Scholarlink

<p>Lichens of the family <i>Parmeliaceae</i> are rich in bioactive metabolites such as depsides, depsidones, and usnic acid derivatives with antioxidant, antimicrobial, and cytotoxic potential. This study compared methanolic and acetonic extracts of <i>Parmelia tiliacea</i>, <i>Pleurosticta acetabulum</i>, and <i>Melanelixia glabra</i> to elucidate solvent-dependent variations in chemistry and bioactivity. Lichen thalli collected from Bursa (Türkiye) were extracted by ultrasound-assisted methanol or acetone, and analyzed using LC-QTOF-MS coupled with spectral dereplication. Total phenolic (TPC) and flavonoid (TFC) contents, antioxidant assays (DPPH, ABTS, CUPRAC, superoxide, metal chelation), and tyrosinase inhibition were evaluated, and correlations were assessed by Pearson statistics. Solvent polarity markedly influenced metabolite recovery and function. In <i>P. tiliacea</i>, acetone yielded higher TPC/TFC (438.9 and 125.4&#xa0;µg/g), whereas methanol favored tyrosinase inhibition (31.4%). <i>P. acetabulum</i> acetone extract exhibited the strongest radical-scavenging activity (DPPH IC₅₀ 79.9&#xa0;µg/mL) despite low totals, while its methanol extract had the richest phenolic content but weaker activity. <i>M. glabra</i> showed solvent-independent high phenolics (≈1.3–1.5&#xa0;mg GAE/g) and exceptionally high vanillic acid (~ 100&#xa0;µg/g) with strong antioxidant but weak enzyme inhibition. Correlation analysis linked vanillic acid, rutin, and epicatechin to antioxidant indices, while evernic and usnic acids correlated weakly, reflecting their known antimicrobial roles. These results demonstrate that while species (and potentially habitat) determine the intrinsic chemistry of Parmeliaceae lichens, solvent polarity modulates the extractable metabolite profile and thus the observed bioactivity. Bulk phenolic totals alone do not predict activity; specific phenolic acids drive functionality. <i>Parmeliaceae</i> lichens thus represent promising natural antioxidant sources for pharmacognostic exploration.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Comparative analysis of phenolic composition and in vitro biological activities in three Parmeliaceae lichens: Parmelia tiliacea, Pleurosticta acetabulum, and Melanelixia glabra

  • 期刊论文

  • 发表日期：

    2026年2月4日

查看全文
  • Burcu Sümer Tüzün,
  • Başak Türkü Karadağ,
  • Tuğçe Fafal,
  • Bijen Kıvçak

摘要

Lichens of the family Parmeliaceae are rich in bioactive metabolites such as depsides, depsidones, and usnic acid derivatives with antioxidant, antimicrobial, and cytotoxic potential. This study compared methanolic and acetonic extracts of Parmelia tiliacea, Pleurosticta acetabulum, and Melanelixia glabra to elucidate solvent-dependent variations in chemistry and bioactivity. Lichen thalli collected from Bursa (Türkiye) were extracted by ultrasound-assisted methanol or acetone, and analyzed using LC-QTOF-MS coupled with spectral dereplication. Total phenolic (TPC) and flavonoid (TFC) contents, antioxidant assays (DPPH, ABTS, CUPRAC, superoxide, metal chelation), and tyrosinase inhibition were evaluated, and correlations were assessed by Pearson statistics. Solvent polarity markedly influenced metabolite recovery and function. In P. tiliacea, acetone yielded higher TPC/TFC (438.9 and 125.4 µg/g), whereas methanol favored tyrosinase inhibition (31.4%). P. acetabulum acetone extract exhibited the strongest radical-scavenging activity (DPPH IC₅₀ 79.9 µg/mL) despite low totals, while its methanol extract had the richest phenolic content but weaker activity. M. glabra showed solvent-independent high phenolics (≈1.3–1.5 mg GAE/g) and exceptionally high vanillic acid (~ 100 µg/g) with strong antioxidant but weak enzyme inhibition. Correlation analysis linked vanillic acid, rutin, and epicatechin to antioxidant indices, while evernic and usnic acids correlated weakly, reflecting their known antimicrobial roles. These results demonstrate that while species (and potentially habitat) determine the intrinsic chemistry of Parmeliaceae lichens, solvent polarity modulates the extractable metabolite profile and thus the observed bioactivity. Bulk phenolic totals alone do not predict activity; specific phenolic acids drive functionality. Parmeliaceae lichens thus represent promising natural antioxidant sources for pharmacognostic exploration.