Exomorfología y anatomía de órganos vegetativos aéreos en especies de Flourensia DC. (Asteraceae) con importancia fitoquímica

El género Flourensia DC. es americano y comprende 32 especies. Son arbustos resinosos utilizados en medicina popular; poseen un potencial valor económico, por lo que, en algunas especies representantes, se han caracterizado sus compuestos químicos y determinado algunos posibles usos. En el presente trabajo, se estudió la exomorfología y anatomía de órganos vegetativos de F. hirta S. F. Blake, F. leptopoda S. F. Blake, F. niederleinii S. F. Blake y F. tortuosa Griseb., especies endémicas del centro de Argentina. Se observó que todas son similares en cuanto a la anatomía de hoja y tallo. En cuanto al estudio de la epidermis foliar, se concluye que es posible diferenciar las especies teniendo en cuenta la frecuencia estomática y la presencia de tricomas. Finalmente, las diferencias más notables se encontraron en la exomorfología foliar ya que se observó una gran variación en cuanto a la forma de las hojas y tamaño de las láminas y pecíolos. Con respecto a las estructuras secretoras, se encontraron tricomas y conductos secretores esquizógenos en las hojas y los tallos de todas las especies, las cuales serían responsables de la producción y secreción de las resinas.The genus Flourensia DC. is American and comprises 32 species. They are resiniferous shrubs used in folk medicine. As they have potential economic value, its chemical compounds have been characterized and some possible uses identified. In this work, the exomorphology and anatomy of vegetative organs of F. hirta S. F. Blake, F. leptopoda S. F. Blake, F. niederleinii S. F. Blake and F. tortuosa Griseb., endemic species from central Argentina, have been studied. All species are similar in leaf and stem anatomy. Regarding the epidermis, it is possible to differentiate the species according to the stomatal frequency and the presence of trichomes. Finally, the most remarkable differences were found in leaf exomorphology, since there was a large variation in shape and size of blades and petioles. Concerning the secretory structures, trichomes and secretory ducts were found in the leaves and stems of all species, which would be responsible for the production and secretion of the resins

Insecticidal Properties of a Highly Potent Wax Isolated from Dolichandra cynanchoides Cham

Bioassay-guided fractionation of an ethanolic extract of the aerial parts of Dolichandra cynanchoides Cham. (Bignoniaceae) led to the isolation of a natural wax with anti-insect activity against Spodoptera frugiperda (Noctuidae) and Epilachna paenulata (Coleptera). The compound was identified spectroscopically as an ester of a C27 fatty acid and a C25 alcohol, pentacosyl heptacosanoate (1). The effective doses of 1 for 50% feeding inhibition (ED50) of S. frugiperda and E. paenulata were 0.82 and 8.53 µg/cm2, respectively, in a choice test, while azadirachtin showed ED50 of 0.10 and 0.59 µg/cm2, respectively. In a no-choice test, both insects refused to feed on leaves treated with 1 at doses of 0.1 µg/cm2 or greater inhibiting larval growth and dramatically reducing survival. The lethal doses 50 (LD50) of 1 were 0.39 and 0.68 µg/cm2 for S. frugiperda and E. paenulata, respectively. These results indicate that 1 has potential for development as botanical insecticides. Similar esters might be obtainable in large quantities as many edible crops produce wax esters that are discarded during food processing. Research on these materials could lead to the detection of similar waxes with insecticidal activity

Actividad biológica de extractos de Melia azedarach sobre larvas de Spodoptera eridania (Lepidoptera: Noctuidae) Biological activity of extracts of Melia azedarach on larvae of Spodoptera eridania (Lepidoptera: Noctuidae)

