Actividad antifúngica in vitro de Sapranthus microcarpus (Annonaceae) contra hongos fitopatógenos

Background and Aims: The phytochemistry study of Annonaceae has intensified in the last decades due to the discovery of secondary metabolites with antimicrobial activities. The inhibitory activities of extracts and compounds from these species for phytopathogens are less known. The antifungal activity of Sapranthus microcarpus was determined in vitro against six fungal pathogens of important crops.Methods: Hexane, methanol, and alkaloid extracts of the leaves and root and stem bark of S. microcarpus were evaluated to determine whether they could inhibit the mycelial growth of the phytopathogens. The combined activity of the most active extracts for each phytopathogen was also determined. The alkaloid liriodenine was isolated and identified as an antifungal principle.Key results: All extracts inhibited the growth of the six phytopathogens to some extent. The root bark alkaloid extract showed the highest activity. Fusarium oxysporum f. sp. lycopersici and Curvularia lunata were the most sensitive phytopathogens. Liriodenine was active against all the plant pathogens (minimum inhibitory concentrations of 125-500 nmol ml-1).Conclusions: Sapranthus microcarpus is a native natural resource with great phytochemical potential.Antecedentes y Objetivos: El estudio de la fitoquímica de Annonaceae se ha intensificado en las últimas décadas debido al descubrimiento de metabolitos secundarios con actividades antimicrobianas. Las actividades inhibidoras de extractos y compuestos de estas especies para fitopatógenos son menos conocidas. Se determinó la actividad antifúngica in vitro de Sapranthus microcarpus contra seis hongos fitopatógenos de cultivos importantes.Métodos: Se evaluaron extractos metanólicos, hexánicos y alcaloidales de las hojas, y corteza de tallos y raíces de S. microcarpus por el método de inhibición micelial. También se determinó la actividad combinada de los extractos más potentes contra cada fitopatógeno. Se aisló e identificó al alcaloide liriodenina como uno de los metabolitos antifúngicos.Resultados clave: Todos los extractos, en alguna medida, inhibieron el crecimiento de los seis fitopatógenos. Los extractos alcaloidales mostraron la mayor actividad. Fusarium oxysporum f. sp. lycopersici y Curvularia lunata fueron los fitopatógenos más sensibles. Liriodenina fue activo contra todos los fitopatógenos (a concentraciones inhibitorias mínimas de 125-500 nmol ml-1).Conclusiones: Sapranthus microcarpus es un recurso nativo con alto potencial fitoquímico

Biosíntesis de alcaloides bencilisoquinolínicos

Benzylisoquinoline alkaloid biosynthesis. The benzylisoquinoline alkaloids (BIA) are specialized metabolites with an ancient phylogeneticdistribution, but still preserved in modern clades. Some of them, such as morphine, sanguinerine or berberine, are important for modernmedicine. This review discusses the highlights of the current state of the biosynthesis of BIA. There have been studies that show thebiosynthesis of 22 of these nitrogenous metabolites. In their formation there are 43 enzymes grouped into oxidoreductases, transferasesand lyases, which in some cases represent atypical examples of the manner in which the secondary metabolism diversification wasoriginated. Two of these examples are the cytochrome proteins P450 (P450), with catalytic activities for ABI route, or the norcoclaurinesynthase enzyme (NCS), which share substantial identity with defense allergenic proteins. Likewise, there are genetic advances thathave produced the characterization of 30 enzymes, allowing knowledge of regulatory processes. Another interesting aspect is thecompartmentation of the biosynthesis sites and accumulation of BIA, since in several cases they are spatially separated and in differentspecies, or in the same species several types of cells may be involved. This has suggested intra and intercellular transport of alkaloids,precursors and enzymes, and it has been documented berberine transport between the cytoplasm and the vacuoles of storage. The picturefor the biosynthesis of BIA has been constructed with exemplary studies of alkaloids with pharmacological importance

