Phytochemical investigation of the inflorescences of Dictyoloma vandellianum A. Juss. (Rutaceae) has led to the isolation of a new A-seco-limonoid, named dictyolomol (1), along with a known quinolone alkaloid, casimiroine (2), previously isolated from the same species. The structures were established by spectroscopic analysis such as one- and two-dimensional NMR, IR, high-resolution mass spectrometry and chemical transformations. The isolated compounds (1 and 2) and O-acetyl derivative (1a) were evaluated for their cytotoxicity against MCF-7 and HeLa cancer cell lines. The results indicated that 1, 1a and 2 showed no significant cytotoxicity.

Resumo Apesar do grande número de pesquisas que vêm sendo realizadas em pós-graduações, as contribuições destas para a melhoria do processo de ensino-aprendizagem ainda não chegam à sala de aula, ficando muitas vezes esquecidas/inutilizadas. Diante da necessidade de integrar a pós-graduação com o ensino básico, nesse trabalho, a emodina, substância isolada de uma espécie vegetal e identificada por métodos espectroscópicos, durante a pós-graduação em produtos naturais, foi utilizada em aulas teóricas e práticas para ensino médio, sendo discutido seus espectros de infravermelho e ultravioleta, e sua atividade como indicador natural de pH. Através disso, foi possível despertar o interesse dos discentes pela pesquisa em química, fortalecendo o processo de ensino-aprendizagem.

Abstract Despite the large number of researches that are being carried out in postgraduate studies, their contributions to the improvement of the teaching-learning process still do not reach the classroom, and are often forgotten/unused. Faced with the need to integrate post-graduation with elementary education, in this work, the emodin, isolated substance of a plant species, and identified by spectroscopic methods, during postgraduate courses in natural products, was used in theoretical and practical classes for teaching high school students, being discussed its infrared and ultraviolet spectrum, and its activity as a natural indicator of pH. Through this, it was possible to arouse the interest of students through chemistry research, strengthening the teaching-learning process.

Abstract Annona leptopetala (R.E.Fr.) H. Rainer, Annonaceae, is used in folk medicine like antitumor and anti-inflammatory. The aim of this study was to determine chemical composition, toxicity and antitumor activity of A. leptopetala leaves volatile oil. Fresh leaves were hydrodistilled and then the volatile oil chemical composition was assessed by gas chromatography and mass spectrometry. Toxicity was assessed using haemolysis, micronucleus and acute toxicity protocols. Antitumor effects were determined in vitro and in vivo, using sulforhodamine B assay and sarcoma 180 murine tumor model, respectively. Spathulenol was the major component identified (12.56%). The volatile oil showed in vitro antitumor activity mainly in leukemia cell line (K-562), with Total growth inhibit (TGI) (concentration producing TGI) of 0.64 µg/ml. In other hand, the volatile oil <250 µg/ml did not inhibit HaCat non-tumor cell line growth. The concentration that produced 50% haemolysis was 372.8 µg/ml. The 50% lethal dose in mice was approximately 447.2 mg/kg intraperitoneally. Sarcoma 180 tumor growth inhibition rates were 59.29% and 58.77% at 100 and 150 mg/kg intraperitoneally, respectively. The volatile oil presented moderate gastrointestinal toxicity and no genotoxicity was observed at 350 mg/kg. Thus, the volatile oil shows antitumor activity with moderate toxicity.

ABSTRACT Harrisia adscendens (Gürke) Britton & Rose is a species of the family Cactaceae found in the northeastern semi-arid and popularly known as foxtail. In folk medicine, the roots of this species are used for the treatment of toothache and heartburn. The objective of this study was to perform the isolation and identification of the secondary metabolites obtained from the vegetal drug by chromatographic and spectroscopic techniques and to evaluate the antimicrobial activity of the extract. The qualitative phytochemical analysis of the extract showed suggestive results for the presence of alkaloids. Two compounds were isolated and identified: 2-methyl-9H-β-carboline-2-ion, a β-carboline alkaloid obtained for the first time as a natural product and 2',6'-dihydroxy-4'-methoxyacetophenone-2'-O-β-glucoside. In the antimicrobial tests, it was possible to observe activity against Pseudomonas aeruginosa. The results obtained by spectroscopic techniques allowed to characterize the phytochemical properties of the vegetal drug and may be useful in future studies for production of herbal medicines.

