Franca Tomè

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.

Flavonoid distribution in Pyracantha coccinea plants at different growth phases

Flavonoid composition during the ontogenetic cycle was examined in Pyracantha coccinea. The flavonoid profiles of plants at different ages showed marked differences in aerial and hypogeal parts. In the vegetative phase there are flavonoids (flavanones, flavones, and flavonols) only in the aerial parts and they appear gradually during the plant life. These secondary metabolites are detectable in the roots exclusively in the reproductive phase.

RAPD analysis and flavonoid composition of Aconitum as an aid for taxonomic discrimination

Abstract The RAPD technique and phytochemical analysis, based on the investigation of flavonoid composition, were used to study Aconitum vulparia , A. paniculatum , A. napellus subsp. tauricum (from two different localities), and A. napellus subsp. neomontanum . Twenty primers were screened for the genetic analysis and 14 were selected providing 51 polymorphic bands. The phenogram based on UPGMA clustering of Jaccard coefficient revealed a clear division between yellowish and blue Aconitum plants and inside this second group A. paniculatum is clearly separated from all populations belonging to A. napellus group. Also the flavonoid profile well characterise all species and subspecies under study.

Flavonoids from Aconitum napellus subsp. neomontanum

Three flavonol glycosides quercetin 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (1), kaempferol 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (2), and kaempferol 7-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (3), together with the known beta-3,4-dihydroxyphenethyl beta-glucopyranoside, were isolated from the flowers of Aconitum napellus subsp. neomontanum. Their structures were elucidated by spectroscopic methods, including 2D NMR spectral techniques.

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 new phenolic compound from Nigella damascena seeds

A new phenolic ester has been isolated from the seeds of Nigella damascena and the structure was established as 1-O-(2,4-dihydroxy)phenylacetyl glycerol (1) by 1H and 13C-NMR spectral data and EI-MS analysis.

Lipid content and fatty acid composition in hypogeous organs ofHelleborus species (Ranunculaceae)

Root and rhizome of fourHelleborus species:H. viridis, H. odorus, H. niger, H. foetidus were examined throughout a two-year period in order to determine the variation of lipid content and fatty acid composition during the ontogenetic cycle. In the deciduous geophytesH. viridis andH. odorus subsp.laxus the lipid content reaches its maximum during the quiescent phase, whereas in the evergreen geophyteH. niger the lipid content is highest during the main growth period. In the chamaephyteH. foetidus lipid content is always very low and it does not show variation throughout the year. In all species the fatty acids detected in the neutral fraction are myristic, palmitic, stearic, oleic and linoleic acid. Palmitic and linoleic acid are always present in larger quantities. The pattern of the relative content of saturated/unsaturated fatty acids seems to be linked to the life form of these species.

Flavonol glycosides from Aconitum vulparia.

The isolation of five flavonol glycosides (1-5) from the flowers of Aconitum vulparia is reported, together with the 1H- and 13C-NMR spectral data in CD(3)OD of compound 3 and 5.

Characterization of a suspension culture of Chelidonium majus L. on growth and accumulation of sanguinarine

Summary Cell suspension cultures of C. majus L. — obtained from callus — were characterized on growth and on accumulation of isoquinoline alkaloids. The liquid batch cultures consisted of coarse cell aggregates; their fresh volume becames triple each 14 days after subcultures. Cell cultures were found to produce relatively large amounts of isoquinoline alkaloids; sanguinarine is accumulated as main alkaloid and also released into the medium.