Rubiadin-1 methyl ether is an anthraquinone that has been found in Heterophyllaea pustulata and has diverse biological activities.1,2,3,4 It generates superoxide radicals in isolated human neutrophils and monocytes when used at a concentration of 20 ?g/ml, an effect that can be enhanced by UV radiation.1 Rubiadin-1 methyl ether (0.1, 1, and 10 ?M) inhibits M-CSF- and RANKL-induced differentiation of osteoclasts.2 It inhibits C. tropicalis biofilm formation (MIC = 31.3 ?g/ml for a clinical isolate).3 Rubiadin-1 methyl ether (30 mg/kg) reduces LPS-induced increases in bronchoalveolar fluid (BALF) levels of TNF-α, IL-6, and IFN-γ in a mouse model of acute lung injury.4
1.Montoya, S.C.N., Comini, L.R., Sarmiento, M., et al.Natural anthraquinones probed as Type I and Type II photosensitizers: Singlet oxygen and superoxide anion productionJ. Photochem. Photobiol. B.78(1)77-83(2005) 2.He, Y.-Q., Zhang, Q., Shen, Y., et al.Rubiadin-1-methyl ether from Morinda officinalis How. Inhibits osteoclastogenesis through blocking RANKL-induced NF-κB pathwayBiochem. Biophys. Res. Commun.506(4)927-931(2018) 3.Marioni, J., da Silva, M.A., Cabrera, J.L., et al.The anthraquinones rubiadin and its 1-methyl ether isolated from Heterophyllaea pustulata reduces Candida tropicalis biofilms formationPhytomedicine23(12)1321-1328(2016) 4.Mohr, E.T.B., Nascimento, M.V.P.D.S., da Rosa, J.S., et al.Evidence that the anti-inflammatory effect of rubiadin-1-methyl ether has an immunomodulatory contextMediators Inflamm.6474168(2019)