Análise química e atividades biológicas de Guatteria elliptica R. E. Fries (Annonaceae)

A espécie endêmica G. elliptica R. E. Fries não apresentava estudos fitoquímicos e biológicos detalhados na literatura. Assim, o objetivo desse trabalho foi avaliar a composição química e as propriedades biológicas dos óleos essenciais, extratos brutos, alcaloides totais, tortas, frações das tortas, amostras isoladas dessa espécie. O material vegetal foi coletado em Paranapiacaba (Santo André, SP, Brasil). O óleo essencial extraído das folhas por destilação à vapor apresentou um rendimento de 0,2%. A análise histológica das folhas encontrou óleo em células oleíferas localizadas no parênquima esponjoso. A composição do óleo (CG-EM) indicou espatulenol e óxido de cariofileno como compostos majoritários. Os alcaloides totais foram obtidos dos extratos brutos das folhas e dos galhos e analisados por CG-EM, identificando quatro aporfinas (nornuciferina, estefarina, corituberina e asimilobina) e duas protoberberinas (discretamina e caseadina). Os alcaloides totais foram fracionados em coluna cromatográfica ou por Extração em Fase Sólida e purificados por cromatografia em camada preparativa, originando duas amostras (Amostra 9 e 10). Na Amostra 9, foram identificados dois alcaloides aporfinicos nornuciferina e asimilobina (CG-EM e RMN-1H). Na Amostra 10, foram identificados (LC-EM/EM) cinco alcaloides aporfínicos (desidronantenina, glaunidina, liriodenina, N-óxido de oliverina e telikovina) e um alcaloide protoberberínico (caseadina). Caseadina, glaunidina, N-óxido de oliverina e telikovina não foram previamente identificados em Guatteria. Os resíduos dos extratos brutos livres de alcaloides foram fracionados pelo método de partição com solventes de polaridade crescente. Os extratos brutos e as frações acetato de etila e butanólicas de folhas e galhos apresentaram flavonoides (NP-PEG). Nos ensaios biológicos, a melhor atividade antioxidante (sequestro do radical DPPH) foi encontrada para a fração clorofórmica dos galhos (EC50=24,25±1,14 µg/mL) e a torta dos galhos (EC50=26,23±4,20 µg/mL). No ensaio antimicrobiano pelo método turbidimétrico a atividade mais importante foi obtida contra Staphylococcus aureus (ATCC 6538) para os alcaloides totais dos galhos (CIM/CBM=0,12±0,01/0,26 mg/mL) e das folhas (CIM/CBM=0,21±0,01/0,28 mg/mL), e fração hexânica das folhas (CIM/CBM=0,24±0,02/>1 mg/mL). Uma alta atividade antitumoral foi observada frente a células humanas de mama (MCF-7) para Amostra 10 (IC50=2,28±0,18 µg/mL), fração de acetato de etila das folhas (IC50=4,47±0,40 µg/mL), óleo essencial (IC50=7,01±0,23 µg/mL) e os alcaloides totais das folhas (IC50=9,32±0,36 µg/mL). Para as células de próstata (PC-3), foi encontrada atividade para a Amostra 10 (IC50=1,37±0,36 µg/mL) e o óleo essencial (IC50=5,32±0,35 µg/mL). A futura aplicação dos extratos e frações de G. elliptica como um agente antitumoral parece ser segura, pois mantiveram uma viabilidade celular maior do que 90% no ensaio de citotoxicidade com culturas de fibroblasto murino (BALB/c 3T3, ATCC CCL-163) nas concentrações onde a atividade antitumoral foi promissora (<30 µg/mL) contra MCF-7 e/ou PC-3.

