RESUMO
Two new phenolic glucosides, hostaflavanone A (1) and anti-1-phenylpropane-1,2-diol-2-O-ß-d-glucopyranoside (2), together with six known compounds, anti-1-phenylpropane-1,2-diol (3), phenethyl-O-ß-d-glucopyranoside (4), phenethanol-ß-d-gentiobioside (5), phenethyl-O-rutinoside (6), (1S, 3S)-1-methyl-1,2,3,4-tetrahydro-ß-carboline-3-carboxylic acid (7), and (1R, 3S)-1-methyl-1,2,3,4-tetrahydro-ß-carboline-3-carboxylic acid (8), were isolated from the flower of Hosta plantaginea, and their structures were elucidated by nuclear magnetic resonance (NMR), high resolution electrospray ionization mass spectroscopy (HRESIMS), and circular dichroism (CD) analyses. The cyclooxygenases (COX-1 and COX-2) inhibition and antioxidant activities of compounds 1 and 4-6 were investigated, and they showed moderate cyclooxygenases inhibition activities. Moreover, only compound 1 exhibited moderate antioxidant activity, with an IC50 value of 83.2 µM, while 4-6 showed insignificant activity with IC50 values of 282, 257, and 275 µM, respectively. This is the first report of compounds 3 and 5-8 from the Liliaceae family. The chemotaxonomic significance of the isolated compounds was also summarized.
Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/farmacologia , Flores/química , Hosta/química , Hosta/classificação , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Compostos Fitoquímicos/químicaRESUMO
The coat protein (CP) gene DNA sequences of nine isolates of Hosta virus X (HVX) from different regions of the Czech Republic were determined and compared with sequences available in GenBank. The sequences were almost uniform, the pairwise nucleotide identities among the Czech HVX isolates were 99-100%. The respective range was 98-100% when sequences from the GenBank were included. Therefore, phylogenetic analyses including Maximum parsimony and Bayesian analyses of either, DNA and deduced amino acid sequences, showed close relationship among isolates. Only the group of two isolates, HVXCR1 and HVXCR8 showed significant sequence divergence in phylogenetic trees. The HVXCR1-HVXCR8 group differs from the others by the substitution of glutamine (Q) by arginine (R). Moreover, these isolates showed different symptoms on infected hosta leaves - deformation on the leaves without a mosaic or mottling. This amino acid change may, therefore, have a biological significance.
