Synergistic inhibition of Aβ production by combinations of γ-secretase modulators

Gamma-secretase modulators: a promising route for the treatment of Alzheimer's disease

Recent clinical data with three therapeutic anti-Aβ antibodies have demonstrated that removal of Aβ-amyloid plaques in early Alzheimer's disease (AD) can attenuate disease progression. This ground-breaking progress in AD medicine has validated both the amyloid cascade hypothesis and Aβ-amyloid as therapeutic targets. These results also strongly support therapeutic approaches that aim to reduce the production of amyloidogenic Aβ to prevent the formation of Aβ-pathology. One such strategy, so-called gamma-secretase modulators (GSM), has been thoroughly explored in preclinical settings but has yet to be fully tested in clinical trials. Recent scientific progress has shed new light on the role of Aβ in Alzheimer's disease and suggests that GSMs exhibit specific pharmacological features that hold great promise for the prevention and treatment of Alzheimer's disease. In this short review, we discuss the data that support why it is important to continue to progress in this class of compounds.

Synthesis of Antimicrobial Benzo[1,2,4]triazoloazepinium Salts and Tetrahydronaphtho[1,2-e][1,2,4]triazines by Polar [3+ + 2] and [4 + 2]-Cycloaddition Reactions

Novel annulated azaheterocycles of benzo[1,2,4]triazoloazepine and tetrahydronaphtho[1,2-e][1,2,4]triazine derivatives have been synthesized. Treatment of 2-diazenyl-1,2,3,4-tetrahydronaphthalen-2-yl acetates with BF₃·Et₂O generates 1-aza-2-azoniaallenium cation intermediates (or azocarbenium ions), which are intercepted by nitriles via cascade polar [3⁺ + 2]-cycloaddition/rearrangement reactions to afford benzo[1,2,4]triazoloazepinium salts. These literature unprecedented fused tricycle compounds have been shown to exhibit antimicrobial activity against Gram-positive Staphylococcus aureus with in silico docking studies, suggesting that they may exhibit their antibiotic activity through inhibition of DNA gyrase. Additionally, when ethyl 2-(1-acetoxy-1,2,3,4-tetrahydronaphthalen-2-yl)diazene-1-carboxylate is employed, the reaction with BF₃·Et₂O produces 1,2-diaza-1,3-diene, which reacts with nitriles via a diaza-Diels-Alder reaction with inverse electron demand, leading to ethyl tetrahydronaphtho[1,2-e][1,2,4]triazine carboxylates. The DFT calculation has been performed to further prove the D-A reaction speculation.