436-32-8

Diffractaic acid is a lichen metabolite that has been found in P. magellanica and has diverse biological activities. It is cytotoxic to HCT116, HeLa, and MCF-7 cancer cells (IC₅₀s = 42.2, 64.6, and 93.4 μM, respectively). Diffractaic acid inhibits growth of M. tuberculosis (MIC = 41.7 μM). In vivo, diffractaic acid (25-200 mg/kg) reduces neutrophil infiltration, lipid peroxidation, myeloperoxidase (MPx) activity, and the number of gastric lesions as well as reverses decreases in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities induced by indomethacin in rat gastric mucosa. Diffractaic acid also has analgesic activity, reducing acetic acid-induced writhing and increasing the pressure pain threshold in mice.

Powder, soluble in organic solvents such as methanol, ethanol, and DMSO. It is derived from Usnea diffracta Vain, Rehmannia glutinosa (Gaetn.) Libosch. ex Fisch. et Mey. of the Gastrodia elata family.

Diffractaic acid, a major constituent of U. longissimi, acts as an effective proapoptotic agent in various disorders research[1]. Diffractaic acid is the analgesic and antipyretic component of Usnea diffracta[2].

ChEBI: 4-[(2,4-dimethoxy-3,6-dimethylphenyl)-oxomethoxy]-2-hydroxy-3,6-dimethylbenzoic acid is a carbonyl compound.

[1] Fehmi Odabasoglu, et al. Diffractaic acid, a novel proapoptotic agent, induces with olive oil both apoptosis and antioxidative systems in Ti-implanted rabbits. Eur J Pharmacol. 2012 Jan 15;674(2-3):171-8. DOI:10.1016/j.ejphar.2011.11.019
[2] E Okuyama, et al. 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