# Seasonal Monitoring of Volatiles and Antioxidant Activity of Brown Alga _Cladosteplus spongiosus_
## 2 Results and Discussion
### Hydrodistillation Obtained Volatile Variations of C. spongiosus
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**No**} & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Group**} & \multirow{2}{*}{**RI**} & \multicolumn{8}{c}{**Area \%**} \\ \cline{5-16}  & & & & \multicolumn{2}{c}{**May**} & \multicolumn{2}{c}{**June**} & \multicolumn{2}{c}{**July**} & \multicolumn{2}{c}{**August**} \\ \cline{5-16}  & & & & \multicolumn{2}{c}{**Fr**} & \multicolumn{2}{c}{**Dr**} & \multicolumn{2}{c}{**Fr**} & \multicolumn{2}{c}{**Dr**} & \multicolumn{2}{c}{**Fr**} & \multicolumn{2}{c}{**Dr**} & \multicolumn{2}{c}{**Fr**} & \multicolumn{2}{c}{**Dr**} \\ \hline
4 & \(n\)-Scheme & Other & & & & & & & & & & & \\  & (benzene derivative) & \(<\)900 & 0.09 & 0.26 & - & - & - & 0.04 & - & - \\
11 & Benzaldehyde & Other & & & & & & & & & & \\
22 & Pharynxotaldehyde & Other & & & & & & & & & & \\
23 & Acetophenone & Other & & & & & & & & & & \\  & (benzene derivative) & 1072 & - & 0.13 & - & - & - & 0.05 & - & - \\
39 & 2,4-Dimethylbenzaldehyde & Other & & & & & & & & & & \\  & (benzene derivative) & 1179 & - & 0.17 & - & - & - & - & - & - \\
40 & \(p\)-Methylacetophenone & Other & & & & & & & & & & \\  & (benzene derivative) & 1190 & - & - & - & - & - & - & - & 0.13 \\
41 & 3,4-Dimethylphenol & Other & & & & & & & & & & \\  & (benzene derivative) & 1197 & - & - & 0.05 & - & - & - & 0.09 & - \\
45 & Indide & Other & & & & & & & & & & \\  & (benzene derivative) & 1296 & - & 0.32 & 0.05 & 0.14 & - & 0.07 & 0.1 & - \\
72 & Benzophenone & Other & & & & & & & & & \\  & (benzene derivative) & 1630 & - & - & - & - & - & - & 0.17 & 0.18 \\
90 & Dissobutyl pHulate & Other & & & & & & & & & \\  & (benzene derivative) & 1872 & - & 0.47 & - & 0.41 & 0.07 & 0.92 & 0.32 & 0.95 \\
96 & Dobutyl glutamate & Other & & & & & & & & & \\  & (benzene derivative) & & & & & & & & & & \\  & (C\({}_{1}\)-proisogenpmod) & & 1149 & - & 0.24 & 0.03 & 0.09 & - & - & - \\
52 & a-Ionone & Other & & & & & & & & & \\  & (C\({}_{2}\)-proisogenpmod) & & 1433 & 0.11 & - & - & - & - & 0.04 & - & - \\
56 & \(\beta\)-Ionone & Other & & & & & & & & & \\  & (C\({}_{3}\)-proisogenpmod) & & 1489 & 0.89 & 3.1 & 0.32 & 0.83 & 0.25 & 0.57 & 0.57 & 0.89 \\
65 & Dodecanoic acid & & & & & & & & & & \\  & (carboxylic acid) & 1573 & - & - & - & - & - & - & 0.16 & - \\
97 & Palmitic acid & & & & & & & & & & \\  & (carboxylic acid) & 1973 & - & 2.35 & - & 1.21 & - & - & - & 0.82 \\
108 & Heptadecomic acid & Other & & & & & & & & & \\  & (carboxylic acid) & 2103 & - & 1.00 & - & 0.34 & 0.1 & 0.3 & 0.34 & 0.29 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Cont. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**No. **} & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Group**} & \multirow{2}{*}{**RI**} & \multicolumn{6}{c}{**Area \%**} \\ \cline{5-10}  & & & & \multicolumn{2}{c  
Fatty acid ethyl ester (FAEE) ethyl icosanoate, assigned to the group of others, was the dominant compound in all air-dried samples (12.85%, Dr_May--30.74%, Dr_July) and in the fresh samples in June (30.84%) and July (34.51%). Naturally occurring FAEEs as well as fatty acid methyl esters (FAMEs) could potentially be used as biofuels [36]. The saturated hydrocarbon heptadecane and aldehyde pentadecanl, as well as the unsaturated hydrocarbons (\(E\))-heptadec-8-ene and (\(Z\))-heptadec-3-ene, were the major aliphatic compounds with the highest percentage in August, contributing to the representation of the aliphatic compounds (Figure 5). All were most abundant in the fresh sample in August except heptadecane which was not detected but was most abundant in the dry sample in the same month (Table 3).