Antifungal Activity of N-(4-Halobenzyl)amides against Candida spp. and Molecular Modeling Studies.

Fungal infections remain a high-incidence worldwide health problem that is aggravated by limited therapeutic options and the emergence of drug-resistant strains. Cinnamic and benzoic acid amides have previously shown bioactivity against different species belonging to the Candida genus. Here, 20 cinnamic and benzoic acid amides were synthesized and tested for inhibition of C. krusei ATCC 14243 and C. parapsilosis ATCC 22019. Five compounds inhibited the Candida strains tested, with compound 16 (MIC = 7.8 µg/mL) producing stronger antifungal activity than fluconazole (MIC = 16 µg/mL) against C. krusei ATCC 14243. It was also tested against eight Candida strains, including five clinical strains resistant to fluconazole, and showed an inhibitory effect against all strains tested (MIC = 85.3-341.3 µg/mL). The MIC value against C. krusei ATCC 6258 was 85.3 mcg/mL, while against C. krusei ATCC 14243, it was 10.9 times smaller. This strain had greater sensitivity to the antifungal action of compound 16. The inhibition of C. krusei ATCC 14243 and C. parapsilosis ATCC 22019 was also achieved by compounds 2, 9, 12, 14 and 15. Computational experiments combining target fishing, molecular docking and molecular dynamics simulations were performed to study the potential mechanism of action of compound 16 against C. krusei. From these, a multi-target mechanism of action is proposed for this compound that involves proteins related to critical cellular processes such as the redox balance, kinases-mediated signaling, protein folding and cell wall synthesis. The modeling results might guide future experiments focusing on the wet-lab investigation of the mechanism of action of this series of compounds, as well as on the optimization of their inhibitory potency.

Curine, an alkaloid isolated from Chondrodendron platyphyllum inhibits prostaglandin E2 in experimental models of inflammation and pain.

Curine is a bisbenzylisoquinoline alkaloid that is isolated from Chondrodendron platyphyllum, a plant that is used to treat malaria, inflammation, and pain. Recent reports have demonstrated the antiallergic effects of curine at nontoxic doses. However, its anti-inflammatory and analgesic properties remain to be elucidated. This study investigated the anti-inflammatory and analgesic effects of curine in mice. We analyzed the effects of an oral treatment with curine in the formation of paw edema, vascular permeability, abdominal contortion, licking behavior, and hyperalgesia using different inflammatory stimuli. Curine significantly inhibited the formation of paw edema by decreasing vascular permeability, inhibited the acetic acid-induced writhing response, inhibited the licking behavior during inflammation but not during the neurogenic phase of the formalin test, and inhibited carrageenan-induced hyperalgesia. Finally, curine inhibited prostaglandin E2 production in vitro without affecting cyclooxygenase-2 expression. The effects of curine treatment were similar to the effects of indomethacin, but were different from the effects of morphine treatment, suggesting that the analgesic effects of curine do not result from the direct inhibition of neuronal activation but instead depend on anti-inflammatory mechanisms that, at least in part, result from the inhibition of prostaglandin E2 production. In conclusion, curine presents anti-inflammatory and analgesic effects at nontoxic doses and has the potential for use in anti-inflammatory drug development.

Brominated compounds from marine sponges of the genus Aplysina and a compilation of their 13C NMR spectral data.

Aplysina is the best representative genus of the family Aplysinidae. Halogenated substances are its main class of metabolites. These substances contribute greatly to the chemotaxonomy and characterization of the sponges belonging to this genus. Due to their pharmacological activities, these alkaloids are of special interest. The chemistry of halogenated substances and of the alkaloids has long been extensively studied in terrestrial organisms, while the number of marine organisms studied has just started to increase in the last decades. This review describes 101 halogenated substances from 14 species of Aplysina from different parts of the world. These substances can be divided into the following classes: bromotyramines (A), cavernicolins (B), hydroverongiaquinols (C), bromotyrosineketals (D), bromotyrosine lactone derivatives (E), oxazolidones (F), spiroisoxazolines (G), verongiabenzenoids (H), verongiaquinols (I), and dibromocyclohexadienes (J). A compilation of their (13)C NMR data is also part of the review. For this purpose 138 references were consulted.

