Atividades larvicida e anticolinesterásica de plantas do gênero Kalanchoe

Acetylcholine esterase inhibitors are successfully used to treat the symptoms of Alzheimer's disease. Extracts of three Kalanchoe species (K. brasiliensis, K. pinnata and K. gastonis-bornieri) showed acetylcholine esterase inhibitory effects and a toxic effect on Aedes aegypti larvae. Here we describe the bioassay guided fractionation of extracts of the most active extracts (K. brasiliensis) which resulted in the isolation of an active mixture of three flavonoids: 8-methoxyquercetin, 3,7-di-O-rhamnopyranoside and 8-methoxykaempferol-3,7-di-O-rhamnopyranoside. On TLC these flavonoids showed an acetylcholine esterase inhibitory effect.

Fenóis totais e atividade antioxidante de cinco plantas medicinais

This paper describes total phenolics content and antioxidant activity in the ethanolic extract of leaves, bark and roots of five medicinal plants: Terminalia brasiliensis Camb., Terminalia fagifolia Mart. & Zucc., Copernicia cerifera (Miller) H.E. Moore, Cenostigma macrophyllum Tul. var. acuminata Teles Freire and Qualea grandiflora Mart. The total phenolics content of the plant extracts, determined by the Folin-Ciocalteu method, varied from 250.0 ±8,2 to 763,63 ± 13.03 mg of gallic acid equivalent/g dry EtOH extract. The antioxidant activity of extracts was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay system. Extract of bark from T. brasiliensis, the most active, with an EC50 value of 27.59 ± 0.82 µg/mL, was comparable to rutin (EC50 = 27.80 ± 1.38) and gallic acid (EC50 = 24.27 ± 0.31), used as positive controls. The relationship between total phenolic content and antioxidant activity was positive and significant for T. brasiliensis, C. macrophyllum and C. cerifera.

Plantas medicinais: fatores de influência no conteúdo de metabólitos secundários

Since secondary metabolites represent a chemical interface between plants and surrounding environment, their syntheses are frequently affected by environmental conditions. Thus, variations in the total content and/or of the relative proportions of secondary metabolites in plants can take place. We review the main environmental factors that can streamline or alter the production or concentration of secondary metabolites in plants. How seasonality, circadian rhythm, developmental stage and age, temperature, water availability, UV radiation, soil nutrients, altitude, atmospheric composition and tissue damage influence secondary metabolism are discussed.

Pectinases: aplicações industriais e perspectivas

Pectic substances are structural heteropolysaccharides that occur in the middle lamellae and primary cell walls of higher plants. They are composed of partially methyl-esterified galacturonic acid residues linked by alpha-1, 4-glycosidic bonds. Pectinolytic enzymes are complex enzymes that degrade pectic polymers and there are several classes of enzymes, which include pectin esterases, pectin and pectate lyases and polygalacturonases. Plants, filamentous fungi, bacteria and yeasts are able to produce pectinases. In the industrial world, pectinases are used in fruit juice clarification, in the production of wine, in the extraction of olive oil, fiber degumming and fermentation of tea, coffee and cocoa.

Determinação do teor de edta remanescente em soluções de limpeza de equipamentos industriais

Cleaning solutions containing EDTA are widely employed to remove incrustation despite of the costs involved. The free content of EDTA in commercial solutions may be determined by mixing an aliquot to ammonium oxalate and using a standard calcium solution as titrant. The end-point is detected by the formation of insoluble calcium oxalate after all EDTA is complexed. A system for turbidimetric detection of the end-point was envisaged to substitute the visual detection, which impaired the analyses of dark samples. The proposed method was tested with real samples and good accuracy and precision was obtained.

Processos avançados de oxidação de compostos fenólicos em efluentes industriais

In an effort to minimize the impact on the environment, removal of pollutants, such as phenolic compounds, from the industrial wastewater has great importance nowadays because of the high toxicity and low biodegradability of these compounds. This work discusses the different methods to remove these compounds from industrial wastewater, showing their advantages and disadvantages. Advanced Oxidation Process (AOPs) are presented as a promising technology for the treatment of wastewater containing phenolic compounds. Among the AOPs, photolysis, photocatalysis and the processes based on hydrogen peroxide and on ozone are discussed with emphasis on the combined processes and the oxidation mechanisms.

Caracterização das cinzas de incineração de resíduos industriais e de serviços de saúde

Three ash samples from an incinerator in Belo Horizonte (Brazil) were physically and chemically characterized. The chemical composition of the ashes was not always the same, neither in terms of the chemical species nor in terms of the quantities of those that are common to the three ashes. The ashes called CF1 and CF3D contain heavy metals above the detection limits of the analytical methods and the zinc concentration is high enough to justify treatment of the ashes. For these ashes, a high loss on ignition was found, indicating that the process of incineration might present failures.

