O estudo fitoquímico do extrato metanólico de galhos de Ouratea hexasperma (Ochnaceae) forneceu dois novos flavonóides, 7-O-β-D-glicopiranosil-6-(3-metilbut-2-enil)-5,4'-diidroxiflavanonol (6-β,β-dimetilalil-7-O-β-D-glucopiranosil-aromadendrina) e 7-O-β-D-glicopiranosil-6-(3-metilbut-2-enil)-3,5,4'-triidroxiflavona (6-β,β-dimetilalil-7-O-β-D-glucopiranosil-kaemperol) além de uma mistura de sitosterol e estigmasterol, lupeol, 3-O-β-D-glicopiranosil-sitosterol e o ácido 2,4-diidroxifenilacético. As estruturas dessas substâncias foram estabelecidas através de análise dos espectros de IV, EM-IES e RMN das substâncias naturais e dos derivados peracetílico e éter dimetílico da nova flavona, além de comparação com dados da literatura.

Chromatographical fractionation of the methanol extract from the branches of Ouratea hexasperma (Ochnaceae) afforded two new flavonoids, 7-O-β-D-glucopyranosyl-6-(3-methylbut-2-enyl)-5,4'-dihydroxyflavanonol (6-β,β-dimethylallylaromadendrin-7-O-β-D-glucoside) and 7-O-β-D-glucopyranosyl-6-(3-methylbut-2-enyl)-3,5,4'-trihydroxyflavone (6-β,β-dimethylallylkaempferol-7-O-β-D-glucoside) besides a mixture of sitosterol and stigmasterol,lupeol, sitosterol-3-O-β-D-glycopyranoside and 2,4-dihydroxyphenylacetic acid. The structures were established by analysis of IR, ESI-MS, and NMR spectra of the natural substances, and those of the dimethyl ether and peracetyl-derivatives of the new flavone, as well as comparison with literature values.

This work describes the flavonoids and biflavonoids found in species of Ouratea and Luxemburgia as chemical markers that serve to detect the difference between these taxa according to the linkage between the flavonoidal units. A rational nomenclature is proposed and the pharmacological potencial is discussed.