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

Eudesmane and rearranged eudesmane sesquiterpenes from Nectandra cissiflora

Four eudesmane-type sesquiterpenes, costic acid (1), 12-carboxyeudesman-3,11(13)-diene (2), viscic acid (3), 3-oxo-γ-costic acid (4) and two rearranged eudesmane derivatives, 3α-hydroxyisoiphion-11(13)-en-12-oic acid (5) and 5β-hydroxy-4-oxo-11(13)-dehydroiphionan-12-oic acid (6), in addition to (-)-epicatechin, have been isolated from the trunk bark of Nectandra cissiflora. This is the first reported occurrence in the Lauraceae of 3-6. The structures of the isolated compounds have been established on the basis of 1D and 2D NMR spectroscopic techniques. The 13C NMR assignments of 3, 5 and 6 are given here for the first time, as well as some corrections to the previously reported chemical shift assignments of 4

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