Two New Alkaloids from Narcissus serotinus L.

Abstract

The Amaryllidaceae family is well known for the presence of an exclusive group of alkaloids with a wide range of biological activities. Narcissus serotinus L. is a plant belonging to this family and its geographical distribution is mainly located along the Mediterranean coast. In the present work, specimens collected near Casablanca (Morocco) were used to study the alkaloid content of this species. Starting with 350 g of the whole plant we used standard extraction and purification procedures to obtain fractions and compounds for GC-MS and NMR analysis. As well as five known alkaloids, we isolated two new compounds: 1-O-(3´-acetoxybutanoyl)lycorine and narseronine. The latter has been previously published, but with an erroneous structure.

A Chemoenzymatic Route to the (+)-Form of the Amaryllidaceae Alkaloid Narseronine

“…[8] (20). The 1 H NMR, 13 C NMR, and infrared spectral data presented above were in good agreement with those reported for the natural product [7] and for the synthetically derived (À)-narseronine. [8] The only minor discrepancy was observed in the 13 C NMR spectra.…”

“…Finally, treatment of compound 8 with (Ph 3 P) 4 Pd in the presence of dimedone resulted in cleavage of the Alloc group, thus allowing the resulting secondary amine 9 (which was not isolated) to undergo an intramolecular hetero-Michael addition reaction/ trans-acylation sequence and so affording (À)-narseronine [(À)-1] (82 %), the structure of which was secured by singlecrystal X-ray analysis. Unfortunately, the specific rotation for the natural product obtained by Bastida et al [7] was not reported and so it has not been possible to establish its absolute configuration.…”

“…[5] Similarly, we have shown that various cis-1,2dihydrocatechols can participate in a range of Diels-Alder cycloaddition processes that permit the assembly of either enantiomeric form of certain polycyclic frameworks, including those associated with sesquiterpenoid natural products. [6] In a related vein, we now detail the outcomes of a study that has culminated in the identification of a method for the assembly of the (þ)-form of the Amaryllidaceae alkaloid narseronine (2) [7] from compound 1, work that complements our recently reported synthesis [8] of its optical antipode [viz. (À)-narseronine] from the same starting material (Chart 1).…”

Amaryllidaceae alkaloids with anti-Trypanosoma cruzi activity

“…Finally, extracts were subjected to a combination of chromatographic techniques and alkaloids identified by GC-MS and NMR (16,17). In order to be able to segregate the order of milligrams of product, the corresponding scale-up attending to the required proportion was made as described (19,20).…”

gem-Dibromocyclopropanes and enzymatically derived cis-1,2-dihydrocatechols as building blocks in alkaloid synthesis

“…In some related studies we have been able to establish a synthesis of narseronine (45), an alkaloid isolated recently from the flowering plant Narcissus serotinus L. that grows in dry coastal regions of many parts of the Mediterranean [26]. Perhaps the most notable structural feature of the compound is the presence of an unsaturated δ-lactone residue within the B-ring.…”