Flavonoids from Annona dioica leaves and their effects in Ehrlich carcinoma cells, DNA-topoisomerase I and II

Abstract

A investigação fitoquímica do extrato metanólico das folhas de Annona dioica (Annonaceae) resultou na identificação dos flavonóides kaempferol (1), 3-O-[3",6"-di-O-p-hidroxicinamoil]-β-galactopiranosil-kaempferol (2), 6"-O-p-hidroxicinamoil-β-galactopiranosil-kaempferol (3) e 3-O-β-galactopiranosil-kaempferol (4). As estruturas foram caracterizadas inequivocamente através de análises espectroscópicas utilizando-se RMN de C NMR spectroscopic analyses using 1D and 2D experiments. The cytotoxic effects of the flavonoids and flavonoid fraction (FF) were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay against Ehrlich carcinoma cells. The results indicated that 1, 2, 3 and FF exhibit significant antiproliferative action when compared to quercetin. The inhibitory action on DNA-topoisomerase I and II of all the flavonoids was evaluated by relaxation assays on pBR322 plasmid DNA. The results indicated the inhibitory and non-selective effects of the flavonoids on DNA-topoisomerase I and II.

Phytochemical screening, cytotoxicity and acute toxicity of Annona vepretorum Mart (Annonaceae) leaf extracts

“…Phytochemical analysis showed the presence of flavonoids, except in crude hexane extract (Av-HexC), confirming previous studies with A. vepretorum [15]. A large number of biological activities have been attributed to these compounds, including anticancer activity [19]. It was also demonstrated the presence of alkaloids and terpenes in the extracts [4].…”

Chemical composition and antioxidant activity of a Lebanese plant Euphorbia macroclada schyzoceras

“…Carbonyl group at the carbon atom C4 was confirmed by 13 C NMR at 178 or 177 mg/L, and as it was showed in MS-ESI, the ions at m/z 367, 339 and 311 were observed, which is attributed to the loss of CO and 2CO respectively. Detailed analysis of 2D NMR spectral data of 6 revealed and affirmed the correlation between these protons for each compound (Figure 2) [20][21][22] . This NMR spectral data (Proton and COSY) combined with the infrared suggested the presence of a flavone derive (Figure 3).…”

Alcaloides e outros constituintes de Xylopia langsdorffiana (Annonaceae)

“…8 Um grande nú-mero de componentes químicos tem sido isolado do gênero Xylopia, dentre eles, diterpenos, 9 sesquiterpenos, 10 alcaloides 11 e flavonoides. 12 Trabalhos realizados por grupos de pesquisas no Brasil com Annonaceae reportaram vários tipos de metabólitos secundários, dentre eles, sesquiterpenos aromadendranos com atividade antifúngica de X. brasiliensis, 13 diterpenos diméricos de X. emarginata 14 e X. frutescens, 15 sesquiterpenos diméricos de X. aromatica, 16 diterpenos traquilobanos e óleos essenciais com atividade acaricida de X. sericea 17 e alcaloides com atividade antifúngica de Porcelia macrocarpa. 18 Xylopia langsdorffiana é uma árvore de 5-7 m de altura, conhecida popularmente como pimenteira-da-terra.…”