Examinando por Autor "Derita, Marcos Gabriel"
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Ítem Acceso Abierto An update on phytochemicals and pharmacological activities of the genus persicaria and polygonum(MDPI, 2021-10-01) Seimandi, Gisela; Álvarez, Norma; Stegmayer, María Inés; Fernández, Laura; Ruiz, Verónica; Favaro, María Alejandra; Derita, Marcos GabrielÍtem Acceso Abierto Botanical control of citrus green mold and peach brown rot on fruits assays using a persicaria acuminata phytochemically characterized extract(MDPI, 2021-02-24) Di Liberto, Melina G.; Seimandi, Gisela; Fernández, Laura; Ruiz, Verónica; Svetaz, Laura Andrea; Derita, Marcos Gabriel; https://orcid.org/0000-0002-0162-2771; https://orcid.org/0000-0001-8148-936XPersicaria acuminata (Polygonaceae) is a perennial herb that grows in the central area of Argentina and it is commonly used by native populations to heal infected wounds and other conditions related to fungal infections. In this article, we explored the in vitro antifungal activity of its ethyl acetate extract against a panel of three fruit phytopathogenic fungi including: Penicillium digitatum, P. italicum, and Monilinia fructicola. The sesquiterpenes isolated from the extract were also evaluated against these strains, demonstrating that the dialdehyde polygodia was the responsible for this activity. In order to encourage the use of the extract rather than the pure compound, we displayed ex vivo assays using fresh oranges and peaches inoculated with P. digitatum and M. fructicola, respectively, and subsequently treated by immersion with an extract solution of 250 and 62.5 µg/mL, respectively. There were no statistically significant differences between the treatments with commercial fungicides and the extract over the control of both fruit rots. The concentration of the active compound present in the extract used on fruit experiments was determined by Gas Chromatography-Mass Spectroscopy. Finally, cytotoxicity evaluation against Huh7 cells showed that P. acuminata extract was less cytotoxic than the commercial fungicides at the assayed concentrations. After these findings we could conclude that a chemically characterized extract of P. acuminata should be further developed to treat fungal diseases in fruits from an agro-ecological model.Ítem Acceso Abierto Búsqueda de biofungicidas pos-cosecha a partir de fuentes vegetales autóctonas, aplicables a naranjas, frutillas y duraznos(2021) Di Liberto, Melina G.; Derita, Marcos Gabriel; Svetaz, Laura AndreaLas causas de pérdidas de frutas durante la etapa de pos-cosecha son generalmente de orden fisiológico y/o patogénico. Las infecciones fúngicas más comunes y destructivas en naranjas, frutillas y duraznos, son causadas por hongos del género Penicillium, Botrytis cinerea y Monilinia fructicola, respectivamente. Además, Rhizopus stolonifer es un importante patógeno de pos-cosecha capaz de infectar tanto a duraznos como a frutillas, entre otras frutas y verduras. Se emplean habitualmente fungicidas de síntesis química para el control de estos patógenos, pero la exigencia de los mercados internacionales referida al límite de residuos de fungicidas para la importación de frutas, ha llevado a disminuir al máximo el empleo de este tipo de sustancias. El uso de productos naturales, menos nocivos para el ser humano y obtenidos por metodologías sencillas, podría representar una alternativa de manejo fitosanitario tanto en cultivos como en pos-cosecha. Los extractos vegetales han sido reconocidos como agentes antimicrobianos desde la antigüedad y recientemente han aumentado el interés científico para distintos fines terapéuticos tanto en la salud humana, animal o vegetal. Éstos representan una importante fuente de metabolitos secundarios que eventualmente podrían poseer efectos fungicidas. El objetivo de la presente tesis fue estudiar la actividad antifúngica de extractos y aceites esenciales vegetales obtenidos de 27 especies de la flora regional como también de productos naturales obtenidos por síntesis química, contra cinco hongos fitopatógenos responsables de importantes pérdidas económicas en la industria frutícola de la región. Para ello, se determinó el efecto de 58 extractos, 11 aceites esenciales y 54 compuestos de síntesis sobre el crecimiento micelial de los cinco hongos del panel. A través del método de microdilución en caldo, se logró determinar si los productos eran fungistáticos o fungicidas. Al menos un extracto de cada especie vegetal y 39 compuestos de síntesis presentaron actividad fungistática o fungicida contra al menos uno de los hongos del panel. Los cuatro extractos más activos fueron seleccionados para su fraccionamiento bioguiado y aislamiento de los compuestos responsables de la actividad. Se aislaron: poligodial (1) a partir de Persicaria acuminata; 2’,4’-dihidroxi-3’-metoxichalcona (DHMC) (2) y 2’,4’- dihidroxichalcona (DHC) (3) de Zuccagnia punctata; pinostrobina (4) y flavokawina B (5) de Polygonum stelligerum y solidagenona (6) de Solidago chilensis. El extracto acetato de etilo de P. acuminata y los compuestos de síntesis: el derivado N-demetilado del compuesto natural zantosimulina (12) y la metoxima derivada de propiofenona (45) fueron sometidos a ensayos ex vivo en naranjas, frutillas y duraznos, obteniéndose en todos los casos resultados comparables a los fungicidas comerciales. Los ensayos de toxicidad demostraron que el extracto vegetal y el compuesto de síntesis más activo, a las dosis evaluadas, presentaban menor citotoxicidad sobre células hepáticas que el antifúngico comercial carbendazim. Se concluye que los productos naturales evaluados en esta tesis presentan un alto potencial para ser desarrollados como fungicidas de pos-cosecha, destacando la importancia de su menor toxicidad comparada con la de los de uso habitual.