A new phragmalin-type limonoid and anti-inflammatory constituents from the fruits of Swietenia macrophylla

The fruit of Swietenia macrophylla is commercially used in healthcare products for the improvement of blood circulation and skin condition. A new phragmalin-type limonoid, 6-O-acetyl-3′-demethylswietephragmin E (1), has been isolated from the fruit of S. macrophylla, together with 16 known compounds. The structure of this new compound was determined through spectroscopic and MS analyses. 6-O-Acetyl-3′-demethylswietephragmin E (1), 3,6-O,O-diacetylswietenolide (5), 3-O-tigloylswietenolide (6), 3-O-tigloyl-6-O-acetylswietenolide (8), swietemahonin E (9), and 6-O-acetylswietemahonin G (10) exhibited inhibition (IC50 ⩽ 35.7 μM) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLP).