1334547-61-3

Upstream product

• 314-19-2 apomorphine hydrochloride 
• 314-19-2 (±)-apomorphine hydrochloride 

Relevant academic research and scientific papers

Mechanistic analyses of the suppression of amyloid β42 aggregation by apomorphine

(R)-Apomorphine (1) has the potential to reduce the accumulation of amyloid β-protein (Aβ42), a causative agent of Alzheimer's disease (AD). Although the inhibition of Aβ42 aggregation by 1 is ascribable to the antioxidative effect of its phenol moiety, its inhibitory mechanism at the molecular level remains to be fully elucidated. LC–MS and UV analyses revealed that 1 is autoxidized during incubation to produce an unstable o-quinone form (2), which formed a Michael adduct with Lys 16 and 28 of Aβ42. A further autoxidized form of 1 (3) with o-quinone and phenanthrene moieties suppressed Aβ42 aggregation comparable to 1, whereas treating 1 with a reductant, tris(2-carboxyethyl)phosphine diminished its inhibitory activity. 1H-15N SOFAST-HMQC NMR studies suggested that 1 interacts with Arg5, His13,14, Gln15, and Lys16 of the Aβ42 monomer. These regions form intermolecular β-sheets in Aβ42 aggregates. Since 3 did not perturb the chemical shift of monomeric Aβ42, we performed aggregation experiments using 1,1,1,3,3,3-hexafluoro-2-propanol-treated Aβ42 to investigate whether 3 associates with Aβ42 oligomers. Compounds 1 and 3 delayed the onset of the oligomer-driven nucleation phase. Despite their cytotoxicity, they did not exacerbate Aβ42-mediated neurotoxicity in SH-SY5Y neuroblastoma cells. These results demonstrate that extension of the conjugated system in 1 by autoxidation can promote its planarity, which is required for intercalation into the β-sheet of Aβ42 nuclei, thereby suppressing further aggregation.

Extensive study of the autooxidation products of apomorphine and its pharmacologically active derivatives

The autooxidation phenomenon of apomorphine and the products of this procedure were analytically and pharmacologically studied, however we found that there have been some unclarified details of this filed. Therefore the synthesis and structure of the autooxidation products of three clinically and pharmacologically relevant aporphinoids (apomoprine, N-propyl-norapomorphine and 2-hydroxy-N-propyl-norapomorphine) were thoroughly investigated. The autooxidation of apomorphine achieved at physiological pH resulted two products; one of them is the known tetracyclic, tertiary amino ortho quinone and the hitherto unknown, fluorescent, derivatized phenanthrene-3,4-quinone. Under the same conditions N-propyl congeners resulted only the expected 1,2-dione products. The analytical structure elucidation involved the full 1H and 13C NMR assignment, UV and IR characterizations of the four isolated ortho quinone-type products exploiting the possibilities of DFT calculations for geometry optimization, NMR and IR simulations. The phenanthrene-3,4-quinone compound can be relevant in further pharmacological studies of aporphine-related oxidation products due to its potential toxicity and investigated fluorescent character.