These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Inhibition of topoisomerase II catalytic activity by pyridoacridine alkaloids from a Cystodytes sp. ascidian: a mechanism for the apparent intercalator-induced inhibition of topoisomerase II.
    Author: McDonald LA, Eldredge GS, Barrows LR, Ireland CM.
    Journal: J Med Chem; 1994 Oct 28; 37(22):3819-27. PubMed ID: 7525959.
    Abstract:
    Several new pyridoacridine alkaloids, dehydrokuanoniamine B (1), shermilamine C (2), and cystodytin J (3), in addition to the known compounds cystodytin A (4), kuanoniamine D (5), shermilamine B (6), and eilatin (7), were isolated from a Fijian Cystodytes sp. ascidian. Their structures were determined by analyses of spectroscopic data. These compounds along with a previously reported pyridoacridine, diplamine (8), showed dose-dependent inhibition of proliferation in human colon tumor (HCT) cells in vitro. All compounds inhibited the topoisomerase (TOPO) II-mediated decatenation of kinetoplast DNA (kDNA) in a dose-dependent manner. The pyridoacridines' ability to inhibit TOPO II-mediated decatenation of kDNA correlated with their cytotoxic potencies and their ability to intercalate into calf thymus DNA. These results suggest that disruption of the function of TOPO II, subsequent to intercalation, is a probable mechanism by which pyridoacridines inhibit the proliferation of HCT cells. Incorporation studies show that pyridoacridines disrupt DNA and RNA synthesis with little effect on protein synthesis. It appears that DNA is the primary cellular target of the pyridoacridine alkaloids. These results are consistent with those for known DNA intercalators.
    [Abstract] [Full Text] [Related] [New Search]