Chrozophorin: a new acylated flavone glucoside from Chrozophora tinctoria (Euphorbiaceae) / Crozoforina: uma nova flavona glicosilada e acetilada de Chrozophora tinctoria (Euphorbiaceae)

Preparative reversed-phase HPLC analysis of the methanol extract of the aerial parts of Chrozophora tinctoria (Euphorbiaceae) yielded five flavonoid glycosides, quercetin 3-O-rutinoside (1, rutin), acacetin 7-O-rutinoside (2), apigenin 7-O-b-D-[(6-p-coumaroyl)]-glucopyranoside (3), apigenin 7-O- b-D-glucopyranoside (4) and apigenin 7-O-b-D-[6-(3,4-dihydroxybenzoyl)]-glucopyranoside (named, chrozophorin, 5), the last one being a new natural product. The structures of these compounds were elucidated unambiguously by UV spectroscopic analyses using shift reagents, ESIMS, and 1D and 2D NMR spectroscopic techniques. The free-radical scavenging activity of the methanol extract (RC50 = 2.24 x 10-1 mg/mL) as well as the isolated compounds (1-5) (RC50 = 4.38 x 10-3, 2.26 x 10-2, 7.69 x 10-4, 8.71 x 10-3 and 3.19 x 10-4 mg/mL, respectively) were assessed by the DPPH assay.

Análise das partes aéreas de Chrozophora tinctoria (Euphorbiaceae) através de HPLC preparativa com coluna de fase reversa produziu cinco glicosídeos de flavonóides, quercetina 3-O-rutinosídeo (1, rutina), acacetina 7-O-rutinosídeo (2), apigenina 7-O-b-D-[(6-p-cumaroil)]-glicopiranosídeo (3), apigenina 7-O-b-D-glicopiranosídeo (4) e apigenina 7-O-b-D-[-(3,4-diidroxibenzoil)]-glicopiranosídeo (chamado crozoforina, 5), sendo o último um novo produto natural. As estruturas dessas substâncias foram inequivocamente elucidadas por análise de espectrofotometria de UV com o uso de reagentes de deslocamento, ESIMS, e técnicas de RMN 1D e 2D. A atividade de captura de radicais livres do extrato metanólico (RC50 = 2,24 x 10-1 mg/mL) bem como das substâncias isoladas (1-5) (RC50 = 4,38 x 10-3, 2,26 x 10-2, 7,69 x 10-4, 8,71 x 10-3 e 3,19 x 10-4 mg/mL, respectivamente) foram analisados pelo método DPPH.

Chenoalbuside: an antioxidant phenolic glycoside from the seeds of Chenopodium album L. (Chenopodiaceae)

In addition to three known phytoecdysteroids, a new phenolic glycoside (named, chenoalbuside) was isolated from the methanol extract of the seeds of Chenopodium album. While the structures of all phytoecdysteroids were elucidated by direct comparison of their spectroscopic data with published data, the structure of chenoalbuside was determined unequivocally by a combination of UV, MS and 1D and 2D NMR spectroscopic analyses. The antioxidant potential of the new compound was assessed by the DPPH assay, and the RC50 value was found to be 1.4 x 10-4 mg/mL.