Chemistry in eriocaulaceae

Eriocaulaceae is a pantropical family that comprises about 1100 species distributed in 11 genera. The infrafamilial relationships are still unsatisfactorily resolved, because of the tiny flowers and generalized morphology, which makes the taxonomy very difficult. Flavonoid and naphthopyranone profiles have proved to be important in order to contribute to the alignment of genera into the family. We here present a survey of the chemical data of Eriocaulaceae with a discussion about their contribution to the taxonomy of Eriocaulaceae. © 2008 Verlag der Zeitschrift für Naturforschung.

Micropropagação de Salvia officinalis L. com avaliação do teor de fenóis totais e atividade antioxidante

Stem cuts and seeds of Salvia officinalis were incubated on nutrient media for plantlets production and analysis of the total phenolic compounds, total flanovoids and antioxidant activity in micropropagated plants. Explants were obtained from seedlings and inoculated on MS with different concentrations of benzylaminopurine (BAP) and indolbutyric acid (IBA). After 30 and 60 days of incubation, the explants were scored for percentage of contaminated, dead and oxidized explants and mean bud numbers. For bud formation, the most efficient treatment was the medium containing BAP at 1 mg L-1, for the plantlet height the better medium was the control without the addition of plant regulator. IBA promoted the formation of few roots. Our results indicated that stem cuts incubated on media containing BAP and/or IBA did not increase the total flavonoid contents, but increased the total phenolics' by BAP and high antioxidant activity by 1 mg L-1 BAP.

rastreamento histoquímico, fitoquímico e biológico de folhas de Plinia cauliflora (DC.) Kausel (Myrtaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pharmacognostical evaluation of fruits of Solanum lycocarpum A. St.-Hill. (Solanaceae)

This study describes the chemical and physical-chemical profile of plant drug and ethanolic extract obtained from fruits of Solanum lycocarpum A. St.-Hill. (Solanaceae). The physical and chemical analysis involved the granulometry determination, non-compacted apparent density, loss on drying in oven and in infrared scale, pH, ash values and extractive values. The results determined the physical-chemical characteristics of the drug plant. It was also carried out the microbiological control of the plant drug. The preliminary phytochemical screening featured the presence of tannins, flavonoids and saponins in the plant drug and alkaloids and steroids in the ethanolic exctract. The solamargine and solasonine glycoalkaloids were identified through TLC and GC/ MS. The levels of total phenols and tannins were quantified in the extract (8.90% and 6,85% respectively). Such studies contribute to the chemical identification and quality control of S. lycocarpum fruits. © 2010 Phcog.net.

Propriedade físico-química da própolis em função da sazonalidade e método de produção

The aim of this work was to investigate monthly, for one year the seasonality effect on the physicochemical properties (dry weight, flavonoids contents, pH and antioxidant activity) of ethanolic extract (EAP) of propolis produced by three different techniques (intelligent propolis collector, plastic screen or scraping) fifteen colonies of africanized bees. No differences (p>0.05) in the physicochemical properties due to the technique of propolis production and seasonality were observed.

Quercetin reduces Staphylococcus aureus interaction with neutrophils

Flavonoids, including quercetin, have been reported to modulate the ability of Staphylococcus aureus to adhere to host tissue without exhibiting direct antibacterial activity. In the present study, we evaluated the interaction of S. aureus pretreated with 40 μg/mL of quercetin with neutrophils to assay oxidative burst stimulation, using luminol-amplified chemiluminescence. S. aureus pre-incubated with subinhibitory concentration of quercetin induced significantly less light emission by neutrophils than did untreated bacteria. The results of the present study demonstrate that quercetin decreases S. aureus uptake by neutrophils.

Avaliação do estresse oxidativo no sangue de consumidores habituais de suco de laranja

Two biomarkers of oxidative stress were evaluated in healthy volunteers treated with daily doses of orange juice that is well known source of vitamin C and citric flavanones, which have been associated with antioxidant, anti-inflammatory and hypolipidemic effects. The antioxidant capacity in the blood serum was evaluated by studying the scavenging of 2,2'-diphenyl-1-picrylhydrazyl (DPPH) free radical, and also lipid peroxidation was evaluated by the thiobarbituric acid reacting substances (TBARS) assay. The results have shown that the regular consumption of orange juice increased 150% and 200% the serum antioxidant capacity for women and men respectively, but it was no significant change in the serum lipid peroxidation. In conclusion, the increase of flavonones and vitamin C in the body due to the regular intake of orange juice expressively improved the antioxidant capacity, but without significant effect on the lipid peroxidation.

