Sample records for lactones
from WorldWideScience.org

Sample records 1 - 12 shown.



1

Eficácia das lactonas macrocíclicas sistêmicas (ivermectina e moxidectina) na terapia da demodicidose canina generalizada/ Efficacy of systemics macrocyclic lactones (ivermectin and moxidectin) for the treatment of generalized canine demodicosis

Delayte, E.H.; Otsuka, M.; Larsson, C.E.; Castro, R.C.C.
2006-02-01

Resumo em português Avaliou-se a eficácia de lactonas macrocíclicas (ivermectina e moxidectina) sobre a eventual ocorrência de efeitos colaterais e acompanharam-se, após a alta parasitológica, por 12 meses, os cães tratados, visando detectar a recidiva do quadro dermatopático. Dos 63 animais, 59% eram fêmeas, 76% apresentavam precisa definição racial e 67% tinham pelame curto. A ivermectina (0,6mg/kg/dia) foi administrada por via oral a 31 cães, e a moxidectina (0,5mg/kg/cada 72 h (mais) oras), pela mesma via, a 32 animais. Os tempos médios para a obtenção da primeira negativação do exame parasitológico do raspado cutâneo e para a consecução da alta foram, respectivamente, de 90 e 130 dias para a ivermectina e de 108 e 147 dias para a moxidectina. A ivermectina acarretou menos (16,1%) efeitos colaterais em relação à moxidectina (37,5%) (P=0,03). As recidivas foram, respectivamente, 10,3% e 13% para ivermectina e moxidectina. Não houve diferença entre os dois protocolos de terapia quanto aos percentuais de recidiva (P=0,67) e eficácia (P=0,61). Ambas as lactonas macrocíclicas mostraram-se eficazes: ivermectina 89,7% e moxidectina 87%. Resumo em inglês The efficacy of ivermectin and moxidectin for treatment of generalized canine demodicosis, was evaluated to detect the eventual occurrence of side effects caused by the use of these drugs, and to follow the treated dogs for 12 months after obtaining parasitologic cure. Of 63 dogs, 59% were females, 76% were defined as purebred and 67% had short hair. Ivermectin (0.6mg/kg/daily) was orally administered to 31 dogs and moxidectin (0.5mg/kg/every 72 hours) to 32 dogs. The ave (mais) rage number of days to obtain the first negative skin scraping results and the parasitologic cure were, respectively, 90 and 130 days for ivermectin, and 108 and 147 days for moxidectin. Ivermectin caused fewer side effects (16.1%) than moxidectin (37.5%) (P0.67) and efficacy (P>0.61). Both drugs were effective and safe to treat generalized canine demodicosis: ivermectin 89.7% and moxidectin 87.0%.

Scientific Electronic Library Online (Portuguese)

2

Métodos de preparação de lactonas de anel médio/ Methods for the preparation of medium ring lactones

Longo Junior, Luiz S.; Bombonato, Fernanda I.; Ferraz, Helena M. C.
2007-04-01

Resumo em inglês There are several natural products bearing medium ring lactone moieties, which are those containing a ring size in the range of 8 to 11 members. This review intends to cover the last 10 years (1996-2005) of the literature concerning the synthesis of medium ring lactones.

Scientific Electronic Library Online (Portuguese)

3

Síntese e avaliação da atividade fitotóxica de lactonas derivadas do 2,4-dimetil-8-oxabiciclo[3.2.1]-oct-6-en-3-ona/ Synthesis and phytotoxic activity evaluation of lactone derivatives of 2,4-dimethyl-8-oxabicyclo[3.2.1]-oct-6-en-3-one

Barbosa, Luiz Cláudio de Almeida; Maltha, Célia Regina Álvares; Borges, Eduardo Euclides Lima
2002-05-01