Biossíntese de alcalóides benzilisoquinolinas

The benzylisoquinoline alkaloids (BIA) are specialized metabolites with an ancient phylogenetic distribution, but still preserved in modern clades. Some of them, such as morphine, sanguinerine or berberine, are important for modern medicine. This review discusses the highlights of the current state of the biosynthesis of BIA. There have been studies that show the biosynthesis of 22 of these nitrogenous metabolites. In their formation there are 43 enzymes grouped into oxidoreductases, transferases and lyases, which in some cases represent atypical examples of the manner in which the secondary metabolism diversification wasoriginated. Two of these examples are the cytochrome proteins P450 (P450), with catalytic activities for ABI route, or the norcoclaurine synthase enzyme (NCS), which share substantial identity with defense allergenic proteins. Likewise, there are genetic advances that have produced the characterization of 30 enzymes, allowing knowledge of regulatory processes. Another interesting aspect is the compartmentation of the biosynthesis sites and accumulation of BIA, since in several cases they are spatially separated and in different species, or in the same species several types of cells may be involved. This has suggested intra and intercellular transport of alkaloids, precursors and enzymes, and it has been documented berberine transport between the cytoplasm and the vacuoles of storage. The picture for the biosynthesis of BIA has been constructed with exemplary studies of alkaloids with pharmacological importance.Key words: specialized metabolism, secondary metabolism, cellular transport, cell compartment, tissue-specific regulationLos alcaloides bencilisoquinolínicos (ABI) son metabolitos especializados con una distribución filogenética antigua pero conservada todavía en clados modernos. Varios de ellos, como la morfina, sanguinerina y berberina tienen importancia en la medicina moderna. En esta revisión se analizan los aspectos más sobresalientes del estado actual de la biosíntesis de ABI. Se han realizado estudios que han permitido conocer la biosíntesis de 22 de estos metabolitos nitrogenados. En su formación participan 43 enzimas agrupadas en oxidoreductasas, transferasas y liasas, que en algunos casos representan ejemplos atípicos de la forma en la que se originó la diversificación del metabolismo secundario, entre ellos proteínas citocromo P450 (CYP450) con actividades catalíticas para la ruta de los ABI, o la enzima norcoclaurina sintasa (NCS) que esta emparentada con proteínas alergénicas de defensa. Así mismo, hay avances genéticos en los que se ha podido caracterizar 30 enzimas, permitiendo conocer procesos de regulación. Otro aspecto interesante es la compartimentaciónde los sitios de biosíntesis y acumulación de ABI ya que en varios casos están separados espacialmente y en distintas especies o en la misma pueden participar varios tipos de células. Ello ha sugerido el transporte intra e intercelular de los alcaloides, los precursores y de las enzimas, se ha documentado el transporte de berberina entre el citoplasma y las vacuolas del almacenamiento. El panorama de la biosíntesis de ABI se ha construido con los estudios de ejemplares de importancia farmacológica.Palabras clave: metabolismo especializado, metabolismo secundario, transporte celular, compartimentación celular, regulación tejidoespecífica.Os alcalóides benzilisoquinolinas (ABI) são metabólitos especializados com uma distribuição filogenética antiga, mas ainda preservada em clados modernos. Vários deles, como a morfina, sanguinarina e berberina sãoimportantes na medicina moderna. Neste artigo, se analisam os aspectos mais destacados do estado atual da biossíntese de ABI; há estudos que tem permitido conhecer a biossíntese de 22 desses metabólitos nitrogenados. Na sua síntese participam 43 enzimas agrupadas emoxidoreductases, transferases, liases e, em alguns casos, representam exemplos atípicos da forma pela qual se originou a diversificação do metabolismo secundário, incluindo as proteínas do citocromo P450 (CYP450), com atividades catalíticas para a rota dos ABI, ou a enzima norcoclaurina sintase (NCS), que está relacionada com proteínas alergênicas de defesa. Da mesma forma, há avanços genéticos na caracterização de 30 enzimas, permitindo conhecer processos de regulação. Outro aspecto interessante é a compartimentalização dossítios de biossíntese e acumulação de ABI uma vez que em muitos casos estão separados espacialmente e em diferentes espécies, ou na mesma podem participar vários tipos de células. Isto há sugerido o transporte intra e intercelular de alcalóides, precursores das enzimas; tem sido documentado o transporte de berberina entre o citoplasma e os vacúolos de armazenamento. A perspectiva na biossíntese de ABI foi construída com os estudos de exemplares de importância farmacológica.Palavras-chave: metabolismo especializado, metabolismo secundário, transporte celular, compartimentalização celular, regulação tecido-específica

Antifungal activity in vitro of Sapranthus microcarpus (Annonaceae) against phytopathogens

Abstract: Background and Aims: The phytochemistry study of Annonaceae has intensified in the last decades due to the discovery of secondary metabolites with antimicrobial activities. The inhibitory activities of extracts and compounds from these species for phytopathogens are less known. The antifungal activity of Sapranthus microcarpus was determined in vitro against six fungal pathogens of important crops. Methods: Hexane, methanol, and alkaloid extracts of the leaves and root and stem bark of S. microcarpus were evaluated to determine whether they could inhibit the mycelial growth of the phytopathogens. The combined activity of the most active extracts for each phytopathogen was also determined. The alkaloid liriodenine was isolated and identified as an antifungal principle. Key results: All extracts inhibited the growth of the six phytopathogens to some extent. The root bark alkaloid extract showed the highest activity. Fusarium oxysporum f. sp. lycopersici and Curvularia lunata were the most sensitive phytopathogens. Liriodenine was active against all the plant pathogens (minimum inhibitory concentrations of 125-500 nmol ml-1). Conclusions: Sapranthus microcarpus is a native natural resource with great phytochemical potential.Resumen: Antecedentes y Objetivos: El estudio de la fitoquímica de Annonaceae se ha intensificado en las últimas décadas debido al descubrimiento de metabolitos secundarios con actividades antimicrobianas. Las actividades inhibidoras de extractos y compuestos de estas especies para fitopatógenos son menos conocidas. Se determinó la actividad antifúngica in vitro de Sapranthus microcarpus contra seis hongos fitopatógenos de cultivos importantes. Métodos: Se evaluaron extractos metanólicos, hexánicos y alcaloidales de las hojas, y corteza de tallos y raíces de S. microcarpus por el método de inhibición micelial. También se determinó la actividad combinada de los extractos más potentes contra cada fitopatógeno. Se aisló e identificó al alcaloide liriodenina como uno de los metabolitos antifúngicos. Resultados clave: Todos los extractos, en alguna medida, inhibieron el crecimiento de los seis fitopatógenos. Los extractos alcaloidales mostraron la mayor actividad. Fusarium oxysporum f. sp. lycopersici y Curvularia lunata fueron los fitopatógenos más sensibles. Liriodenina fue activo contra todos los fitopatógenos (a concentraciones inhibitorias mínimas de 125-500 nmol ml-1). Conclusiones: Sapranthus microcarpus es un recurso nativo con alto potencial fitoquímico