J. M. Llabrés

Alkaloids from Narcissus confusus

Abstract We report the isolation of haemanthamine, galanthamine, pretazettine and the new alkaloid N-formylgalanthamine from Narcissus confusus plants. Structural determination was carried out by spectroscopic analyses and application of two-dimensional NMR spectroscopy.

Phenanthridine alkaloids from Narcissus assoanus

Abstract The rare phenanthridine alkaloid assoanine and its new 7-oxo derivative, oxoassoanine, have been isolated from Narcissus assoanus collected at flowering. HPLC analysis of crude extracts of the plant has been carried out to ascertain that oxoassoanine is not an artefact.

Two alkaloids from Narcissus requienii

The aerial part of Narcissus requienii (Amaryllidaceae) was found to contain pseudolycorine as the major alkaloid, and two new phenolic bases: 2-O-acetylpseudolycorine and 1-O-acetylpseudolycorine. The present communication reports the complete assignments of the NMR spectra of pseudolycorine, and the structure elucidation of the other comnounds by means of 2D 1H-1H and 1H-13C NMR chemical shift correlation experiments.

Dubiusine from Narcissus dubius

Abstract A single alkaloid, dubiusine, has been isolated from Narcissus dubius growing in Candasnos (Spain). The structure 2α-acetoxy-9-(3-hydroxybutyryl)homolycorine is proposed for the compound from spectroscopic analysis and chemical correlation.

Alkaloid Screening of Plants of Catalonia (Spain) III

AbstractEighty plant extracts were screened for the presence of both tertiary and quaternary alkaloids. 9 species were found to contain alkaloids and 8 of these are reported for the first time.

Free amino acids and alkaloid content in snapdragon plants grown with nitrate, urea or ammonium nutrition

Abstract The effect of different nitrogen sources (urea, nitrate and ammonium) on the free amino acids and alkaloid content in leaves and roots of snapdragon (Antirrhinum majus) was studied. The nitrate treatment produced the highest plant dry weights, and urea the lowest. The all ammonium grown plants finished their biologic cycle one month earlier than the nitrate plants. Results indicate that the most abundant free amino acids are glutamic and aspartic acids and glutamine, which constituted for about 50% of the whole pool. Free methionine and cysteine are absent from both leaves and roots. The highest alkaloid levels occur for all tests during full flowering, the ammonium treated plants containing the most alkaloids.

Alkaloid Screening of Catalonia (Spain) Plants. II

AbstractOne hundred sixteen plant extracts were screened for the presence of both tertiary and quaternary alkaloids. 20 Species were found to contain alkaloids and 17 of them are reported here for the first time.

Screening of Higher Fungi from Catalonia for Alkaloids-II

AbstractEighty extracts of higher fungi from Catalonia (Spain) were screened for alkaloids. Five mushrooms were found to be alkaloid-bearing, four of them being described as such for the first time: Boletus impolitus, Entoloma sinuatum, Melanoleuca melaleuca and Rhizopogon luteolus.