Resumo em inglês The alkene 2,4-dimethyl-8-oxabicyclo[3.2.1]-oct-6-en-3-one (3) was converted to 1,3,10-trimethyl-8-oxabicyclo[5.3.0]-dec-3-ene-2,9-dione (7) and 1,3-dimethyl-8-oxabicyclo[5.3.0]-dec-3-ene-2,9-dione (8) with a 55% overall yield in both cases. Lactones (7) and (8) were converted in two steps to 1,3,4-trimethyl-13-methylene-6-oxatricyclo[8.3.0.0(3,7)]-trideca-2,5,12-trione (12) (63%) and 1,3-dimethyl-13-methylene-6-oxatricycle[8.3.0.0(3,7)]-trideca-2,5,12-trione (13) (45% fr (mais) om 8). The effect of lactones (7), (8), (12), (13) and the intermediates (5) and (6), at the concentration of 250 mug mL-1, on the growth of Cucumis sativus L. and Sorghum bicolor L. was evaluated. The best results were observed for lactone (13) that caused 100% inhibition on the root growth of C. sativus and lactone (12) that inhibited 90% of the root growth for S. bicolor.

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4

Ação anti-helmíntica de diferentes formulações de lactonas macrocíclicas em cepas resistentes de nematódeos de bovinos/ Anthelmintic action of different formulations of macrocyclic lactones on resistant strains of nematodes of cattle

Cezar, Alfredo Skrebsky; Vogel, Fernanda S.F.; Sangioni, Luís Antônio; Antonello, Ana Maria; Camillo, Giovana; Toscan, Gustavo; Araujo, Luciana O. de
2010-07-01

Resumo em português As lactonas macrocíclicas (LMs) (avermectinas e milbemicinas) são endectocidas amplamente utilizados em animais e em algumas parasitoses humanas. Em bovinos, a resistência parasitária às LMs é emergente, e o surgimento de formulações que diferem nas suas propriedades farmacológicas tornou complexa a escolha da droga mais indicada a cada caso. Com o objetivo de avaliar possíveis alternativas para recuperar a eficácia de LMs sobre cepas resistentes de nematódeos (mais) gastrintestinais, testaram-se, neste estudo, dez diferentes tratamentos a base de LMs sobre uma população de nematódeos gastrintestinais de bovinos a qual, sabidamente, sofrera pressão de seleção por avermectinas a 1%. Adicionalmente, testou-se um benzimidazol. A eficácia das drogas foi calculada com base na redução de ovos por grama de fezes (OPG) dos bovinos. A resistência de cada gênero foi avaliada por meio de identificação de larvas, obtidas de cultivos nas fezes, pré- e pós-tratamentos. Não se obteve a eficácia desejada com o emprego de avermectinas de longa ação - com alta concentração e em associação - ou mesmo, com a aplicação de superdoses. Os gêneros Cooperia spp., Haemonchus spp. e Trichostrongylus spp. foram resistentes às avermectinas, e Ostertagia spp. à ivermectina. Observou-se que, uma vez estabelecida a resistência parasitária a LMs a 1%, a aplicação de fármacos, deste mesmo grupo químico, ainda que em formulações mais concentradas, asso-ciações ou superdoses, pode não resultar na eficácia esperada. Resumo em inglês The macrocyclic lactones (MLs) (avermectins and milbemycins) are endectocides broadly used in livestock and in some parasitic diseases of humans. In cattle, parasite resistance to MLs is emerging, and the appearance of formulations that differ in their pharmacological properties become complex the choice of the most appropriate drug to each case. In order to evaluate possible alternatives to restore the effectiveness of MLs on resistant strains of gastrointestinal nematod (mais) es, were tested, in this study, ten different treatments based on the MLs on a population of gastrointestinal nematodes of cattle which, known, was under pressure of selection by 1% avermectins. Additionally, was tested a benzimidazole. The efficacy of the drugs was calculated with basis on the reduction of eggs per gram of feces (EPG) of cattle. The resistance of each genus was evaluated by identification of the larvae, obtained from culture in the feces, pre- and post-treatments. The desired efficacy was not obtained using long action avermectins - with high concentration and in association - even with the application of high doses. The genera Cooperia spp., Haemonchus spp. and Trichostrongylus spp. were resistant to avermectins, and Ostertagia spp. to ivermectin. It was observed that, once established parasite resistance to the 1% MLs, the application of drugs, of this same chemical group, even in formulations of high concentration, association or in high doses, may not result in the expected efficacy.