The phytochemical investigation of Erythroxylum pulchrum St. Hil. (Erythroxylaceae) led to the isolation of three known flavonoid glycosides quercetin-3-O-α-L-rhaminoside, ombuin-3-ruthinoside and ombuin-3-ruthinoside-5-glucoside. These flavonoids are being described for the first time in this E. pulchrum. The structures of the compounds were determined by analysis of IR, MS and NMR data, as well as by comparison with literature data. The methanolic extract of leaves from E. pulchrum inhibited the growth of the Bacillus subtilis CCT 0516, Escherichia coli ATCC 2536, Pseudomonas aeruginosa ATCC 8027, P. aeruginosa ATCC 25619, Staphylococcus aureus ATCC 6538, S. aureus ATCC 25925, Streptococcus sanguinis ATCC 15300, S. salivarius ATCC 7073, S. mutans ATCC 25175 and Streptococcus ATCC. S. aureus ATCC 25925 was the most sensitive among the other S. sanguinis while S. salivarius proved the most resistant.

O estudo fitoquímico das folhas de Maytenus distichophylla Mart. ex Reissek levou ao isolamento de um novo triterpeno 3,16,21-trioxo-6β,12α-dihidroxi-1-en-friedelano, nomeado maytensifolona, juntamente com os triterpenos conhecidos, 3-oxofriedelano, 3,12-dioxofriedelano, 3β-hidroxifriedelano, 3-oxo-29-hidroxifriedelano, 3-oxo-12α-hidroxifriedelano e 3-oxo-30-hidroxifriedelano. A identificação estrutural foi baseada em métodos espectroscópicos e comparação com dados da literatura

Phytochemical study of the leaves of Maytenus distichophylla Mart. ex Reissek led to the isolation of the new triterpene 3,16,21-trioxo-6β,12α-dihydroxy-1-en-friedelane, named maytensifolone, along with the known triterpenes 3-oxofriedelane, 3,12-dioxofriedelane, 3β-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 3-oxo-12α-hydroxyfriedelane and 3-oxo-30-hydroxyfriedelane. Their structural identification was based on spectroscopic methods and comparison with literature data.

The phytochemical investigation of Byrsonima gardneriana led to the isolation of five triterpenes and one flavonoid: D:B-Friedoolean-5-en-3-one (1), friedoolean-14-en-3-one (2), friedelan-3-one (3), lup-20(29)-en-3-ol (4), 3β-hydroxiolean-12-ene (5) and 3,3',4',5,7-pentahydroxyflavan (6). Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques and comparison with published spectral data. Antioxidant activities of ethanol extract and phases were measured using the 1,2-diphenyl- 2-picryl-hydrazyl (DPPH) free radical scavenging assay, evaluation of total phenolic content and trolox equivalent antioxidant capacity (TEAC).

The phytochemical investigation of L. macrophylla Benth led to the isolation of a new flavanol named licanol: (-)-4'-O-methyl-epigallocatechin-3'-O-α-L-rhamnoside, along with nine known compounds, identified as: (-)-4'-O-methyl-epigallocatechin, pheophytin A, 13²-hydroxy-(13²-S)-pheophytin A, pheophytin B, sitosterol, stigmasterol, sitosterol-β-O-glucoside, betulinic alcohol and oleanolic acid. The structures were established based on IR, HR-ESI-MS, and NMR spectrometric data analysis with the aid of 2D techniques. The methanolic extracts of leaves and stem bark as well as the compounds licanol, 13²-hidroxi-(13²-S)-feofitina A, and betulinic alcohol demonstrated antimicrobial activity against several bacterial strains.

