Lysidicins F-H, three new phloroglucinols from Lysidice rhodostegia

Three new phloroglucinols, named lysidicins F-H (1-3), were isolated from the roots of Lysidice rhodostegia. These compounds have a unprecedented benzyl benzo[b]furo[3,2-d]furan skeleton, and lysidicin F (1) is the first example of natural product with trans-fused furan rings. Their structures were established on the basis of extensive spectroscopic analysis, and the absolute configurations of them were determined by computational methods. A possible biosynthetic pathway for 1-3 was also postulated.