En la búsqueda de compuestos botánicos con potencial uso insecticida, se evaluó la actividad de extractos de fruto maduro y hojas senescentes de Melia azedarach L. (2, 5 y 10%), sobre larvas de Spodoptera eridania Cramer (Lepidoptera: Noctuidae) especie polífaga considerada plaga esporádica de importantes cultivos. Mediante pruebas de elección, se registró el consumo y se calculó un índice de inhibición alimentaria. En pruebas sin posibilidad de elección se estimó el consumo, la mortalidad, el peso de larvas y excretas, y se calcularon índices nutricionales. Cuando las larvas pudieron optar, se observó un fuerte efecto antialimentario de los extractos. En los ensayos de alimentación obligada, los extractos de fruto y hoja redujeron fuertemente el consumo y peso larval respecto al control, excepto la menor dosis de fruto. Ninguna oruga llegó a pupar al entregarle alimento rociado con extracto de hoja o con extracto de fruto en las dosis más altas. Los índices nutricionales corroboraron la actividad antialimentaria, revelando efectos negativos de los extractos sobre las tasas relativas de consumo y crecimiento, y sobre la eficiencia de utilización del alimento ingerido y digerido, aunque la digestibilidad no fue afectada. Los resultados sugieren que los extractos de M. azedarach podrían ser incorporados en programas de manejo de este insecto plaga.<br>In the course of searching for plant chemicals with potential insecticide properties, the activity of Melia azedarach L. senescent leaf and ripe fruit extracts (2, 5 and 10%) was evaluated on larvae of Spodoptera eridania Cramer (Lepidoptera: Noctuidae). This polyphagous species is considered a sporadic pest on many important crops. Food consumption was assessed and an antifeedant index was calculated through choice tests. Also, food consumption, larval mortality, weight and depositions were recorded and nutritional indices were calculated in no-choice tests. Results from choice tests showed a strong antifeedant effect of both extracts. In no-choice tests, the leaf and fruit extracts strongly reduced food consumption and larval weight, except with fruit extract at the lowest concentration. Larvae did not reach the pupal stage when high concentrations of leaf or fruit extract were used. Antifeedant activity was corroborated by nutritional indices, which also revealed negative effects of extracts on relative consumption, growth rates and efficiency in utilization of ingested and digested food, although digestibility was not affected. Our results suggest that M. azedarach extracts could be incorporated in management programs for this insect pest

Screening of native plants from central Argentina against the leaf-cutting ant Acromyrmex lundi (Guérin) and its symbiotic fungus

Leaf-cutting ants are major agricultural and forestry pests in the New World. Attempts to control themhave most frequently involved the use of chemical insecticides, with mixed results. Among alternativemethods, botanical pesticides may provide a sustainable and efficient control of leaf-cutting ants. In thepresent study, we screened the activity of plant extracts derived from 89 species native to Argentina,against the leaf-cutting ant Acromyrmex lundi (Guérin) and its mutualistic fungus, Leucoagaricus gongy-lophorus, through a pick-up assay and bioautography, respectively. The pick-up assay revealed moderateto strong anti-foraging activity for just over 13.5% of the assayed species, including complete ant foraginginhibition for Aristolochia argentina, Flourensia oolepis, Gaillardia megapotamica, Lantana grisebachii andLithrea molleoides. Most plant extracts were well tolerated by fungi, with only 12.3% of the species testedshowing some degree of fungus growth inhibition. Among these, A. argentina, F. oolepis and Pterocaulonalopecuroides were the strongest inhibitors, whereas Baccharis flabellata, Dalea elegans and Zanthoxylumcoco revealed a more moderate activity. Only A. argentina and F. oolepis extracts showed strong antifor-aging effects and affected fungus growth at the same time. Values of IC50and MIC indicated that extractsinhibiting ant foraging at lower concentrations did not necessarily also inhibit fungus growth at lowerdoses. The active principle of A. argentina, on both ant foraging and fungal growth, was identified asargentilactone.Fil: Diaz Napal, Georgina Nata. Area de Cs. Agrarias, Ingeniería, Cs. Biológicas y de la Salud de la Universidad Catolica de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Buffa, Liliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Nolli, Laura C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Defagó, María Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Valladares, Graciela Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Carpinella, Maria Cecilia. Area de Cs. Agrarias, Ingeniería, Cs. Biológicas y de la Salud de la Universidad Catollica de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruiz, Gustavo Miguel. Area de Cs. Agrarias, Ingeniería, Cs. Biológicas y de la Salud de la Universidad Catolica de Córdoba; ArgentinaFil: Palacios, Sara Maria. Area de Cs. Agrarias, Ingeniería, Cs. Biológicas y de la Salud de la Universidad Catolica de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Antibacterial effects of extracts obtained from plants of Argentina: Bioguided isolation of compounds from the anti-infectious medicinal plant Lepechinia meyenii

