Search

Montrichardia linifera (Araceae), conhecida popularmente como 'aninga', faz parte dos ecossistemas de várzea da Amazônia e da dieta natural de animais como peixe-boi, tartarugas, peixes, búfalo e gado. Com o objetivo de contribuir para o conhecimento químico e valor nutricional da mesma, folhas e frutos de M. linifera foram coletados às margens dos rios Guamá e Maratauíra, no Estado do Pará, Brasil. Em folhas e frutos foram realizadas análises de umidade, resíduo mineral fixo (cinzas), lipídios, proteínas, fibra bruta, concentração de carboidratos e valor calórico. A composição mineral (Ca, Mg, Cu, Fe, Zn e Mn) foi obtida por espectrometria de absorção atômica de chama. Observou-se que tanto as folhas quanto os frutos da aninga, apesar de calóricos (289,75 kcal e 355,12 kcal, respectivamente), possuem baixo valor protéico (0,44% e 0,24 %, respectivamente). As concentrações de manganês obtidas (folha = 3279,46 mg kg-1e fruto = 18151,53 mg kg-1) foram consideradas tóxicas, extrapolando o limite máximo tolerável para ruminantes (1000 mg kg-1). A M. linifera, tem capacidade de absorver e bioacumular grandes quantidades de Ca, Mg e Mn presentes no solo, o que torna inadequada a sua utilização exclusiva na alimentação de quelônios, bovinos e bubalinos, havendo necessidade de mais estudos para sua aplicação como parte da ração. The aninga (Montrichardia linifera, Araceae) is often found in the floodplain ecosystems of the Amazon and is the natural diet of animals such as manatees, turtles, fish, buffalo and cattle. Aiming to contribute to the chemical knowledge and nutritional value of this plant, leaves and fruits of M. linifera were collected on the banks of the Guama and Maratauira rivers, Para State, Brazil. We determined the moisture content, ash mineral composition, lipids, protein, fiber, carbohydrate and caloric value of the fruits and leaves. The mineral composition (Ca, Mg, Cu, Fe, Zn and Mn) was obtained by flame atomic absorption spectrometry. The leaves and the fruits of M. linifera had caloric values of 289.75 kcal and 355.12 kcal, respectively; and a low protein concentration, 0.44% for leaves and 0.24% for fruits. Manganese concentrations were 3279.46 mg kg-1 for leaves and 18151.53 mg kg-1 for fruits. These Mn concentrations are considered toxic, as they exceed the maximum tolerable for the ruminants (1000 mg kg-1). The M. linifera has the capacity to absorb and bioaccumulate large amounts of Ca, Mg and Mn in the soil, which makes it inappropriate for exclusive use as food for turtles, cattle and buffaloes, requiring more studies for its application as part of the diet. MÜLLER, R. C. S.; DANTAS, K. G. F.; ALVES, C. N. Universidade Federal do Pará

Labdane diterpenes exhibit important bioactivities such as cardiovascular effects in rats as well as effects in the treatment of autoimmune diseases and Alzheimer syndrome. Recently, the labdane diterpenes ent-13-epi-manoil oxide, ribenone and ribenol were isolated from Croton palanostigma. The computational method DFT/B3LYP/cc-pVDZ was used to optimize the structures of these diterpenes and to calculate infrared data. Chemical shifts (δH and δC) of the minimum energy structures (local minimum) were calculated and compared with the experimental data. Comparison of the NMR data by simple linear regression (SLR) showed satisfactory statistical results with a correlation coefficient (R2) and predictive ability (Q2) of over 98%. The predicted NMR data were used to confirm the δH values that have not been published.

Levels of Ca, Mg, Fe, Zn, Cu and Mn were determinated by FAAS in the tea and dry matter from senescent leaf from Montrichardia linifera, plant used in folk medicine Amazon. The content of these metals that are transferred of the leaf to the infusions have presented significant reductions, however, the Mn values in the infusion may exceed the tolerable daily intake (11 mg) if consumption of this tea is greater than 1.0 L per day. So the tea of senescent leaves of M. linifera may be considered as a toxic beverage and thus its use is not advised.

