Hyperisampsins N and O, two new benzoylated phloroglucinol derivatives from Hypericum sampsonii

Twenty-one benzoylated phloroglucinol derivatives bearing homoadamantyl frameworks were isolated from the aerial parts of Hypericum sampsonii, including two new ones named hyperisampsins N and 0 (1 and 2). The structures of 1 and 2 were elucidated by extensive NMR and mass spectrometric analyses. Their absolute configurations were further determined by using TDDFT ECD calculations. Compounds 2, 7, and 8 were evaluated for their cytotoxic activities against five human cancer cell lines, of which, 2 and 8 exhibited significant cytotoxic activities toward HL-60 cell and moderate activities against others cell lines. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.