Opioid conformations: The remarkable effect of C-14 substituents on ring c conformations of 6α and 6β epimers of 6-substituted epoxymorphinan opioid ligands

Opioid ligands addressing unconventional binding sites and more than one opioid receptor subtype

Opioid receptors (ORs) represent one of the most significant groups of G-protein coupled receptor (GPCR) drug targets and also act as prototypical models for GPCR function. In a constant effort to develop drugs with less side effects, and tools to explore the ORs nature and function, various (poly)pharmacological ligand design approaches have been performed. That is, besides classical ligands, a great number of bivalent ligands (i.e. aiming on two distinct OR subtypes), univalent heteromer-selective ligands and bitopic and allosteric ligands have been synthesized for the ORs. The scope of our review is to present the most important of the aforementioned ligands, highlight their properties and exhibit the current state-of-the-art pallet of promising drug candidates or useful molecular tools for the ORs.

Practical and high-yield syntheses of dihydromorphine from tetrahydrothebaine and efficient syntheses of (8S)-8-bromomorphide

A practical method for the conversion of tetrahydrothebaine to dihydromorphine in 92% yield is described. The procedure should allow more efficient production of opium products and may be easily modified for large-scale synthesis. The conversion of codeine to (8S)-8-bromomorphide, a potentially valuable intermediate to 6-demethoxyoripavine and derivatives, is also described. The absolute configuration of (8S)-8-bromomorphide was determined by a single-crystal X-ray diffraction study of the hydrobromide salt.

Transformations of morphine alkaloids by Pseudomonas putida M10

The oxidation of morphine by washed-cell incubations of Pseudomonas putida M10 gave rise to a large number of transformation products including hydromorphone (dihydromorphinone), 14 beta-hydroxymorphine, 14 beta-hydroxymorphinone, and dihydromorphine. Similarly, in incubations with oxymorphone (14 beta-hydroxydihydromorphinone) as substrate, the major transformation product was identified as oxymorphol (14 beta-hydroxydihydromorphine). The identities of all these biological products were confirmed by mass spectrometry and 1H nuclear magnetic resonance spectroscopy. This is the first report describing structural evidence for the biological synthesis of 14 beta-hydroxymorphine and 14 beta-hydroxymorphinone. These products have applications as intermediates in the synthesis of semisynthetic opiate drugs.