Anti-HSV-1 and anti-HIV-1 activity of gallic acid and pentyl gallate

The synthetic n-alkyl esters of gallic acid (GA), also known as gallates, especially propyl, octyl and dodecyl gallates, are widely employed as antioxidants by food and pharmaceutical industries. The inhibitory effects of GA and 15 gallates on Herpes Simplex Virus type 1 (HSV-1) and Human Immunodeficiency Virus (HIV-1) replication were investigated here. After a preliminary screening of these compounds, GA and pentyl gallate (PG) seemed to be the most active compounds against HSV-1 replication and their mode of action was characterized through a set of assays, which attempted to localize the step of the viral multiplication cycle where impairment occurred. The detected anti-HSV-1 activity was mediated by the inhibition of virus attachment to and penetration into cells, and by virucidal properties. Furthermore, an anti-HIV-1 activity was also found, to different degrees. In summary, our results suggest that both compounds could be regarded as promising candidates for the development of topical anti-HSV-1 agents, and further studies concerning the anti-HIV-1 activity of this group of molecules are merited.

Effect of JJYMD-C, a novel synthetic derivative of gallic acid, on proliferation and phenotype maintenance in rabbit articular chondrocytes in vitro

Tissue engineering encapsulated cells such as chondrocytes in the carrier matrix have been widely used to repair cartilage defects. However, chondrocyte phenotype is easily lost when chondrocytes are expanded in vitro by a process defined as “dedifferentiation”. To ensure successful therapy, an effective pro-chondrogenic agent is necessary to overcome the obstacle of limited cell numbers in the restoration process, and dedifferentiation is a prerequisite. Gallic acid (GA) has been used in the treatment of arthritis, but its biocompatibility is inferior to that of other compounds. In this study, we modified GA by incorporating sulfamonomethoxine sodium and synthesized a sulfonamido-based gallate, JJYMD-C, and evaluated its effect on chondrocyte metabolism. Our results showed that JJYMD-C could effectively increase the levels of the collagen II, Sox9, and aggrecan genes, promote chondrocyte growth, and enhance secretion and synthesis of cartilage extracellular matrix. On the other hand, expression of the collagen I gene was effectively down-regulated, demonstrating inhibition of chondrocyte dedifferentiation by JJYMD-C. Hypertrophy, as a characteristic of chondrocyte ossification, was undetectable in the JJYMD-C groups. We used JJYMD-C at doses of 0.125, 0.25, and 0.5 µg/mL, and the strongest response was observed with 0.25 µg/mL. This study provides a basis for further studies on a novel agent in the treatment of articular cartilage defects.

Basic density and pulp yield relationship with some chemical parameters in eucalyptus trees

The objective of this work was to evaluate the use of basic density and pulp yield correlations with some chemical parameters, in order to differentiate an homogeneous eucalyptus tree population, in terms of its potential for pulp production or some other technological applications. Basic density and kraft pulp yield were determined for 120 Eucalyptus globulus trees, and the values were plotted as frequency distributions. Homogenized samples from the first and fourth density quartiles and first and fourth yield quartiles were submitted to total phenols, total sugars and methoxyl group analysis. Syringyl/guaiacyl (S/G) and syringaldehyde/vanillin (S/V) ratios were determined on the kraft lignins from wood of the same quartiles. The results show the similarity between samples from high density and low yield quartiles, both with lower S/G (3.88-4.12) and S/V (3.99-4.09) ratios and higher total phenols (13.3-14.3 g gallic acid kg-1 ). Woods from the high yield quartile are statistically distinguished from all the others because of their higher S/G (5.15) and S/V (4.98) ratios and lower total phenols (8.7 g gallic acid kg-1 ). Methoxyl group and total sugars parameters are more adequate to distinguish wood samples with lower density.

