M. L. Colombo

Distribution of alkaloids in Chelidonium majus and factors affecting their accumulation

The alkaloid content in Chelidonium majus has been examined during the day, both in summer and in winter. Sanguinarine, chelidonine, chelerythrine, berberine and coptisine were detected in all parts of the plant. While the berberine content was rather stable, the other alkaloids undergo remarkable daily variations probably due to the combined effect of light and temperature.

Supercritical carbon dioxide extraction, fluorimetric and electrochemical high performance liquid chromatrographic detection of vitamin E from Hordeum vulgare L.

A supercritical fluid extraction (SFE), method has been applied to extract the natural vitamin E components, tocopherols and tocotrienols, from fruits of Hordeum vulgare L. The fractions were monitored by analytical high performance liquid chromatography using fluorimetric and electrochemical detectors. High yields, and clear and purified extracts were obtained by SFE; compared with the n-hexane extract, the SFE extract was lighter in colour and more concentrated in vitamin E components.

Phytochemical evaluation of Helleborus species growing in northern Italy.

AbstractHellebrin, desglucohellebrin, hellebrigenin, bufatetraenolide and traces of spirostane-types steroids have been isolated from roots and rhizomes of Helleborus odorus ssp. laxus, Helleborus viridis ssp. viridis and Helleborus “viridis”. In addition, β-ecdysterone and 5B-hydroxyecdysterone have been isolated for the first time from these species.

A comparative investigation on alkaloid composition in different populations of Eschscholtzia californica cham.

The alkaloid compositions of different populations of Eschscholtzia californica Cham. grown under controlled conditions and of some samples of the commercial drug have been examined using a reversed-phase HPLC method. Seven compounds have been detected (O-methylcaryachine, protopine, α-allocryptopine, eschscholtzine, californidine, sanguinarine and chelerytrine). In all samples the major components were the pavine alkaloids eschscholtzine and californidine, although their content varied to a large extent (from 1 to 10-fold). The commericial drug contained a significantly lower concentration of alkaloids. Copyright

A study of the diterpene alkaloids of Aconitum napellus ssp. neomontanum During its onthogenetic cycle

Qualitative and quantitative variations in the diterpene alkaloids content in the neomontanum subspecies of Aconitum napellus, growing near lake of Como, were studied throughout its complete onthogenetic cycle. Aconitine, N-deethylaconitine and two compounds with m.w. = 688 and m.w. = 629 have been detected in the various organs of plant almost at any time during the vegetative cycle.

Ecdysteroid Production in Helleborus odorus ssp. laxus: Response to Different Environments

AbstractTwo ecdysteroids, 5β-ecdysone And 5P-hydroxyecdysterone, were separated from hypogeous organs of five populations of Helleborus odorus ssp. laxus (Host) Merxm. & Podl. (Ranunculaceae). The ecdysteroid content is higher during the vegetative growth (summer) AND lower during flowering (spring) AND quiescency (autumn-winter). Plants growing in short grass plains have an ecdysteroid content higher (30-40%) than plants from oak AND chestnut woods.

Osservazioni sulla polistelia in Primula glaucescens Moretti e Primula longobarda Porta

Abstract Notes on the polystelic structure in Primula glaucescens Moretti and Primula longobarda Porta. — The rhizome anatomy of Primula glaucescens Moretti and Primula longobarda Porta (two species endemic to Lombardy) have been studied. It has been found that the polystelic structure is present in the rhizome of both species, but with some differences. The taxa show a difference in the number and size of steles and amount of sclerenchymatic tissue within the single stele. Our investigations confirm the necessity to separate in a specific rank Primula glaucescens Moretti from Primula longobarda Porta, as already proposed by Arietti and Crescini (1976).