Two new phragmalin-type limonoids orthoesters from Entandrophragma candollei

Two new phragmalin-type limonoids orthoesters, encandollens A and B ( 1 and 2 ), were isolated from the stem barks of Entandrophragma candollei collected in Ghana. The structures of these compounds were elucidated on the basis of HR-ESI-MS, ¹H and ¹³C NMR, HSQC, HMBC, and ROESY data. Compound 1 was a rare C-15 enolic acyl phragmalin-type limonoid orthoester. Compounds 1 and 2 exhibited weak inhibitory effects on NO production in lipopolysaccharide (LPS)-induced RAW 264.7 cells.