Growth and yield of Anão Verde coconut under fertigation with nitrogen and potassium

Tal como ocorre em outras culturas, no cultivo de coco irrigado a utilização da técnica da fertigação também tende a aumentar. Objetivou-se com este trabalho estudar os efeitos de doses de N e K2O via fertigação no desenvolvimento vegetativo e na produção do coqueiro Anão verde. O ensaio foi conduzido no período de abril de 2002 a março de 2004, em campo experimental da Empresa de Pesquisa Agropecuária do Rio Grande do Norte - EMPARN, em Parnamirim, RN. O delineamento estatístico adotado foi em blocos inteiramente casualizados, com 4 repetições utilizando-se, para composição dos tratamentos, a matriz experimental Plan Puebla III, compostos da combinação de dois fatores: doses de nitrogênio e de potássio aplicados nas formas de uréia e cloreto de potássio, respectivamente, obtendo-se 10 tratamentos, definindo-se o intervalo para as doses de N (256 a 4874 g planta-1 ano-1) e K2O (258 a 4872 g planta-1 ano-1) aplicados via fertigação. O número de folhas, diâmetro de copa, altura e circunferência do estipe, foram favorecidos pela aplicação de N e K2O, em que as doses 2910 g planta-1 ano-1 de K2O e 2353 g planta-1 ano-1 de N, representaram maiores produções no 6º ano de cultivo e no 7º ano as doses de 1540 g planta-1 ano-1 de 2O e 1539 g planta-1 ano-1 de N, representaram maiores produções.In irrigated coconut, similar to trend in other crops the use of technique of fertigation is increasing. The objective of this study was to evaluate the effect of N and K2O doses under fertigation in development and the production of Anão Verde coconut palm. In April of 2002 until March of 2004, an experiment was carried out at the Empresa de Pesquisa Agropecuária do Estado do Rio Grande do Norte, Brazil. The adopted statistical design was in randomized blocks, with 4 repetitions, using for composition of treatments Puebla Plan III experimental matrix, consisting of combination of two factors: nitrogen and potassium doses in the form of urea and potassium chloride, respectively, testing 10 treatments. The interval of N being 256 the 4874 g plant-1 year-1 and 258 to 4872 g plant-1 year-1 of K2O applied through fertigation. The number of leaves, diameter of canopy, height and circumference of estipe were favored with 2910 g plant-1 year-1 of K2O and 2353 g plant-1 year-1 of N representing highest productions in 6th year of crop. In the 7th year the dose of 1540 and 1539 g plant-1 year-1 of K2 e N, respectively promoted maximum productions

Host-defense peptides AC12, DK16 and RC11 with immunomodulatory activity isolated from Hypsiboas raniceps skin secretion

Inflammation is a natural defense mechanism of the immune system; however, when unregulated, it can lead to chronic illness. Glucocorticoids are the most commonly used agents to effectively treat inflammatory conditions, including autoimmune diseases, however these substances can trigger a number of side effects. Thus, viable alternatives to the use of these drugs would be advantageous. In this study, we have analyzed the anti-inflammatory profile of three synthetic peptides first identified in skin secretion of the tree frog Hypsiboas raniceps. Structural characterization was performed using NMR spectroscopy and Mass Spectrometry, and the peptides were tested in vitro in RAW 264.7 cells and in vivo in Balb/c mice for their functional properties. The samples did not show a significant antimicrobial profile. NMR spectroscopy indicated that AC12 (ACFLTRLGTYVC) has a disulfide bond between C2 and C11 and a β-sheet-turn-β-sheet conformation in aqueous solution. This peptide showed no cytotoxic effect in mammalian cells and it was the most effective in reducing anti-inflammatory markers, such as NO, TNF-α and IL-12. Peptide DK16 (DKERPICSNTFRGRKC) demonstrated anti-inflammatory properties in vitro, while RC11 (RCFRRRGKLTC) significantly altered the cell viability in RAW 264.7 but was shown to be safe in Balb/c erythrocytes. Our results indicate that, of the three peptides studied, AC12 is the most efficient in reducing anti-inflammatory markers, and it could be a potential agent for the treatment of inflammatory diseases.publishe

Chemical composition, cytotoxicity and larvicidal activity against Aedes aegypti of essential oils from Vitex gardineriana Schauer

Vitex gardneriana Schauer (Lamiaceae) popularly known as “jaramataia”, is a shrub commonly found in caatinga biome located in Northeast Brazil. In folk medicine, its leaves have been used as analgesic and anti-inflammatory agents. The chemical composition of the essential oil from leaves obtained by hydrodistillation was analyzed and identified by GC-MS and GC-FID and showing a total of 26 constituents (95.9%) being 2 monoterpenes (0.4%) and 24 sesquiterpenes (95.4%). The main constituents identified were cis-calamenene (29.7%), 6,9-guaiadiene (14.5%) and caryophyllene oxide (14.0%). The essential oil has been demonstrated high larvicidal activity againstAedes aegypti (LC50 = 28.0 μg/mL). In the evaluation of the bioassay with Artemia salina the essential oil showed LC50 = 98.11 μg/mL. Inaddition, the essential oil did not show cytotoxicity (IC50 > 2.50 mg/mL) by the hemolysis assay