Pyrazolo[3,4-b]pyridine emerges as a privileged scaffold in anti-Alzheimer’s drug design

Chemists reviewing decades of medicinal chemistry literature have concluded that pyrazolo[3,4-b]pyridine, a fused nitrogen-containing ring system, deserves its reputation as a privileged scaffold for designing anti-Alzheimer’s agents. The assessment appears in a review published on 10 August 2026 in Future Journal of Pharmaceutical Sciences by Omnia M. Waly, Selwan M. El-Sayed, Mariam A. Ghaly and Hussein I. El-Subbagh, who compiled reported pyrazolo[3,4-b]pyridine derivatives from data gathered without date restriction and analysed their synthetic pathways and structure–activity relationships.

Alzheimer’s disease is described in the review as the most prevalent neurodegenerative disorder that results in dementia and produces a variety of cognitive symptoms. The authors note that there are many important aspects of Alzheimer's disease that should be considered, even though the exact sequence of events is unclear.

Three of those aspects dominate the review’s mechanistic background. The first is the cholinergic theory; the review's abbreviation list includes acetylcholine, acetylcholinesterase and butyrylcholinesterase. The second is the amyloid beta hypothesis; the abbreviation list includes amyloid beta, amyloid precursor protein and beta-site APP cleaving enzyme-1 (BACE-1). The third is the hyperphosphorylated tau protein that forms neurofibrillary tangles; the abbreviation list includes glycogen synthase kinase 3 beta, cyclin-dependent kinase 5, casein kinase 1 and the microtubule affinity-regulating kinases.

Against this backdrop, the review’s central claim is that pyrazolo[3,4-b]pyridine-based derivatives exhibited therapeutic potential in Alzheimer’s disease management. The authors direct particular attention to multitargeted directed ligands (MTDLs); their conclusion states that pyrazolo[3,4-b]pyridine is an attractive scaffold to design MTDLs to stop the progression of AD.

The review's abbreviation list spans cholinesterase and its subtypes, amyloid beta and BACE-1, tau-related kinases, monoamine oxidase-A, phosphodiesterase 4, 5-hydroxytryptamine, the A1-adenosine receptor, lipoxygenase, cyclooxygenase and peroxisomal proliferators-activated receptor. For each class, the synthetic routes used to build the fused pyrazolopyridine core and append the pharmacophoric substituents are summarised, giving synthetic chemists a practical map of how the reported compounds were assembled.

A distinctive contribution is the collective structure–activity relationship, or SAR, study that closes the article. Rather than analysing each published series in isolation, the authors pool the reported data to extract the structural requirements needed to design a multitargeted directed ligand on the pyrazolo[3,4-b]pyridine scaffold.

The authors are candid about the limits of that analysis. In their conclusion they note that further investigation is still needed to study the effect of various substituents at position 5 of the scaffold on both cholinesterase and amyloid beta activities.

It is worth stressing what this review is and is not. It is a review of reported data gathered without date restriction, not a report of new experiments. According to the journal's data availability statement, the data supporting the findings are available from the corresponding author upon reasonable request. Readers should therefore treat the collective SAR as a design hypothesis for medicinal chemists, not as evidence that any pyrazolo[3,4-b]pyridine drug is close to approval.

By consolidating the etiology of Alzheimer’s disease alongside every reported pyrazolopyridine derivative acting as an anti-Alzheimer’s agent, and by distilling the main structural requirements for multitargeted directed ligands, the authors have produced a reference point for the next round of scaffold hopping. Whether position 5 substitutions or other unexplored vectors will yield compounds that advance beyond the laboratory remains an open experimental question, but the review makes a clear case that this privileged scaffold has earned a central place in that search.

Subject of Research: A review of pyrazolo[3,4-b]pyridine derivatives as multitargeted anti-Alzheimer's drug candidates

Article Title: Pyrazolo[3,4-b]pyridine: a privileged scaffold for the synthesis of anti-Alzheimer’s agents

Article References: Waly, O. M., El-Sayed, S. M., Ghaly, M. A., & El-Subbagh, H. I. (2026). Pyrazolo[3,4-b]pyridine: a privileged scaffold for the synthesis of anti-Alzheimer’s agents. Future Journal of Pharmaceutical Sciences, 12(1), Article 80. https://doi.org/10.1186/s43094-026-01006-6

Image Credits: AI Generated

DOI: 10.1186/s43094-026-01006-6

Keywords: Alzheimer's disease, pyrazolo[3,4-b]pyridine, medicinal chemistry, multitargeted directed ligands, structure–activity relationship, cholinesterase inhibitors, amyloid beta, tau protein, drug design, review article, Pyrazolo, pyridine