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5

Atividade antibacteriana de furanoeliangólidos/ Antibacterial activity of furanoeliangolides

Saúde, D. A.; Barrero, A. F.; Oltra, J. E.; Justicia, J.; Raslan, D. S.; Silva, E. A.
2002-01-01

Resumo em português As lactonas sesquiterpênicas licnofólido (1) e eremantólido C (2) e alguns derivados: 1 ,2 -epóxieremantólido C (3), 1 β -hidróxi-2,3-diidroeremantólido C (4), 3 - hidróxieremantólido C (5), cloreto de 4,5-diidroeremantólido-5-n-propilamônio (6) e 1 β -hidróxi- 2,3-diidrolicnofólido (7) foram testadas contra as bactérias Enterococus faecalis S48, Bacillus subtilis CECT 397, Staphylococus aureus ATCC 8, Salmonella typhymurium LT2, Escherichia coli U9 e Proteus sp. Os compostos 1, 4, 5 e 7 apresentaram atividade antibacteriana. Resumo em inglês Sesquiterpene lactones lychnopholide (1) and eremantholide C (2) and some derivatives: 1 ,2 -epoxyeremantholide C (3), 1 β -hidroxy-2,3-dihydroeremantolide C (4), 3 -hydroxyeremantholide C (5), 5-n- propylamonium- 4,5-dihydroeremantholide C chloride (6) and 1 β -hydroxy-2,3- dihydrolychnopholide (7) were tested against Enterococus faecalis S48, Bacillus subtilis CECT 397, Staphylococus aureus ATCC 8, Salmonella typhymurium LT2, Escherichia coli U9 e Proteus sp. Compounds 1, 4, 5 and 7 showed activity.

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6

Identificação de espécies da família Asteraceae, revisão sobre usos e triagem fitoquímica do gênero Eremanthus da Reserva Boqueirão, Ingaí-MG/ Asteraceae species identification, use revision and phytochemical screening of Eremanthus genus in Boqueirão Ecological Reserve, Ingaí - Minas Gerais State, Brazil

Ribeiro, A.O.; Silva, A.F.; Castro, A.H.F.
2010-12-01

Resumo em português Com o objetivo de identificar espécies da família Asteraceae, revisar seus usos e realizar triagem fitoquímica preliminar do gênero Eremanthus procederam-se coletas botânicas semanais de espécimes na Reserva Boqueirão, localizada em Ingaí, Minas Gerais. As amostras foram herborizadas e identificadas utilizando-se bibliografia especializada e comparação com espécimes disponíveis no Herbário ESAL, da Universidade Federal de Lavras. A revisão dos usos foi feita (mais) através de consulta a obras clássicas e artigos científicos contendo relatos sobre levantamentos etnobotânicos realizados na área de estudo. Para triagem fitoquímica empregaram-se reagentes específicos para cada grupo de metabólito. Foram levantadas 102 espécies da família Asteraceae, sendo 32 delas úteis para o homem. A triagem fitoquímica dos extratos hidroalcoólicos indicaram a presença de açúcares redutores, carboidratos, aminoácidos, taninos, flavonóides, glicosídeos cardiotônicos, carotenóides, esteróides e triterpenóides, depsídeos e depsidonas, derivados de cumarina, saponinas espumídicas, alcalóides, purinas, polissacarídeos e antraquinonas. Não foram detectados ácidos orgânicos, catequinas, lactonas sesquiterpênicas e azulenos. Resumo em inglês To identify Asteraceae species, review the utilization and perform a preliminary phytochemical screening of some species of Eremanthus genus, plants were weekly collected in Boqueirão Ecological Reserve, located in Ingaí, Minas Gerais State, Brazil. The samples were herborized and identified by using a specialized bibliography and comparison with the species available in the Herbarium ESAL of the Federal University of Lavras. The utilization review was carried out by me (mais) ans of bibliographical research and ethnobotanical surveys in the sampling area. Specific reagents for each group of compounds were used for phytochemical screening. From the 102 Asteraceae species investigated, 32 were reported to be of use to humans. The phytochemical screening of the hydroalcoholic extracts indicated the presence of reducing sugars, carbohydrates, amino acids, tannins, flavonoids, glycosides cardiotonics, carotenoids, steroids and triterpenoids, depsides and depsidones, coumarin derivatives, soapy saponins, alkaloids, purines, polysaccharides and anthraquinones. On the other hand, organic acids, catechins, sesquiterpene lactones and azulenes were not detected.

