Fifteen Amaryllidaceae alkaloids (1-15) were evaluated for their antiproliferative activities against six distinct cancer cell lines. Several of these natural products were found to have low micromolar antiproliferative potencies. The log P values of these compounds did not influence their observed activity. When active, the compounds displayed cytostatic, not cytotoxic activity, with the exception of pseudolycorine (3), which exhibited cytotoxic profiles. The active compounds showed similar efficacies toward cancer cells irrespective of whether the cell lines were responsive or resistant to proapoptotic stimuli. Altogether, the data from the present study revealed that lycorine (1), amarbellisine (6), haemanthamine (14), and haemanthidine (15) are potentially useful chemical scaffolds to generate further compounds to combat cancers associated with poor prognoses, especially those naturally resistant to apoptosis, such as glioblastoma, melanoma, non-small-cell lung, and metastatic cancers.

Amaryllidaceae alkaloids belonging to different structural subgroups display activity against apoptosis-resistant cancer cells.

Alkaloids of Crinum pratense

Infrared Absorption Spectra of Methylenedioxy and Aryl Ether Groups

A general and high yielding annulation strategy for the synthesis of various carbo- and heterocycles, based on an intramolecular aryne ene reaction is described. It was found that the geometry of the olefin is crucial to the success of the reaction, with exclusive migration of the trans-allylic-H taking place. Furthermore, the electronic nature of the aryne was found to be important to the success of the reaction. Deuterium labeling studies and DFT calculations provided insight into the reaction mechanism. The data suggests a concerted asynchronous transition state, resembling a nucleophilic attack on the aryne. This strategy was successfully applied to the formal synthesis of the ethanophenanthridine alkaloid (±)-crinine.

Development of an intramolecular aryne ene reaction and application to the formal synthesis of (±)-crinine.

Oxocrinine and other alkaloids from Crinum americanum

Alkaloids of the Amaryllidaceae. IV. Crystalline Alkaloids of Ammocharis coranica (Ker-Gawl.) Herb., Brunsvigia rosea (Lam.) Hannibal and Two Crinum Species

L. H. Mason

Papers

Alkaloids of the Amaryllidaceae. IV. Crystalline Alkaloids of Ammocharis coranica (Ker-Gawl.) Herb., Brunsvigia rosea (Lam.) Hannibal and Two Crinum Species