Chromatographic profile of xanthones and flavonoids in the anti-dengue extracts of Fridericia samydoides (Cham. ) L. G. Lohmann (Bignoniaceae)

Abstract The flavonoids and xanthones present in the ethanol extracts of leaves and stems of Fridericia samydoides showed that anti-dengue activities in vitro were investigated qualitatively by liquid chromatography-ultraviolet-mass spectrometry in series. Nineteen flavones and fifteen xanthones were detected and characterized on the basis of their fragmentation pattern in the positive and negative ion mode tandem mass spectrometry spectra and ultraviolet bands. Acacetin, chrysin, vitexin, isovitexin, orientin, isoorientin, mangiferin, 2'-O-trans-caffeoylmangiferin, 2'-O-trans-coumaroylmangiferin and 2'-O-trans-cinnamoylmangiferin were identified by comparison with authentic samples. The other compounds detected were tentatively assigned by analysis of the spectral data and by comparison with literature reports. In addition, it performed the fractionation of the leaves extract leading to the isolation of mangiferin, isovitexin and isoorientin. All extracts and isolated compounds inhibited the Dengue virus replication cycle with EC50 less than 25.0 µg/mL for extracts and 272.5, 85.6 and 79.3 µg/mL for mangiferin, isovitexin and isoorientin, respectively.

Activation of endogenous angiotensin converting enzyme 2 prevents early injuries induced by hyperglycemia in rat retina

Diabetic retinopathy (DR) is a serious complication of diabetes mellitus that may result in blindness. We evaluated the effects of activation of endogenous angiotensin converting enzyme (ACE) 2 on the early stages of DR. Rats were administered an intravenous injection of streptozotocin to induce hyperglycemia. The ACE2 activator 1-[[2-(dimethylamino) ethyl] amino]-4-(hydroxymethyl)-7-[[(4-methylphenyl) sulfonyl] oxy]-9H-xanthone 9 (XNT) was administered by daily gavage. The death of retinal ganglion cells (RGC) was evaluated in histological sections, and retinal ACE2, caspase-3, and vascular endothelial growth factor (VEGF) expressions were analyzed by immunohistochemistry. XNT treatment increased ACE2 expression in retinas of hyperglycemic (HG) rats (control: 13.81±2.71 area%; HG: 14.29±4.30 area%; HG+XNT: 26.87±1.86 area%; P<0.05). Importantly, ACE2 activation significantly increased the RCG number in comparison with HG animals (control: 553.5±14.29; HG: 530.8±10.3 cells; HG+XNT: 575.3±16.5 cells; P<0.05). This effect was accompanied by a reduction in the expression of caspase-3 in RGC of the HG+XNT group when compared with untreated HG rats (control: 18.74±1.59; HG: 38.39±3.39 area%; HG+XNT: 27.83±2.80 area%; P<0.05). Treatment with XNT did not alter the VEGF expression in HG animals (P>0.05). Altogether, these findings indicate that activation of ACE2 reduced the death of retinal ganglion cells by apoptosis in HG rats.

Acute toxicity and sublethal effects of the mixture glyphosate (Roundup® Active) and Cosmo-Flux®411F to anuran embryos and tadpoles of four Colombian species / Toxicidad aguda y efectos subletales de la mezcla glifosato (Roundup® Activo) y Cosmo-Flux®411F en embriones y renacuajos de cuatro especies de anuros colombianos

Glyphosate is the most widely used herbicide in the world with application in agriculture, forestry, industrial weed control, garden and aquatic environments. However, its use is highly controversial for the possible impact on not-target organisms, such as amphibians, which are vanishing at an alarming and rapid rate. Due to the high solubility in water and ionic nature, the glyphosate requires of surfactants to increase activity. In addition, for the control of coca (Erythroxylum coca) and agricultural weeds in Colombia, formulated glyphosate is mixed and sprayed with the adjuvant Cosmo-Flux®411F to increase the penetration and activity of the herbicide. This study evaluates the acute toxic and sublethal effects (embryonic development, tadpole body size, tadpole swimming performance) of the mixture of the formulated glyphosate Roundup® Active and Cosmo-Flux®411F to anuran embryos and tadpoles of four Colombian species under 96h laboratory standard tests and microcosms, which are more similar to field conditions as they include soil, sand and macrophytes. In the laboratory, embryos and tadpoles of Engystomops pustulosus were the most tolerant (LC50=3 904µg a.e./L; LC50=2 799µg a.e./L, respectively), while embryos and tadpoles of Hypsiboas crepitans (LC50=2 203µg a.e./L; LC50=1 424µg a.e./L, respectively) were the most sensitive. R. humboldti and R. marina presented an intermediate toxicity. Embryos were significantly more tolerant to the mixture than tadpoles, which could be likely attributed to the exclusion of chemicals by the embryonic membranes and the lack of organs, such as gills, which are sensitive to surfactants. Sublethal effects were observed for the tadpole body size, but not for the embryonic development and tadpole swimming performance. In microcosms, no toxicity (LC50 could not be estimated), or sublethal responses were observed at concentrations up to fourfold (14.76kg glyphosate a.e./ha) the highest field application rate of 3.69kg glyphosate a.e./ha. Thus, toxicity was less in the microcosms than in laboratory tests, which may be attributed to the presence of sediments and organic matter which rapidly adsorb glyphosate and surfactants such as POEA. It is concluded that the mixture of glyphosate (Roundup® Active) and Cosmo-Flux®411F, as used in the field, has a negligible toxic effect to embryos and tadpoles of the species tested in this study.

