Trichiconlides A and B: two novel limonoids from the fruits of Trichilia connaroides

Trichiconlides A (1) and B (2), two novel limonoids, were isolated from the fruits of Trichilia connaroides. Compound 1 is a novel limonoid with a highly rearranged A/B ring system and an intact D ring, which formed an unprecedented 5/6/5/6/5 carbon skeleton. Trichiconlide B (2) possesses a 10-oxatricyclo[3.3.1.(3,8)] decane core and formed a cage-like structure located between rings A and C. Their structures and absolute configurations were elucidated by spectroscopic methods, single crystal X-ray diffraction, the ECD exciton chirality method and TDDFT/ECD calculations. 1 showed a moderate inhibitory effect on nitric oxide (NO) production.