Phloroglucinols with prooxidant activity from Garcinia subelliptica

A new phloroglucinol, garcinielliptone HF (1), possessing an unprecedented skeleton, and the tautomeric pair of garcinielliptone FC (2/2a) were isolated from the heartwood and pericarp of Garcinia subelliptica, respectively. Their structures, including relative configurations, were elucidated by means of spectroscopic methods. The ability of compounds 1 and 2/2a to induce DNA-cleavage activity was examined using supercoiled plasmid pBR322 DNA. In the presence of Cu(II), compounds 1 and 2/2a caused significant breakage of pBR322 DNA. The involvement Of H2O2 and O-2(center dot-), and H2O2, O-2(center dot-), and OH center dot in 1- and 2/2a-mediated scission, respectively, was established by inhibition or no protection of DNA breakage by various oxygen radical scavengers. Thus, in the presence Cu(II), 1 and 2/2a may show a prooxidant effect on DNA and induce cell death.