Rosangela Laurentiz

The reaction of phenols or aryl ethers with tetronic acid mediated by BF3·OMe2 was investigated. This strategy allowed for the preparation of β-(hydroxyaryl)butenolides and β-arylbutenolides in a single step in a simpler way than previously reported synthetic methods

Six dibenzylbutyrolactonic lignans ((-)-hinokinin (1), (-)-cubebin (2), (-)-yatein (3), (-)-5-methoxy-yatein (4), dihydrocubebin (5) and dihydroclusin (6)) were isolated from Piper cubeba seed extract and evaluated against Schistosoma mansoni. All lignans, except 5, were able to separate the adult worm pairs and reduce the egg numbers during the 24 h of incubation. Lignans 1, 3 and 4 (containing a lactone ring) were the most efficient concerning anti-parasitary activity. Comparing structures 3 and 4, the presence of the methoxy group at position 5 appears to be important for this activity. Considering 1 and 3, it is possible to see that the substitution pattern change (methylenedioxy or methoxyl groups) in positions 3' and 4' alter the biological response, with 1 being the second most active compound. Computational calculations suggest that the activity of compound 4 can be correlated with the largest lipophilicity value.

Encouraged by the anti-inflammatory activity of hinokinin in vivo, which is also observed for the analogues dinitrohinokinin and diidrocubebin, herein we used in vitro and in silico methods to assess their selectivity profiles and predict their binding modes with Cyclooxygenases (COX-1 and 2). The in vitro assays demonstrated dinitrohinokinin is about 13 times more selective for COX-2 than for COX-1, a similar profile observed for the drugs celecoxib (selective index ≈9) and meloxicam (selective index ≈11). Predictions of the binding modes suggested dinitrohinokinin interacts with COX-2 very similarly to rofecoxib, exploring residues at the hydrophilic pocket of the enzyme that accessible to ligands only in this isoform. This lignan also interacts with COX-1 in a similar mode to meloxicam, blocking the access of the substrate to the catalytic cleft. Therefore, dinitrohinokinin is a promising lead for the design of selective COX-2 inhibitors.

RESUMO: Dois experimentos foram realizados com o objetivo de avaliar o uso das sementes secas de Piper cubeba nas dietas de frangos de corte de 1 a 21 dias de idades e seus efeitos sobre o perfil bioquímicos do sangue e na biometria dos órgãos das aves. Em cada experimento 240 pintos de corte machos, com um dia de idade da linhagem Cobb foram distribuídos em um delineamento inteiramente casualizado, com cinco tratamentos e quatro repetições de 12 aves por parcela experimental. No primeiro experimento foi avaliado o uso da Piper cubeba em dietas consideradas de alta digestibilidade, a base de milho e farelo de soja, e no segundo avaliou-se o uso da pimenta em dietas de baixa digestibilidade, as quais foram obtidas com a inclusão de farinha de carne e ossos. Com relação aos dados de perfil bioquímico sanguíneo do experimento I, com exceção da gama glutamil transferase, todos os demais níveis séricos se apresentaram dentro dos limites recomendados para aves, e apenas os níveis de trigl...

Resumo Introdução A espécie Psidium cattleianum Sabine tem despertado o interesse dos pesquisadores por apresentar, além de atividade cicatrizante, analgésica e antioxidante, propriedades antimicrobianas frente a micro-organismos da mucosa oral que podem atuar como agentes cariogênicos. Objetivo Foi avaliada, neste trabalho, a atividade antimicrobiana de extratos bruto e fracionados das folhas do araçá, além do seu perfil cromatográfico. Material e método Para avaliação da atividade antimicrobiana, foi utilizada a técnica de microdiluição, para determinação da Concentração Inibitória Mínima (CIM), e repique do inóculo em Ágar Muller Hinton (Himedia), para averiguação da Concentração Bactericida Mínima (CBM). O extrato foi testado nas concentrações entre 10 e 500 µg/mL. O perfil cromatográfico foi realizado pelo método de Cromatografia Líquida de Alta Eficiência (CLAE). Resultado Os resultados obtidos foram submetidos a uma análise descritiva e foi possível observar a atividade inibi...

