RESUMO
The rhizosphere microbial community in a hydroponics system with multiple parallel mineralization (MPM) can potentially suppress root-borne diseases. This study focused on revealing the biological nature of the suppression against Fusarium wilt disease, which is caused by the fungus Fusarium oxysporum, and describing the factors that may influence the fungal pathogen in the MPM system. We demonstrated that the rhizosphere microbiota that developed in the MPM system could suppress Fusarium wilt disease under in vitro and greenhouse conditions. The microbiological characteristics of the MPM system were able to control the population dynamics of F. oxysporum, but did not eradicate the fungal pathogen. The roles of the microbiological agents underlying the disease suppression and the magnitude of the disease suppression in the MPM system appear to depend on the microbial density. F. oxysporum that survived in the MPM system formed chlamydospores when exposed to the rhizosphere microbiota. These results suggest that the microbiota suppresses proliferation of F. oxysporum by controlling the pathogen's morphogenesis and by developing an ecosystem that permits coexistence with F. oxysporum.
Assuntos
Fenômenos Fisiológicos Bacterianos , Biota , Fusarium/crescimento & desenvolvimento , Interações Microbianas , Doenças das Plantas/prevenção & controle , Rizosfera , Microbiologia do Solo , Solanum lycopersicum/microbiologia , Dados de Sequência Molecular , Doenças das Plantas/microbiologia , Análise de Sequência de DNARESUMO
Gneyulins A (1) and B (2), two new stilbene trimers consisting of oxyresveratrol constituent units, and noidesols A (3) and B (4), two new dihydroflavonol-C-glucosides, were isolated from the bark of Gnetum gnemonoides. The structures and configurations of 1-4 were elucidated on the basis of 2D NMR correlations and X-ray analysis. Gneyulins A (1) and B (2) showed inhibition of Na(+)-glucose transporters (SGLT-1 and SGLT-2).
Assuntos
Flavonóis/isolamento & purificação , Glucosídeos/isolamento & purificação , Gnetum/química , Estilbenos/isolamento & purificação , Cristalografia por Raios X , Flavonóis/química , Flavonóis/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Malásia , Conformação Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/química , Transportador 1 de Glucose-Sódio/antagonistas & inibidores , Inibidores do Transportador 2 de Sódio-Glicose , Estilbenos/química , Estilbenos/farmacologiaRESUMO
Three new picraline-type alkaloids, alstiphyllanines E-G (1-3) and a new ajmaline-type alkaloid, alstiphyllanine H (4) were isolated from the leaves of Alstonia macrophylla together with 16 related alkaloids (5-20). Structures and stereochemistry of 1-4 were fully elucidated and characterized by 2D NMR analysis. Alstiphyllanines E and F (1 and 2) showed moderate Na(+)-glucose cotransporter (SGLT1 and SGLT2) inhibitory activity. A series of a hydroxy substituted derivatives 21-28 at C-17 of the picraline-type alkaloids have been derived as having potent SGLT inhibitory activity. 10-Methoxy-N(1)-methylburnamine-17-O-veratrate (6) exhibited potent inhibitory activity, suggesting that the presence of an ester side chain at C-17 may be important to show SGLT inhibitory activity. Structure activity relationship of alstiphyllanines on inhibitory activity of SGLT was discussed.
Assuntos
Alstonia/química , Alcaloides Indólicos/farmacologia , Folhas de Planta/química , Transportador 1 de Glucose-Sódio/antagonistas & inibidores , Inibidores do Transportador 2 de Sódio-Glicose , Animais , Células COS , Células Cultivadas , Chlorocebus aethiops , Alcaloides Indólicos/química , Alcaloides Indólicos/isolamento & purificação , Conformação Molecular , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Two cyclic diarylheptanoids, acerogenins A (1) and B (2) have been isolated from the bark of Acer nikoense as inhibitors of Na(+)-glucose cotransporter (SGLT). Acerogenins A (1) and B (2) inhibited both isoforms, SGLT1 and SGLT2. Structure-activity relationship of acerogenin derivatives on inhibitory activity of SGLT as well as conformational analysis of 1 and 2 on the basis of J-resolved HMBC spectra and X-ray analysis were discussed.
Assuntos
Acer , Diarileptanoides/química , Extratos Vegetais/química , Transportador 1 de Glucose-Sódio/antagonistas & inibidores , Inibidores do Transportador 2 de Sódio-Glicose , Cristalografia por Raios X , Diarileptanoides/isolamento & purificação , Diarileptanoides/farmacologia , Casca de Planta , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Transportador 1 de Glucose-Sódio/metabolismo , Transportador 2 de Glucose-Sódio/metabolismoRESUMO
The methanol extract of Sophora flavescens, which is used in traditional Chinese medicine (sophorae radix), showed potent Na(+)-glucose cotransporter (SGLT) inhibitory activity. Our search for active components identified many well-known flavonoid antioxidants: kurarinone, sophoraflavanone G, kushenol K, and kushenol N.