Walsogynes B-G, limonoids from Walsura chrysogyne

Six new limonoids, Walsogynes B (1)-G (6), were isolated from the barks of Walsura chrysogyne, and their structures were determined on the basis of NMR and MS spectroscopic analyses in combination with NMR chemical shifts calculations. Walsogynes (1)-E (4) were concluded to be 11,12-seco limonoids sharing a unique dodecahydronaphtho[1,8-bc:5,4-b′c′]difuran skeleton, and walsogynes F (5) and G (6) to be 11,12-seco limonoids with a dodecahydro-1H-naphtho[1,8-bc:3,4-c′]difuran skeleton. Their absolute configurations were assigned through comparison of the calculated and experimental CD spectra. Walsogynes showed a moderate in vitro cytotoxic activity against various cancer cell lines.