Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Mais filtros

Base de dados
Intervalo de ano de publicação
Chem Biodivers ; 17(2): e1900473, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31961474


Veratrum plant contains a family of compounds called steroidal alkaloids which have been previously reported to cause DNA damage and blood pressure decrease in vivo. In this study, the antihypertensive effects and DNA damage in brain cells of 12 steroidal alkaloids separated from Veratrum plant were all evaluated to develop a relationship among chemical structure, antihypertensive activity and neurotoxicity by utilization of chemical principal component analysis (PCA) and hierarchical cluster analysis (HCA). Twelve steroidal alkaloids markedly reduced high blood pressure of hypertensive mice and also similarly induced varying degrees of DNA single-strand breaks in mouse cerebellum and cerebral cortex after oral administration. On the basis of the PCA and HCA results, it was suggested that the 3-carboxylic esters and benzene group play a core role in the DNA damage of brain cells, while more hydroxy groups in the A-ring and B-ring structure of jervine-type alkaloid led to stronger antihypertensive activity. The primary structure, activity and neurotoxicity relationship were discussed briefly.

Anti-Hipertensivos/química , Alcaloides de Veratrum/química , Veratrum/química , Administração Oral , Animais , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Análise por Conglomerados , Dano ao DNA/efeitos dos fármacos , Camundongos , Extratos Vegetais/química , Análise de Componente Principal , Relação Estrutura-Atividade , Veratrum/metabolismo , Alcaloides de Veratrum/farmacologia
Gene ; 712: 143962, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31288057


Veratrum nigrum is protected plant of Melanthiaceae family, able to synthetize unique steroidal alkaloids important for pharmacy. Transcriptomes from leaves, stems and rhizomes of in vitro maintained V. nigrum plants were sequenced and annotated for genes and markers discovery. Sequencing of samples derived from the different organs resulted in a total of 108,511 contigs with a mean length of 596 bp. Transcripts derived from leaf and stalk were annotated at 28%, and 38% in Nr nucleotide database, respectively. The sequencing revealed 949 unigenes related with lipid metabolism, including 73 transcripts involved in steroids and genus-specific steroid alkaloids biosynthesis. Additionally, 3203 candidate SSRs markers we identified in unigenes with average density of one SSR locus every 6.2 kb sequence. Unraveling of biochemical machinery of the pathway responsible for steroidal alkaloids will open possibility to design and optimize biotechnological process. The transcriptomic data provide valuable resources for biochemical, molecular genetics, comparative transcriptomics, functional genomics, ecological and evolutionary studies of V. nigrum.

Alcaloides/biossíntese , Regulação da Expressão Gênica de Plantas , Esteroides/biossíntese , Transcriptoma , Veratrum/metabolismo , Mapeamento de Sequências Contíguas , DNA Complementar/metabolismo , Biblioteca Gênica , Ontologia Genética , Marcadores Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Repetições de Microssatélites , Anotação de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Análise de Sequência de RNA
Plant J ; 82(6): 991-1003, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25939370


Steroid alkaloids have been shown to elicit a wide range of pharmacological effects that include anticancer and antifungal activities. Understanding the biosynthesis of these molecules is essential to bioengineering for sustainable production. Herein, we investigate the biosynthetic pathway to cyclopamine, a steroid alkaloid that shows promising antineoplastic activities. Supply of cyclopamine is limited, as the current source is solely derived from wild collection of the plant Veratrum californicum. To elucidate the early stages of the pathway to cyclopamine, we interrogated a V. californicum RNA-seq dataset using the cyclopamine accumulation profile as a predefined model for gene expression with the pattern-matching algorithm Haystack. Refactoring candidate genes in Sf9 insect cells led to discovery of four enzymes that catalyze the first six steps in steroid alkaloid biosynthesis to produce verazine, a predicted precursor to cyclopamine. Three of the enzymes are cytochromes P450 while the fourth is a γ-aminobutyrate transaminase; together they produce verazine from cholesterol.

