The powerful anti-cancer properties of Pheasant's-Eye Daffodil was already known to Greek philosopher Hippocrates, who used Narcissus Oil for treating uterine tumours, a practice which was common later in the Middle Ages. It is likely that the constituents Narciclasine, Pancratistatin and their congeners are the most important factors contributing to the anti-cancer properties of this oil. A great many other chemically very similar analogues are also present. Pancratistine is a phenanthridine alkaloid.
Narciclasine, a phenanthridine alkaloid, is responsible for the so-called vase-effect whereby introducing Narcissus bulbs into the same vase as other plants (particularly Roses) leads to the reduction in uptake of water by the Rose, and its subsequent withering. Both Pancratistatin and Narciclassine suppress growth in other plants, such is the competition between plants. Lycorine, present in Wild Daffodil also possesses similar growth inhibitory effects on other plants. These compounds inhibit growth via differing biochemical pathways.
Narcissidine is a phenanthridine alkaloid similar to Lycorine, another amaryllidaceae alkaloid.
Ambelline is a phenanthridine alkaloid, one of the amarillidaceae alkaloids with a resemblance to the chemical structure of both Haemanthamine and to Galanthamine, both of which are also phenanthridine amarillidaceae alkaloids.
Pancracine is a phenanthridine alkaloid, one of the amarillidaceae alkaloids present in a wide range of Amarillidaceae Family plants.