The pharmacology and biology of minor opium alkaloids have been surveyed previously in two comprehensive reviews (). Thebaine The pharmacology of thebaine was summarized by Reynolds and Randall in 1957 and studied comprehensively by a WHO Advisory Group in 1980. The pharmacological actions of thebaine in various isolated organs have been studied. Thebaine can induce a temporary decrease in blood pressure in anaesthetized dogs and this depressor effect showed a marked tachyphylaxis. In isolated guinea pig atrium, thebaine decreased the heart rate and contractions depending on the concentration. In isolated rabbit ileum it decreased the peristaltic movement and contractions (). The predominant effect of thebaine is stimulation of the central nervous system. In the mouse, rabbit, cat and dog increases in motor activity and reflex excitability were observed at doses around 2-10mg/kg s.c. or i.m. The Straub-tail response was noted only occasionally. The effects of thebaine on body temperature and respiration have also been studied. Convulsions were observed in almost all species of animals including the frog, pigeon, mouse, guinea pig, cat and dog. Transient tremors, restlessness and convulsions were observed in the Read more […]
Archive for category Poppy'
The latex obtained by the incision of unripe seed capsules of Papaver somniferum and which is known as opium is the source of several pharmacologically important alkaloids. Dioskorides, in about AD 77, referred to both the latex (opos) and the total plant extract (mekonion) and to the use of oral and inhaled (pipe smoked) opium to induce a state of euphoria and sedation. Since before the Christian era the therapeutic properties of opium were evident, with the first written reference to poppy juice by Theophrastus in the third century BC. Powdered opium contains more than 40 alkaloids which constitute about 25% by weight of the opium and are responsible for its pharmacological activity. In 1803 the German pharmacist Sertiirner achieved the isolation of morphine as one of the active ingredients of opium. Morphine, codeine, thebaine, papaverine, narcotine and narceine are the most important bases, with many of the remaining (minor) alkaloids occurring only in traces. Morphine Morphine has long occupied an eminent position on the list of useful drugs. As a pure alkaloid, it has been employed for over a century and a half and, as the most important constituent of opium, it has contributed to the comfort of the human Read more […]
Poppy germinates and comes up within 10-14 days of sowing. During this period cracking of the soil surface may severely hamper or even stop this process and thus soils liable to cracking have to be loosened regularly. In early spring in the case of the winter poppy, rolling with a light roller is necessary if the soil structure of the plantation is frost damaged. If the plantation is set up using traditional methods, the poppy stand should be thinned when the plants are at the 4-6 leaf stage. On smaller fields or in high-density stands thinning has to be repeated twice (at the 2-3 leaf and 5-6 leaf phases), but this procedure requires a lot of labour and costs can reach a third of the whole production expenses (). Plant Density and Thinning The optimum plant density should be reached in order to get optimal yields. Plants at a distance of 3-4cm apart are capable of developing one capsule per plant, but those spaced 10-20cm apart may produce 3-4 capsules; higher capsule numbers per plant are, however, dependent on many other climatic and agro-technical factors. Muchova et al. () proved that a significant positive correlation exists to a certain extent between seed yield and the number of plants per unit area. The Read more […]
Poppy is cultivated in several countries of the temperate zone. It is cultivated for two purposes: for straw, which is an important pharmaceutical raw; and for seeds and fatty oils which are used in both alimentary and industrial production processes. In certain cases and countries the seeds are marketed as the only product of local poppy cultivation (e.g. in Germany and Austria). However, both the straw and the seed have significant market value and use of them both obviously increases the profitability of the crop. Poppy plants also have a small but increasing importance as an ornamental species and the dried capsules are used in dried flower compositions. Special cultivars have been developed and produced for this purpose. Considering the production areas and quantities of harvested poppy straw and seed, the main European countries involved are Hungary, Spain, France, Romania, Slovakia, the Czech Republic and Austria. Although very low production capacity in the 1990s has been recorded in Poland, Bulgaria and Yugoslavia (INCB, 1995), these countries are traditional poppy producers and after the recent economic crisis they may become important players in the market again. Turkey is reported to cultivate several Read more […]
The opium poppy, like many other important crop species, has provided a number of technical challenges for the application of modern molecular approaches. These difficulties include, but are not limited to, problems in protein and nucleic acid purification, as well as the transformation and regeneration of fertile plants. Over the past decade most of these barriers have been overcome so that the opium poppy is poised to become a model system for the study of latex cell gene regulation as well as a target for metabolic engineering of important pharmaceuticals. This section will review the features which make the opium poppy recalcitrant to standard molecular procedures and how protocols have been successfully adapted in order to work with poppies. In addition, the cloning and characterization of several poppy genes will be described. Their potential application in the metabolic engineering of transgenic poppy plants for altered alkaloid synthesis is also discussed. Characterization Of Major Latex Proteins Laticifers are internal secretory systems which occur in both primitive and advanced flowering plants. Although they are present in only fifteen families, latex-bearing plants may be quite valuable due to their Read more […]