Interestingly, 5b, not only natural product but also one of the favored starting materials for rutaecarpine synthesis, showed promising inhibitory activity on AChE (IC50 = 83.38 μM) [84], implying a new vista towards designing new analogues of rutaecarpine for the treatment of Alzheimer’s disease. This evidence concerns the gene ACHE and early-onset autosomal dominant Alzheimer disease.