The new dibromotyrosine derivative 3,5-dibromo-4-[3'dimethylamonium]propoxyphenyl]-N,N,N-trimethylethanamonium, here referred to as aplysfistularine (1), was isolated from the marine sponge Aplysina fistularis along with 2-(3,5-dibromo-4methoxyphenyl)-N,N,N-trimethylethanamonium (2), aplysterol (3) and 24,28-didehydroaplysterol (4). Their identification was performed by mass spectrometry, infrared, ¹H and 13C NMR, and by comparison with literature data. Compound 2 and the mixture of 3 and 4 were tested in vitro (inhibitory activity) with supercoiled DNA relaxation techniques, and showed inhibitory activity on human DNA topoisomerase II-α. Compound 1 was not tested due to paucity of the material.

The Annonaceae family is distributed throughout Neotropical regions of the world. In Brazil, it covers nearly all natural formations particularly Annona, Xylopia and Polyalthia and is characterized chemically by the production of sources of terpenoids (mainly diterpenes), alkaloids, steroids, polyphenols and, flavonoids. Studies from 13C NMR data of diterpenes related with their botanical occurrence were used to generate self-organizing maps (SOM). Results corroborate those in the literature obtained from morphological and molecular data for three genera and the model can be used to project other diterpenes. Therefore, the model produced can predict which genera are likely to contain a compound.

The phytochemical investigation of Rollinia leptopetala led to the isolation of a new compound named α-terpinyl caffeate, and five known compounds, being three sesquiterpenes, spathulenol, β-caryophyllene and 4β,10α-aromadendrane-diol, and two alkaloids, (-)-3-hydroxynornuciferine and (+)-norisocorydine. These alkaloids are being described for the first time in this genus. The structures of the compounds were determined by analysis of IR, MS and NMR data, as well as by comparison with literature data. The crude extract of R. leptopetala leaves demonstrated a weak cytotoxicity on sarcoma 180 cells with an IC50 of 512.3 µg/mL. However, the in vivo results showed that the extract exhibited a significant dose-dependent tumor growth reduction.

Danos aos tecidos devido ao estresse oxidativo estão diretamente ligados ao desenvolvimento de muitos, senão todos, os fatores de sedentarismo e de doenças crônicas. Neste contexto, a busca de moléculas naturais, que participam da nossa dieta e que possuam atividade antioxidante, flavonóides, torna-se de grande interesse. Neste estudo, nós investigamos um conjunto de 41 flavonóides (23 flavonas e 18 flavonóis), relacionando suas estruturas e atividade antioxidante. Os dados experimentais foram submetidos à análise de QSAR (relações quantitativas estrutura-atividade). Dados de RMN 13C foram utilizados para realizar um estudo do mapa auto-organizável de Kohonen, analisando o peso que cada carbono tem na atividade. Além disso, realizamos uma MLR (regressão múltipla) usando GA (algoritmos genéticos) e descritores moleculares para avaliar a influência de carbonos e substituições na atividade.

Tissue damage due to oxidative stress is directly linked to development of many, if not all, human morbidity factors and chronic diseases. In this context, the search for dietary natural occurring molecules with antioxidant activity, such as flavonoids, has become essential. In this study, we investigated a set of 41 flavonoids (23 flavones and 18 flavonols) analyzing their structures and biological antioxidant activity. The experimental data were submitted to a QSAR (quantitative structure-activity relationships) study. NMR 13C data were used to perform a Kohonen self-organizing map study, analyzing the weight that each carbon has in the activity. Additionally, we performed MLR (multilinear regression) using GA (genetic algorithms) and molecular descriptors to analyze the role that specific carbons and substitutions play in the activity.