Biological activity of yangambin on the postembryonic development of Chrysomya megacephala (Diptera: Calliphoridae).

Phytochemicals endowed with hormonal, antihormonal, or toxic activity are potential agents for insect control. Thus, we became interested in testing Brazilian plant metabolites on Chrysomya megacephala (F.) (Diptera: Calliphoridae), a public health menace that is one of the most prevalent flies in Brazilian urban areas. We tested the lignan yangambin, from the leaves of Ocotea duckei Vattimo (Lauraceae). Topical treatment of eggs and first instars with yangambin as well as feeding larvae a yangambin-treated diet resulted in inhibition of postembryonic development, morphological alteration, and oviposition reduction.

Evaluation of the mutagenic potential of yangambin and of the hydroalcoholic extract of Ocotea duckei by the Ames test.

Ocotea duckei Vattimo is a plant popularly known as "louro-de-cheiro" found in the northeast of Brazil. Traditional medicinal uses of this plant are not known, but recent pharmacological studies with the isolated major constituent yangambin have shown various qualities: platelet activating factor (PAF) antagonist, protective effects against cardiovascular collapse and anaphylactic shock, anti-allergic properties, analgesic activity, and depressant effect in the central nervous system. In this work, the Ames test was used to evaluate the mutagenic potential of the hydroalcoholic extract of O. duckei leaves and of yangambin. Using TA97a, TA98, TA100, TA102 and TA1535 strains of Salmonella typhimurium, positive results were obtained only with the hydroalcoholic extract, with or without metabolic activation. Yangambin was not mutagenic, which is of interest due to its pharmacological properties.

Curine inhibits mast cell-dependent responses in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Curine is a bisbenzylisoquinoline alkaloid and the major constituent isolated from Chondrodendron platyphyllum, a plant that is used to treat inflammatory diseases in Brazilian folk medicine. This study investigates the effectiveness of curine on mast cell-dependent responses in mice. MATERIALS AND METHODS: To induce mast cell-dependent responses, Swiss mice were subcutaneously sensitized with ovalbumin (OVA-12 µg/mouse) and Al(OH)3 in a 0.9% NaCl solution. Fifteen days later, the animals were challenged with OVA through different pathways. Alternatively, the animals were injected with compound 48/80 or histamine, and several parameters, including anaphylaxis, itching, edema and inflammatory mediator production, were analyzed. Promethazine, cromoglycate, and verapamil were used as control drugs, and all of the treatments were performed 1h before the challenges. RESULTS: Curine pre-treatment significantly inhibited the scratching behavior and the paw edema induced by either compound 48/80 or OVA, and this protective effect was comparable in magnitude with those associated with treatment with either cromoglycate or verapamil. In contrast, curine was a weak inhibitor of histamine-induced paw edema, which was completely inhibited by promethazine. Curine and verapamil significantly inhibited pleural protein extravasations and prostaglandin D2 (PGD2) and cysteinyl leukotrienes (CysLTs) production following allergen-induced pleurisy. Furthermore, like verapamil, curine inhibited the anaphylactic shock caused by either compound 48/80 or an allergen. In in vitro settings, these treatments also inhibited degranulation as well as PGD2 and CysLT production through IgE-dependent activation of the mast cell lineage RBL-2H3. CONCLUSION: Curine significantly inhibited immediate allergic reactions through mechanisms more related to mast cell stabilization and activation inhibition than interference with the pro-inflammatory effects of mast cell products. These findings are in line with the hypothesis that the alkaloid curine may be beneficial for the treatment of allergic disorders.

