Two New Flavonoids from the Rhizomes of Abacopteris penangiana

A new flavan-4-ol glycoside, abacopterin K (1), and a new dihydrochalcone glycoside, abacopterin L (2), were isolated from the rhizomes of Abacopteris penangiana. Their structures were elucidated on the basis of various spectroscopic analyses and chemical evidences. The novel glucosylation pattern of abacopterin K consisting of two 'glucose-fused' dioxepine ring moieties is found for the first time within natural flavonoids.