Psidium cattleianum Sabine is extensively used in Brazilian traditional medicine to treat several diseases including painful disorders. Aim of the study to investigate the toxicity and the possible analgesic activities of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine (ELPCS), to support its use in folk medicine. To screen the major phytochemical constituents of this extract and evaluate their antioxidant activity. ELPCS was assessed for its antioxidant activity using the DPPH model. Its analgesic activity was examined using mouse models of acetic acid-induced writhing and hot plate paw licking models. The major phytochemical constituents of the extract were screened; their toxicity on LLC-MK2 mammalian cells was evaluated. ELPCS exhibited significant peripheral analgesic activity at doses of 60, 80, 100, 200 and 400mg/kg in mice, but it did not display central analgesic activity and not was toxic to LLC-MK2 cell (LD50>400 µg/mL). The extract exhibited free radical scavenging activity as evidenced by IC50 values (15.9 µg/mL) obtained by the DPPH method. Phytochemical screening detected flavonoids, saponins, cardiac glycosides, anthraquinones, and tannins. The results of the experimental studies proved the analgesic activity of ELPCS and supported the traditional use of this plant.

(-)-Hinokinin, a dibenzylbutyrolactone lignan, exhibits significant trypanocidal activity both in vitro and in vivo, and was obtained by partial synthesis from (-)-cubebin isolated from the dry seeds of Piper cubeba. Considering the good trypanocidal activity of (-)-hinokinin, as well as its potential for the development of new drugs, it is extremely important to evaluate its possible mutagenic activity to allow its safe use in humans. In the present study, we evaluated the antimutagenic effect of (-)-hinokinin on the chromosome damage induced by the chemotherapeutic agent doxorubicin (DXR). The test system employed was the analysis of micronucleated polychromatic erythrocytes in peripheral blood of Wistar rats. Additionally, the antioxidant activity of (-)-hinokinin was evaluated in in vitro experiments by measuring the production of hydrogen peroxide and other peroxides. Our results showed that animals treated with different doses of (-)-hinokinin (10, 20, and 40mg/kgb.w.) exhibited micronucleated cell frequencies similar to that of the negative control. In addition, treatment with combinations of (-)-hinokinin and DXR resulted in lower micronucleated cell frequencies than those observed for animals treated with DXR alone. The present study shows that (-)-hinokinin not only has no genotoxic effect, but is also effective in reducing the chromosome damage induced by DXR. (-)-Hinokinin exerted a significant antioxidant effect on parasite mitochondria in the protocol used, which might be one possible mechanism by which this compound may exert a protective effect on the chromosome damage induced by the free radicals generated by DXR.

This paper describes the reaction of a Poly(propylene)imine hexadecylamine dendrimer (DAB-Am-16) with methyl acrylate. The modified dendrimer obtained (DKMA) was characterized by vibrational spectroscopy, nuclear resonance magnetic (13C), thermogravimetry and scanning electron microscopy. The dielectric properties of DKMA were studied in a temperature range of -40 to 100°C varying the frequency from 10 to 1000 KHz. A relative thermal stability was found for DKMA. The modified dendrimer behaved as an organic insulating (ε' = 5.1). The synthesis performed at basic medium results in a corresponding change in the conformational property of the precursor. The electron microscopy indicated that the dendrimer presented a modified collapsed shape, expected by the proposed route of synthesis.

The chemotherapy of schistosomiasis relies on the use of praziquantel. However, concerns over drug resistance have encouraged the search for new drug leads. This paper is the first report on the in vitro and in vivo activity of (-)-6,6'-dinitrohinokinin (DNK) against Schistosoma mansoni. In vitro, the lethal concentrations for 50% of parasites (LC50) of DNK against adult worms were 103.9 ± 3.6 and 102.5 ± 4.8μM at 24 and 72h, respectively. Scanning electron microscopy images showed extensive tegumental alterations such as peeling and smaller numbers of tubercles in the spine of adult worms. DNK also elicited high mortality of schistosomula, with LC50 values of 57.4 ± 2.3, 32.5 ± 0.9, and 20.4 ± 1.2μM at 24, 48, and 72h, respectively. DNK displayed moderate activity against the juvenile liver parasite, with an LC50 value of 179.5 ± 2.3 μM at 72 h. This compound reduced the total number of eggs by over 83%, and it affected the development of eggs produced by adult worms. The selectivity index showed that at 24h, DNK was 8.5 and 15.4 times more toxic to the adult worms and schistosomula than to Chinese hamster lung fibroblast cells, respectively. Treatment of infected mice with DNK moderately decreased worm burden (33.8%-52.3%), egg production (40.7%-60.0%), and spleen and liver weights. Together, our results indicated that DNK presents moderate in vitro and in vivo activities against S. mansoni, and it might therefore be interesting to explore the structure-activity relationship of the antischistosomal activity of this compound.