Determinação não destrutiva do nitrogênio total em plantas por espectroscopia de reflectância difusa no infravermelho próximo

Diffuse reflectance near-infrared (DR-NIR) spectroscopy associated with partial least squares (PLS) multivariate calibration is proposed for a direct, non-destructive, determination of total nitrogen in wheat leaves. The procedure was developed for an Analytical Instrumental Analysis course, carried out at the Institute of Chemistry of the State University of Campinas. The DR-NIR results are in good agreement with those obtained by the Kjeldhal standard procedure, with a relative error of less than ± 3% and the method may be used for teaching purposes as well as for routine analysis.

Produção de matéria seca e de grãos por plantas de feijoeiro (Phaseolus vulgaris L.) cultivadas em solos tratados com metais pesados

This work aimed at evaluating the contents of extractable Cd, Pb, Zn and Cu with a solution of DTPA (diethyleneaminopentacetic acid) and to relate them with the production of dry material and grain production of bean plants under two conditions of experimentally contaminated soil materials with Cd, Pb, Cu and Zn: (i) samples of distrofic red latosol and (ii) humic yellow-red latosol. A decrease in the yield of dry matter was observed for all treatments, if compared with the zero-dose control sample; the grain yield was affected for the soil samples treated with Cd and Cu but only slightly for those treated with Pb and Zn.

Avaliação do potencial antioxidante de extratos ativos de plantas obtidos por extração com fluido supercrítico

The aim of this work was to evaluate the antioxidant properties of ginger and rosemary extracts, obtained by supercritical extraction. The extracts were characterized by HPLC, GC-MS, phenolic compounds content and antioxidant activity. The main active compounds were identified and high content of phenolic compounds was observed. The extracts presented high antioxidant activity against the free radicals ABTS•+ (350 and 200 mM Trolox/g, for ginger and rosemary, respectively) and DPPH•+ (145 and 80 mM Trolox/g, for ginger and rosemary, respectively). These results suggested that the attained extracts are potential substitutes of synthetic antioxidants used in chemical, food and pharmaceutical industries.

Cutinases fúngicas: propriedades e aplicações industriais

Cutinases (EC 3.1.1.74) are also known as cutin hidrolases. These enzymes share catalytic properties of lipases and esterases, presenting a unique feature of being active regardless the presence of an oil-water interface, making them interesting as biocatalysts in several industrial processes involving hydrolysis, esterification and trans-esterification reactions. They are also active in different reaction media, allowing their applications in different areas such as food industry, cosmetics, fine chemicals, pesticide and insecticide degradation, treatment and laundry of fiber textiles and polymer chemistry. The present review describes the characteristics, potential applications and new perspectives for these enzymes.

Química e farmacologia de quimioterápicos antineoplásicos derivados de plantas

This review demonstrates the importance of plants as sources of molecules used in anticancer therapies. The approach is performed by relating the active molecules to their origins, details, mechanisms of action, structure-activity relationship and chemical characteristics of chemotherapeutical medicines. It was also described the development of anticancer agents from plants by the pharmaceutical industry and the difficulties to release these compounds as a trademark. These include the well known paclitaxel, docetaxel, vincristine, vinblastine, vinorelbine, vindesine, etoposide, teniposide, and other molecules that are undergoing clinical trials.

Substitutos do " novo" mundo para as antigas plantas raras: um estudo de caso dos bálsamos

Convinced that the " true balsam" was lost forever, Conrad Gesner described other substances with similar healing virtues. However, he was not the only one in the 16th to search for other varieties of balsamic oleoresins. The arrival of the Europeans to the Americas allowed the finding of native plants with properties similar to those of the original balsam, including Balsam of Peru, Balsam of Tolu and particularly in the Brazilian area, Balsam of Copaiba. Focusing on the Brazilian context, this paper analyzes two different moments in the transit of the newly found varieties of balsams to the pharmacopeia and materia medica.

HIV: mecanismo de replicação, alvos farmacológicos e inibição por produtos derivados de plantas

The AIDS epidemy has spread out and led to the diversification on the research for new antiviral drugs. Natural products, especially those derived from plants, are well-recognized as excellent sources of new drugs. Several of them have inhibitory activity against HIV replication, and some have been already clinically tested, with favorable results. This review presents the biochemical basis of the viral cycle and the research up to date on the identification, determination of the mechanism of biological action together with the therapeutical potential of plants-derived natural products, in the inhibition of HIV.

De praerogativis Finlandiae praecipue quoad plantas spontaneas in bellariis adhibitas

Inv: D.D.