B-seco-29-nor-Limonoids from the stem barks of Toona ciliate var. yunnanensis

Eight new compounds, including four rare B-seco-29-nor-limonoids, toonaciliatones A-D (1–4), and four normal B-seco-limonoids, toonaciliatones E-H (5–8), together with six known compounds (9–14), were isolated from the stem barks of Toona ciliata var. yunnanensis. Toonaciliatones A and B (1–2) are the first examples of B-seco-29-nor-limonoids without the common five-membered 4, 7-lactone. Their structures were elucidated by extensive spectroscopic analysis including UV, IR, NMR and HRMS, and the absolute configurations of isolates with α, β-unsaturated ketone moiety (1, 5–7) were determined by CD exciton chirality method and electronic circular dichroism (ECD) calculation. Compounds 3 and 11 exhibited modest cytotoxicities against HL-60 and HepG2 cells.

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