Chemical investigations of the dichloromethane extracts of Ixora philippinensis Merr., a plant endemic to the Philippines, led to the isolation of syringaresinol (1), pinoresinol (2), isoscopoletin (3), squalene (4), β-sitosterol (5a), and stigmasterol (5b) from the stems; and 4, 5a, 5b, lupeol (6), and lutein (7) from the leaves. The structures of 1 and 3 were elucidated by extensive 1D and 2D NMR spectroscopy, while those of 2 and 4-7 were identified by comparison of their NMR data with literature data.
Key words: Ixora philippinensis, Rubiaceae, syringaresinol, pinoresinol, isoscopoletin, lupeol, squalene, lutein, β-sitosterol, stigmasterol
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