New phragmalin-type limonoids from Swietenia macrophylla King

The fruit of Swietenia macrophylla is commonly known as “sky fruit”. The fruit, which contains flavonoids and saponins, is processed commercially into a wide range of health foods and healthcare products. The fruit concentrate is used traditionally to improve blood circulation and impart a healthy skin. In this paper, we describe the isolation and structure elucidation of three new phragmalin ortho esters, named swietephragmin H-J (1–3), and a new polyhydroxylated phragmalin, named swietemacrophine (4), from the leaves of S. macrophylla. The structures of the compounds were elucidated by spectroscopic methods, including HRESIMS, 1H NMR, 13C NMR, DEPT, 1H–1H COSY, HMQC, HMBC and NOESY spectra. This is the first report of phragmalin ortho esters and a polyhydroxylated phragmalin from this plant.