Biogeographical Patterns and Phenological Changes in Lapiedra martinezii Lag. Related to Its Alkaloid Diversity

The aim of this work was to investigate the alkaloid patterns of Lapiedra martinezii and their relation to biogeography and phenology focused in a phylogenetic comparison. Plants from 14 populations of L. martinezii, covering almost its entire distribution area, were subjected to morphological, ecological, and phytochemical analysis. Experiments for different alkaloid-type content are proposed as a new tool for analysis of plant distribution. Several plants were transplanted for weekly observation of their phenological changes, and alkaloids from different plant organs were extracted, listed, and compared. The alkaloid pattern of L. martinezii comprises 49 compounds of homolycorine, lycorine, tazettine, haemantamine, and narciclasine types. The populations located in the north and south margins of the distribution area displayed alkaloid patterns different from those of the central area. Changes in these patterns during their phenological cycle may be related to a better defence for plant reproduction. L. martinezii is an old relict plant, and it has maintained some of the more primitive morphological features and alkaloid profiles of the Mediterranean Amaryllidaceae. The variations in alkaloid content observed could be interpreted in a phylogenetic sense, and those found in their phenological changes, in an adaptive one.

Evolution of alkaloid biosynthesis in the genus Narcissus

In an attempt to reveal the relationships between alkaloid biosynthesis and phylogeny, we investigated by GC–MS the alkaloid patterns of 22 species and 3 hybrids (from 45 locations) from seven main sections of the genus Narcissus (Amaryllidaceae). The results indicate that the first alkaloids to evolve in the genus Narcissus were of the lycorine- and homolycorine-type. The alkaloid pattern of the Nevadensis section supports its recent separation from the Pseudonarcissus section. The plants of Narcissus pallidulus (Ganymedes section) show a predominance of Sceletium-type compounds, which are quite rare in the Amaryllidaceae family. Two successful evolutionary strategies involving alkaloid biosynthesis and leading to an expansion in taxa and occupied area were determined. Firstly, a diversification of alkaloid patterns and a high alkaloid concentration in the organs of the large Narcissus species (in the Pseudonarcissus section) resulted in an improved chemical defence in diverse habitats. Secondly, both plant size and alkaloid biosynthesis were reduced (in the Bulbocodium and Apodanthi sections) relegated to dry pastures and rocky places.

Alcaloïdes: histoire, propriétés chimiques et physiques, extraction, action physiologique, effets thérapeutiques, toxicologie, observations, usages en médecine, formules, etc.

Mode of access: Internet.

Über Hordenin und siene physiologische Wirkung ...

Inaug.-diss.--Hannover.

Erfahrungen über die praktische Verwendung des Yohimbins und Untersuchungen über einige Nebenwirkungen desselben.

Inaug.-diss.--Hannover, 1912.

[Alcaloides de las papaveráceas] : discurso leido en la Universidad Central el día 26 de junio de 1865 en el solemne acto de recibir la investidura de Doctor en la Facultad de Farmacia /

Tesis de la Universidad Central (Madrid), Facultad de Farmacia, leída el 20-06-1865.

Nouvelle expérimentations sur les alcalis végétaux, effets obtenus : thèse présentée et soutenue è l'École de Pharmacie... /

Tesis, École de Pharmacie, 1842.

The Alkaloidal clinic.

Mode of access: Internet.

Commercial organic analysis. A treatise on the properties, proximate analytical examination, and modes of assaying the various organic chemicals and products employed in the arts, manufactures, medicine, etc., with concise methods for the detection and determination of their impurities, adulterations, and products of decomposition.

v.I. Introduction. Alcohols, neutral alcoholic derivatives, sugars, starch and its isomers, vegetable acids, etc. 2d ed., rev. & enl.--v.II. Fixed oils, fats, waxes, glycerol, nitroglycerin and nitroglycerin explosives. Hydrocarbons, petroleum and coal-tar products, asphalt, phenols and creosotes. 2d ed., rev. & enl.--v. III, pt.I. Acid derivatives of phenols, aromatic acids, resins, and essential oils. Tannins, dyes, and colouring matters, writing inks. 2d ed., rev. & enl.--v. III, pt.II. Amines and ammonium bases, hydrarzines, bases from tar, vegetable alkaloids. 2d ed., rev. and enl. [1892] --v.III, pt.III. Vegetable alkaloids (concluded), non-basic vegetable bitter principles, animal bases, animal acids, cyanogen and its derivatives. 2d ed., rev. & enl. [1896]--v.IV. Proteids and albuminous principles, proteoïds or albuminoïds. 2d ed., rev. & enl. 1898.

