Maria Carmen S. Tan

Chemical Constituents of Ixora philippinensis Merr.

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.

Triterpenes and Sterol from Tabernaemontana pandacaqui poir.

Tabernaemontana pandacaqui Poir., commonly known as banana bush and locally known as pandakaking-puti and kampupot, is found in thickets at low altitudes throughout the Philippines [1]. An earlier study [2] reported that the crude alcoholic extract from the dried leaves of T. pandacaqui afforded α-amyrin acetate. Another study [3] reported that the stems of T. pandacaqui showed significant anti-inflammatory, antipyretic and antinociceptive properties which were attributed to the alkaloids found in the stems. Voacangine, a major component of T. pandacaqui possessed analgesic and hypothermic activities and revealed surface anesthesia [4] in mice. The stems of T. pandacaqui crude alkaloidal fraction exerted a hypotensive activity and bradycardiac response [5], and possessed a CNS depressant activity [6] in rats. Another study reported the isolation of coronaridine from T. pandacaqui [7]. In this study, the flowers of T. pandacaqui afforded α-amyrin acetate (1), a mixture of α-amyrin acetate (1), lupeol acetate (2) and β-amyrin acetate (3), α-amyrin fatty acid ester (4), a mixture of ursolic acid (5) and oleanolic acid (6), and β-sitosterol (7). To the best of our knowledge, this is the first report on the isolation of compounds 2-7 from T. pandacaqui. NMR spectra were recorded on a Varian VNMRS spectrometer in CDCl3 at 600 MHz for H NMR and 150 MHz for C NMR spectra. Column chromatography was performed, with silica gel 60 (70-230 mesh). Thin layer chromatography was performed with plastic backed plates coated with silica gel NOTE