Tripanocide and antibacterial activity ofAlvaradoa subovata Cronquist extracts / Actividad tripanocida y antibacteriana de extractos de Alvaradoa subovata Cronquist

We studied antioxidant, antibacterial and tripanocide activities of Alvaradoa subovata extracts. The ethanolic extracts showed the greatest DPPH radical scavenging capacity, especially that of bark with an IC50 = 4.7 +/- 0.18 ug/mL. Wood dichloromethane extract displayed growth inhibition of the phytopathogenic bacteria Xanthomona axonopodis in the disk diffusion assay and showed a MIC value of 100 ug/ml. It also showed growth inhibition of Trypanosoma cruzi (IC50 = 0.063 +/- 0.003 mg/mL). A fraction of this extract, which has emodin as the main component, showed tripanocide activity (60 percent of growth inhibition at 100 ug/mL). The main compounds in wood dichloromethane extract were anthraquinones, identified as chrysophanol and emodin, and coumarins, of which scopoletin was identified. These three compound s could serve as analytical markers of the extract. The results of this study show that wood extract of A. subovata constitute a source of bioactive compounds such as antiparasitic and pesticides agents.

En el presente trabajo se estudió la actividad antioxidante, antibacteriana y tripanocida de extractos de Alvaradoa subovata. La mayor actividad depuradora de radicales libres se observó en el extracto etanólico de corteza (CI50 = 4.7 +/- 0.18 ug/mL). El extracto en diclorometano de madera inhibió el crecimiento de la bacteria fitopatógena Xanthomona axonopodis con una CIM = 100 ug/mL. El mismo extracto mostró inhibición del crecimiento de Trypanosoma cruzi (CI50 = 0.063 +/- 0.003 mg/mL). Una fracción de este extracto (100 ug/mL), cuyo componente mayoritario es emodina, inhibió en un 60 por ciento el crecimiento del parásito. Los compuestos mayoritarios detectados en el extracto de madera fueron antraquinonas, entre las cuales se identificaron emodina y crisofanol, y la cumarina escopoletina. Estos tres compuestos podrían servir como marcadores analíticos del extracto. Los resultados de este trabajo muestran que los extractos de A. subovata constituyen una fuente de compuestos bioactivos con potencial como antiparasitarios y plaguicidas.

Actividad antioxidante, análisis fitoquímico y micrografía analítica de hojas de Castela tweedii (Simaroubaceae) / Antioxidant activity, phytochemical analisys and micrographic characterization of Castela tweedii (Simaroubaceae) leaves

Castela tweedii is a small tree belonging to Simaroubaceae family. Infusions of its leaves are used in folk medicine to treat gastrointestinal disorders and diarrhea. In this work, we evaluated the antioxidant activity of ethanol and dicloromethane leaves extracts against DPPH radical (2,2-difenilpicrilhidrazil) in order to justify, at least in part, its popular use. Ethanol extract showed scavenging activity, with an IC50=0.1288 mg/mL. Responsible compounds for these activity were tannins, flavonoids and phenylcarboxilic acids, among them we identified rutine and chlorogenic acid. Microscopic and histochemical analysis of leaves was carry out to developed useful characterizations that will allow a future identification and authentication of raw material: such as, the presence of mucilaginous hypodermis, leaf of dorsiventral structure, 1 to 2 rows of empalisade parenchyma with tannin deposits, anomocytic stomata in low epidermis and simple, unicellular trichomes in both epidermis.