Antioxidant and cytotoxic studies for kaempferol, quercetin and isoquercitrin

The aim of the present study was to investigate a cytotoxic oxidative cell stress related and the antioxidant profile of kaempferol, quercetin, and isoquercitrin. The flavonol compounds were able to act as scavengers of superoxide anion (but not hydrogen peroxide), hypochlorous acid, chloramine and nitric oxide. Although flavonoids are widely described as antioxidants and this activity is generally related to beneficial effects on human health, here we show important cytotoxic actions of three well known flavonoids. They were able to promote hemolysis which one was exacerbated on the presence of hypochlorous acid but not by AAPH radical. Therefore, despite they expected scavenger action over free radicals an oxidants, these compounds could be very lesive to living organisms by acting over erythrocytes and maybe other cellular types.

Evaluation of the toxicity of Virola sebifera crude extracts, fractions and isolated compounds on the nest of leaf-cutting ants

The phytochemical study of Virola sebifera leaves led to the isolation of three lignans: (+)-sesamin, (-)-hinokinin, and (-)-kusunokinin and three flavonoids: quercetin-3-O - L-rhamnoside, quercetin-3-O - D-glucoside, and quercetin-3-methoxy-7-O - D-glucoside by using techniques as high-speed counter-current chromatography and high-performance liquid chromatography. The crude extracts, fractions, and isolated compounds were evaluated for their insecticidal and fungicidal potential against Atta sexdens rubropilosa and its symbiotic fungus Leucoagaricus gongylophorus. The bioassay results showed a high insecticidal activity for the methanol crude extract of the leaves of V. sebifera and its n-hexane, dichloromethane and ethyl acetate fractions. The fungicidal bioassay revealed high toxicity of the lignans against L. gongylophorus. © 2012 Keylla Utherdyany Bicalho et al.

Baccharis dracunculifolia, the main source of green propolis, exhibits potent antioxidant activity and prevents oxidative mitochondrial damage

Baccharis dracunculifolia DC (Asteraceae) is the main botanical source used by honeybees to produce Brazilian green propolis whose hepatoprotective properties have been already described. In this work we investigated the protective effects of the glycolic extract of B. dracunculifolia (GEBd) against oxidative stress in isolated rat liver mitochondria (RLM). The GEBd was prepared by fractionated percolation using propylene glycol as solvent. The total phenols and flavonoids, which are substances with recognized antioxidant action, were quantified in GEBd and the phytochemical analysis was carried out by HPLC. GEBd exhibited significant scavenger activity towards DPPH radicals and superoxide anions in a concentration-dependent manner, and also a Fe 2+ chelating activity. GEBd decreased the basal H 2O 2 generation and the Fe 2+- or t-BuOOH-induced ROS production in isolated mitochondria. Lipid oxidation of mitochondrial membranes, protein thiol groups and GSH oxidation were also prevented by GEBd. This shows that B. dracunculifolia exhibit potent antioxidant activity protecting liver mitochondria against oxidative damage and such action probably contribute to the antioxidant and hepatoprotective effects of green propolis. © 2011 Elsevier Ltd.

Development of a topical formulation containing S. Lutea extract: Stability, in vitro studies and cutaneous permeation

Flavonoids have been widely incorporated into cosmetic and dermatological formulations, affording benefits such as antioxidant action, improved skin tone and fewer lines and wrinkles. Brazil has a huge biodiversity, with one of the richest flora in the world, and existing studies justify the quest for greater research efforts in this area. The cajazeira (Spondias lutea L.), a plant of the Anacardiaceae family from tropical America, is widely disseminated in Brazil. This plant was chosen because of the presence of flavonoids that exhibit antioxidant activity. The purpose of this research was to develop a stable topical formulation containing Spondias lutea extract with the aim of preventing skin diseases caused by UV radiation. Hydro ethanolic extract of Spondias lutea fruit was prepared and assayed for its the flavonoids content. The antioxidant activity was estimated by DPPH and superoxide assay. The physicochemical stability and skin permeation of the cream containing 8% (w/w) of extract were assessed. The results showed that the S. lutea extract possessed antioxidant activity, and that it is possible to obtain a stable cosmetic containing the extract, which is able to penetrate the skin. Thus, it is possible to use this extract to produce an anti-aging cosmetic.

