Diffractaic acid

Diffractaic acid（CAS号：436-32-8）是一种来源于地衣Pseudocyphellaria magellanica的次级代谢产物，表现出显著的生物活性，包括对多种人类癌细胞系（HCT116、HeLa和MCF-7）具有细胞毒性作用，其IC₅₀值范围为42.2至93.4 μM，并对结核分枝杆菌具有抑制活性（MIC为41.7 μM）。大鼠体内研究显示，diffractaic acid（25–200 mg/kg）能够通过减少中性粒细胞浸润、脂质过氧化、髓过氧化物酶活性和胃损伤，同时恢复抗氧化酶（SOD和GPx）活性，从而减轻吲哚美辛诱导的胃黏膜损伤。此外，diffractaic acid还通过减少醋酸诱导的扭体反应和提高动物模型的压力痛阈，表现出镇痛作用。

参考文献：

[1] Brisdelli F, Perilli M, Sellitri D, Piovano M, Garbarino JA, Nicoletti M, Bozzi A, Amicosante G, Celenza G. Cytotoxic activity and antioxidant capacity of purified lichen metabolites: an in vitro study. Phytother Res. 2013 Mar;27(3):431-7. doi: 10.1002/ptr.4739. Epub 2012 May 25. PMID: 22628260.

[2] Honda NK, Pavan FR, Coelho RG, de Andrade Leite SR, Micheletti AC, Lopes TI, Misutsu MY, Beatriz A, Brum RL, Leite CQ. Antimycobacterial activity of lichen substances. Phytomedicine. 2010 Apr;17(5):328-32. doi: 10.1016/j.phymed.2009.07.018. Epub 2009 Aug 14. PMID: 19683421.

[3] Bayir Y, Odabasoglu F, Cakir A, Aslan A, Suleyman H, Halici M, Kazaz C. The inhibition of gastric mucosal lesion, oxidative stress, and neutrophil-infiltration in rats by the lichen constituent diffractaic acid. Phytomedicine. 2006 Sep;13(8):584-90. doi: 10.1016/j.phymed.2005.07.002. Epub 2005 Oct 28. PMID: 16920514. </p><p>[4] Okuyama E, Umeyama K, Yamazaki M, Kinoshita Y, Yamamoto Y. Usnic acid and diffractaic acid as analgesic and antipyretic components of Usnea diffracta. Planta Med. 1995 Apr;61(2):113-5. doi: 10.1055/s-2006-958027. PMID: 7753915.