Melipatulinones A-C, Three Lignan-Phloroglucinol Hybrids from Melicope patulinervia .

(±)-Melipatulinones A-C ( 1 - 3 ), three unique enantiomeric pairs of lignan-phloroglucinol hybrids along with the biogenetically related compound melipatulignan A ( 4 ), were isolated from the leaves of Melicope patulinervia . Melipatulinones A ( 1 ) and B ( 2 ) share a novel spiro[hydrobenzofuran-2,3'-furan] 5/5/6 tricyclic ring system, while melipatulinone C ( 3 ) features an unprecedented spiro[cyclopenta[ b ]hydrofuran-2,3'-furan] 5/5/5 tricyclic framework. Their structures were determined by spectroscopic methods, electronic circular dichroism (ECD) calculations, and X-ray diffraction. Compounds 1 - 3 exhibited a pancreatic lipase inhibitory effect.