The chemical examination of the ethanolic extract of manglicolous lichen Parmotrema tinctorum (Pt-Et) has resulted in isolation of six known metabolites, i.e., methyl-β-orcinolcarboxylate (1), isolecanoric acid (2), methyl-2,6-dihydroxy-4-methylbenzoate (3), haematommic acid (4), ethyl haematommate (5), and atranorin (6). All the isolates 1-6 and Pt-Et have been screened against DPPH and superoxide free radicals, six different cancer cell lines (MDA-MB-231, SW620, HeLa, FADU, A549, SKOV3) and one normal human cell line (NHME). Compound 3 exhibits prominent inhibition of superoxide free radical, which appears to be better than that of the standard (ascorbic acid) with an IC₅₀ value of 26.0 µg/mL. From the SRB assay results, it is observed that the better IC₅₀ values have been obtained from 4 and 5 on HeLa, FADU, and A549, respectively. In addition, all the tested samples show low cell lysis on NHME, which indicates low toxicity. Consequently, the outcomes revealed that P. tinctorum could be a new source to treat oxidative stress and cancer. This work is the first report of antioxidant and cytotoxicity studies on the isolated metabolites 1-6.

中文翻译：

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牙龈地衣Parmotrema tinctorum（Despr。ex Nyl。）黑尔：分离，鉴定和生物学评估

对山楂地衣嗜冰小夜蛾 （Pt-Et）的乙醇提取物进行化学检查，已分离出六种已知的代谢物，即。例如，β-甲氧基亚麻酸甲酯（1），异高癸酸（2），2,6-二羟基-4-甲基苯甲酸甲酯（3），血腥酸（4），血腥酸乙酯（5）和atranorin （6）。已针对DPPH和超氧化物自由基，六种不同的癌细胞系（MDA-MB-231，SW620，HeLa，FADU，A549，SKOV3）和一种正常的人类细胞系（NHME）筛选了所有分离株1-6和Pt-Et）。复合3表现出对超氧化物自由基的显着抑制作用，似乎比标准品（抗坏血酸）更好，IC ₅₀值为26.0 µg / mL。从SRB分析结果可以看出，分别从HeLa，FADU和A549上的4和5获得了更好的IC ₅₀值。此外，所有测试样品在NHME上的细胞裂解均较低，这表明毒性较低。因此，结果表明，锡青霉可能是治疗氧化应激和癌症的新来源。这项工作是对分离出的代谢物1-6进行抗氧化剂和细胞毒性研究的第一份报告。