Benzothiazole-based ureas as potential ABAD/17beta-HSD10 modulators for Alzheimer’s disease treatment

Challenge

Amyloid beta peptide (Aβ) interactions with mitochondrial proteins may become therapeutic targets for cellular protection in Alzheimer’s disease (AD). Several mitochondrial proteins have been shown to interact directly with Aβ, possibly influencing mitochondrial metabolism. The amyloid-binding alcohol dehydrogenase enzyme is one such Aβ binding protein.

Technology

Aβ has been recognized to interact with numerous proteins, which may lead to pathological changes in cell metabolism of AD patients. One such known metabolic enzyme is mitochondrial amyloid-binding alcohol dehydrogenase (ABAD), also known as 17b-hydroxysteroid dehydrogenase type 10 (17b-HSD10). Altered enzyme function caused by the Aβ -ABAD interaction, was previously shown to cause mitochondrial distress and a consequent cytotoxic effect, therefore providing a feasible target in AD drug development. Cell based assays and transgenic mice experiments demonstrated that the overexpression of both Aβ and ABAD show enhanced cell cytotoxicity, reduced levels of ATP and COX activity along with impaired energy metabolism in mice. Conversely, the overexpression of Ab with inactive ABAD displayed less cytotoxicity and transgenic (ABAD) mice when compared with non-transgenic mice do not display these changes. In ABAD inhibition study the compound (AG18051) appeared to reduce the levels of Aβ-induced oxidative stress and mitochondrial respiration impairment, as well as alleviate the Aβ-induced downregulation of ABAD activity. Whereas elevated levels of ABAD have been associated with AD pathology. Reduced levels of ABAD has been reported in brain of Parkinson’s disease patients. These findings suggest that both ABAD-Aβ interaction and ABAD itself may represent a viable objective for deeper understanding of AD pathogenesis in context of Aβ-induced toxicity. Consequently, it may also aid in the development of novel AD therapeutics. Based on previous frentizole derivatives studies, we report two novel series of benzothiazolyl ureas along with novel insights into the structure and activity relationships for inhibition of ABAD. Over 200 compounds were designed, prepared and identified as ABAD inhibitors, where some of them exhibited very high ABAD inhibition and comparable cytotoxicity with the standard. The compounds could be easily prepared in larger quantity (grams). The calculated and experimental physical chemical properties of the most compounds showed promising features for blood–brain barrier penetration and markedly increased solubility in water/buffer systems than standard. The in vivo studies on the compound´s bioavailability and pharmacokinetics in naïve rats for the selected candidates are in progress.

Commercial Opportunity

Considered partnership – license agreement, research collaboration agreement

Development Status

In vitro and in vivo experiments

Patent Situation

Patent for first generation of molecules (CZ20140539); further generation unpublished (patent application under preparation)

Further Reading

ctbt.cz/en/intro/