Two New Phragmalin-Type Limonoids from Chukrasiatabularis var. velutina

摘要

Two new phragmalin-type limonoids with different structural skeletons, chuktabrin K (>1) and tabulalin J (>2), were isolated from the stem barks of Chukrasia tabularis var. velutina in the course of our ongoing research work in this area. Compound >1 was a 16-norphragmalin with an enolic alkyl appendage at C-15, and the carbonate moiety in >1 was also rare in natural organic molecules. The basic skeleton of compound >2 was a D-ring-opened phragmalin. Their structures were elucidated on HR-ESI-MS, ¹H and ¹³C-NMR, HSQC, HMBC, and ROESY experiments.