Coumarins and alkaloids from Rauia resinosa (rutaceae)

The genus Rauia, that is poorly chemically studied, belongs to the Rutaceae family. This family has been known to contain a large variety of secondary metabolites. Our phytochemical investigation of the stem and leaves of Rauia resinosa has led to the identification of the structurally related coumarins: murralongin (1), murrangatin (2), munomicrolin (3), murrangatin diacetate (4), umbelliferone (5), rauianin (6) and one novel coumarin: 3-ethylrauianin (7); the alkaloids: N-methyl-4-methoxy-2-quinolone (8), mirtopsine (9), dictamine (10), γ-fagarine (11), skimmianine (12), Z-dimethylrhoifolinate (13), zantodioline (14), zantobungeanine (15), veprissine (16), one novel alkaloid 7-hydroxy-8-methoxy-N-methylflindersine (17) and 8-hydroxy-N-methylflindersine (18) that is described as a natural product for the first time, and a mixture of steroids: as sitosterol and stigmasterol.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Herbicide Resistance in Brazil: Status, Impacts, and Future Challenges

Brazil is a large producer and exporter of crops in global terms. Weeds may be responsible for ~14% of crop losses, depending on the crop system. Herbicides occupy 58% of the Brazilian pesticide market; however, the continuous use of these products and the high selection pressure have led to the emergence of weeds resistant to herbicides. Today, there are 51 weed species reported as being resistant to herbicides in Brazil, of which 17 involves cross and multiple-resistance. Acetolactate synthase (ALS), acetyl coenzyme A carboxylase (ACCase) and 5-enolpiruvylshikimate-3-phosphate synthase (EPSPs) inhibitors are the herbicidal groups with the most resistance cases. Soybean, corn, rice, wheat and cotton present 30, 12, 10, 9 and 8 cases, respectively, occurring mainly in herbicide-resistant crop fields from the Southern and Central West regions of the country. To better understand the dimensions of herbicide resistance, in this chapter, we will explore the size of agricultural activity in Brazil, the pesticide market and the use of herbicides in the main crops. In addition, the agronomic, scientific-technical and economic aspects that have contributed, directly or indirectly, to the selection of resistant weeds will be discussed in order to have an overview of the economic impact of herbicide resistance management

Evaluation of furocoumarins as photosynthetic inhibitor by chlorophyll a fluorescence assay

The evaluations of Chorophyll a fluorescence emitted by superior plants carry structural information and photosynthetic apparatus function. Quantitative analysis apparatus of fluorescence kinetic were measured by energy flows (ABS), (TR), (ET) and (DI), known as phenomenological phenomena of OJIP test. Four furocoumarins were isolated from Ruta graveolens (Rutaceae), and chorophyll a (Chl a) fluorescence assays were performed with these compounds to evaluate the photosynthesis inhibition potential. This test was realized in spinach`s leaf discs and in Lolium perenne leaves. The results indicated the herbicide potential mainly for bergapten and chalepin.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Carlos Departamento de QuímicaUniversidade Federal de São Paulo (UNIFESP) Instituto de Ciências Ambientais, Químicas e FarmacêuticasUniversidad Nacional Autónoma de México Facultad de Química Departamento de BioquímicaUNIFESP, Instituto de Ciências Ambientais, Químicas e FarmacêuticasSciEL

Preparation and characterization of polymeric nanoparticles loaded with the flavonoid luteolin, by using factorial design.

Nanoparticles containing luteolin flavonoid were prepared by using interfacial polymer deposition following solvent displacement. The formulation was optimized using factorial design. The parameters studied were the type of polymer [poly(ε-caprolactone) and poly(lactic-co-glycolic acid)], nature oil (isodecyl oleate and oleic acid) and the quantity of luteolin. Nanocapsules and nanospheres were also prepared and evaluated. Colloidal suspensions were characterized by evaluating pH, the particle size, the zeta potential, the morphological aspect and the kinetic release. A new High Performance Liquid Chromatography method was developed and validated in order to quantify luteolin in colloidal suspension allowing the analyses of the absolute recovery, entrapment efficiency and the kinetic release. The luteolin-absolute recovery ranged from 61.6% to 95%; entrapment efficiency was nearly 100% in all formulations and the particle sizes were smaller than 185.5 nm. The nanoparticles prepared with isodecyl oleate show a negative zeta potential. On the other hand, when oleic acid was utilized, the zeta potential was positive. The nanoparticles prepared by using isodecyl oleate have a more perfect spherical shape with a regular surface and form, homogeneity, and lower size dispersion. Nanocapsules and nanospheres have a similar release mechanism of pure diffusion according with Korsmeyer-Peppas’s model

