## 4 Bioactive Compounds on Cork and Cork By-Products
### Biological Activity of Cork Extracts and Cork By-Products  
Cork and its by-products constitute a source of bioactive compounds with antioxidant activity that can be of use to the cosmetic industry [87]. In the scientific literature, some studies have already described the extraction of compounds from cork, cork acorns, and cork by-products, such as cork powder, black condensate, and cork-cooking wastewater. These extracts showed the presence of phenolic acids, such as ellagic (**10**), protocatechuic (**11**), gallic (**12**), vanillic (**13**), ferulic (**14**), and caffeic (**15**) and ellagitannins with antioxidant  
Figure 5: Chemical structures of coumarins extracted by a mixture of 20% methanol in water. Figure 6: Chemical structures of phenolic acids present on cork powder and black condensate extracts. and protective DNA activity as well as collagenase and elastase inhibitory activity that can be interesting for antiaging cosmetics (Table 1) [4; 79; 88; 89]. \begin{table}
\begin{tabular}{c l c c c} \hline \hline
**Extraction Solvent** & & & & **Biological Activity** & **References** \\
**and Source Material** & **Composition** & & & **Activity** & **References** \\ \hline  & Ellagic acid (**10**) & 228.4 & & & \\  & Protocatechuic acid (**11**) & 48.8 & & & \\  & Vanillic acid (**13**) & 27.4 & & & \\ methanol/water & Gallic acid (**12**) & 18.3 & & & \\  (80:20); diethylether & Scopoletin (**23**) & 12.7 & & & \\  & Vanillin (**16**) & 16.1 & \(\upmu\)g of compound/g & & \\ _gramulated cork from_ & Contieraldehyde (**18**) & 11.2 & of dry cork & & \\ _Spain_ & Protocatechuic aldehyde (**17**) & 8.1 & & & \\  & Caffe acid (**15**) & 12.1 & & & \\  & Ferulic acid (**14**) & 10.7 & & & \\  & Aesculetin (**24**) & 7.5 & & & \\  & Sinapaldehyde & 4.5 & & & \\ \hline  & Friedelin (**2**) & 30.6 & & & \\ supercritical CO\({}_{2}\) & Sitost-4-en-3-one (**6**) & 22.5 & & & \\  & \(\beta\)-Sitosterol & 6.59 & mg of compound/extract & & \\ _granulated cork_ & Betulinic acid (**4**) & 4.93 & & & \\  & Betulin (**3**) & 3.13 & & & \\ \hline  & Friedrichin (**2**) & 30.2 & & & \\  & Sitost-4-en-3-one (**6**) & 4.1 & mg of compound/extract & & \\ _granulated cork_ & Betulinic acid (**4**) & 10.5 & & & \\  & Betulin (**3**) & 3.9 & & & \\ \hline  & Protocatechuic aldehyde (**17**) & & & & \\  & Vanillin (**16**) & & & & \\  & Protocatechuic acid (**11**) & & & \\  & Gallic acid (**12**) & & & \\  & Conyferaldehyde (**18**) & & & & \\  & Caffe acid (**15**) & & & \\  & Ferulic acid (**14**) & & & \\  & Ellagic acid (**10**) & & & \\  & Ellagic acid-pentose & & & \\  & Ellagic acid-deoxyhexose & & & \\ wine solution (12\% & Ellagic acid-hexose & & \\ ethanol, 5.0 g/L & Valoneic acid dilatone & & & \\ tartaric acid, pH = 3.2); & HHDP-glucose & & & \\ ethyl acetate & Valoneic acid & & & \\  & Dehydrated & & & \\ _granulated cork_ & tergallic-C-glucoside & & & \\  & HHDP-galloyl-glucose & & & \\  & Trigalloy-glucose & & & \\  & Di-HHDP-glucose & & & \\  & HHDP-galloyl-glucose & & & \\  & Tetragonally-glucose & & & \\  & Castalagin (**19**) & & & \\  & Vescalagin (**21**) & & & \\  & Di-HHDP-galloyl-glucose & & & Trigalloyl-HHDP-glucose & \\  & Pentagalloyl-glucose & & & \\  & Mongolicain A and B & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Chemical composition and biological activity of cork extracts and cork by-products.