El glifosato es el herbicida más usado en el mundo con aplicaciones para la agricultura, control de malezas forestales, industriales, en jardines y ambientes acuáticos. Sin embargo, su uso es altamente controversial por el posible impacto sobre organismos no blanco, como los anfibios, los cuales están desapareciendo a una tasa alarmantemente rápida. Debido a su alta solubilidad en agua y naturaleza iónica, el glifosato requiere de surfactantes para incrementar su actividad. Además, para el control de Erythroxylum coca y de malezas en la agricultura en Colombia, el glifosato formulado es mezclado y rociado con el coadyuvante Cosmo-Flux®411F para incrementar la penetración y actividad del herbicida. Este estudio evalúa los efectos tóxicos agudos y subletales (desarrollo embrionario, tamaño corporal y desempeño natatorio de los renacuajos) de la mezcla del glifosato formulado Roundup® Activo con el Cosmo-Flux®411F en embriones y renacuajos de cuatro especies de anuros colombianos, bajo pruebas de 96h en condiciones estándar de laboratorio y microcosmos, que son más similares a las condiciones de campo al incluir tierra, arena y macrófitas. En laboratorio, los embriones y renacuajos de Engystomops pustulosus fueron los más tolerantes (CL50=3 904µg a.e./L; CL50=2 799µg a.e./L, respectivamente), mientras que los embriones y renacuajos de Hypsiboas crepitans fueron los más sensibles (CL50=2 203µg a.e./L; CL50=1 424µg a.e./L, respectivamente). R. humboldti y R. marina presentaron una toxicidad intermedia. Los embriones fueron más tolerantes a la mezcla que los renacuajos, lo cual podría ser atribuido a la exclusión de los químicos por las membranas embrionarias y a la falta de órganos, como las branquias, que son más sensibles a los surfactantes. Se observaron efectos subletales en el tamaño corporal de los renacuajos, pero no en el desarrollo embrionario ni el desempeño natatorio de los renacuajos. En microcosmos no se observaron efectos tóxicos ni respuestas subletales a concentraciones hasta cuatro veces (14.67kg glifosato a.e./ha) la tasa de aplicación más alta de 3.69kg glifosato a.e./ha. Por lo tanto, la toxicidad fue menor en los microcosmos que en las pruebas de laboratorio, lo que puede ser atribuido a la presencia de sedimentos y materia orgánica que absorbe rápidamente el glifosato y surfactantes como el POEA. Se concluye que la mezcla del glifosato (Roundup® Activo) y Cosmo-Flux®411F, como se aplica en campo, tiene un efecto tóxico bajo en los embriones y renacuajos de las especies estudiadas.

Uso do extrato de folhas de Mangifera indica L. e da mangiferina na lesão aterosclerótica em camundongos ApoE-/- / Use of Mangifera indica L. leaves extract and mangiferin on the atherosclerotic lesion in ApoE-/- mice

