Contribution to the chemodiversity of ex Cystoseira sp. - Gongolaria barbata and Ericaria crinita from the Adriatic Sea: Volatiles, fatty acids and major pigments

The aim of present research was to contribute to G. barbata and E. crinita chemodiversity and to the knowledge of specially protected Cystoseira areas. Headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) were applied to the fresh (FrGb) and air-dried G. barbata (DrGb) and to the fresh (FrEc) and air-dried E. crinita (DrEc). Sesquiterpenes dominated in the headspace (HS) of FrGb, particularly τ-cadinol and δ-cadinene. Drying of G. barbata caused major change in the HS profile (reduction of the major compounds and increase of alkanes and benzyl alcohol). Cadinane-type sesquiterpenes were the major constituents in HD of FrGb and predominant was τ-cadinol and dolabella-4(16),7-diene-3,18-diol similar as in DrGb HD. The major saturated fatty acid (SFA) in G. barbata was palmitic acid followed by stearic and myristic acids. Besides oleic acid isomers, a significant amounts of arachidonic acid (ARA) were found among polyunsaturated FAs. The major G. barbata pigment was fucoxanthin in F3 fraction and β-carotene in F4 fraction. HS-FrEc main compound was dictyopterene D followed by dictyopterene C. HS-DrEc chemical profile was notable different from HS-FrEc (dictyopterene D was significantly reduced while benzyl alcohol and benzaldehyde increased). The most prominent compound in HD-FrEc was (E)-phytol followed by isopachydictyol A along with different FA esters and hexadecanoic acid. Drying of E. crinita caused notable changes in HD profile (the percentage of phytol decreased followed by the increased of phytone and phyatne and different carbonyl compounds). Like in G. barbata, palmitic, stearic and myristic acids were major SFAs, while higher levels of oleic acid isomers and ARA were determined in E. crinita in comparison to G. barbata. In E. crinita, fucoxanthin was dominant in F3, while in F4 chlorophyll a was detected. Performed research indicates great variability, particularly among the volatile organic compounds of both algae suggesting their chemotaxonomic differences.