Lichens in symbiosis produce a wide range of primary and secondary fine compounds in extreme environmental conditions that have a broad range of biological properties as well as antioxidant potential and can be used in future pharmaceuticals as a natural source of antioxidant molecules. The two microlichen species collected are identified based on morphological and molecular techniques; further studies are carried out by analyzing phytochemicals (FTIR, GC MS), and antioxidant assays are evaluated. The non-enzymatic antioxidant activity is evaluated by DPPH and FRAP assays. The methanol extract of both lichens showed virtuous DPPH scavenge with IC50 of P. nitida (125.76 ± 0.023 µg/ml) and G. scripta IC50 (176.90 ± 0.058 µg/ml). FRAP activity was prominent in the methalonic extract. The enzymatic antioxidant activity is observed by SOD and catalase activity. The cytosolic (Cu–Zn-SOD and Fe-SOD) and mitochondrial SOD (Mn-SOD) are detected in lichens, though P. nitida shows mitochondrial Mn-SOD and cytosolic Cu–Zn-SOD and Fe-SOD, whereas G. scripta has a single cytosolic Cu–Zn-SOD; however, two isoforms of catalase were reported. GC–MS analysis screened bioactive metabolites such as phenols, Quinons, heterocyclic compounds, benzofurans, fatty acids, pyrans, carboxylic acid, aliphatic aldehydes, organic alcohol, fluorinated aliphatic substances, ketones, terpenes and fatty alcohols in P. nitida, whereas, in G. scripta screened fatty acids, alcohols, hydrocarbons, carbonyl compounds, polyols, terpenes, glycosides, phenols, and sugar alcohols detected in the chromatogram peak. FTIR analysis revealed functional groups like Alcohols, Amines, Amides, Alkanes, Aldehydes, Carboxylic acid, Alkynes, Esters, Ketones, Anhydrides, Acid chlorides, Alkenes, Aromatic compounds, Nitro compounds, Alkyl and Aryl Halides in both lichens. The results obtained in the present study proved that P. nitida and G. scripta have promising antioxidant activity owing to the presence of polyphenols and terpenes, as evidenced by DPPH and FRAP assay along with enzymatic analysis (SOD and CAT). Thus both the lichens may be used as natural sources of new bioactive molecules having pharmaceutical interest.

中文翻译：

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两种附生微地衣生物活性化合物的筛选、表征及其体外抗氧化活性评价

共生的地衣在极端环境条件下产生多种初级和次级精细化合物，这些化合物具有广泛的生物特性和抗氧化潜力，可作为抗氧化剂分子的天然来源用于未来的药物中。根据形态学和分子技术鉴定了收集到的两种微地衣物种；通过分析植物化学物质（FTIR、GC MS）进行进一步研究，并评估抗氧化剂测定。通过 DPPH 和 FRAP 测定评估非酶抗氧化活性。两种地衣的甲醇提取物均表现出良好的 DPPH 清除作用，P. nitida (125.76 ± 0.023 µg/ml) 和 G. scripta IC50 (176.90 ± 0.058 µg/ml)。甲二醛提取物中的 FRAP 活性非常显着。通过SOD和过氧化氢酶活性观察酶促抗氧化活性。在地衣中检测到细胞质（Cu-Zn-SOD 和 Fe-SOD）和线粒体 SOD（Mn-SOD），尽管 P.nitida 显示线粒体 Mn-SOD 和细胞质 Cu-Zn-SOD 和 Fe-SOD，而 G. scripta 具有单一胞质 Cu-Zn-SOD；然而，报道了过氧化氢酶的两种亚型。GC-MS分析筛选了金针菇中的酚类、醌类、杂环化合物、苯并呋喃、脂肪酸、吡喃、羧酸、脂肪醛、有机醇、氟化脂肪族物质、酮类、萜烯类和脂肪醇等生物活性代谢物，而G. scripta 筛选了色谱峰中检测到的脂肪酸、醇、碳氢化合物、羰基化合物、多元醇、萜烯、糖苷、酚类和糖醇。FTIR 分析揭示了两种地衣中的醇、胺、酰胺、烷烃、醛、羧酸、炔烃、酯、酮、酸酐、酰氯、烯烃、芳香族化合物、硝基化合物、烷基和芳基卤化物等官能团。本研究获得的结果证明，由于多酚和萜烯的存在，P.nitida 和 G.scripta 具有良好的抗氧化活性，DPPH 和 FRAP 测定以及酶分析（SOD 和 CAT）证明了这一点。因此，这两种地衣都可以用作具有药学意义的新生物活性分子的天然来源。