Synthesis of deoxy-Andrographolide Triazolyl Glycoconjugates for the Treatment of Alzheimer’s Disease

A new andrographolide-based terminal alkyne 3 was synthesized in good yield from deoxy-andrographolide 2, obtained from a natural compound andrographolide 1, which in turn was isolated from the leaves of the plant Andrographis paniculata. Copper(I)-catalyzed azide–alkyne cycloaddition reaction of alkyne 3 with azido-sugars 4a–f furnished a library of andrographolide-fastened triazolyl glycoconjugates 5a–f in good yields. The structures of these semisynthetic andrographolide derivatives were established by Fourier transform infrared, NMR, and mass spectroscopy. The compounds 5a–f were further evaluated against Alzheimer's disease (AD) using a scopolamine (SCOP)-induced memory impairment mice model. It was observed that antioxidant and anticholinesterase properties of these compounds contribute significantly toward their remarkable potential to improve cognitive functioning.