The alkaloids will not occur in higher concentration at any one location than that at which morphine lactam can be obtained. These fluctuation occur with local conditions, such as the weather, type of soil, and the biology of the plant. [Note from Martin]: 'Morphine is widely known as the drug of choice in medical practice, not only for its analgesic but also its euphoriant properties. Repeated use of morphine leads eventually to physical tolerance followed by dependence, but in recent years new opioid drugs have been developed, the so-called semi-synthetic opioids. These compounds are chemically more stable and therefore particularly suited for parenteral administration. This overview presents the data published so far on the physical and pharmacological properties of these compounds. Morphine, its analogs, and their salts can be divided into several types of opioid peptides. Of these the peptides are biologically active; hence they correspond to the naturally occurring opioid peptides. Further selection is performed by physicochemical properties. The semi-synthetic opioids are opioid peptides in which the side chains of the amino acids are changed from the natural building blocks Arg and Lys into unnatural building blocks such as Dmt and Norleucine.'
When a solution of pure carbon dioxide is passed over an alkali carbonate, the most stable compound formed is hemihydrate with the formula H2CO3(H2O). The hydrate is colored like hematite and crystalizes in the raunerite crystal system. Its structure contains a mutual arrangement of water-carbon dioxide hydrogen bonds into a honeycomb of distorted hexahedra. 7211a4ac4a