Um novo método para agrupar parâmetros quimiotaxonômicos

This work presents a new methodology for searching the present state of chemical evolution for different taxa, grouping five classes of secondary metabolites. Ocurrences of 10370 natural products isolated from Asteraceae were used to exemplify the method. Relationships among tribes are discussed.

Diterpenos, triterpenos e esteróides das flores de Wedelia paludosa

Phytochemical investigation of the flowers of Wedelia paludosa afforded two diterpenes, ent-kaur-16-en-19-oic acid and ent-kaur-9(11),16-dien-19-oic acid, three acylated triterpenes, 3beta-O-hexa-decanoylolean-12-en-28-oic acid, 3beta-O-pentadecanoylolean-12-en-28-oic acid and 3beta-O-tetradecanoylolean-12-en-28-oic acid, and three steroids, stigmasterol, 3beta-O-beta-D-glycopyranosyl sitosterol and 3beta-O-beta-D-glycopyrano-sylstigmasterol. The substances were identified by their spectral data.

O gênero copaifera L.

This review details the history, chemistry and pharmacology of the Copaifera L. genus (Leguminosae - Caesalpinoideae), including copaiba oils.

Gênero Baccharis (Asteraceae): aspectos químicos, econômicos e biológicos

The Baccharis genus is represented by more than 500 species distributed mainly in the tropical areas of South America. Many of them are extensively used in folk medicine in the treatment or prevention of anemias, inflammations, diabetes and stomach, liver and prostate diseases. Phytochemical and biological investigations in about 120 species resulted mainly in the isolation of clerodane and labdane diterpenes and flavonoid aglicones with the flavone unit being the most frequent.

Cromatografia de troca-iônica aplicada ao isolamento da fração ácida do óleo de copaíba (Copaifera multijuga) e da sacaca (Croton cajucara)

Plant extracts are usually complex mixtures which contain several molecules of different sizes with varied functional groups. Such extracts are a challenge to the chemist of natural products. Ion exchange chromatography in non-aqueous medium, used for separation of basic or acidic fractions from plant extracts, is an important unit operation in preparative scale separations. Anionic macroporous resin in non-aqueous medium was used with success in this study for separation of the acid fraction of Copaifera multijuga (Copaiba oil), rich in labdanic diterpenes and for the methanolic extract of Croton cajucara (acetyl aleuritoric acid).

Antifungal activity against postharvest fungi by extracts from Colombian propolis

The aims of the present study were to evaluate the antifungal properties of Colombian propolis extracts against Colletotrichum gloeosporioides and Botryodiplodia theobromae, and to isolate and identify the main constituents from the active extracts. Therefore, propolis samples were thoroughly extracted with n-hexane/methanol (EPEM), dichloromethane, ethyl acetate, and methanol. Experimental results indicated that mycelial growth of all selected microorganisms was reduced in culture media containing EPEM and dichloromethane fractions. Furthermore, through antifungal bioassay-guided fractionation, three known labdane-type diterpenes: isocupressic acid (1), (+)-agathadiol (2) and epi-13-torulosol (3) were isolated as the main constituents from the active fractions.

Triterpenoids from Azorella trifurcata (Gaertn.) Pers and their effect against the enzyme acetylcholinesterase

The inhibition of the enzyme acetylcholinesterase is considered as a strategy for the treatment of Alzheimer's disease, senile dementia, ataxia, and myasthenia gravis. Three lanostane- and two cycloartane-type triterpenes, together with two mulinane-type diterpenes were isolated from petroleum ether extract of the whole shrub of Azorella trifurcata (Gaertn.) Pers. Their effect on the enzyme acetylcholinesterase was assessed as well. In addition, this is the first report of these triterpenes in the genus Azorella.

Teores de compostos bioativos em cafés torrados e moídos comerciais

The amounts of nicotinic acid, trigonelline, 5-CQA, caffeine, kahweol and cafestol in 38 commercial roasted coffees ranged from 0.02 to 0.04; 0.22 to 0.96; 0.14 to 1.20; 1.00 to 2.02; 0.10 to 0.80 and 0.25 to 0.55 g/100 g, respectively. Evaluation of color and content of thermo-labile compounds indicated similarity in roasting degree. Differences in the levels of diterpenes and caffeine, components less influenced by the roasting degree, could be mainly explained by the species used (arabica and robusta). Gourmet coffees showed high concentrations of diterpenes, trigonelline and 5-CQA and low levels of caffeine, indicating high proportion of arabica coffee.

Terpenos em cupins do gênero Nasutitermes (Isoptera, Termitidae, Nasutitermitinae)

The chemical composition of the front gland of termites has been studied for over 40 years. The genus Nasutitermes, considered the most evolved of the Termitidae family, has a peculiarity that sets it apart from the others: a caste of soldiers that carry a terpenic mixture used in defense. This secretion is formed by mono, sesqui and diterpenes from trinervitane, kempane and rippertane skeletons, only found in termites. This article sought to review the scientific literature and contribute to the knowledge on the chemical composition of the secretion of the Nasutitermes soldiers from the interesting aspects of its behavior.

Estudo químico das folhas de Trichilia silvatica (Meliaceae)

From the leaves of a specimen of Trichilia silvatica Meliaceae, eight known compounds were isolated, namely, two pregnanes, 2α,3β,4β-trihydroxypregnan-16-one (1) and 2β,3β,4β-trihydroxypregnan-16-one (2), three diterpenes, cneorubine X (3), kolavelool (4) and kolavenol (5), in addition to γ-tocopherol, 3-O-β-D-glucopyranosyl-β-sitosterol and 3-O-β-D-glucopyranosyl-stigmasterol. This is the first reported occurrence of pregnane 1, diterpenes 3-5 and µ-tocopherol in the genus Trichilia. The structures of the isolated compounds were determined on the basis of their spectral data.

Aristolactams and further constituents from Aristolochia chamissonis

From the ethanol extract of the stems of Aristolochia chamissonis, spathulenol, sitosterol, beta-sitosteryl-D-glucoside, kolavelool, 13-epi-2-oxo-kolavelool, trans-N-p-coumaroyltyramine, allantoin, aristolochic acid I, and aristolactam AII were isolated. The structures of aristolactam AII and piperolactam A have been revised by means of spectroscopic methods and chemical derivatizations.