As folhas de Mangifera indica L são importantes como fonte de compostos fenólicos, especialmente mangiferina, que apresentam propriedades antidiabética, hipolipemiante, antioxidante e anti-inflamatória. O estudo teve como objetivo avaliar os efeitos do extrato etanólico de folhas de M. indica e da mangiferina isolada sobre a lesão aterosclerótica em camundongos ApoE-/-. Métodos: Camundongos ApoE-/- com 15 semanas de idade foram divididos aleatoriamente em 4 grupos de acordo com o tratamento, por gavagem, durante 56 dias: controle (veículo, dimetil sulfóxido); E200 (200 mg/kg/dia de extrato da folha de M. indica), E400 (400 mg/kg/dia de extrato da folha de M. indica); M40 (40 mg/kg/dia de mangiferina). Parâmetros sanguíneos foram dosados utilizando-se kits enzimáticos e as lesões ateroscleróticas foram avaliadas pelo método en face. Resultados: O extrato seco apresentou 17% de mangiferina. Os níveis sanguíneos de colesterol total, frações HDLc e LDLc e triacilgliceróis, bem como o percentual de deposição lipídica no arco aórtico e aorta torácica não diferiram significativamente entre os grupos (p>0,05). Conclusão: A administração do extrato de folhas de M. indica e da mangiferina em camundongos ApoE-/- não afetou a lipidemia e não diminuiu as lesões ateroscleróticas pré-existentes.

Mangifera indica L leaf are an important source of phenolic compounds, especially mangiferin, that exhibits antidiabetic, hypolipidemic, anti-oxidant and anti-inflammatory activities. This study aimed to evaluate the effects of mangiferin and ethanolic extract of M. indica leaf on atherosclerotic lesions in mice ApoE-/-. Methods: Fifteenweek- old ApoE-/- mice were randomly divided into 4 groups according to the treatment giving by gavage during 56 days: control - vehicle (dimethyl sulfoxide); E200 - 200 mg/kg/day M. indica leaf extract; E400 - 400 mg/kg/day M. indica leaf extract, M40 - 40 mg/kg/day mangiferin. Administrations of vehicle, extracts and mangiferin were performed every day by gavage during 8 weeks. Blood parameters were measured using enzymatic kits and atherosclerotic lesions were evaluated by en face method. Results: The dired extract showed 17% of mangiferin. Total cholesterol, HDLc, LDLc and triglycerides blood levels, as well as the percentage of lipid deposition in the aortic arch and thoracic aorta were not significantly different between the groups (p> 0.05). Conclusion: The administration of M. indica leaf extract and mangiferin in ApoE-/- mice did not affect serum lipids and did not decreased pre-existing atherosclerotic lesions

El árbol tropical Calophyllum brasiliense: una revisión botánica, química y farmacológica / The tropical tree Calophyllum brasiliense: a botanical, chemical and pharmacological review

Antecedentes: Calophyllum brasiliense Cambess. Es un árbol de la familia Calophyllaceae, separada recientemente de Clusiaceae (Guttiferae). Se distribuye ampliamente en selvas tropicales lluviosas del continente americano, desde Brasil hasta México. Esta especie sintetiza diversos metabolitos secundarios en hojas, flores, frutos, corteza y raíz, tales como cumarinas, cromanonas, xantonas, terpenos, flavonoides y compuestos fenólicos, los cuales presentan múltiples propiedades biológicas. Objetivos: Ofrecer una visión general de las características botánicas, químicas y farmacológicas de C. brasiliense, así como evidencias químicas, anatómicas y genéticas que sugieren la existencia de quimiotipos (fenotipos químicos) en la especie. Métodos: Se revisó la información disponible en las bases de datos NCBI y SciFinder®, se seleccionaron investigaciones relevantes que permitieron conocer los compuestos químicos aislados y su actividad biológica. Resultados: Entre los compuestos sintetizados por C. brasiliense destacan calanólidos e inofilums, especialmente el (+)-calanólido A, como inhibidores potentes de la enzima transcriptasa reversa del virus de inmunodeficiencia humana tipo 1 (VIH-1) y baja toxicidad a linfocitos humanos. El (+)-calanólido A, una dipiranocumarina tetracíclica, podría ser el primer fármaco de origen natural aprobado por la FDA (EUA) en el tratamiento del VIH/SIDA. Otros compuestos, tales como cumarinas tipo mammea, cromanonas, xantonas y triterpenos, mostraron actividad contra protozoarios, células tumorales humanas, como bactericidas y antiespasmódicos. La actividad más importante de cumarinas tipo mammea es contra protozoarios como Leishmania y Trypanosoma. En relación a L. amazonensis, destacó (-)-mammea A/BB presentando buena actividad y selectividad contra amastigotes y promastigotes, y baja toxicidad en macrófagos humanos. La (-)-mammea A/BA, y las xantonas preniladas mostraron alta citotoxicidad sobre líneas celulares tumorales humanas y T. cruzi. Las evidencias químicas, anatómicas y genéticas indican que existen quimiotipos en C. brasiliense, sugiriendo un proceso de especiación en curso en el taxón. Las secuencias ribosomales (ITS) discriminaron al quimiotipo 1 (produce coumarinas tipo mammea) de los quimiotipos 2 y 3 (biosintetizan calanólidos e inofilums), siendo útiles como posibles códigos de barras. Conclusiones: El adecuado manejo de C. brasiliense mediante técnicas silvícolas y biotecnológicas, así como el conocimiento científico y tecnológico, podrían aportar soluciones a países en desarrollo, por ejemplo mediante producción de fitomedicamentos, a enfermedades como el VIH/ SIDA, Leshmaniasis y la Enfermedad de Chagas.

