Detailed Chemical Prospecting of Volatile Organic Compounds Variations from Adriatic Macroalga Halopteris scoparia

Abstract

The present study aimed to isolate volatile organic compounds (VOCs) from fresh (FrHSc) and air-dried (DrHSc) Halopteris scoparia (from the Adriatic Sea) by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) and to analyse them by gas chromatography and mass spectrometry (GC–MS). The impact of the season of growth (May–September) and air-drying on VOC composition was studied for the first time, and the obtained data were elaborated by principal component analysis (PCA). The most abundant headspace compounds were benzaldehyde, pentadecane (a chemical marker of brown macroalgae), and pentadec-1-ene. Benzaldehyde abundance decreased after air-drying while an increment of benzyl alcohol after drying was noticed. The percentage of pentadecane and heptadecane increased after drying, while pentadec-1-ene abundance decreased. Octan-1-ol decreased from May to September. In HD-FrHSc, terpenes were the most abundant in June, July, and August, while, in May and September, unsaturated aliphatic compounds were dominant. In HD-DrHSc terpenes, unsaturated and saturated aliphatic compounds dominated. (E)-Phytol was the most abundant compound in HD-FrHSc through all months except September. Its abundance increased from May to August. Two more diterpene alcohols (isopachydictyol A and cembra-4,7,11,15-tetraen-3-ol) and sesquiterpene alcohol gleenol were also detected in high abundance. Among aliphatic compounds, the dominant was pentadec-1-ene with its peak in September, while pentadecane was present with lower abundance. PCA (based on the dominant compound analyses) showed distinct separation of the fresh and dried samples. No correlation was found between compound abundance and temperature change. The results indicate great seasonal variability of isolated VOCs, as well among fresh and dried samples, which is important for further chemical biodiversity studies.

Seasonal Monitoring of Volatiles and Antioxidant Activity of Brown Alga Cladostephus spongiosus

“…Phytol content was the highest in August. A similar behaviour was observed in H. scoparia where phytol was the predominant compound [30]. Phytol and its derivatives have a wide range of bioactive functions such as antioxidant, cytotoxic, anti-inflammatory, antimicrobial, autophagy-and apoptosis-inducing, immune-and metabolism-modulating, and anxiety-relieving activities [31].…”

“…All three detected sesquiterpenes were the predominant sesquiterpenes in the hydrodistillate of brown alga T. atomaria which belongs to the same subclass Dictyotophycidae [29]. When observing the seasonal changes in H. scoparia, which belongs to the same order of Sphacelariales, the highest proportion of germacrene D and gleenol in the hydrodistillate of the fresh sample was also found in May and later decreased each month until September [30].…”

“…Phytol and its derivatives have a wide range of bioactive functions such as antioxidant, cytotoxic, anti-inflammatory, antimicrobial, autophagy-and apoptosis-inducing, immune-and metabolism-modulating, and anxiety-relieving activities [31]. Cembra-4,7,11,15-tetraen-3-ol was also found to be a very dominant terpene in D. dichotoma and H. scoparia, as was pachydictyol A in D. dichotoma [30,32]. Cembranoid-type diterpenes have good antitumor, antimicrobial, and neuroprotective activity [33], and pachydictyol A can be used as an antifouling paint, among other applications [34].…”

Optimization of Protein Extraction from Halopteris scoparia Macroalgae by Ultrasonic-Assisted Enzymatic Extraction (UAEE): Bioactive, Chemical, and Technological Properties

“…9 Moreover, the extract obtained from H. scoparia shows many health benefits including antioxidant, antibacterial, anti-inflammatory, and antiacetylcholinesterase activities. 10 Previously, H. scoparia was studied for polysaccharide extraction, and the physicochemical and biological properties were investigated. 11 O'Connor et al 12 extracted proteins from two brown macroalgae, Fucus vesiculosus and Alaria esculenta, and they investigated the effect of the pretreatment application on the protein yield.…”

“…Moreover, the extract obtained from H. scoparia shows many health benefits including antioxidant, antibacterial, anti-inflammatory, and antiacetylcholinesterase activities …”