Enzimas/metabolismo , Alcaloides de Veratrum/metabolismo , Veratrum/genética , Veratrum/metabolismo , 4-Aminobutirato Transaminase/genética , 4-Aminobutirato Transaminase/metabolismo , Algoritmos , Animais , Vias Biossintéticas , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Enzimas/genética , Perfilação da Expressão Gênica/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Análise de Sequência de RNA/métodos , Células Sf9 , Transcriptoma
Chem Biodivers ; 11(8): 1192-204, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25146763


The dried rhizomes of Veratrum album were individually extracted with CHCl3 , acetone, and NH4 OH/benzene to test the toxic effects against the Colorado potato beetle, Leptinotarsa decemlineata, which is an important agricultural pest. Fifteen compounds in various amounts were isolated from the extracts using column and thin-layer chromatography. The chemical structures of 14 compounds were characterized as octacosan-1-ol (1), ß-sitosterol (2), stearic acid (3), diosgenin (4), resveratrol (5), wittifuran X (6), oxyresveratrol (7), ß-sitosterol 3-O-ß-D-glucopyranoside (8), diosgenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyronoside (9), oxyresveratrol 3-O-ß-D-glucopyranoside (10), jervine (11), pseudojervine (13), 5,6-dihydro-1-hydroxyjervine (14), and saccharose (15) using UV, IR, MS, (1) H- and (13)C-NMR, and 2D-NMR spectroscopic methods. However, the chemical structure of 12, an oligosaccharide, has not fully been elucidated. Compounds 4, 6, 9, and 10 were isolated from V. album rhizomes for the first time in the current study. The toxic effects of three extracts (acetone, CHCl3 , and NH4 OH/benzene) and six metabolites, 2, 2+4, 5, 7, 8, and 11, were evaluated against the Colorado potato beetle. The assay revealed that all three extracts, and compounds 7, 8, and 11 exhibited potent toxic effects against this pest. This is the first report on the evaluation of the toxic effects of the extracts and secondary metabolites of V. album rhizomes against L. decemlineata. Based on these results, it can be concluded that the extracts can be used as natural insecticides.

Besouros/efeitos dos fármacos , Inseticidas/química , Inseticidas/farmacologia , Veratrum/química , Animais , Cromatografia em Camada Delgada , Inseticidas/isolamento & purificação , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Rizoma/química , Veratrum/metabolismo
New Phytol ; 166(2): 565-75, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15819918


We examined whether nitrogen (N) and carbohydrates reserves allow Veratrum album, an alpine forb, to start spring growth earlier than the neighbouring vegetation and to survive unpredictable disturbances resulting in loss of above-ground biomass. * Seasonal dynamics of plant reserves, soil N availability and vegetation growth were monitored. Veratrum album shoots were experimentally removed when carbohydrate reserves were at a seasonal minimum and the subsequent changes in biomass and reserves were compared with those in control plants. Reserves did not give V. album a competitive advantage in spring; however, they did function as a buffer against the impact of calamities. Shoot removal resulted in significantly lower root dry weight, higher N concentration in rhizome and roots and lower starch concentrations in rhizome and roots but no plant mortality was observed. Veratrum album used stored N reserves to supplement N uptake and establish high leaf N concentrations, which facilitated a rapid refilling of depleted carbohydrate reserves. The primary function of N reserves appears to be to allow V. album to complete the growing cycle in as short a period as possible, thus minimizing exposure to above-ground risks.

Carboidratos/fisiologia , Nitrogênio/fisiologia , Veratrum/crescimento & desenvolvimento , Metabolismo dos Carboidratos , Clima , Nitrogênio/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Rizoma/metabolismo , Estações do Ano , Veratrum/metabolismo
Biotechnol Bioeng ; 87(7): 849-54, 2004 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-15334411


Inhibitors of melanin biosynthesis were screened by using three different methods. The extract of Veratrum patulum contains hydroxystilbene compounds that are potent tyrosinase inhibitors. We evaluated the enzyme inhibitory property on the mushroom tyrosinase of hydroxystilbene compounds including resveratrol, oxyresveratrol, and their analogs. Biotransformation using cellulase of the whole extract brought about an increase in the inhibitory activity of the products on mushroom tyrosinase. The enhancement of tyrosinase inhibition is supposed to increase the concentration of aglycon, which has superior inhibitory activity to its glycoside. Eventually, melanin biosynthesis was inhibited by the enhanced tyrosinase inhibitory activity of the extract. This result indicated that deglycosylation of stilbene compounds has exerted more effective inhibition on the enzyme than that of the unprocessed plant extract.

Melaninas/biossíntese , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Extratos Vegetais/farmacologia , Estilbenos/farmacologia , Streptomyces/metabolismo , Veratrum/metabolismo , Agaricales/enzimologia , Biotransformação , Celulase/metabolismo , Inibidores Enzimáticos/farmacologia , Extratos Vegetais/metabolismo , Estilbenos/metabolismo , Streptomyces/efeitos dos fármacos