Two new five-membered heterocyclic compounds isolated from Polygonum tinctorium

Polygonum tinctorium Ait., a well-documented medicinal herb in traditional Chinese medicine, is commonly utilised in the form of its leaves, known as 'Liao da qing ye' in Chinese Pharmacopoeia. Investigations into the phytochemical constituents of P. tinctorium have resulted in the identification of three distinct five-membered heterocyclic frameworks. This includes the isolation of two novel heterocyclic compounds (1 and 2) alongside four previously characterised pyrrolidine alkaloids. Structural elucidation of these compounds was achieved through HRESIMS and comprehensive spectroscopic analysis. Notably, compound 1 features a furan-based core structure, while compound 2 possesses a pyrrole-based framework. The isolated compounds were subsequently evaluated for their inhibitory potential against α-glycosidase and acetylcholinesterase enzymes.