Bioprospecting of Coralline Red Alga Amphiroa rigida J.V. Lamouroux: Volatiles, Fatty Acids and Pigments

Abstract

Due to the lack of phytochemical composition data, the major goals of the present study on Amphiroa rigida J.V. Lamouroux were to: (a) investigate and compare volatilome profiles of fresh and air-dried samples obtained by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) followed by gas chromatography and mass spectrometry (GC/MS) analysis; (b) determine fatty acids profile by gas chromatography with flame ionization detector (GC-FID); (c) obtain the pigment profiles of semipurified extracts by high performance liquid chromatography (HPLC) and (d) evaluate the antioxidant and antimicrobial activities of its less polar fractions. The comparison of headspace of fresh (FrAr) and air-dried (DrAr) samples revealed many similarities regarding the presence and abundance of the major (heptadecane and pentadecane) and minor compounds. The hydrodistillate (HD) of DrAr profile was quite different in comparison to HD-FrAr. The predominant compound in HD-FrAr was (E)-phytol. In HD-DrAr, its percentage was approximately one-half reduced, but the abundance of its degradation product phytone and of unsaturated and oxygenated compounds increased indicating more intense fatty acid decomposition and oxidation during drying. The fatty acid determination revealed that the most dominant was palmitic acid (42.86%) followed by eicosapentaenoic acid (19.14%) and stearic acid (11.65%). Among the pigments, A. rigida contained fucoxanthin (0.63 mg g−1 of dry fraction), lutein (5.83 mg g−1), β-carotene (6.18 mg g−1) and chlorophyll a (13.65 mg g−1). The analyzed less polar fractions of A. rigida exhibited antioxidant scavenging activity with diammonium salt of 2,2′-azino-bis (3-ethylbenzthiazolin-6-yl) sulfonic acid (ABTS) assay up to 3.87 mg g−1 trolox equivalents (TE), and with the oxygen radical absorbance capacity (ORAC) assay up to 825.63 μmol g−1 TE (with carotenoids as the major contributors).

Bioprospecting of Less-Polar Constituents from Endemic Brown Macroalga Fucus virsoides J. Agardh from the Adriatic Sea and Targeted Antioxidant Effects In Vitro and In Vivo (Zebrafish Model)

“…After the extraction, the SPME fiber was withdrawn, taken away from the vial, and inserted into the GC-FID and GC-MS injector (250 °C) for the thermal desorption (6 min). The treatment was similar to previous research [ 15 , 53 , 73 ]. HS-SPME was performed in triplicate.…”

“…Different results regarding polyphenolic content within genus Fucus indicate that the diverse chemical composition of each species is dependent on location and climate conditions, but also on the possible interaction of present nonphenolic compounds with F-C reagent. In correlation, we have also recently studied the composition and activity of another alga collected from the Adriatic Sea, red alga Amphiroa rigida [ 53 ]. The F-C assay showed that the antioxidant capacity of F3 and F4 fractions of A. rigida were 1.3- and 3.3-fold lower than in F. virsoides .…”

“…Before HS-SPME and HD, the sample was held at 4 °C in the dark and the extraction and HD were conducted within 48 h of the sampling. The sample of F. virsoides was cut into small pieces, and the excess seawater was removed by the filter paper layers as was performed in the previous investigations [ 15 , 53 , 73 ]. A part of collected F. virsoides was air-dried 14 days at a room temperature in the dark and used as air-dried material for HD and HS-SPME.…”

“…GC-MS analyses were performed on a gas chromatograph model 7890A (Agilent Technologies, Palo Alto, CA, USA) equipped with an HP-5MS capillary column (5% phenyl-methylpolysiloxane, Agilent J and W; 30 m × 0.25 mm i.d., coating thickness 0.25 µm) and a flame ionization detector (FID). The GC conditions were described previously [ 15 , 53 , 73 ]. The carrier gas was helium (He 1.0 mL/min).…”

Less Polar Compounds and Targeted Antioxidant Potential (In Vitro and In Vivo) of Codium adhaerens C. Agardh 1822

“…The results obtained using F–C assay indicated 3-fold higher ( p < 0.0001) activity of F4 (64.27 ± 0.73 mg GAE/g F4) then F3 (21.12 ± 0.91 mg GAE /g F3). Interestingly, although the obtained values correspond to the values from our two previously published studies on Amphiroa rigida [ 41 ] and Fucus virsoides [ 11 ], one peculiarity can be observed. In C. adhaerens , higher activity was observed for F4, which is not the case in the other two macroalgae where higher activity is obtained in F3.…”