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7

Síntese e avaliação da atividade fitotóxica de derivados da α-Santonina/ Synthesis and evaluation of the phytotoxic activity of α-Santonin derivatives

Alvarenga, Elson S.; Barbosa, Luiz C. A.; Saliba, William A.; Arantes, Francisco F. P.; Demuner, Antônio J.; Silva, Antônio A.
2009-01-01

Resumo em inglês Mixtures of α-Santonin and various solvents were irradiated by either high or low pressure mercury lamps. The photochemical reactions afforded lumisantonin (11) (76% in acetonitrile), (3S,3aS,9bS)-3,6,6-trimethyl-3,3a,4,5-tetrahydronafto[1,2-b]furan-2,7(6H,9bH)dione (12) (100% in acetonitrile), 10α-acetoxy-3-oxo-1,7αH,6,11βH-guaia-4-en-6,12-olide (8) (26% in acetic acid), 10α-hydroxy-3-oxo-1,7αH,6,11βH-guaia-4-en-6,12-olide (10) (32%) an (mais) d (E)-3-((3S,3aS,7aS)-3-methyl-2-oxo-6-(propan-2-ylidene)hexahydrobenzofuran-7-(7aH)-ylidene)propanoic acid (9) (44%) (in water/ acetic acid 1:1, v/v). Lactone 12 was also prepared by irradiation of lumisantonin in diethyl ether. Lactones 8 and 10 were converted, respectively, into the 10α-acetoxy-3β-hydroxy-1,7αH,6,11βH-guaia-4-en-6,12-olide (13) (87%) and 3β,10α-dihydroxy-1,7αH,6,11βH-guaia-4-en-6,12-olide (14) (75%) by sodium borohydride reduction. The effects of the compounds on the development of radicle of Sorghum bicolor and Cucumis sativus were evaluated.

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8

Síntese e avaliação da atividade antimicrobiana de furanonas halogenadas e de compostos análogos aos nostoclídeos/ Synthesis and evaluation of antimicrobial activity of halogenated furanones and compounds analogues to nostoclides

Barbosa, Luiz C. A.; Maltha, Célia R. A.; Demuner, Antônio J.; Pinheiro, Patrícia F.; Varejão, Jodieh O. S.; Montanari, Ricardo M.; Andrade, Nélio J.
2010-01-01

Resumo em inglês Considering the broad spectrum of biological activity of gamma-butyrolactone derivatives, we presented the synthesis of 3,4-dihalo-5-arylidenefuran-2(5H)-ones (17-21) and analogues (24-28) of the natural product nostoclide (7,8). Furanones 17-21 were synthesized from the condensation of aromatic aldehydes with lactones 14 and 15, that were obtained from mucobromic and mucochloric acids. Lactone 15 was converted into the intermediate 23 in 36% overall yield. Compound 23 wa (mais) s then transformed into the nostoclide analogues 24-28. Some of the compounds prepared showed antimicrobial activities against Escherichia coli, Staphylococcus aureus and Bacillus cereus comparable to commercial antibiotics.

