## Results and Discussion
### Analysis of F3 and F4 Fractions Containing Less Polar Nonvolatile Compounds
**} & \multicolumn{2}{c}{**tg**} & \multicolumn{2}{c}{**Mono-**} & \multicolumn{2}{c}{**Mass**} \\  & **(min)** & **Name** & **Structure** & **Isotopic** & **[M + H]\({}^{+}\)** & **Difference** & **Area (Counts)** \\  & & & & & **Mass** & **(ppm)** & \\ \hline \multicolumn{10}{c}{**Pigments**} \\
**F4 Fatty Acid Derivatives** \\
6** & 13.96 & Palmitamide & C\({}_{16}\)H\({}_{33}\)NO & 255.25621 & 256.26349 & \(-\)2.0 & 243,821 & 3,675,708 \\
7** & 13.99 & 1,3-Dihydroxy-2-propanyl & C\({}_{23}\)H\({}_{38}\)O\({}_{4}\) & 378.277008 & 379.28429 & 3.0 & 16,874 & - \\
8 & 14.23 & 2,3-Dihydroxypropyl palmitate & C\({}_{19}\)H\({}_{38}\)O\({}_{4}\) & 330.277008 & 331.28429 & \(-\)5.2 & 110,342 & 253,278 \\
9 & 14.35 & & & & & & \\
10 & 14.57 & 2,3-Dihydroxypropyl 9-octadecenoate & C\({}_{21}\)H\({}_{42}\)O\({}_{4}\) & 356.292664 & 357.29994 & 2.0 & 19,415 & - \\
13 & 15.30 & 2,3-Dihydroxypropyl 8-iterate & C\({}_{21}\)H\({}_{42}\)O\({}_{4}\) & 358.308319 & 359.31559 & 2.9 & 221,566 & 518,492 \\
16 & 16.19 & Erucamide & C\({}_{22}\)H\({}_{43}\)NO & 337.334473 & 338.34174 & 2.4 &  
No chlorophyll was detected, but its derivatives, porphyrin-based compounds (C\({}_{55}\)H\({}_{74}\)N\({}_{4}\)O\({}_{5-7}\)), were abundant, especially in F4 (Figure 3). Among them, the main component was compound 29 (C\({}_{55}\)H\({}_{74}\)N\({}_{4}\)O\({}_{6}\)). Two other compounds were less polar, so they were much more abundant in F4. It is well known that the porphyrin ring is an essential part of the chlorophyll structure responsible for the antioxidant activity [18]. Antimutagenic and anti-inflammatory effects of pheophytin \(a\) were found in green alga _Ulva prolifera_ (formerly known as _Enteromorpha prolifera_) [19] and its neuroprotective effect was found in brown alga _Sargassum fulvellum_[20]. Pheophorbide \(a\) was also detected but in a small amount, more in F3 than in F4. It has also shown antioxidant activity in green alga _Ulva prolifera_[21]. Figure 1: Total ion chromatograms (TIC) of the fractions (**a**) F3 and (**b**) F4. Figure 2: Extracted ion chromatograms (XIC) of the most abundant ions in the fractions (**a**) F3 and (**b**) F4. Xanthophyls, both present in green algae, zeaxanthin (or lutein; the isomers that could not be specified), and the one more characteristic for brown algae, fucoxanthin, were detected and identified (Figure 3) with a greater abundance in F3. In algae, xanthophyls play an important role to protect photosynthetic apparatus against damage induced by high light intensities. This photoprotective role directly purges ROS (reactive oxygen species) within the thylakoid membrane [22; 23]. Similarly, they act as anti-tumour and anti-inflammatory agents and are utilised for the prevention of coronary syndromes, cardiovascular diseases, and they play roles in structural action in neural tissue [24]. Supercritical fluid extraction was used to extract zeaxanthin from green alga _Nannochloropsisulata_[25] and lutein was extracted from green alga _Scenedesmus almeriensis_[26]. The ester of siphonaxanthin, another xanthophyll specific for green algae, siphonein, was detected in both fractions, more abundant in F4. Fatty acid derivatives in F3 and F4 originate from palmitic, stearic, oleic, and behenic acids (Table 3). Sphingolipid compounds 22 and 25 (Figure 4) were the most abundant of all detected components of F4, but were also present in F3. Sphingolipids as a part of macroalgae membranes play one of the crucial structural and physiological roles [27]. Recently, studies have shown that sphingolipid, together with associated enzymes and receptors, were involved in the inflammatory process and can provide effective drug targets for the treatment of pathological inflammation [28]. Three fatty acid amides were found: oleamide, erucamide, and palmitamide. They were more abundant in F4 even though oleamide was the most abundant of all detected compounds in F3. Oleamide is an endogenous bioactive signalling molecule found in both marine and terrestrial plants.