Castela tweedii es un árbol de bajo porte perteneciente a la Familia Simaroubaceae, las infusiones de sus hojas son utilizadas en la medicina popular Argentina para el tratamiento de desordenes gastrointestinales y diarreas. Con el objetivo de fundamentar el uso popular de esta especie se evaluó la actividad antioxidante de los extractos etanólicos y diclorometánicos de forma cuantitativa y cualitativa frente al radical 2,2-difenilpicrilhidrazilo (DPPH); el extracto etanólico demostró actividad obteniéndose una CI50= 0,1288 mg/mL. El análisis fitoquímico mostró que los compuestos responsables de esta actividad fueron taninos, flavonoides y ácidos fenilcarboxílicos, entre ellos se identificó rutina y ácido clorogénico. Además se realizó el estudio morfoanatómico e histoquímico de las hojas que aportó datos de valor diagnostico para el control de calidad de la droga vegetal: presencia de una hipodermis mucilaginosa, estructura dorsiventral con una a dos hileras de parénquima en empalizada conteniendo taninos, estomas anomocíticos solo en la epidermis abaxial y tricomas simples unicelulares en ambas epidermis.

Biological activity of neosergeolide and isobrucein B (and two semi-synthetic derivatives) isolated from the Amazonian medicinal plant Picrolemma sprucei (Simaroubaceae)

In the present study, in vitro techniques were used to investigate a range of biological activities of known natural quassinoids isobrucein B (1) and neosergeolide (2), known semi-synthetic derivative 1,12-diacetylisobrucein B (3), and a new semi-synthetic derivative, 12-acetylneosergeolide (4). These compounds were evaluated for general toxicity toward the brine shrimp species Artemia franciscana, cytotoxicity toward human tumour cells, larvicidal activity toward the dengue fever mosquito vector Aedes aegypti, haemolytic activity in mouse erythrocytes and antimalarial activity against the human malaria parasite Plasmodium falciparum. Compounds 1 and 2 exhibited the greatest cytotoxicity against all the tumor cells tested (IC50 = 5-27 µg/L) and against multidrug-resistant P. falciparum K1 strain (IC50 = 1.0-4.0 g/L) and 3 was only cytotoxic toward the leukaemia HL-60 strain (IC50 = 11.8 µg/L). Quassinoids 1 and 2 (LC50 = 3.2-4.4 mg/L) displayed greater lethality than derivative 4 (LC50 = 75.0 mg/L) toward A. aegypti larvae, while derivative 3 was inactive. These results suggest a novel application for these natural quassinoids as larvicides. The toxicity toward A. franciscana could be correlated with the activity in several biological models, a finding that is in agreement with the literature. Importantly, none of the studied compounds exhibited in vitro haemolytic activity, suggesting specificity of the observed cytotoxic effects. This study reveals the biological potential of quassinoids 1 and 2 and to a lesser extent their semi-synthetic derivatives for their in vitro antimalarial and cytotoxic activities.

In vitro inhibition of Plasmodium falciparum by substances isolated from Amazonian antimalarial plants

In the present study, a quassinoid, neosergeolide, isolated from the roots and stems of Picrolemma sprucei (Simaroubaceae), the indole alkaloids ellipticine and aspidocarpine, isolated from the bark of Aspidosperma vargasii and A. desmanthum (Apocynaceae), respectively, and 4-nerolidylcatechol, isolated from the roots of Pothomorphe peltata (Piperaceae), all presented significant in vitro inhibition (more active than quinine and chloroquine) of the multi-drug resistant K1 strain of Plasmodium falciparum. Neosergeolide presented activity in the nanomolar range. This is the first report on the antimalarial activity of these known, natural compounds. This is also the first report on the isolation of aspidocarpine from A. desmanthum. These compounds are good candidates for pre-clinical tests as novel lead structures with the aim of finding new antimalarial prototypes and lend support to the traditional use of the plants from which these compounds are derived.

Chemical constituents of Simarouba versicolor

From the roots, stems and fruits of Simarouba versicolor (Simaroubaceae) were isolated quassinoids (3, 5-7), triterpenoids (8-14), a mixture of steroids (15-17), the flavonoid kaempferol (18) and the squalene derivative 11,14-diacetoxy-7,10; 15,18-diepoxy-6,19-dihidroxy-6,7,10,11,14,15,18,19-octahydrosqualene (19). Spectral data were used for structural characterization