Die pflanzen-alkaloide

Mode of access: Internet.

Convulsive ergotism: epidemics of the serotonin syndrome?

Between 1085 and 1927, epidemics of convulsive ergotism were widespread east of the Rhine in Europe due to consumption of grain contaminated with ergot, which is produced by the fungus Claviceps purpurea. West of the Rhine, consumption of ergot-contaminated food caused epidemics of gangrenous ergotism. The clinical features of convulsive ergotism-muscle twitching and spasms, changes in mental state, hallucinations, sweating, and fever lasting for several weeks-suggest serotonergic overstimulation of the CNS (ie, the serotonin syndrome). The ergot alkaloids are serotonin agonists. Dihydroergotamine binds to serotonin receptors in the dorsal horn of the spinal cord, which is the site of neuropathological changes in convulsive ergotism. Dihydroergotamine given to human beings can cause the serotonin syndrome. Ergots produced by different strains of Claviceps purpurea, and those growing in different soils, may have different ergot alkaloid compositions. An alkaloid, present in high concentrations in ergots from east of the Rhine, may have caused convulsive ergotism at a circulating concentration insufficient to produce peripheral ischaemia. The serotonin syndrome may, therefore, have been a public-health problem long before it was recognised as a complication of modem psychopharmacology.

Ergot of rye - the first specific for migraine

Over the past decade the various triptan derivatives have been accepted as the most effective available agents for relieving migraine attacks. Prior to that, for a period of half a century, ergotamine was the only 'specific' available for this purpose. In 1918, Stoll had isolated it from the various alkaloids present in extracts of the sclerotia of the fungus Claviceps purpurea (ergot), which grow on rye and, to a lesser extent, on other grasses. By 1925 ergotamine was beginning to be used to treat migraine attacks. However, as ergotamine was present in extracts of ergot, which had been used to treat migraine first, In Italy in 1862, and then by Edward Woakes (11868) in England, and after him by Albert Eulenburg in Germany (1883), the drug had actually come into unrecognised use for the disorder more than half a century before ergotamine itself was known to exist. Unfortunately, because of ergotamine's chemical and pharmacokinetic properties, extracts of ergot of rye were incapable of producing consistent therapeutic results, so that general acceptance that the first specific substance for migraine treatment existed had to wait until pure ergotamine was available for administration. (C) 2003 Elsevier Ltd. All rights reserved.

HPLC analyses of flavanols and phenolic acids in the fresh young shoots of tea (Camellia sinensis) grown in Australia

As part of a 4-year project to study phenolic compounds in tea shoots over the growing seasons and during black tea processing in Australia, an HPLC method was developed and optimised for the identification and quantification of phenolic compounds, mainly flavanols and phenolic acids, in fresh tea shoots. Methanol proved to be the most suitable solvent for extracting the phenolic compounds, compared with chloroform, ethyl acetate and water. Immediate analysis, by HPLC, of the methanol extract showed higher separation efficiency than analyses after being dried and redissolved. This method exhibited good repeatability (CV 3-9%) and recovery rate (88-116%). Epigallocatechin gallate alone constituted up to 115 mg/g, on a dry basis, in the single sample of Australian fresh tea shoots examined. Four catechins (catechin, gallocatechin, epicatechin and epigallocatechin) and six catechin gallates (epigallocatechin gallate, catechin gallate, epicatechin gallate, gallocatechin gallate, epicatechin digallate and epigallocatechin digallate) have been identified and quantified by this HPLC method. In addition, two major tea alkaloids, caffeine and theobromine, have been quantified, while five flavonol glycosides and six phenolic acids, including quinic acids and esters, were identified and quantified. (C) 2003 Elsevier Ltd. All rights reserved.

Nitrogen is a requirement for the photochemical induced 3-azabicyclo[3.3.1]nonane skeletal rearrangement!

Specific 3-azabicyclo[3.3.1]nonane derivatives undergo skeletal cleavage when subjected to light or Lewis acidic conditions affording novel heteratricycles, which is in stark contrast to 3-oxabicyclo[3.3.1]nonanes. (c) 2005 Elsevier Ltd. All rights reserved.