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9

Estudo das condições reacionais da reação de clivagem oxidativa de β-hidróxi éteres bicíclicos promovida por tetróxido de rutênio/ Study of the conditions of the ruthenium tetraoxide-promoted oxidative cleavage reaction of bicyclic β-hydroxy ethers

Ferraz, Helena M. C.; Scalfo, Alexsandra C.; Vilalba, Bruno T.; Longo Jr, Luiz S.
2010-01-01

Resumo em inglês A systematic study of the reaction of β-hydroxy ethers with ruthenium tetraoxide (RuO4), generated in situ from ruthenium trichloride and sodium periodate, is presented, leading to nine-membered ring keto-lactones in moderate yields. Three different solvent systems - AcOEt/MeCN/H2O, MeCN/H2O and DMC/H2O - were studied leading to the desired products in lower yields than those obtained with the classical mixture of CCl4/MeCN/H2O, commonly used in reactions promoted by (mais) this oxidant. However, it is noteworthy that these new solvent systems represent greener alternatives to the chlorinated solvents used in the oxidative cleavage of β-hydroxy ethers by RuO4.

Scientific Electronic Library Online (Portuguese)

10

Estratégias para a síntese de γ-alquilidenobutenolídeos/ Strategies for the synthesis of γ-alkilidenebutenolides

Barbosa, Luiz Cláudio Almeida; Teixeira, Róbson Ricardo; Pinheiro, Patrícia Fontes; Maltha, Célia Regina Álvares; Demuner, Antônio Jacinto
2010-01-01

Resumo em inglês α,β-unsaturated lactones possessing an alkylidene appendage group at the γ-position, are frequently termed γ-alkylidenebutenolides. Over the past decades, an increasing number of these compounds have been isolated from various natural sources. Members of this class of substances vary greatly in structural complexity and functionality. Besides that, many of them have been shown to display a wide range of biological activities. The γ-alkylidenebuten (mais) olides has attracted the attention of the organic synthetic chemists resulting in the development of a variety of process to synthesize them. This article review is concerned with the different approaches that can be utilized to prepare γ-alkylidenebutenolides.

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11

Efeito da presença e concentração de compostos carbonílicos na qualidade de vinhos/ Effects of carbonylic compound presence and concentration on wine quality

Azevêdo, Luciana C. de; Reis, Marina M.; Silva, Luciana A. da; Andrade, Jailson B. de
2007-01-01

Resumo em inglês Studies on identification of compounds that make up the aroma and flavor in wines involve research evaluating mainly the influence of terpenes, esters, lactones and alcohols upon these sensory characteristics. However, carbonylic compounds (CC) play an important role concerning the substances that impact aroma to these drinks. Their origin is reported to be linked to the grape's chemical composition, must fermentation or micro-oxidation occurring during storage in barrels (mais) . Some CCs, like E-ionone, E-damascenone, siryngaldehyde, can contribute a pleasant aroma and improve the wine quality whereas others are responsible for unpleasant characteristics (acetaldehyde, furfural, 5-hydroxy-methyl furfural, diacetil, E-non-2-enal, etc). A fraction of CCs present is associated with bisulfite ions in the form of hydroxyalkylsulfonic acids. Some of them are stable and play an important role in determining wine quality. The reaction involving the formation of this aduct commonly occurs with CCs of low molar mass, such as formaldehyde and acetaldehyde. The reaction involving CCs with more than three carbon atoms demands further studies.

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12

Componentes voláteis do café torrado. Parte II. Compostos alifáticos, alicíclicos e aromáticos/ Volatile components in roasted coffee. Part II. Aliphatic, alicyclic and aromatic compounds

Moreira, Ricardo Felipe Alves; Trugo, Luiz Carlos; De Maria, Carlos Alberto Bastos
2000-04-01

Resumo em inglês This review is about the aliphatic, alicyclic and aromatic compounds (non-heterocyclic compounds) that are present in the volatile fractions of roasted coffees. Herein, the contents, aroma precursors and the sensorial properties of volatile phenols, aldehydes, ketones, alcohols, ethers, hydrocarbons, carboxylic acids, anhydrides, esters, lactones, amines and sulphur compounds are discussed. Special attention is given to the compounds of these groups that are actually important to the final aroma of roasted coffees.

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