Swieteliacates S–U, phragmalin limonoids, from the leaves of Swietenia macrophylla

Abstract

Three novel phragmalin-type limonoids, swieteliacates S–U (1–3), were isolated from Swietenia macrophylla leaves, alongside four previously identified limonoids (4–7). The structures, encompassing absolute configurations, were delineated through 1D and 2D NMR analyses, high-resolution mass spectrometry (HR-MS), and NMR and ECD calculations. Swieteliacate S (1) is a distinctive cryptate comprising a tricyclo[4.2.1^10,30.1^1,4]decane fragment and an additional five-membered oxygen ring. Compounds 3 and 5 exhibited inhibition rates of 26.08 ± 2.26% and 15.42 ± 3.66%, respectively, on triglyceride (TG) production in Hep G2 cells at 40 μM.