## 2 Results and Discussion
### Antiradical and Antioxidant Capacity of the Honeydew and Extracts (DPPH and FRAP assay)  
The antiradical activities (DPPH assay) of oak honeydew and ultrasonic solvent extracts were evaluated from a Trolox solution, Table 1. Antiradical activity was very similar for both oak honeydew samples: 4.5 mmol TEAC/kg (sample I) and 5.1 mmol TEAC/kg (sample II). Therefore it can be \begin{table}
\begin{tabular}{l l c c c c} \hline
32. & 5-Hydroymethylfurfurfural & 1230 & 42.5 & 64.2 & 4.7 & 6.2 \\
33. & Phenylacetic acid\({}^{\text{a}}\) & 1269 & 8.1 & 4.7 & 16.4 & 11.6 \\
34. & Nonanoic acid\({}^{\text{a}}\) & 1273 & - & - & - & 0.1 \\
35. & 2-Hydroybenzoic acid & 1311 & 0.5 & 0.2 & 1.6 & - \\
36. & 3-Methoxyacetophenone & 1321 & - & - & 0.3 & - \\
37. & 3-Hydroxy-4-phenyl-butan-2-one & 1354 & - & 0.5 & 1.4 & 0.8 \\
38. & Tetradecane\({}^{\text{a}}\) & 1400 & 0.3 & 0.1 & 0.4 & 0.4 \\
39. & 4-Hydroybenzyl alcohol & 1426 & 0.4 & 0.2 & 0.6 & 0.8 \\
40. & Cinnamic acid & 1434 & 0.2 & 0.2 & - & 0.2 \\
41. & 8-Hydroyoctanoic acid & 1465 & 0.4 & 0.3 & 0.4 & 0.6 \\
42. & Pentadecane\({}^{\text{a}}\) & 1500 & - & - & 0.2 & - \\
43. & 4-Methyl-2,6-bis(1,1-dimethylethyl)-phenol & 1514 & 1.4 & - & 3.6 & 5.7 \\
44. & 4-Hydroybenzoic acid & 1558 & 1.7 & - & 2.9 & - \\
45. & Vanillic acid & 1566 & 0.6 & 0.1 & 0.4 & 0.2 \\
46. & Hexadecane & 1600 & 0.8 & - & 1.5 & 0.1 \\
47. & 3-Oxo-a-ionol & 1656 & 0.3 & 0.2 & - & - \\
48. & Homovanillic acid & 1659 & - & - & - & 0.5 \\
49. & Syringaldehyde & 1662 & 0.1 & 0.1 & - & 0.4 \\
50. & 8-Quinolinol & 1713 & 0.2 & 1.2 & - & - \\
51. & Methyl syringae\({}^{\text{a}}\) & 1744 & 1.6 & 1.2 & 4.6 & 3.2 \\
52. & Octadecane\({}^{\text{a}}\) & 1800 & 0.1 & - & 0.2 & - \\
53. & Vomifoliol & 1802 & 1.2 & - & 1.8 & 2.4 \\
54. & 4-Hydroycinamic acid & 1817 & 1.9 & - & 6.6 & - \\
55. & Hexadecan-1-ol\({}^{\text{a}}\) & 1882 & 1.2 & 0.8 & 2.0 & 2.9 \\
56. & Hexadecanoic acid\({}^{\text{a}}\) & 1963 & 0.3 & 0.6 & 1.7 & 0.9 \\
57. & (Z)-Octadec-9-en-1-ol & 2060 & 2.7 & 2.8 & 3.9 & 8.1 \\
58. & Octadecan-1-ol\({}^{\text{a}}\) & 2084 & 0.4 & 0.6 & 0.8 & 1.5 \\
59. & (Z)-Octadec-9-enoic acid & 2147 & - & 0.3 & 2.0 & - \\
60. & Tricosane\({}^{\text{a}}\) & 2300 & 0.3 & 0.3 & 2.3 & 2.4 \\ \cline{3-6}  & Total identified & 91.8 & 88.4 & 91.9 & 92.6 \\ \hline \end{tabular}  
* = not identified; \({}^{\text{a}}\) – identification confirmed with reference compound; \({}^{\text{a}}\)
- tentatively identified; \({}^{\text{a}}\)
- correct isomer not identified.  
\end{table} 
Table 2: _Cont._concluded that high concentration of 5-HMF in the sample I does not effect antiradical capacity of the honeydew. The percent inhibition of the DPPH radical as a function of the honeydew samples and their ultrasonic solvent extracts concentrations is shown in Figure 2.  
Data from Figure 2 show that when the samples are concentrated, they could saturate DPPH. Also the IC\({}_{50}\), corresponding to the concentration where 50% of the maximal effect on reduction of DPPH radical, is undetermined because at the maximum concentration of all the samples a maximum of 40% of DPPH inhibition was achieved. These measurements show that the ultrasonic solvent extracts  
Figure 2: DPPH reduction percentage against increasing concentration of oak honeydew (**A**), pentane - diethyl ether extract (**B**) and dichloromethane extract (**C**). exhibited similar free radical scavenging potential than the honey samples at approximately 4-10 times lower concentration ranges. Ultrasonic solvent extract with solvent A (sample I) showed _cca._ 38 times higher antiradical capacity in comparison to the honeydew, while the extract with solvent B (sample I) showed _cca._ 22 times better antiradical activity (Table 3). Antiradical capacity of the extract with solvent A from sample II was 50 times better than oak honeydew capacity, whereas the extract with solvent B (sample II) showed 26 times higher activity.