Pyrrolizidine alkaloid profiles of the Senecio cineraria group (Asteraceae).

Pyrrolizidine alkaloid profiles of some Senecio species from Egypt.

Alkaloid profiles of two Egyptian Senecio species (Senecio aegyptius var. discoideus and S. desfontainei) in addition to a cultivated species (S. cineraria) were studied using capillary GLC and GLC-mass spectrometry with respect to pyrrolizidine alkaloids (PAs). Four alkaloids were identified in S. aegyptius var. discoideus, 8 in S. desfontainei and 13 in S. cineraria. Some of these alkaloids h...

Diversity of pyrrolizidine alkaloids in native and invasive Senecio pterophorus (Asteraceae): implications for toxicity. Phytochemistry 108: 137-146 DOI 10.1016/j.phytochem.2014.06.006 Diversity of pyrrolizidine alkaloids in native and invasive Senecio pterophorus (Asteraceae): implications for toxicity

Cell-specific expression of homospermidine synthase, the entry enzyme of the pyrrolizidine alkaloid pathway in Senecio vernalis, in comparison with its ancestor, deoxyhypusine synthase.

Pyrrolizidine alkaloids (PAs) are constitutive plant defense compounds with a sporadic taxonomic occurrence. The first committed step in PA biosynthesis is catalyzed by homospermidine synthase (HSS). Recent evidence confirmed that HSS evolved by gene duplication from deoxyhypusine synthase (DHS), an enzyme involved in the posttranslational activation of the eukaryotic translation initiation fac...

Natural hybridization between Senecio jacobaea and Senecio aquaticus: molecular and chemical evidence.

Hybridization is known to be involved in a number of evolutionary processes, including species formation, and the generation of novel defence characteristics in plants. The genus Senecio of the Asteraceae family is highly speciose and has historically demonstrated significant levels of interspecific hybridization. The evolution of novel chemical defence characteristics may have contributed to t...

Ornithine decarboxylase, polyamines, and pyrrolizidine alkaloids in senecio and crotalaria.

When tested for ornithine and arginine decarboxylases, pyrrolizidine alkaloid-bearing Senecio riddellii, S. longilobus (Compositae), and Crotalaria retusa (Leguminosae) plants exhibited only ornithine decarboxylase activity. This contrasts with previous studies of four species of pyrrolizidine alkaloid-bearing Heliotropium (Boraginaceae) in which arginine decarboxylase activity was very high re...