New mescaline-related N-acylhydrazone and its unsubstituted benzoyl derivative: Promising metallophores for copper-associated deleterious effects relief in Alzheimer's disease.
Alessandra Carvalho, Barbara Marinho Barbosa, Jesica S Flores, Phelippe Do Carmo Gonçalves, Renata Diniz, Yraima Cordeiro, Claudio O Fernández, Daphne S Cukierman, Nicolás A Rey
Journal of inorganic biochemistry January 1, 2023 Peer reviewed DOI: 10.1016/j.jinorgbio.2022.112033 via PubMed
Summary
The N-acylhydrazones X1TMP and X1Benz have shown potential as agents for treating Alzheimer's disease by reducing reactive oxygen species (ROS) and preventing amyloid-β (Aβ) fibrillation. These compounds were synthesized and characterized, with X1Benz demonstrating a direct interaction with Aβ. Although it was not effective at removing metal-induced changes in Aβ, its ability to form a ternary complex with Aβ and copper may contribute to its beneficial effects.
Study at a glance
| Key finding | N-acylhydrazones X1TMP and X1Benz can reduce ROS production and prevent Aβ fibrillation in the presence of copper. |
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Abstract
Alzheimer's disease (AD) is related to the presence of extracellular aggregated amyloid-β peptide (Aβ), which binds copper(II) with high affinity in its N-terminal region. In this sense, two new 1-methylimidazole-containing N-acylhydrazonic metallophores, namely, X1TMP and X1Benz, were synthesized as hydrochlorides and characterized. The compound X1TMP contains the 3,4,5-trimethoxybenzoyl moiety present in the structure of mescaline, a natural hallucinogenic protoalkaloid that occurs in some species of cacti. Single crystals of X1Benz, the unsubstituted derivative of X1TMP, were obtained. The experimental partition coefficients of both compounds were determined, as well as their apparent affinity for Cu2+ in aqueous solution. Ascorbate consumption assays showed that these N-acylhydrazones are able to lessen the production of ROS by the Cu(Aβ)-system, and a short-time scale aggregation study, measured through turbidity and confirmed by TEM images, revealed their capacity in preventing Aβ fibrillation at equimolar conditions in the presence and absence of copper. 1H15N HSQC NMR experiments demonstrated a direct interaction between Aβ and X1Benz, the most soluble of the compounds. The Cu2+ sequestering potential of this hydrazone towards Aβ was explored by 1H NMR. Although increasing amounts of X1Benz were unexpectedly not efficient at removing the metal-induced perturbations in Aβ backbone amides, the broadening effects observed on the compound's signals indicate the formation of a ternary Aβ‑copper-X1Benz species, which can be responsible for the observed ROS-lessening and aggregation-preventing activities. Overall, the N-acylhydrazones X1TMP and X1Benz have shown promising prospects as agents for the treatment of AD.