Foi isolado das folhas de Nanuza plicata um novo biflavonóide, chamado 3',8"-biisocampferideo (1), juntamente com os conhecidos compostos amentoflavona (2), ácido patagônico(3),(4aR,5S,6R,8aR)-5-[2-(2,5-dihidro-5-metóxi-2-oxofuran-3-il)etil]-3,4,4a,5,6,7,8, 8a-octahidro-5,6,8a-trimetilnaftaleno-1-ácido carboxílico (4), cafeoilquinato de metila (5), ácido 3,5-di-cafeoilquínico (6) e luteolina (7). Os compostos 3, 4, 5 e 6 são relatados pela primeira vez em Velloziaceae. As estruturas dos compostos foram elucidadas com base em métodos espectroscópicos, especialmente RMN e EM. A citotoxicidade de 3',8"-biisocampferideo foi estudada em células de glioblastoma humano (GL-15). A concentração efetiva, que produziu morte em 50% das células após 72 h foi 36,5 µmol L-1. Alterações na morfologia celular, incluindo retração e degradação de citoplasma, foram observadas quando as células foram tratadas com concentrações a partir de 20 µmol L-1 de 3',8"-biisocampferideo por 72h.

A novel biflavonoid, named 3',8"-biisokaempferide (1), along with the known compounds amentoflavone (2), patagonic acid (3), (4aR,5S,6R,8aR)-5-[2-(2,5-Dihydro-5-methoxy-2-oxofuran-3-yl)ethyl]-3,4,4a,5,6,7,8,8a-octahydro-5,6,8a-trimethylnaphthalene-1-carboxylic acid (4), 5-caffeoylquinic acid methyl ester (5), 3,5-di-caffeoylquinic acid (6) and luteolin (7), were isolated of the leaves from Nanuza plicata. The compounds 3, 4, 5 and 6 are reported for the first time in Velloziaceae. The structures of the compounds were elucidated on the basis of spectroscopic methods, especially NMR and MS analyses. The cytotoxicity of 3',8"-biisokaempferide was studied in cultures of human glioblastoma GL-15 cells. The effective concentration, which killed 50 % of cells after 72 h was 36.5 µmol L-1. Changes in cellular morphology, including retraction and degradation of cytoplasm, were observed when cells were treated with concentrations from 20 µmol L-1 of 3',8"-biisokaempferide for 72 h.

Malária é uma doença parasitária humana causada por protozoários do gênero Plasmodium. Esta doença tem acometido populações que habitam regiões tropicais e subtropicais. Anualmente, cerca de 500 milhões de casos ocorrem no mundo, o que permite ser considerada uma doença emergente de importância para a saúde pública. Neste contexto, os produtos naturais, a exemplo das espécies vegetais, têm suas moléculas bioativas como alvo para estudos farmacológicos, toxicológicos e fitoquímicos destinados à síntese de medicamentos mais eficazes para o tratamento de inúmeras doenças. Portanto, este trabalho fornece subsídio às pesquisas com produtos naturais para o tratamento da malária. Nesta revisão, 476 espécies de plantas do continente Americano foram relatadas para a atividade antimalárica, sendo destas 198 ativas e 278 inativas para algum tipo de Plasmodium, quando avaliados através de modelos in vitro e in vivo.

Malaria is a human parasitic disease caused by protozoa species of the Plasmodium genus. This disease has affected populations of the tropical and subtropical regions. About 500 million new cases occur annually on the world and therefore it is considered an emerging disease of important public health problem. In this context, the natural products as vegetables species have their bioactive molecules as targets for pharmacological, toxicological and phytochemical studies towards the development of more effective medicines for the treatment of many diseases. So this work intends to aid the researchers in the study of natural products to the treatment of malaria. In this review, 476 plants of the American continent were related for the antimalarial activity and of these vegetables species 198 were active and 278 inactive for some type of Plasmodium when they were evaluated through of in vitro or in vivo bioassays models.