| Abstract: | Four thebaine-rich varieties of P. bracteatum have been grown in the open over two seasons and the thebaine distribution in aerial parts examined to determine the most suitable source material for commercial production. The leaves contained only 0·1 to 0·15%; the capsules 0·5 to 3·0% and the bled latex 28 to 53%. The maximum for the latter occurred about 3–4 weeks after petal opening and during the day, at about 15.00 h. A product ‘bractium’ prepared exactly as opium from P. somniferum contained up to 55% thebaine and calculations from the 1974 results gave theoretical yields up to 58 kg of thebaine per hectare. However this is a very labour intensive method; furthermore bled latex only represents about 46% of the total thebaine of the capsule. In addition the pedicels contain significant amounts of thebaine, so that fruiting tops may be recommended as source material. In the capsule the thebaine content reaches a peak 3 to 4 weeks after petal opening and again two weeks later. At this fully ripe stage there is a theoretical yield of 50 kg per hectare. Two further advantages accrue from collection at this time: the ripe seeds can probably be used for similar purposes as poppy seed; and the pericarps at this stage contain no ‘bound thebaine’ (i.e., thebaine insoluble in MeOH:NH4OH but soluble in acetic acid—in unripe capsules bound thebaine represents 18 to 36% of the total thebaine). There is some evidence that, as this perennial plant increases in age, the capacity for thebaine production seems to continue increasing. Storage of raw material, even in ideal conditions, led to a loss of thebaine of 12 to 20% in one year. |