Trata da investigação química das folhas e caule da espécie Ouratea castaneifolia (DC.) Engl., sobre a qual não há registros de estudos químicos ou farmacológicos anteriores. O estudo fitoquímico clássico dos extratos orgânicos do caule e das folhas de O. castaneifolia foi aliado à técnica da cromatografia líquida de alta eficiência (CLAE) e resultou na identificação de dezessete metabólitos: sete triperpenos (friedelina, 3β-friedelinol, α-amirina, β-amirina, lupeol, taraxerol e germanicol), quatro esteróides (sitosterol, estigmasterol e os glucosídeos sitosteril 3-O-β-D-glicopiranosídeo e estigmasteril 3-O-β-D-glicopiranosídeo), uma isoflavona (5,7,4´-trimetoxiisoflavona), uma flavona (5,4´-diidroxi-7,3´,5´-trimetoxiflavona), quatro biflavonas (amentoflavona, 7,7”-O-dimetil-amentoflavona, heveaflavona e tetrametilamentoflavona). A identificação das substâncias foi feita com base na análise de espectros de RMN de 1H, 13C e técnicas bidimensionais. As classes dos metabólitos identificados estão de acordo com aquelas citadas em estudos químicos do gênero Ouratea. This paper presents the chemical investigation of the leaves and stems of Ouratea castaneifolia (DC.) Engl.. There are no chemical or pharmacological studies with this species. Classic phytochemical investigation of the organic extracts together with high pressure liquid chromatography (HPLC) procedures lead to the identification of seventeen metabolites: seven triterpenes (friedelin, 3β-friedelinol, α-amyrin, β-amyrin, lupeol, germanicol and taraxerol), four steroids (sitosterol, stigmasterol and the glycosides sitosteryl 3-O-β-D-glucopyranoside and stigmasteryl 3-O-β-D-glucopyranoside), one isoflavone (5,7,4’-trimethoxyisoflavone), one flavone (5,4’-dihydroxy-7,3’,5’-trimethoxyflavone) and four biflavones (amenthoflavone, 7,7”- O-dimethylamenthoflavone, heveaflavone and tetramethylamenthoflavone). The structures of the compounds were established by the analysis of 1H, 13C NMR spectra including bidimensional techniques. The classes of the identified metabolites are in agreement with previous studies of the Ouratea genus.

Os óleos essenciais das folhas, ramos finos, galhos, cascas do caule e frutos de Croton palanostigma foram analisados por CG e CG-EM. Os componentes principais determinados no óleo das folhas foram linalol (25,4%), (E)-cariofileno (21,0%), metileugenol (17,2%) e β-elemeno (6,0%); no óleo dos ramos finos foram α-pineno (41,4%), limoneno (29,0%), sabineno (11,5%) e β-pineno (5,7%); no óleo dos galhos foram metileugenol (24,1%), (E)-metilisoeugenol (15,3%), α-pineno (11,2%) e (E)-cariofileno (8,5%); no óleo das cascas do caule foram a-pineno (31,6%), metileugenol (25,6%) e (E)-metilisoeugenol (23,7%); e no óleo dos frutos foram linalol (42,7%), metileugenol (16,3%) e β-elemeno (6,4%). Análise estatística mostrou que as folhas e os frutos apresentam significante similaridade entre si, assim como os galhos e as cascas do caule. Adicionalmente, o óleo obtido das cascas do caule possui elevada atividade larvicida sobre Artemia salina (CL50, 3,71 ± 0,01 mg mL-1). The essential oils of leaves, twigs, branches, trunk bark and fruits of Croton palanostigma were analyzed by GC and GC-MS. The main compounds found in the oil of the leaves were linalool (25.4%), (E)-caryophyllene (21.0%), methyleugenol (17.2%) and β-elemene (6.0%); in the oil of the twigs were α-pinene (41.4%), limonene (29.0%), sabinene (11.5%) and β-pinene (5.7%); in the oil of the branches were methyleugenol (24.1%), (E)-methylisoeugenol (15.3%), α-pinene (11.2%) and (E)-caryophyllene (8.5%); in the oil of the trunk bark were a-pinene (31.6%), methyleugenol (25.6%) and (E)-methylisoeugenol (23.7%); and in the oil of the fruits were linalool (42.7%), methyleugenol (16.3%) and β-elemene (6.4%). Statistical analysis showed that the leaves and fruit, and the branches and trunk bark, have significant similarities between them. In addition, the trunk bark oil has high brine shrimp larvicidal activity (LC50, 3.71 ± 0.01 mg mL-1).

Two compounds, (+)-catechin and epicatechin, were isolated from leaves of T. myrmecophyla, using chromatographic techniques. The structural identification was carried out on the basis of 1H and 13C NMR spectral data and comparison with literature data. The compounds (+)-catechin and epicatechin were submitted to germination inhibition and radicle and hypocotyl growth assays. Results showed some significant activities confirming the initial hypothesis about allelopathic properties of that plant.

Two compounds, (+)-catechin and epicatechin, were isolated from leaves of T. myrmecophyla, using chromatographic techniques. The structural identification was carried out on the basis of ¹H and 13C NMR spectral data and comparison with literature data. The compounds (+)-catechin and epicatechin were submitted to germination inhibition and radicle and hypocotyl growth assays. Results showed some significant activities confirming the initial hypothesis about allelopathic properties of that plant.

