Morphinan alkaloids applications

The qualitative and quantitative determinations of morphinane alkaloids or their derivatives in opium were studied by application of different methods (278, 533, 534), by differentia] spectrophotometry (535, 536), thin-layer chromatography (509, 537, 538), gas chromatography in conjunction with mass spectrometry (539, 540), and high-speed liquid chromatography (thebaine) (327, 534). A procedure for the quantitative determination of morphine in opium by isotopic dilution has been developed (541). 

Kinetic inhibition experiments revealed that the molecular action of the base on the lipase is a noncompetitive inhibititm — i.e., the base attaches itself to the lipase at a site other than the active site - which inhibits the transformation of one enantiomer but not that of its mirror image. Moreover, the chirality of the base has only a marginal impact on the selectivity enhancement effect. The general applicability of this method - impeded by the high cost of morphinan alkaloids and their questionable use for large-scale synthesis — has been extended by the use of more simple amines such as N, A -dimethyl-4-methoxyphenethylamine (DMPA) [235]. 

Applications to alkaloid synthesis are exemplified by the construction of the morphinan ring system (I) and synthesis of the oxocrinine analog (II). 

Noscapine or narcotine (3) is a phthalideisoquinoline alkaloid from plants of the Papaveraceae family. It is an important alkaloid from the opium poppy (Papaver somniferum L.), occurring in variable quantities (level ranges from 2% to 10%) [38]. Unlike opioid morphinane drugs, noscapine lacks hypnoanalgesic, euphoric, and respiratory depressant properties. Its main therapeutic application is as oral antitussive drug, which is indicated to treat nonproductive coughs [39, 40]. 

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