Aspidosperma (Apocynaceae) plant cytotoxicity and activity towards malaria parasites. Part I: Aspidosperma nitidum (Benth) used as a remedy to treat fever and malaria in the Amazon

Infusions of Aspidosperma nitidum (Apocynaceae) wood bark are used to treat fever and malaria in the Amazon Region. Several species of this family are known to possess indole alkaloids and other classes of secondary metabolites, whereas terpenoids, an inositol and the indole alkaloids harmane-3 acid and braznitidumine have been described in A. nitidum . In the present study, extracts from the wood bark, leaves and branches of this species were prepared for assays against malaria parasites and cytotoxicity testing using human hepatoma and normal monkey kidney cells. The wood bark extracts were active against Plasmodium falciparum and showed a low cytotoxicity in vitro, whereas the leaf and branch extracts and the pure alkaloid braznitidumine were inactive. A crude methanol extract was subjected to acid-base fractionation aimed at obtaining alkaloid-rich fractions, which were active at low concentrations against P. falciparum and in mice infected with and sensitive Plasmodium berghei parasites. Our data validate the antimalarial usefulness of A. nitidum wood bark, a remedy that can most likely help to control malaria. However, the molecules responsible for this antimalarial activity have not yet been identified. Considering their high selectivity index, the alkaloid-rich fractions from the plant bark might be useful in the development of new antimalarials.

Stachytarpheta gesnerioides Cham: chemical composition of hexane fraction and essential oil, antioxidant and antimicrobial activities / Stachytarpheta gesnerioides Cham: composición química de la fracción hexánica y aceite esencial, actividades antioxidante y antimicrobiana

In the present study we investigated the chemical composition of hexane fraction and essential oil of Stachytarpheta gesnerioides (Verbenaceae) by GC-MS, total phenol and flavonoid contents. The antioxidant capacity and antimicrobial activity were investigated in five extracts of leaves of S. gesnerioides. Aqueous and 100 percent ethanol extracts were prepared by dynamic maceration. Hexane, ethyl acetate and methanol extracts were prepared by Soxhlet extraction. The essential oil (EO) and hexane fraction (HF) are mainly composed by guaiol. Moreover, the HF is also rich in the monoterpene alpha-pinene. The total phenol content ranged from 0.85 to 22.74 mg gallic acid equivalent /100mg dry extract at Folin–Ciocalteu’s reagent method. The total flavonoid concentration ranged from 0.68 to 13.65 mg rutin equivalent /100mg dry extract, detected using 8 percent aluminium chloride. The ethyl acetate extract (IC50=9.41 ug/ml) showed the highest antioxidant activity. The extracts were found to be effective to inhibit the microorganisms tested.

Se han investigado la composición química de la fracción hexánica (FH) y aceite esencial (AE) de Stachytarpheta gesnerioides (Verbenaceae) por GC-MS, el contenido de fenoles totales y flavonoides. La capacidad antioxidante y actividad antimicrobiana fueron investigadas en cinco extractos de hojas de S gesnerioides. Extractos acuosos y etanolico fueron preparados por la maceración dinámica y extracción continua en Soxhlet con hexano, acetato de etilo y metanol. Las fracciones AE y FH están compuestas principalmente por guaiol. La fracción FH es también rica en alfa-pineno. El contenido de fenoles totales varió desde 0,85 hasta 22,74 mg de ácido gálico/100 mg de extracto seco (Folin-Ciocalteu). La concentración total de flavonoides varió desde 0,68 hasta 13,65 mg en equivalentes de rutina/100 mg de extracto seco, que se detectó mediante reacción con cloruro de aluminio al 8 por ciento. El extracto de acetato de etilo (CI50=9,41 ug/ml) enseño la más grande actividad antioxidante. Los extractos se encontraron eficaces para inhibir los microorganismos ensayados.

Morphological, anatomical, macro and micromolecular markers for Solanum cernuum identification

The plants consumed as remedy by the population may have imprecise taxonomical identification. If these plants are used for the production of phytomedicines such misidentification may affect the quality of the product. Hereby, we describe markers for identification of the entire plant or grounded plant material or the crude extract of Solanum cernuum Vell. (Solanaceae). Specimens from four localities were collected, analyzed and compared. Morphological characters were used to identify the plant when it is not grounded or extracted. However, when the plant material is grounded, the set of trichomes may be used as anatomical marker. The region ITS1, 5.8S and ITS2 of the nuclear ribosomal DNA was cloned and sequenced. The sequence, with length of about 600 base pairs, being 48.1 percent AT , was deposited in GenBank under the accession number DQ837371. Once this sequence is specific to S. cernuum, it was used as marker for this species. For the crude extract, chromatographic profiles of the leaves extracts were obtained by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Two flavonoids were isolated and identified as quercitrin and afzelin. So, this study presents morphological, anatomical, macro and micromolecular markers to identify S. cernuum.

Plantas consumidas como remédio nem sempre são identificadas taxonomicamente de maneira correta. Se estas plantas forem utilizadas para obtenção de uma droga vegetal ou um fitoterápico, tal erro pode afetar a qualidade do produto final. Neste trabalho são descritos marcadores para a identificação de Solanum cernuum Vell. (Solanaceae), esteja a planta íntegra, triturada ou como extrato bruto. Indivíduos de quatro localidades de Minas Gerais foram coletados, analisados e comparados. Os caracteres morfológicos foram utilizados para a planta íntegra. Para a planta triturada, o conjunto dos tricomas foi utilizado como marcador anatômico. Um marcador macromolecular também foi determinado. Para tal a região ITS1, 5.8S e ITS2 do DNAr foi clonada e seqüenciada. A seqüência, com cerca de 600 pares de bases dos quais 48,1 por cento são AT, foi depositada no GenBank sob o número de acesso DQ837371. Por ser uma seqüência específica para S. cernuum, ela pode ser usada como marcador desta espécie. Para o extrato bruto foram determinados perfis cromatográficos de extratos das folhas por cromatografia em camada delgada e por cromatografia líquida de alta eficiência. Dois flavonóides foram isolados e identificados como quercitrina e afzelina. Assim, neste trabalho foram determinados marcadores morfológicos, anatômicos, macro e micromoleculares para identificar S. cernuum.

Eleutherinone, a novel fungitoxic naphthoquinone from Eleutherine bulbosa (Iridaceae)

The dichloromethane extract prepared from the underground parts of Eleutherine bulbosa (Miller) Urban (Iridaceae) showed strong activity in the direct bioautography assay with the phytopathogenic fungus Cladosporium sphaerospermum. This assay was used to guide the fractionation of this extract and allowed the isolation of four compounds: the new naphthoquinone eleutherinone[8-methoxy-1-methyl-1,3-dihydro-naphtho(2,3-c)furan-4,9 -dione] and the known compounds, previously isolated from this species, eleutherin [9-methoxy-1(R),3(S)-dimethyl-3,4-dihydro-1H-benzo(g)isochromene-5,10-dione], isoeleutherin [9-methoxy-1(R),3(R)-dimethyl-3,4-dihydro-1H-benzo(g)isochromene-5,10-dione], and eleutherol [4-hydroxy-5-methoxy-3(R)-methyl-3H-naphtho(2,3-c)furan-1 -one]. All quinonoid compounds showed strong antifungal activity in the bioautography assay at 100 æg/spot, while eleutherol was inactive