O uso do fogo e de roçadeira para controle de plantas daninhas em pastagens tem se mostrado pouco efetivo. Já o uso de herbicidas sintéticos, embora mais eficaz no controle de plantas daninhas, tem sido questionado quanto ao impacto ambiental. Portanto, a busca de compostos naturais para possível utilização como herbicida é de fundamental importância. Esses fatos motivaram o presente estudo, que teve como objetivos isolar, identificar e caracterizar a atividade alelopática potencial de substâncias químicas produzidas por Myrcia guianensis (pedra-ume-caá). Foram analisados os efeitos potenciais alelopáticos de extratos brutos, partições, óleo essencial e das substâncias químicas isoladas (ácido gálico e ácido protocatecuico) sobre a germinação e o desenvolvimento da radícula e do hipocótilo das plantas daninhas Mimosa pudica (malícia) e Senna obtusifolia (mata-pasto) em pastagens. Os extratos brutos e as partições foram analisados em concentração de 1%; o óleo essencial, em concentrações de 1, 5, 10, 15 e 20 ppm; e as substâncias isoladas, em concentrações de 15, 30, 45 e 60 ppm. A espécie malícia se mostrou mais sensível aos efeitos alelopáticos dos extratos brutos e das partições. O óleo essencial inibiu a germinação da malícia e estimulou a germinação no mata-pasto. A atividade alelopática das substâncias químicas isoladas esteve associada à concentração, e a atividade mais intensa foi em 60 ppm. The use of fire and mowing as weed methods have proved inefficient. Although more efficient, synthetic chemical herbicides are usually related to environmental problems. Thus, the search for natural herbicides has become a priority matter. Based on these facts, research was conducted on Myrcia guianensis (pedra-ume-caá) including the isolation and identification of chemical substances with allelophatic activity. The allelophatic effects of extracts, fractions, essential oils, and isolated chemical substances (gallic acid and protocatechuic acid) on germination and radicle and hypocotyl growth of weed species Mimosa pudica (malícia) and Senna obtusifolia (mata-pasto) were analyzed. Extracts and fractions were analyzed at a concentration of 1%, essential oils at 15, 30, 45, 60 ppm and the isolated chemical substances at 15, 30, 45, 60 ppm. Malicia showed more sensitivity to the allelophatic effects of extracts and fractions. The essential oil inhibited the germination of M. pudica but stimulated that of S. obtusifolia. The allelophatic effects of the chemical substances were concentration dependent and the strongest activity was observed at 60 ppm.

O fracionamento do extrato hexânico do caule de um espécime de reflorestamento de Tectona grandis (Verbenaceae), através de procedimentos fitoquímicos clássicos, levou ao isolamento das naftoquinonas lapachol e desidro-a-lapachona e das antraquinonas tectoquinona e obtusifolina. As estruturas das substâncias foram caracterizadas através da análise de métodos espectrométricos de RMN. Este é o primeiro estudo fitoquímico de um espécime de reflorestamento de Tectona grandis, no Brasil, sendo o objetivo principal deste trabalho a comprovação da presença de tectoquinona em espécimes cultivados. The hexane extract of the bark of Tectona grandis (Verbenaceae) afforded two anthraquinones and two naphtoquinones. Their caracterizations were obtained through NMR spectroscopic techniques. This is the first phytochemical study of the bark of Tectona grandis reforestation specimen in Brazil. The main interest in this work is proving the presence of tectoquinone in reforestation specimen.

Duas novas flavonas, 5 -hidroxi -7,5' -dimetoxi -3',4' -metilenodioxiflavona e 5 -hidroxi -7,3',5' -trimetoxi -4' -(3,3 -dimetilaliloxi) flavona foram isoladas das folhas de Ficus gomelleira, juntamente com três flavonas conhecidas, a 5,6,7,3',4',5' -hexametoxiflavona, 5 -hidroxi -8,3',4' -trimetoxi -2'',2'' -dimetilpirano (5",6":6,7) -flavona e 5 -hidroxi -8,3',4',5' -tetrametoxi -2'',2'' -dimetilpirano (5",6":6,7) -flavona. As estruturas das substâncias isoladas foram elucidadas com base na análise de seus dados espectrais, bem como por comparação com dados da literatura. Two new flavones, 5 -hydroxy -7,5' -dimethoxy -3',4' -methylenedioxyflavone and 5 -hydroxy -7,3',5' -trimethoxy -4' -(3,3 -dimethylallyloxy) flavone, as well as three known flavones: 5,6,7,3',4',5' -hexamethoxyflavone, 5 -hydroxy -8,3',4' -trimethoxy -2'',2'' -dimethylpyrano (5",6":6,7) -flavone and 5 -hydroxy -8,3',4',5' -tetramethoxy -2'',2'' -dimethylpyrano (5",6":6,7) -flavone were isolated from the leaves of Ficus gomelleira. Their structures were elucidated by spectroscopic methods and comparison with literature data.

Uma nova cumarina , a 5,6-metilenodioxi-7,8-dimetoxicumarina, foi isolada a partir dos galhos de Metrodorea flavida, juntamente com outras cumarinas e alcalóides conhecidos. As estruturas das substâncias isoladas foram definidas por análises de seus dados espectrais , bem como por comparação com dados da literatura. A new coumarin, 5,6-methylenedioxy-7,8-dimethoxycoumarin has been isolated from the stems of Metrodorea flavida, as well as known coumarins and alkaloids. The structures of the new and the known compounds were established by spectral data and by comparison with the literature data.