Four new cinnamoyl-phloroglucinols from the leaves of Xanthostemon chrysanthus.

ABSTRACT

Four new cinnamoyl-phloroglucinols (1-4) were isolated from the leaves of Xanthostemon chrysanthus. Compounds 1 and 2 represent the first example of natural phloroglucinols with an oxazole unit. Their structures were elucidated on the basis of NMR spectroscopic data and single crystal X-ray diffraction. Compound 3 showed moderate cytotoxic activity against MDA-MB-231 and SGC-7901 cells with IC50 values of 25.26 ±â€¯0.35 µM and 31.2 ±â€¯0.94 µM, respectively.