Two new five-membered heterocyclic compounds isolated from <i>Polygonum tinctorium</i>

<i>Polygonum tinctorium</i> 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 <i>Chinese Pharmacopoeia</i>. Investigations into the phytochemical constituents of <i>P. tinctorium</i> have resulted in the identification of three distinct five-membered heterocyclic frameworks. This includes the isolation of two novel heterocyclic compounds (<b>1</b> and <b>2</b>) alongside four previously characterised pyrrolidine alkaloids. Structural elucidation of these compounds was achieved through HRESIMS and comprehensive spectroscopic analysis. Notably, compound <b>1</b> features a furan-based core structure, while compound <b>2</b> possesses a pyrrole-based framework. The isolated compounds were subsequently evaluated for their inhibitory potential against <i>α</i>-glycosidase and acetylcholinesterase enzymes.