Extraction of the Volatile Oils of Dictyopteris membranacea Batters 1902 by Focused Microwave-assisted Hydrodistillation and Supercritical Carbon Dioxide: Empirical Kinetic Modelling Approach, Apparent Solubility and Rate Constants

Supercritical carbon dioxide extraction (SCCO2) and focused microwave-assisted hydrodistillation (FMAHD) were used comparatively to isolate the volatile oils of the brown alga Dictyopteris membranacea from the crude ether extract. The volatiles fractions were analysed by GC/MS, the major compounds were: dictyopterene A, 6-butyl-1,4-cycloheptadiene, 1-undecen-3-one, 1,4-undecadien-3-one, (3-oxoundec-4-enyl) sulphur, tetradecanoic acid, hexadecanoic acid, 3-hexyl-4,5-dithiacycloheptanone, and albicanol. A kinetics study of the extraction of the volatile fractions obtained by the two processes was carried out, an external calibration allowed to quantify the content of the main metabolites. Empirical models were applied to adjust the experimental kinetics values but also to determine the values of apparent solubilities for SCCO2 and the rate constants for FMAHD. The results obtained revealed that the SCCO2 process was characterized by the coexistence of three distinct phases. For FMAHD, the extraction mechanism included two steps. This work is licensed under a Creative Commons Attribution 4.0 International License

Determination Of Caulerpenyne, A Toxin From The Green-Alga Caulerpa-Taxifolia (Caulerpaceae)

International audienceA high-performance liquid chromatographic method is described for the determination of caulerpenyne, a neurotoxic sesquiterpenoid isolated from the green alga Caulerpa taxifolia. UV and refractometric detection were compared in order to determine the amounts of this toxin in the alga and the alimentary chain. UV detection at 252 nm was more sensitive and could be applied to the determination of very low concentrations of caulerpenyne (the detection limit per gram of dried seaweed was 27 mu g/g). The chromatographic conditions adopted were a 5-mu m silica column with isocratic binary elution with ethyl acetate-hexane (23:77, v/v) at a flow-rate of 1 ml/min

Meroditerpenoids and derivatives from the brown alga Cystoseira baccata and their antifouling properties

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