Uso de CLAE no controle de qualidade em produtos comerciais de Nim: reprodutibilidade da ação inseticida

The Neem tree, Azadirachta indica, provides many useful compounds that are used as pesticides. However, the efficiency in field of products like neem oil can be committed because they have not been observed reproductive content of secondary metabolic like azadirachtin. Based on reverse-phase high-performance liquid chromatography (HPLC) a new method was developed to permit the rapid quantitative analysis of azadirachtin from seeds, extracts and oil of Neem. In the present study it was evaluated the azadirachtin quantitative variation among various Neem's extracts and seeds showing the importance of quality control for reproduction of the insecticide efficiency, using S. frugiperda as target insect

Preparation and characterization of polymeric nanoparticles loaded with the flavonoid luteolin, by using factorial design

Nanoparticles containing luteolin flavonoid were prepared by using interfacial polymer deposition following solvent displacement. The formulation was optimized using factorial design. The parameters studied were the type of polymer [poly(-caprolactone) and poly(lactic-co-glycolic acid)], nature oil (isodecyl oleate and oleic acid) and the quantity of luteolin. Nanocapsules and nanospheres were also prepared and evaluated. Colloidal suspensions were characterized by evaluating pH, the particle size, the zeta potential, the morphological aspect and the kinetic release. A new High Performance Liquid Chromatography method was developed and validated in order to quantify luteolin in colloidal suspension allowing the analyses of the absolute recovery, entrapment efficiency and the kinetic release. The luteolin-absolute recovery ranged from 61.6% to 95%; entrapment efficiency was nearly 100% in all formulations and the particle sizes were smaller than 185.5 nm. The nanoparticles prepared with isodecyl oleate show a negative zeta potential. On the other hand, when oleic acid was utilized, the zeta potential was positive. The nanoparticles prepared by using isodecyl oleate have a more perfect spherical shape with a regular surface and form, homogeneity, and lower size dispersion. Nanocapsules and nanospheres have a similar release mechanism of pure diffusion according with Korsmeyer-Peppas’s model.CNPqCAPESFAPES

Atividade antimicrobiana de compostos isolados e derivados semissintéticos de Miconia ferruginata

This study evaluated the antimicrobial activity of isolated compounds and semisynthetic derivatives from Miconia ferruginata (Melastomataceae) against five microorganisms: Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Bacillus subtilis (ATCC 6623), Pseudomonas aeruginosa (ATCC 15442), and Candida albicans (ATCC 10231). The isomeric mixture of ursolic and oleanolic acids was active against S. aureus (MIC = 250 μg mL-1) and against E. coli, B. subtilis, and P. aeruginosa (MIC = 500 μg mL-1). The flavone 5,6,7-trihydroxy-4’-methoxyflavone and the methyl esters, semisynthetic derivatives of a mixture of ursolic and oleanolic acids, showed no activity against the tested microorganisms. These results suggest that the carboxyl group present in the triterpenes may contribute to antimicrobial activity.Este estudo descreve a avaliação da atividade antimicrobiana de compostos isolados e derivados semissintéticos de Miconia ferruginata (Melastomataceae) contra cinco microorganismos: Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Bacillus subtilis (ATCC 6623), Pseudomonas aeruginosa (ATCC 15442) and Candida albicans (ATCC 10231). A mistura isomérica dos ácidos ursólico e oleanólico foi ativa contra S. aureus (CIM = 250 μg mL-1) e contra E. coli, B. subtilis e P. aeruginosa (CIM = 500 μg mL-1). A flavona 5,6,7-trihidroxi-4’-metóxiflavona e os ésteres metílicos, derivados semissintéticos da mistura dos ácidos ursólico e oleanólico, não apresentaram atividade contra os microrganismos testados. Estes resultados sugerem que o grupo carboxila presente nos triterpenos podem contribuir para a atividade antimicrobiana

Chemical constituents and antimicrobial activity of extracts from Dilodendron bipinnatum (sapindaceae)

The phytochemical investigation of ethanolic extracts from leaves, branches and stems of D. bipinnatum afforded the steroids β-sitosterol, stigmasterol, campesterol, sitostenone and sitosterol-3-O-β-D-glycopyranoside, along with two cycloartane triterpenes: cycloeucalenol and 24-methylenecycloartenol. The antimicrobial activity of the extracts was evaluated against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Bacillus subtilis (ATCC 6623), Pseudomonas aeruginosa (ATCC 15442), Micrococcus luteus (ATCC 9341) and Candida albicans (ATCC 10231). The extracts of the leaves and branches showed moderate activity against Candida albicans. The extract of the branches was active against Micrococcus luteus. This is the first report on the phytochemical study of D. bipinnatum.CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPES