Norito KanedaJohn M. PezzutoDouglas KinghornNorman R. FarnsworthThawatchai SantisukPatoomratana TuchindaJinda UdchachonVichai ReutrakulUniversity of Illinois at ChicagoThailand Royal Forest DepartmentMahidol University2018-08-102018-08-101992-05-01Journal of Natural Products. Vol.55, No.5 (1992), 654-65915206025016338642-s2.0-0026752589https://repository.li.mahidol.ac.th/handle/20.500.14594/22256A new ring-A secotriterpene, koetjapic acid [1], and five known compounds, 3-oxo-olean-12-en-29-oic acid [2] (a novel natural product), katonic acid [3], (−)-alloaromadendrene, (−)-caryophyllene oxide, and (+)-spathulenol, have been isolated and characterized from a cytotoxic Et2O-soluble extract of Sandoricum koetjape stems. Of these compounds, 2 and 3 demonstrated significant cytotoxic activity against cultured P-388 cells (ED50values of 0.61 and 0.11 μg/ml, respectively). Significant, albeit less intense, cytotoxicity was also observed with a variety of cultured human cancer cells. The13C-nmr chemical shifts of these triterpenes were assigned unambiguously using selective INEPT nmr experiments. Aside from compounds 2 and 3, these substances were not toxic with cultured cells. © 1992, American Chemical Society. All rights reserved.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemistryMedicinePharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1021/np50083a016