Ethnopharmacological relevance: The mostly native species from Argentina are used in traditional medicine generally for the treatment of pain and inflammation, respiratory, gastro-intestinal and urinary disorders and as antiseptics.Aim of the study: Since these ailments may be associated with bacterial infections, 69 extracts from these plants were screened for their activity against pathogenic bacteria. The most effective extract was then submitted to bioguided isolation to obtain the compounds responsible for this activity.Materials and methods: Extracts and fractions were screened using agar dilution, and compounds using microbroth dilution methods. A large panel of pathogenic bacteria was used, especially methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA). Bioguided fractionation was performed using successive chromatographic techniques, while the chemical structures of the isolated compounds were determined by nuclear magnetic resonance (NMR). Additionally, a series of derivatives of the most active compound were prepared in order to study the chemical features required for achieving the antibacterial effect.Results: Lepechinia meyenii (Walp.) Epling (Lamiaceae) extract showed itself the most effective, with minimum inhibitory concentration (MIC) against Gram positive and negative bacteria ranging from 62.5 to 500 μg/mL, and showing better activity on MRSA than on MSSA. Activity-guided fractionation yielded the abietanes carnosol (1), rosmanol (2) and carnosic acid (3) as active principles, with MICs ranging from 15.6-31.2, 15.6-62.5 and 7.8-15.6 μg/mL, respectively against 15 MRSA strains, and 15.6-31.2, 31.2-62.5 and 7.8-15.6 μg/mL, respectively against 11 MSSA strains, maintaining higher activity against the resistant bacteria, as does the extract. In addition, Enterococcus faecalis was sensitive to 1-3 with MICs of 15.6-62.5 μg/mL. The structure activity analysis showed that 12-OH is necessary for remarkable activity, but methylation in C-20 significantly increased this, as observed with 20-methyl carnosate (5) displaying the greatest effect, even more so than 3, with MICs of 3.9 μg/mL against all the tested MRSA and 1.9-3.9 μg/mL against the MSSA. The results of this study contribute to validate the traditional antibacterial use of species native to Argentina, particularly of L. meyenii. The chemical structures of the compounds obtained may aid the design of antibacterial agents, especially those effective against MRSA.Fil: Funes Chabán, Macarena. Universidad Católica de Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J.; ArgentinaFil: Karagianni, C. A.. Department Of Chemistry, University Of Patras; GreciaFil: Joray, Mariana Belén. Universidad Católica de Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J.; ArgentinaFil: Toumpa, D.. Department Of Chemistry, University Of Patras; GreciaFil: Sola, Claudia del Valle. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Crespo, María Inés. Universidad Católica de Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J.; ArgentinaFil: Palacios, Sara Maria. Universidad Católica de Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J.; ArgentinaFil: Athanassopoulos, C. M.. Department Of Chemistry, University Of Patras; GreciaFil: Carpinella, Maria Cecilia. Universidad Católica de Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J.; Argentin

Dysphania ambrosioides (L.) Mosyakin & Clemants

Dysphania ambrosioides (L.) Mosyakin & Clemants (= Chenopodium ambrosioides L.) is an American aromatic species used as medicinal and culinary purposes since pre-Columbian times by Aztecs and Mayans in Mesoamerica (where is called epazote) and Andean communities and many others in South America (where is better known as paico). Currently, it is globally known by a wide diversity of cultures around the world, due to its cultivation and naturalization. Its uses are currently widespread in pluricultural contexts, by means the commercial circuits and mass media, especially the Internet. The main active constituents are essential oils, to which owes its aroma and flavor. It is toxic in high doses, but safe if is consumed in appropriated concentrations. The most widespread folk therapeutic use is as antiparasitic (anthelmintic, antimicrobial), and it is also employed against gastrointestinal disorders, as hypotensive, antipyretic, vulnerary, analgesic, anti-inflammatory, antitumor, sedative and anxiolytic, among others, many of which have been evaluated scientifically. The researches on its anticancer activity are very promising.Fil: Hurrell, Julio Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Etnobotánica y Botánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin