Bracken (Pteridium aquilinum) is a toxic and yet edible plant which is distributed in many parts of the world. The carcinogenicity of bracken has been a long-standing problem. This review provides an account of the extensive studies on a bracken carcinogen. Development of a new and mild extraction method coupled with a carcinogenicity test for rats as a bioassay led to the discovery and isolation of ptaquiloside; the biological activities of this long-sought carcinogen are described here. The ultimate carcinogen derived from ptaquiloside is so reactive that it not only efficiently alkylates sulfur-containing amino acids and DNA, but also cleaves DNA. The molecular mechanism of this DNA cleavage was determined. Furthermore, both enantiomers as well as artificial analogues of the ultimate carcinogen were synthesized, and their DNA-cleaving activities were evaluated. Related studies on the bracken carcinogen are also briefly described.
structure elucidation, glycosides, Bioorganic chemistry, terpenoids, DNA cleavage
Publication DOI: 10.1002/(sici)1521-3773(19980803)37:13/14<1818::aid-anie1818>3.0.co;2-8Journal NLM ID: 0370543Publisher: Weinheim: Wiley-VCH
Correspondence: Yamada K
Institutions: Department of Chemistry, Faculty of Science, Chikusa, Nagoya 464, Japan
Found