Rationale: Calophyllum brasiliense Cambess. Is a tree belonging to Calophyllaceae family, recently separated from Clusiaceae (= Guttiferae). This species is widely distributed in the Tropical Rain Forests of the American continent, from Brazil to Mexico. It synthesizes a wide variety of secondary metabolites isolated from leaves, flowers, fruits, bark and roots, such as coumarins, chromanones, xanthones, terpenes,flavonoids and phenolic compounds, which exhibit multiple biological properites. Objective: To provide a comprehensive view of the botanical, chemical and pharmacological characteristics of C. brasiliense, and to present chemical, anatomical and genetic evidences supporting the notion of chemotypes (chemical phenotypes) in this species. Methods: Information available in the databases NCBI and SciFinder® was reviewed, and relevant investigations were selected regarding to chemical compounds isolated and their biological activity. Results: Among compounds synthesized by C. brasiliense, calanolides and inophyllums stand out, specially (+)-calanolide A, since these can inhibit reverse transcriptase of human immunodeficiency virus type 1 (HIV-1). (+)-Calanolide A, a tetracyclic dipyranocoumarin, could be the first drug of natural origin approved by the FDA (US) in the treatment of HIV/AIDS. Other compounds, such as mammea type-coumarins, chromanones, xanthones, and triterpenes showed antitumor, antiparasitic, antibacterial and antispasmodic activity. Most important activity of mammea type-coumarins is against protozoa, such as Leishmania, and Trypanosoma. Regarding to L. amazonensis, (-)-mammea A/BB stands out, being highly potent and selective against amastigotes, and promastigotes, but poorly toxic to human macrophages. (-)-Mammea A/BA as well as prenylated xanthones showed high citotoxicity against human tumor cell lines and T. cruzi. The chemical, anatomical and genetical evidences supported the idea of chemotypes in C. brasiliense, suggesting a current process of speciation in this taxon. The ribosomal ITS sequences discriminate chemotype 1 (produces mammea type coumarins) from chemotypes 2 and 3(synthesize calanolides and inophyllums) being useful like possible barcodes. Conclusions: The proper management of Calophyllum brasiliense with forestry and biotechnological methods, as well as scientific and technological knowledge, could provide solutions to developing countries, for instance through the production of phytomedicines against HIV/AIDS, and illnesses caused by protozoa such as Leshmaniasis and Chaga's Disease.

Revisión bibliográfica sobre la composición química y actividades farmacológicas del género Vismia (Guttiferae) / A review on the chemical composition and pharmacological activities of Vismia genus (Guttiferae)

Vismia genus is an important source of natural medicinal products, thus, information collected in this review is an attempt to cover the most recent developments in the ethnopharmacology, pharmacology and phytochemistry of this genus. Anthraquinones and other quinonoid derivates, terpenoids and volatile constituents have been reported as the major constituents isolated from different Vismia species. On the other hand, pharmacological studies carried out to date have revealed the variety of anti-plasmodium, antioxidant, antimicrobial and antifungical properties of extracts and pure isolated compounds of the different species tested. The information summarized in this paper intends to serve as a reference tool to practitioners in the fields of etnopharmacology and chemistry of natural products.

El género Vismia es una fuente importante de productos naturales medicinales, es por esto que la información reunida en la presente revisión cubre los estudios más recientes en la etnofarmacología, farmacología y fitoquímica de este género. Antraquinonas y otros derivados quinoides, terpenos y constituyentes volátiles han sido reportados como los compuestos mayormente aislados de las diferentes especies de Vismia. Por otro lado, los estudios farmacológicos realizados hasta los momentos muestran las diversas propiedades antiplasmodicas, antioxidantes, antimicrobianas y antifúngicas que presentan tanto los extractos como los compuestos puros aislados de las diferentes especies ensayadas. La información resumida en este documento intenta servir de material de apoyo para investigadores en los campos de la etnofarmacologia y la química de productos naturales.

