From petroleum ether extracts of the bark of M. azedarach four novel tetracyclic triterpenoids have been isolated and characterized to be C 30 compounds of the euphane (20 R ) series. Previously known triterpenoids from Meliaceae have all been 20 S compounds. Kulinone 1 is the first known euphane or tirucallane (20 S ) derivative oxygenated in the D ring; kulactone 2 , kulolactone 3 and methyl kulonate 4 are additionally oxygenated in the side chain. Compounds 2 and 3 have a 2-oxa- trans -bicyclo[3,3,0]-octanone structure.