Délio S. Raslan

Trypanocidal activity and redox potential of heterocyclic- and 2-hydroxy-naphthoquinones

Abstract With the aim of understanding the influence of redox potentials on the trypanocidal activity, a series of quinones were tested in vitro with trypomastigotes of Trypanosoma cruzi and their first cathodic potentials (Epcl) measured by cyclic voltammetry. All quinones with Epcl > −0.72V were active, while most of those with Epcl

Antimicrobial and cytotoxic activities screening of some Brazilian medicinal plants used in Governador Valadares district

Os extratos etanolicos de plantas medicinais utilizadas por moradores da cidade de Governador Valadares foram avaliados quanto as atividades antimicrobiana e citotoxica. A pesquisa de campo foi realizada durante o periodo de 1997-2000, por meio de entrevistas com os raizeiros locais. Foram avaliados 33 extratos brutos de um total de 32 especies. Desses extratos, dez apresentaram toxicidade as larvas de Artemia salina (DL50<1000 ppm): Costus pisonis, Cymbopogon nardus, Eclipta alba, Eleutherine bulbosa, Erigium foetidium, Euphorbia tirucalli, Mikania hirsutissima, Momordica charantia, Solidago microglossa e Plectranthus ornatus. Quanto a atividade antimicrobiana, nenhum dos extratos apresentou atividade contra Escherichia coli. Entretanto, treze extratos mostraram-se ativos contra Staphylococcus aureus: E. alba, Scoparia sp., Arctium lappa, Chammomila tinctoria, E. bulbosa, M. hirsutissima, S. microglossa, Stachytarpheta dichotoma, Pffafia glomerata, Stenorrhyrchnus lanceolatum, Vernonia condensata e Lippia alba.

Trypanocidal Sesquiterpenes from Lychnophora Species

The bioguided fractionation of the crude extracts of Lychnophora passerina (Mart. ex DC) Gardn., L. pinaster Mart. and L. trichocarpha Spreng. led to the isolation of four compounds active against the trypomastigote forms of Trypanosoma cruzi: the sesquiterpene lactones goyazensolide (1), eremantholide C (2), and lychnopholide (3) and a new caryophyllene derivative, which was named lychnophoic acid (4).

ALCALÓIDES INDÓLICOS ISOLADOS DE ESPÉCIES DO GÊNERO Aspidosperma (APOCYNACEAE)

Species from genus Aspidosperma (Apocynaceae) are popularly employed to treat various diseases. This genus is characterized by the occurrence of indole alkaloids. Taking into account the various biological activities attributed to these alkaloids, the description of the chemical diversity in genus Aspidosperma is important. A review of simple carbolinic alkaloids isolated from species of various genera was published in 1979. In 1987, it was published another one dealing with the relationships between the chemical structures of the indole alkaloids and the evolution of Aspidosperma species. This work updates the information about the indole alkaloids isolated from Aspidosperma species.

Chemical characterization and biological activity of Macfadyena unguis-cati (Bignoniaceae).

Macfadyena unguis‐cati (L.) has been widely used in folk medicine as an anti‐inflammatory, antimalarial and antivenereal. The purpose of this study was to chemically characterize the main plant components, and to evaluate the biological properties of some of the fractions derived from leaves (MACb) and liana (MACa) of this plant.

Lignans and naphthoquinones from Tabebuia incana

Abstract The trunkwood of Tabebuia incana afforded the lignans pawlownin and cycloolivil as the major constituents together with a cycloolivil acetonide, la

Synthesis of the naturally occurring naphtho-z.sfnc;2,3-bz.sfnc;pyran-5,10-quinones α-caryopterone,dihydro-α-caryopterone and their isomers 6-hydroxy-dehydro-α-lapachone and 6-hydroxy-α-lapachone

Abstract Isomeric 6- and 9-hydroxy-naphtho-z.sfnc;2,3-bz.sfnc;pyran-5,10-quinones were synthesised by alkylation-cyclisation of 2- and 3-hydroxyjuglone in a single step and can be distinguished by UV-visible spectra in the presence of additives and 1 HNMR.

Análise de naftoquinonas em extratos brutos de raízes de Zeyheria montana M. (bolsa-de-pastor)

Four naphthoquinones, lapachol, a-lapachone, dehydro-a-lapachone and 4-hydroxy-a-lapachone were isolated from the ethanol extract of Zeyheria montana M. roots (Bignoniaceae) and were identified by spectroscopic methods. These naphthoquinones, except 4-hydroxy-a-lapachone, were quantified by HPLC, in the crude ethanol extracts of Z. montana roots. The separation of lapachol, a-lapachone and dehydro-a-lapachone was achieved and these compounds were identified in the chromatograms by their retention times and by their on line UV-spectra. The quantification of the three naphthoquinones, in four different samples showed medium contents of 11,0 mg of lapachol, 6,1 mg of a-lapachone and 4,3 mg of dehydro-a-lapachone, in 100 mg of Z.montana roots.

Volatile substances in floral honey and honeydew honey

Although honey seems to possess a characteristic flavor, variety of flowers avaiable to bees gives differents flavors and aromas, indicating the presence of various volatile compounds. Some of these also depends on the phisiology of the bee, the processing after harvest and in honeydew honey there is the interference of sucking insects and ants. Many volatile substances have already been identified and some of them are specific of typical unifloral honeys. With the purpose of finding a characteristic volatile substance of honeydew honey, six samples of this kind and six floral honeys were analysed by extraction using hidrogen steam and gas chromathography with mass spectrometry. Acetic acid has been found in four honeydew honey and in one floral honey, but with less abundance.

Synthesis of 2-Substituted Furanonaphthoquinones Using Directed Metalation and Cross Coupling Reactions

Abstract A synthetic method for the preparation of C-2 substituted furanonaphthoquinones from ortholithium-benzamide and the 2-furan-carboxaldehyde derivative is described. Four 2-alkyl-furanonaphthoquinones and the 2-phenyl-substituted were prepared via phathalide. This route has been shown to be general application to the synthesis of furanonaphthoquinones.