Tociliatonoid B-E, novel limonoids from Toona ciliata var. yunnanensis

Four new limonoids, tociliatonoid B-E (1–4) were obtained from the EtOAc extract of the twigs and leaves of Toona ciliata var. yunnanensis. Their structures were elucidated through comprehensive spectroscopic and X-ray crystallographic analysis. Compounds 1–4 are rare limonoids which feature unusual 3-substituted 1,5-dihydro-2H-pyrrol-2-one or maleimide ring moiety at C-17 and Compound 1 possess an aldehyde group at C-4.