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<p>This study presents a comprehensive chemical characterization of the Antarctic endemic brown macroalga <i>Desmarestia menziesii</i>, collected from Penguin and Livingston Islands (Antarctic Peninsula). Sequential extraction with solvents of increasing polarity (hexane, dichloromethane, ethyl acetate, and methanol) was performed on 601.43&#xa0;g of lyophilized biomass, followed by GC–MS, NMR, IR, and mass spectrometry analyses. The apolar extracts revealed a complex lipophilic profile including marine sterols (fucosterol, isofucosterol, 24-ethylcholesta-5,24(25)-dienol, and stigmasta-5,24(28)-dien-3-ol), saturated and unsaturated fatty acids, phenolic derivatives, and rare long-chain hydrocarbons (&gt; C23). These metabolites are associated with membrane stabilization, homeoviscous adaptation, and oxidative stress mitigation under chronic low temperatures and high UV radiation typical of Antarctic environments. The ethyl acetate extract contained UV-fluorescent aromatic meroterpenoids with confirmed antioxidant activity via TLC-DPPH bioautography, reinforcing their ecological role in photoprotection. The methanolic extract was predominantly composed of mannitol (52.5%; 17.55&#xa0;g isolated), highlighting its central function as an osmoprotectant, cryoprotectant, carbon reserve, and antioxidant molecule in freeze–thaw resilience. Additionally, phthalates, siloxanes, and other plastic-derived additives were detected in apolar fractions, suggesting adsorption onto the polysaccharide-rich thallus. This dual chemical signature reflects both adaptive metabolic plasticity and the influence of long-range anthropogenic contamination in protected Antarctic areas. Overall, these findings expand the chemodiversity known for Antarctic macroalgae and position <i>D. menziesii</i> as both a promising source of bioactive compounds and a sensitive bioindicator of environmental change in polar marine ecosystems.</p>

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Study on the chemical constituents of Desmarestia menziesii (Heterokontophyta, Desmarestiales), an Antarctic seaweed

  • 期刊论文

  • 发表日期：

    2026年4月30日

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  • Isac José da Silva Filho,
  • Erika Mattos Stein,
  • Aline Paternostro Martins,
  • Angelica Nunes Garcia,
  • Pio Colepicolo,
  • Nair S. Yokoya,
  • Luciana Retz de Carvalho

摘要

This study presents a comprehensive chemical characterization of the Antarctic endemic brown macroalga Desmarestia menziesii, collected from Penguin and Livingston Islands (Antarctic Peninsula). Sequential extraction with solvents of increasing polarity (hexane, dichloromethane, ethyl acetate, and methanol) was performed on 601.43 g of lyophilized biomass, followed by GC–MS, NMR, IR, and mass spectrometry analyses. The apolar extracts revealed a complex lipophilic profile including marine sterols (fucosterol, isofucosterol, 24-ethylcholesta-5,24(25)-dienol, and stigmasta-5,24(28)-dien-3-ol), saturated and unsaturated fatty acids, phenolic derivatives, and rare long-chain hydrocarbons (> C23). These metabolites are associated with membrane stabilization, homeoviscous adaptation, and oxidative stress mitigation under chronic low temperatures and high UV radiation typical of Antarctic environments. The ethyl acetate extract contained UV-fluorescent aromatic meroterpenoids with confirmed antioxidant activity via TLC-DPPH bioautography, reinforcing their ecological role in photoprotection. The methanolic extract was predominantly composed of mannitol (52.5%; 17.55 g isolated), highlighting its central function as an osmoprotectant, cryoprotectant, carbon reserve, and antioxidant molecule in freeze–thaw resilience. Additionally, phthalates, siloxanes, and other plastic-derived additives were detected in apolar fractions, suggesting adsorption onto the polysaccharide-rich thallus. This dual chemical signature reflects both adaptive metabolic plasticity and the influence of long-range anthropogenic contamination in protected Antarctic areas. Overall, these findings expand the chemodiversity known for Antarctic macroalgae and position D. menziesii as both a promising source of bioactive compounds and a sensitive bioindicator of environmental change in polar marine ecosystems.