Carotenoids profile and total polyphenols in fruits of Pereskia aculeata Miller

Pereskia aculeata Mill. (Ora-pro-nóbis) is a native cactaceae from tropical America, whose leaves have high protein content. In Brazil it is found in all territorial extension between the states of Bahia and Rio Grande do Sul. Most studies have focused on chemical characterization of the leaves of this specie. The objective was to assess the carotenoids profile and the total polyphenols present in the fruits of P. aculeate. Carotenoids were determined by HPLC-PAD (high performance liquid chromatography - photodiode array detector), total polyphenols were determined by Folin-Ciocalteu and vanillin methods. Trans-β-carotene was the main carotenoid, followed by α-carotene, lutein and other minor carotenoids. It was found 64.9 ± 1.1 mg.100g-1 of gallic acid equivalent, 14.8 ± 0.2 mg.100g-1 of catechin equivalent. Carotenoid identification of P. aculeate fruits are presented here by the first time and indicate that these fruits can be researched as source of bioactive substances, especially antioxidant and provitamin A carotenoids.

DIETARY FIBRE CONTENT, PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY IN SOURSOPS (Annona muricata L.)

ABSTRACT Healthy eating is associated with the consumption of fruits, which are notable for their beneficial effects on human health. The aim of this study was to evaluate the proximate composition, composition of fibers and components with antioxidant activity in soursops varieties Crioula, Lisa and Morada of physiological maturity (PM) and mature (M). The protein, lipid and moisture contents did not differ between soursop varieties, but the ash contents were higher in the Morada-PM (0.56%±0.03) and the Morada-M (0.82%±0.10) varieties. The Crioula-M variety showed higher levels of total dietary fibre (5.76%±0.12). The Lisa-M variety showed higher levels of insoluble dietary fibre (4.46%±0.00). The Lisa-M variety also showed a higher level of phenolic compounds (284.25 mg gallic acid/100 g of soursop pulp), differing significantly (p <0.05) from the Crioula-PM soursop (154.40 mg of gallic acid/100 g of soursop pulp). Under the DPPH• system, the soursops that showed highest antioxidant activity were the Crioula-M (EC50 of 156.40 g.g DPPH-1) and the Crioula-PM (EC50 of 162.41 g.g DPPH-1), which differed significantly from the Morada soursops. The results suggest that the consumption of soursops is useful for increasing concentrations of bioactive compounds and dietary fibre.

Antioxidant and antiviral properties of Pseudopiptadenia contorta (Leguminosae) and of quebracho (Schinopsis sp.) extracts

Proanthocyanidins from P. contorta leaves and from a commercial quebracho extract were isolated and characterized. Flavonoids, catechins and gallic acid were also identified in the extracts of P. contorta. Compounds were evaluated for their antioxidant properties and for their antiviral activity against an acyclovir-resistant herpes simplex virus type 1 strain. The low molecular weight phenolic derivatives and the proanthocyanidins from P. contorta showed the highest antioxidant activity. Purified proanthocyanidins from both P. contorta and quebracho showed the same maximum non toxic concentrations (25 µg/mL), with 82.2% and 100% of virus inhibition, respectively.

Quimioluminiscencia electrogenerada del luminol usando electrodos de bajo costo

The purpose of the study was to observe eletrogenerated chemiluminescence (ECL) of luminol using different materials as electrodes such as wires, nails, coins, razor blades, etc. Based on the experimental observations and the mechanisms proposed in the literature, students should be capable of analyzing their results in order to understand the phenomena studied. Students could then elaborate a mechanism of action consistent with the experimental results which could rationalize the formation of intermediates in the reaction and the dependence of ECL on solution pH in addition to other points of interest

Chemical study of leaves of Chrysophyllum marginatum (Hook. & Arn.) Radlk (Sapotaceae)

The fractionation of the antioxidant ethyl acetate extract obtained from the dried leaves of Chrysophyllum marginatum afforded six substances identified as: alpha-amirin, gallic acid, myricitrin, quercitrin, (-)-epigallocatechin and (-)-epigallocatechin-3-O-gallate. This study contributes to the knowledge of the secondary metabolites produced by one more species of the Brazilian Flora, until now not investigated. Moreover, this study allowed the identification of three substances with antioxidant activity previously detected in this species.

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.

Avaliação das variáveis analíticas do método de Folin-Ciocalteu para determinação do teor de taninos totais utilizando como modelo o extrato aquoso de folhas de psidium guajava L.

The main analytical variables of a modified Folin-Ciocalteu method were studied by UV-Vis and gradient HPLC-PDA methods, using purified (PC) and technical grade (TGC) casein. Rutin and an aqueous extract of Psidium guajava L. leaves were used as models. The best results were ascribed to TGC. Certainly PC bonds the polyphenols of the P. guajava extract better than TGC, but TGC afforded better precision. A lack of specificity occurred when rutin was analyzed together with the P guajava extract. Additional analyses performed with the flavonoid fraction of P. guajava extract by HPLC-PDA had confirmed that casein was able to bind catechin, gallic acid and P. guajava flavonoids in a non-specific way.

