Abstract
A novel bioassay was developed to permit the identification of cytotoxic natural principles that bind to DNA. A hexane extract of Schoepfia californica cytotoxic to cultured KB cells displayed much less cytotoxic potential when the culture medium contained exogenously added calf thymus DNA. Fractionation of the extract afforded a purified principle shown to be 9-octadecynoic acid, an 18-carbon, unbranched acetylenic fatty acid. 9-Octadecynoic acid had an apparent DNA dissociation constant of 1.8 mM; it inhibited topoisomerase I mediated DNA filter binding but did not inhibit the DNA topoisomerase I mediated relaxation of a supercoiled plasmid DNA. The fatty acid was weakly inhibitory to DNA polymerase alpha. 9-Octadecynoic acid possesses none of the structural characteristics of known DNA binding molecules and may bind to DNA by some novel mechanism.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
