Trichiconlides CF, four new limonoids with 1,2-seco phragmalin-type carbon skeleton from the fruits of Trichilia connaroides

Abstract Phytochemical investigation of the fruits from Trichilia connaroides led to the isolation of four rare 1,2- seco phragmalin-type limonoids ( 1 – 4 ) with C-7/28 δ -lactone ring along with two known triterpenoids ( 5 – 6 ). An oxygen bridge between C-1 and C-2 formed an rare 9- oxa -tricyclo[3.3.2.1 7,10 ]undecane-2-ene moiety in structure of 1 and 2 , and 3 – 4 possessed a bicyclo[5.2.1 4,10 ]decane skeleton. Their structures were established based on extensive spectroscopic methods and their absolute configurations of 1 were confirmed by TDDFT/ECD calculation and comparative analysis. Compounds 5–6 showed moderate inhibitory effects on Hela tumor cell lines with inhibition ratio values of 83.8% and 87.1% at concentration 40 μM, respectively.