Robinetin (3,3',4',5',7-Pentahydroxyflavone), a naturally occurring flavonoid with remarkable 'two color' intrinsic fluorescence properties, has antifungal, antiviral, antibacterial, antimutagenesis, and antioxidant activity. Robinetin also can inhibit lipid peroxidation and protein glycosylation[1][2][3][4][5].

Robinetin (0.1-10 μM; 1 h) inhibits HIV integrase cleavage and integration in a dose-dependent manner[1].Robinetin inhibits the DNA synthesis in Proteus vulgaris, and the RNA synthesis in S. aureus[2].Robinetin (100-200 or 25 μM; 1 or 72 h) inhibits egg yolk phosphatidylcholine (EYPC) membrane lipid peroxidation and hemoglobin A (HbA) glycosylation with high efficiency[3].Robinetin exhibits photo-induced excited-state intramolecular proton transfer resulting in 'two color' (in 'blue-violet' and 'yellow-green' regions) fluorescence characteristic of flavonols, the relative contributions between the two colors being strongly modulated by the local environment of the fluorophore[3].

[1]. Fesen MR, et, al. Inhibition of HIV-1 integrase by flavones, caffeic acid phenethyl ester (CAPE) and related compounds. Biochem Pharmacol. 1994 Aug 3;48(3):595-608. [2]. Cushnie TPT, et, al. Antimicrobial activity of flavonoids. Int J Antimicrob Agents. 2005 Nov;26(5):343-56. [3]. Chaudhuri S, et, al. Binding of the bioflavonoid robinetin with model membranes and hemoglobin: Inhibition of lipid peroxidation and protein glycosylation. J Photochem Photobiol B. 2010 Jan 21;98(1):12-9. [4]. Birt DF, et, al. Anti-mutagenesis and anti-promotion by apigenin, robinetin and indole-3-carbinol. Carcinogenesis. 1986 Jun;7(6):959-63. [5]. Manrique-de-la-Cuba MF, et, al. Theoretical study of the antioxidant capacity of the flavonoids present in the Annona muricata (Soursop) leaves. J Mol Model. 2019 Jun 25;25(7):200.