Abstract

Two previously known phenanthroindolizidine alkaloids, (-)-10beta-antofine N-oxide (1) and (-)-10beta, 13aalpha-14beta-hydroxyantofine N-oxide (2), and a novel alkaloid, (-)-10beta,13aalpha-secoantofine N-oxide (3), were isolated from aerial parts of Cynanchum vincetoxicum. Their structures were established by means of NMR methods, including COSY, NOESY, HSQC, and HMBC experiments, as well as from their CD spectra. Cytotoxic activity of the alkaloids was assessed in vitro using both a drug-sensitive KB-3-1 and a multi-drug-resistant KB-V1 cancer cell line. The antofine derivatives (1 and 2) showed pronounced cytotoxicity against the drug-sensitive cell line (IC(50) values about 100 nM), whereas the secoantofine derivative (3) was considerably less active. The KB-V1 cell line showed a marginal resistance against all alkaloids, demonstrating that these compounds are poor substrates for the P-glycoprotein (P-170) efflux pump.

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 call

Disclaimer: 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.