Constituintes químicos das flores de Pterogyne nitens (Caesalpinioideae)

The phytochemical investigation of the flowers of Pterogyne nitens (Caesalpinioideae) resulted in the isolation and identification of nine phenolic derivatives, quercetin 3-O-sophoroside, taxifolin, astilbin, ourateacatechin, caffeic, ferulic, sinapic, chlorogenic and gallic acid, besides two guanidine alkaloids, pterogynine, pterogynidine. This is the first time these compounds have been reported in P. nitens flowers. As this is a monospecific genus, these secondary metabolites may have taxonomical significance. Their structures were assigned on the basis of spectroscopic analyses, including two-dimensional NMR techniques.

Constituintes químicos de Sebastiania macrocarpa Muell. Arg. (Euphorbiaceae)

The chemical investigation of the methanolic extract of the aerial part of Sebastiania macrocarpa allowed the isolation of the mixture of steroids β-sitosterol and stigmasterol, gallic acid, and scopoletin. The hexane extract of the roots allowed the isolation of the triterpene lupeol and of the macrociclic diterpene (+)-tonantzitlolone. The structures of all compounds isolated were identified on the basis of their spectral data and by comparison of their spectral data with values described in the literature. This is the first report involving the chemical investigation of this species.

Development and validation of a LC-method for the determination of phenols in a pharmaceutical formulation containing extracts from Stryphnodendron adstringens

A sensitive RP-HPLC method with UV detection successfully measured phenol(s) in an ointment containing 3% Stryphnodendron adstringens extract. Chromatography used acetonitrile (0.05% trifluoroacetic acid):water (0.05% trifluoroacetic acid) (v/v), flow rate 0.8 mL min-1. Quantitation was accomplished by the external-standard method. Linearity for 2.00 to 16.00 μg mL-1 (gallic acid) and 1.14 to 18.24 μg mL-1 (gallocatechin) was established. Intra- and inter-day precision levels were under 5%. LOD and LOQ were 0.231 and 0.770 μg mL-1 (gallic acid) and 0.151 and 0.504 μg mL-1 (gallocatechin), respectively. Determination of phenols was unaffected by product excipients.

Determination of polyphenol contents and antioxidant capacity of no-alcoholic red grape products (vitis labrusca) from conventional and organic crops

The polyphenol contents and antioxidant capacity of Brazilian red grape juices and wine vinegars were analyzed. Additionally, it was analyzed the human polyphenol absorption and acute effect in plasmatic oxidative metabolism biomarkers after juice ingestion. The organic Bordo grape juice (GBO) presented a higher level of trans-resveratrol, quercitin, rutin, gallic acid, caffeic acid and total flavonoids then other juices and vinegars as well as antioxidant capacity. The plasmatic polyphenol increased 27.2% after GBO juice ingestion. The results showed that juices and vinegars from Brazilian crops present similar chemical and functional properties described in studies performed in other countries.

Identificação de alguns constituintes químicos de Indigofera hirsuta Linn. (Fabaceae) por CLAE-IES-EM (TOF) e avaliação da atividade antirradicalar

A rapid analytical approach, suitable to characterize the compounds present in the aqueous and methanol extracts prepared from the aerial parts of Indigofera hirsute, was developed. The method based on high-performance liquid chromatography coupled to mass spectrometry, electrospray positive ionization and detection by time of flight (HPLC-ESI-MS-TOF) identified, tryptophan, uracil, rutin, kaempferol-3-O-β-D-glucopyranoside, gallic acid and methyl gallate. The antiradical activity of this extract was evaluated using DPPH assay, with gallic acid as antiradical pattern. The study revealed the antiradical activity of methyl galatte (EC50 = 5 ± 0.3 µg mL-1) galic acid (EC50 = 5 ± 0.2 µg mL-1) and rutin (EC50 = 21.6 ± 0.6 µg m L-1), isolated from methanol extract (EC50 = 67.7 ± 0.9 µg mL-1), which showed strong antiradical activity.