Antinociceptive activity of Sargassum polyceratium and the isolation of its chemical components

Abstract Marine algae have been the focus of important studies over the past fifty years, with a considerable number of components important to chemists and taxonomists having been isolated and characterized. The scientific data available on Sargassum polyceratium are extremely limited. The objective of the present study was to evaluate the antinociceptive activity of an ethanol extract of S. polyceratium and to isolate its components. Intraperitoneal treatment with ethanol extract of S. polyceratium reduced the number of acetic acid-induced writhes and the amount of time spent in paw-licking in the second phase of the formalin test. Ethanol extract of S. polyceratium also reduced the amount of time spent in paw-licking in the glutamate test; however, there was no difference in the reaction time in the hot plate test at any of the doses tested. The chemical components isolated from ethanol extract of S. polyceratium were identified using one- and two-dimensional spectroscopic methods such as infrared spectroscopy, mass spectrometry and 1H and 13C nuclear magnetic resonance spectroscopy. The analytical results were also compared with data obtained in the literature. The following porphyrin derivatives were isolated from S. polyceratium: 132-hydroxy-(132-R)-pheophytin-a, 132-hydroxy-(132-S)-pheophytin-a, pheophytin-a, and the steroid fucosterol. The present results indicate that the ethanol extract of S. polyceratium has antinociceptive activity. In addition, four new substances were isolated from the species evaluated.

Secondary metabolites isolated from Richardia brasiliensis Gomes (Rubiaceae) / Metabólitos secundários isolados de Richardia brasiliensis Gomes (Rubiaceae)

A família Rubiaceae compreende cerca de 637 gêneros e aproximadamente 10700 espécies, ocorrendo essencialmente nas regiões tropicais do Brasil. Richardia brasiliensis Gomes, popularmente conhecida por "poaia branca", é uma planta nativa da região sul do Brasil, utilizada na medicina popular como anti-emética e no tratamento de diabetes. Este trabalho reporta o isolamento e identificação estrutural de um flavonóide glicosilado, um triterpeno, uma cumarina e dois derivados de ácido benzóico, objetivando contribuir para quimiotaxonomia do gênero Richardia. Através deste estudo foi possível isolar e identificar os metabólitos isorametina-3-O-rutinosídeo, ácido oleanólico, a cumarina escopoletina e os ácidos p-hidroxi-benzóico e m-metoxi-p-hidroxi-benzóico, todos isolados pela primeira vez no gênero, exceto o último, apresentando, portanto, relevante importância quimiotaxonômica para o mesmo. As estruturas foram identificadas com o uso de técnicas espectroscópicas de IV, RMN ¹H e 13C uni e bidimensionais e comparação com dados da literatura.

The family Rubiaceae comprises around 637 genera and approximately 10,700 species, occurring essentially in tropical regions of Brazil. Richardia brasiliensis Gomes, known popularly as "poaia branca", is native to Brazil south region, used in folk medicine as anti-emetic and in the treatment of diabetes. This work reports the isolation and structural identification of a flavonoid glycoside, a triterpene, a coumarin and two benzoic acid derivatives, aiming at contributing to the chemotaxonomy of the genus Richardia, through a phytochemical study of Richardia brasiliensis. By means of this study the metabolites isorhamnetin-3-O-rutinoside, oleanolic acid, the coumarin scopoletin and p-hydroxy-benzoic and m-methoxy-p-hydroxy-benzoic acids were isolated and identified. All of them, but the latter, were isolated for the first time in the genus, thereby presenting relevant chemotaxonomic importance to it. The structures were identified using spectroscopic techniques such as IR, one and two-dimensional ¹H and 13C NMR besides comparison with literature data.

Antimicrobial activity of the essential oil of Bowdichia virgilioides Kunt. / Atividade antimicrobiana do óleo essencial de Bowdichia virgilioides Kunt.

The essential oil of Bowdichia virgilioides Kunt. (Fabaceae) leaves was tested for their antimicrobial activity against eighteen pathogenic microorganisms using standard gel diffusion method. It showed activity against Candida albicans, Candida guilliermondii, Candida stellatoidea, Micrococcus luteus and Trichophyton rubrum.

O óleo essencial das folhas de Bowdichia virgilioides Kunt. (Fabaceae) foi testado para a verificação da sua atividade antimicrobiana contra dezoito microorganismos patogênicos, usando o método de difusão em meio sólido. Foi observada atividade contra Candida albicans, Candida guilliermondii, Candida stellatoidea, Micrococcus luteus e Trichophyton rubrum.