Fenilpropanóides e outros constituintes bioativos de Nectandra megapotamica

From the trunk bark of Nectandra megapotamica (Lauraceae) four phenylpropanoids, elemicin, isoelemicin, (±)-erythro-1-(3,4,5-trimethoxyphenyl)-1,2-propanediol and (±)-threo-1-(3,4,5-trimetoxyphenyl)-1,2-propanediol have been isolated, in addition to 3,4,5-trimethoxybenzoic acid, (-)-epicatechin and trans-1(10)-epoxy-4(15)-caryophyllene. The diastereoisomeric erythro- and threo- phenylpropanoids are being reported for the first time in a plant taxon as well as the occurrence of the other compounds in Nectandra. The structures of the isolated compounds have been established on the basis of 1D and 2D NMR spectroscopic techniques. Their in vitro antifungal activities against standard strains of Candida albicans, C. krusei, C. tropicalis and Cryptococcus neoformans and antioxidant properties were also evaluated in this work

Chemical constituents of the underground stem bark of Duguetia furfuracea (Annonaceae)

In the present investigation the underground parts of Duguetia furfuracea (Annonaceae) were used to conduct a phytochemical study that included the brine shrimp (Artemia salina) lethality bioassay. The substances (-)-duguetine beta-N-oxide, (-)-duguetine, dicentrinone, (-)-N-methyltetrahydropalmatine, and (+)-N-methylglaucine were isolated from the alkaloid extract of the bark of the underground stem, and the ureide allantoin was also isolated by precipitation from the ethanol extract of the wood of the underground stem. A fresh volatile oil and a nonpolar extract were also obtained from the underground stem bark. The substances 2,4,5-trimethoxystyrene, a-gurjunene, aromadendrene, bicyclogermacrene, (E)-methylisoeugenol, and alpha-asarone were isolated from the fresh volatile oil and polycarpol, beta-caryophyllene oxide, 2,4,5-trimethoxystyrene, a-asarone, and asaraldehyde were obtained from the petroleum ether extract. The present study describes for the first time the alkaloid (-)-duguetine beta-N-oxide and the occurrence of (-)-N-methyltetrahydropalmatine and (+)-N-methylglaucine in the family Annonaceae. All extracts were active in the brine shrimp lethality bioassay

Chemical constituents from Terminalia glabrescens

A new oleanane-type triterpene (3beta,6beta,23,28-tetrahydroxyolean-12-ene) was isolated from the leaves of Terminalia glabrescens, together with ursolic, 2alpha-hydroxyursolic, oleanolic, maslinic, arjunolic, sumaresinolic and asiatic acids, squalene, phytol, sitosterol-3-O-beta-D-glucopyranoside and n-alkanes. Friedelin, taraxerol, lupeol, lupenone, betulin, betulone, betulinic acid, arjunglucoside I, stigmastane-3beta,6alpha-diol, beta-sitosterol, (-) catechin,beta-D-pyranotagatose, beta-D-furanofructose and alpha-D-furanofructose were obtained from the trunk bark

Evaluation of mutagenic and antimicrobial properties of brown propolis essential oil from the Brazilian Cerrado biome

Biological, and particularly antimicrobial, activities have been demonstrated for the essential oil of propolis samples worlwide, yet their mutagenic effects remain unknown. To correlate antimicrobial effects with mutagenic risks, the present study evaluated the antifungal and antibacterial activities of the essential oil obtained from brown propolis collected from the Cerrado biome in Midwest Brazil (EOP), testing it against nine pathogenic microorganisms. Evaluation of mutagenic potential was based on the somatic mutation and recombination test (SMART) performed on wing cells of standard (ST) and high-bioactivation (HB) crosses of Drosophila melanogaster. EOP was extracted by hydrodistillation, and sesquiterpenes were characterized by GC–MS as its major constituents. The crude oil proved active against Cryptococcus neoformans and Enterococcus faecalis, as did two of its major constituents, spathulenol and (E)-nerolidol – the latter being also active against Staphylococcus aureus – isolated using chromatographic procedures. No significant increase in the number of somatic mutations was observed in the offspring of ST or HB crosses – the latter exhibiting enhanced levels of metabolizing enzymes of the cytochrome P450 type – treated with 0.05%, 0.1%, and 0.2% EOP. These findings revealed no mutagenic activity of EOP, even when tested against the HB strain, and demonstrated that its antimicrobial activities are not associated with DNA damage induction (investigated with SMART), suggesting the potential of EOP as a natural preservative