purpureum* and *G. verum* extracts contained the highest total phenolic and flavonoid contents, respectively. *G. purpureum* extract was the most active extract in terms of antioxidant capacity, whereas the *G. album* extract exhibited the strongest inhibitory effect against tyrosinase, an enzyme involved in several skin disorders. The results indicate that *Galium* extracts have the potential to be used as an alternative source of multifunctional agents and are a promising starting point for development of new bioactive formulations. Further studies are essential for the isolation of pure bioactive compounds and investigation of their molecular mechanisms of action.

**Supplementary Materials:** The following are available online. In section S1 were reported all the raw data obtained using GraphPad v.4 and Bonferroni post-test related to the statistical analyses for Figures and Tables present in the main text. In section S2 the chromatograms of dry extracts of Galium species obtained using DLLME (@ 278 nm as example of wavelength in which all compounds show absorbance) were reported. In section S3 the chromatogram (@ 278 nm as example of wavelength in which all compounds show absorbance) for the 22 chemical standards, with a table reporting the retention times and the maximum wavelengths used for the quantitative analyses was reported.

**Author Contributions:** Data curation, A.T., A.D., and M.D.S.; Investigation, A.T., A.D., and M.D.S.; Methodology, M.L., A.M., S.B., C.M., V.A., S.C., C.C., M.T., R.G., D.V. and G.C.; Project administration, M.L., A.M., S.B., C.M., V.A., S.C., D.V. and G.C.; Supervision, M.L., A.M., S.B., C.M., V.A., S.C., D.V. and G.C.

**Funding:** This work was financially supported by MIUR ex 60%, University "G. d'Annunzio" of Chieti – Pescara, Chieti, Italy, and the Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic (VEGA 1/0010/15). Andrei Mocan was supported by the Competitiveness Operational Programme, Priority Axis 1, Action 114, Project Type "Attracting high level personal from abroad" POC-A1-A1.1.4-E\_2015 developed with the support of MCI (Acronym: ProGlyCom, Project ID: POC/ID P\_37\_637, 2016-2020).

**Acknowledgments:** A.D. gratefully thanks the University "G. d'Annunzio" of Chieti—Pescara, Dept. of Pharmacy and Erasmus+ program for giving her the opportunity of the research project implementation.

**Conflicts of Interest:** Authors declare no competing financial interest.