Ítem Acceso Abierto Control of brown rot produced by Monilinia fructicola in peaches ssing a full-spectrum extract of Zuccagnia punctata Cav(Multidisciplinary Digital Publishing Institute (MDPI), 2023-10-17) Di Liberto, Melina G.; Stegmayer, María Inés; Fernández, Laura; Quiroga, Ariel Darío; Svetaz, Laura Andrea; Derita, Marcos GabrielBrown rot of stone fruit, caused by Monilinia spp., is one of the most important diseases worldwide, causing significant production losses. Currently, the standard practices for controlling this infection consist of repetitive use of synthetic fungicides. The global tendency encourages the demand for high-quality food products harmless to health and the environment, leading to a reduction in the use of these types of substances. Zuccagnia punctata (Fabaceae) is a perennial shrub extensively used for the treatment of fungal and bacterial infections in Argentinean traditional medicine. In this study, we isolated and characterized (morphologically and molecularly) a pathogenic and virulent strain of Monilinia fructicola, which is the most hostile species of the genus. Consequently, we explored the in vitro antifungal activity of the ethanolic extract of Z. punctata against this phytopathogen. The chalcones 2´,4´-dihydroxy-3´-methoxychalcone and 2´,4´-dihydroxychalcone were isolated from the extract and evaluated against M. fructicola demonstrating that they were responsible for this activity. To promote full-spectrum extract rather than pure compounds, we performed ex-vivo assays using fresh peaches inoculated with the pathogen, and then treated by immersion in an extract solution of 250 µg/mL concentration. Treatment with Z. punctata extract did not show a statistically significant difference from commercial fungicides in the control of fruit rot. In addition, Huh7 cell cytotoxicity evaluation showed that Z. punctata extract was less cytotoxic than commercial fungicides at the assayed concentrations. Based on our research, this plant extract could potentially offer a safer alternative to commercial fungicides for treating peach brown rot.Ítem Acceso Abierto Hybrid molecules containing a 7-chloro-4-aminoquinoline nucleus and a substituted 2-Pyrazoline with antiproliferative and antifungal activity(MDPI, 2016-07-27) Montoya, Alba; Quiroga, Jairo; Abonia, Rodrigo; Derita, Marcos Gabriel; Sortino, Maximiliano Andrés ; Ornelas, Alfredo; Zacchino, Susana; Insuasty, BraulioÍtem Acceso Abierto Structural requirements for the antifungal activities of natural drimane sesquiterpenes and analogues, supported by conformational and electronic studies(MDPI, 2013-02-05) Derita, Marcos Gabriel; Montenegro, Iván; Garibotto, Francisco; Enriz, Ricardo Daniel; Cuellar Fritis, Mauricio; Zacchino, Susana; https://orcid.org/0000-0002-7112-5500Seventeen drimanes including polygodial (1), isopolygodial (2), drimenol (3) and confertifolin (4) obtained from natural sources and the semi-synthetic derivatives 5–17 obtained from 1–3, were evaluated in vitro for antifungal properties against a unique panel of fungi with standardized procedures by using two end-points, MIC100 and MIC50. A SAR analysis of the whole series, supported by conformational and electronic studies, allowed us to show that the Δ7,8 -double bond would be one of the key structural features related to the antifungal activity. The MEPs obtained for active compounds exhibit a clear negative minimum value (deep red zone) in the vicinity of the Δ7,8 -double bond, which is not present in the inactive ones. Apart of this negative zone, a positive region (deep blue) appears in 1, which is not observed either in its epimer 2 nor in the rest of the active compounds. The LogP of active compounds varies between 2.33 and 3.84, but differences in MICs are not correlated with concomitant variations in LogP values.Ítem Acceso Abierto Synthesis, Bioevaluation and Structural Study of Substituted Phthalazin-1(2H)-ones Acting as Antifungal Agents(MDPI Open Access Publishing, 2013-03) Derita, Marcos Gabriel; Del Olmo, Esther; Barboza, Bianca; García Cadenas, Ana E.; López Pérez, José L.; Andújar, Sebastián; Enriz, Ricardo Daniel; Zacchino, Susana; San Feliciano, ArturoTwenty-five polysubstituted phthalazinone derivatives were synthesized and tested for their antifungal activity against a panel of pathogenic and clinically important yeasts and filamentous fungi. Among them, the compound 4-(4-chlorobenzyl)-2- methylphthalazin-1(2H)-one (5) exhibited a remarkable antifungal activity against standardised strains of dermatophytes and Cryptococcus neoformans, as well as against some clinical isolates. A physicochemical study performed on compound 5 revealed its conformational and electronic characteristics, providing us with useful data for the future design of novel related antifungal analogues.Ítem Acceso Abierto Zanthosimuline and Related Pyranoquinolines as Antifungal Agents for Postharvest Fruit Disease Control(American Chemical Society, 2020) Di Liberto, Melina G.; Caldo, Agustín J.; Quiroga, Ariel Darío; Riveira, Martín Jorge; Derita, Marcos Gabriel