Assessment of the chemical profile, polyphenol content and antioxidant activity in extracts of Psidium Guajava L. fruits

Fruits and vegetables that are rich in polyphenolic compounds, especially flavonoids, may be used to benefit human health by reducing the incidence of cancers and cardiovascular diseases. Previous studies have demonstrated the antioxidant activity of guava, a fruit widely available in Brazil, possibly due to the presence of these polyphenolic compounds. The aim of this study was to analyze the total phenolic and flavonoid contents of various guava extracts, assay their antioxidant activity and record the chromatographic profiles of these extracts, to determine a simple and low way of extracting these compounds efficiently from guava. The results confirmed the presence of polyphenols in guava, including flavonoids, and its antioxidant activity. Furthermore, it was demonstrated that the 70% ethanol (by volume) was the most effective solvent to extract these compounds from the fruit, among those tested.

Characterization of a tannase from Emericela nidulans immobilized on ionic and covalent supports for propyl gallate synthesis

The extracellular tannase from Emericela nidulans was immobilized on different ionic and covalent supports. The derivatives obtained using DEAE-Sepharose and Q-Sepharose were thermally stable from 60 to 75 °C, with a half life (t50) >24 h at 80 °C at pH 5. 0. The glyoxyl-agarose and amino-glyoxyl derivatives showed a thermal stability which was lower than that observed for ionic supports. However, when the stability to pH was considered, the derivatives obtained from covalent supports were more stable than those obtained from ionic supports. DEAE-Sepharose and Q-Sepharose derivatives as well as the free enzyme were stable in 30 and 50 % (v/v) 1-propanol. The CNBr-agarose derivative catalyzed complete tannic acid hydrolysis, whereas the Q-Sepharose derivative catalyzed the transesterification reaction to produce propyl gallate (88 % recovery), which is an important antioxidant. © 2012 Springer Science+Business Media Dordrecht.

Characterization of a glucose- and solvent-tolerant extracellular tannase from Aspergillus phoenicis

Tannases have attracted wider attention because of their biotechnological potential, especially enzymes from filamentous fungi and other microorganisms. However, the biodiversity of these microorganisms has been poorly explored, and few strains were identified for tannase production and characterization. This article describes the production, purification and characterization of a glucose- and solvent-tolerant extracellular tannase from Aspergillus phoenicis. High enzymatic levels were obtained in Khanna medium containing tannic acid up to 72 h at 30 °C under 100 rpm. The purified enzyme with 65% of carbohydrate content had an apparent native molecular mass of 218 kDa with subunits of 120 kDa and 93 kDa and was stable at 50 °C for 1 h. Optima of temperature and pH were 60 °C and 5.0-6.5, respectively. The enzyme was not affected significantly by most ions, detergents and organic solvents. While glucose did not affect the tannase activity, the addition of a high concentration of gallic acid did. The Km values were 1.7 mM (tannic acid), 14.3 mM (methyl-gallate) and 0.6 mM (propyl-gallate). The enzyme was able to catalyze the transesterification reaction to produce propyl-gallate. All biochemical properties suggest the biotechnological potential of the glucose- and solvent-tolerant tannase from A. phoenicis. © 2012 Elsevier B.V. All rights reserved.

Influence of treatment with quercetin on lipid parameters and oxidative stress of pregnant diabetic rats

Among the numerous coadjuvant therapies that could influence the incidence and progression of diabetic complications, antioxidants and flavonoids are currently being tested in clinical trials. We investigated the effect of quercetin on biochemical parameters in streptozotocin-induced (60 mg/kg body mass, by intraperitoneal injection) diabetic rats. A total of 32 female Wistar rats were distributed among 4 groups as follows: control (G1); control treated with quercetin (G2); diabetic (G3); and diabetic treated with quercetin (G4). Quercetin administered to pregnant diabetic rats controlled dyslipidemia and improved lipid profiles in diabetes mellitus, regulated oxidative stress by reducing the generation of lipid hydroperoxides, and increased the activity of the antioxidant enzyme glutathione peroxidase.