Polysaccharides, lipids and amino acid profiles were investigated to understand the nutritional value of Caulerpa racemosa and Ulva fasciata from the Philippines. The results revealed that both species contain high amounts of proteins (8.8–19.9% for C. racemosa and 8.0–11.1% for U. fasciata). The portions of the total amino acids that were essential amino acids (EAAs) (45.28 ± 0.12% for C. racemosa and 42.17 ± 0.12% for U. fasciata) out were comparable to FAO/WHO requirements. Leucine, valine, isoleucine, and lysine are the dominant EAAs in C. racemosa, while leucine, valine, lysine, and phenylalanine are those in U. fasciata. The fatty acid profiles are dominated by monounsaturated fatty acids and polyunsaturated fatty acids in C. racemosa (56.2%), while saturated fatty acids (72.1%) are dominant in U. fasciata. High C18/C20 polyunsaturated fatty acid ratios were recorded in both species. Mineral contents for both seaweeds were within levels considered safe for functional foods. Total pigment content of C. racemosa (140.84 mg/g dw) was almost 20 times higher than that of U. fasciata (7.54 mg/g dw). Hot water extract (HWE) from C. racemosa showed in vitro antiherpetic activity without cytotoxicity. Nutritional characteristics confirmed that C. racemosa could be potentially used as a nutritious and functional food items for human consumption.

In vitro antioxidant activities of the lipid fractions from two selected seaweeds, Solieria chordalis and Sargassum muticum were investigated according to the extraction methods. The activity of neutral lipids, glycolipids and phospholipids, thanks to extraction by chloroform/methanol (1/1 v/v; CM) mixture, pure supercritical carbon dioxide (sc-CO2), supercritical carbon dioxide with 2% of ethanol (sc-CO2 + EtOH 2%) and supercritical carbon dioxide with 8% of ethanol as co-solvent (sc-CO2 + EtOH 8%), were studied using DPPH radical scavenging assays. All the lipid classes demonstrated a free radical scavenging activity at the concentration of 1 mg/ml. The best scavenging activity (86.6 ± 5.7%) was obtained when the neutral lipid fraction was extracted from S. chordalis with a CM mixture. The neutral lipid fraction extracted with sc-CO2 showed a lower activity than those obtained with solvents. However, the addition of ethanol in sc-CO2 did not affect the antioxidant activity of neutral lipids fixed at around 16% of radical scavenging. For S. muticum, the activity of glycolipids (50.9 ± 0.8%) and phospholipids (48.4 ± 1.6%) obtained with sc-CO2 were twice as large as that of fractions obtained with CM, 29.6 ± 3.4% and 28.0 ± 4.2%, respectively. The activity of neutral lipids did not change with the extraction method with around 25% of radical scavenging. This is the first report of free radical scavenging activity of lipid classes obtained by supercritical carbon dioxide extraction from seaweeds.

Data on fractionation and depolymerization of the matrix ulvan polysaccharides, and studies on the biological activities on skin cells, are very scarce. In this work, crude ulvans were produced by using EAE (enzyme-assisted extraction) and compared to maceration (an established procedure). After different fractionation procedures—ethanolic precipitation, dialysis, or ammonium sulfate precipitation—the biochemical composition showed that EAE led to an increased content in ulvans. Coupling EAE to sulfate ammonium precipitation led to protein enrichment. Oligosaccharides were obtained by using radical depolymerization by H2O2 and ion-exchange resin depolymerization. Sulfate groups were partially cleaved during these chemical treatments. The potential bioactivity of the fractions was assessed using a lipoxygenase inhibition assay for anti-inflammatory activity and a WST-1 assay for human dermal fibroblast viability and proliferation. All ulvans extracts, poly- and oligosaccharidic fractions from EAE, expanded the fibroblast proliferation rate up to 62%. Our research emphasizes the potential use of poly- and oligosaccharidic fractions of Ulva sp. for further development in cosmetic applications.

Algae are organisms with an enormous biodiversity and contain manifold fatty acid molecular structures and ratios. This chapter presents information about the structure and distribution of fatty acids in algae whether microalgae or macroalgae. The parameters affecting lipid and fatty acid contents as well as distribution are also discussed. Methods for isolation and purification of fatty acids from algae to obtain highly pure fatty acid or fatty acid fractions with good overall yields are presented. Algal fatty acids are known as sources of bioactive compounds for health promotion and wellness. Lipid fractions and fatty acids act as actives or additives for cosmeceutical applications. For health promotion, preventive effects of n-3 polyunsaturated fatty acids on cardiovascular disease, metabolic syndrome and cancer are discussed. The role of n-3 fatty acids in cancer therapy and antiviral activities of lipids are also exposed. Furthermore, potential commercial application domains and concepts are discussed in this chapter.

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This article describes a comparative study of several bipolar lipids derived from tetraether structures. The sole structural difference between the main two glycolipids is a unique stereochemical variation on a cyclopentyl ring placed in the middle of the lipids. We discuss the comparative results obtained at the air/water interface on the basis of tensiometry and ellipsometry. Langmuir-Blodgett depositions during lipid film compressions and decompressions were also analyzed by AFM. The lactosylated tetraether (bipolar) lipid structures involved the formation of highly stable multilayers, which are still present at 10 mN m(-1) during decompression. This study suggests also that the stereochemistry of a central cyclopentyl ring dramatically drives the conformation of the corresponding bipolar lipids. Both isomers (trans and cis) adopt a U-shaped (bent) conformation at the air/water interface but the trans cyclopentyl ring induces a much more frustration within this type of conformation. Consequently, this bipolar lipid (trans-tetraether) undergoes a flip of one polar head-group (lactosyl) leading to a stretched conformation during collapse.

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