NMR elucidation and crystal structure analysis of 1-hydroxy-3, 6-dimethoxy-8-methyl-9h-xanthen-9-one (lichexanthone) isolated from Vismia baccifera (Guttiferae) / Elucidación por RMN y análisis de la estructura cristalina de 1-hidroxi-3,6-dimetox1-8-methil-9h-xanten-9-ona (lichexanthone)

In the present investigation the structural analysis of 1-hydroxy-3,6-dimethoxy-8-methyl-9h-xanthen-9-one (lichexanthone) isolated from Vismia baccifera var. dealbata collected in Mérida-Venezuela, was established by NMR (1H and 13C), mass spectrometry and single crystal X-ray diffraction. Lichexanthone crystallizes in the monoclinic system, space group P21/c (No 14) with unit cell parameters a = 11.6405(5) Å; b = 7.5444(3) Å; c = 15.2341(6) Å; = 102.280(1)°; V = 1307.26(9) Å3; Z = 4. The structure refinement converged to R = 0.0397, wR2 = 0.1076, S = 1.04. Lichexanthone had been isolated before from Parmotrema sp and Ruprechtia tangarana (Polygonaceae). However, to the best of our knowledge, this is the first report of this compound obtained from V. baccifera var. dealbata (Guttiferae).

En la presente investigación el análisis estructural de 1-hidroxi-3,6-dimetoxi-8-metil-9h-xanten-9-ona (lichexanthone) aislada de Vismia baccifera var. dealbata colectada en Mérida-Venezuela, fue determinado por RMN (1H y 13C), espectrometría de masas y difracción de rayos X. La lichexanthona cristaliza en un sistema monoclínico con un grupo espacial P21/c (No 14) y parámetros de celda de a = 11.6405 (5) Å; b = 7.5444 (3) Å; c = 15.2341 (6) Å; = 102.280(1)°; V = 1307.26(9) Å3; Z = 4. El refinamiento de la estructura convergió a los valores de R = 0.0397, wR2 = 0.1076, S = 1.04. La lichexanthona ha sido aislada de Parmotrema sp y Ruprechtia tangarana (Polygonaceae). Sin embargo, para nuestro conocimiento, esta es la primera vez que se reporta el aislamiento de este compuesto en la especie V. baccifera var. dealbata (Guttiferae).

Phytochemical and antioxidant studies of Laurera benguelensis growing in Thailand

The aim of this study was to investigate metabolites of the lichen Laurera benguelensis. A high-performance liquid chromatographic (HPLC) method has been developed for the characterization of xanthones and anthraquinones in extracts of this lichen. Lichexanthone, secalonic acid D, norlichexanthon, parietin, emodin, teloschistin and citreorosein were detected in the lichen samples, which were collected from two places in Thailand. Components of the lichen were identifed by relative retention time and spectral data. This is the frst time that a detailed phytochemical analysis of the lichen L. benguelensis was reported and this paper has chemotaxonomic signifcance because very little has been published on the secondary metabolites present in Laurera species. Some of the metabolites were detected for the frst time in the family Trypetheliaceae. The results of preliminary testing of benzene extract and its chloroform and methanol fractions showed that all samples showed a weak radical scavenging activity. The chloroform extract showed the highest antioxidant activity.

Indução de metabólitos secundários em plântulas de Hypericum brasiliense Choisy crescendo in vitro / Induction of secondary metabolites in plantlets of Hypericum brasiliense Choisy in vitro

A produção de rutina, quercetina, 1,5-diidroxixantona e ácido betulínico foi investigada em plântulas de H. brasiliense crescendo in vitro, sob a influência de ácido salicílico, polietilenoglicol, NaCl, 24-epibrassinolídeo, benzotiadiazole (BION), metiljasmonato e concentrações aumentadas de boro e nitrogênio no meio líquido de cultura. As avaliações foram feitas após 5 e 10 dias do início dos tratamentos. Os maiores aumentos de conteúdo foram observados com quercetina para boro e ácido salicílico aos 5 dias, e 24-epibrassinolídeo e BION aos 10 dias.

The production of rutin, quercetin, 1,5-dihydroxyxanthone and betulinic acid was investigated in plantlets of H. brasieliense in vitro, and exposed to salycilic acid, poliethylene glycol, NaCl, 24-epibrassinolide, benzothiadiazole (BION), methyljasmonate and increased concentrations of boron and nitrogen in the liquid culture medium. Evaluations of the contents were carried out after 5 and 10 days of treatments. The highest increase was observed in quercetin in the salycilic acid and B treatments after 5 days of exposure, and in 24-epibrassinolide and BION after 10 days.