Vilailak PrachyawarakornChulabhorn MahidolSomsak RuchirawatChulabhorn Research InstituteMahidol UniversityThe Institute of Science and Technology for Research and Development, Mahidol University2018-08-202018-08-202006-06-01Chemical and Pharmaceutical Bulletin. Vol.54, No.6 (2006), 884-88613475223000923632-s2.0-33744776582https://repository.li.mahidol.ac.th/handle/20.500.14594/23160Further investigation of the dichloromethane extract of the twigs of Mammea siamensis led to the isolation of four novel coumarins, named siamenols A - D (1 - 4) together with three known xanthones. The structures of the new coumarins were elucidated by spectroscopic analysis, including 2D NMR spectroscopic data. In addition, the absolute stereochemistry of hydroxyl group of siamenol C (3) was determined to be S configuration by using modified Mosher's method. © 2006 Pharmaceutical Society of Japan.Mahidol UniversityChemistryPharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1248/cpb.54.884