Unusual ent-isopimarane-type diterpenoids from the wood of Excoecaria agallocha

Abstract Three new ent -isopimarane-type diterpenoids with unusual 3,4-seco ( 1 ) and seven membered lactone moieties ( 1 – 2 ), along with four known compounds ( 4 – 7 ) were isolated from the wood of medicinal mangrove plant, Excoecaria agallocha . Their structures were established as agallochaexcoerins D-F ( 1 – 3 ) by spectroscopic data interpretation and chemical evidence.