Phaeophytins from Thyrsacanthus ramosissimus Moric. with inhibitory activity on human dna topoisomerase II-α

Abstract

Recebido em 22/5/12; aceito em 21/7/12; publicado na web em 15/10/12Our study reports the extraction and isolation of a new phaeophytin derivative 15 1 -hydroxy-(15 1 -S)-porphyrinolactone, designated anamariaine (1) herein, isolated from the chloroform fraction of aerial parts of Thyrsacanthus ramosissimus Moric. along with the known 15 1 -ethoxy-(15 1 -S)-porphyrinolactone (2). These compounds were identified by usual spectroscopic methods. Both compounds were subjected to in vitro (inhibitory activity) tests by means of supercoiled DNA relaxation techniques and were shown to display inhibitory activity against human DNA topoisomerase II-a at 50 µM. Interconversion of these two pigments under the mild conditions of the isolation techniques should be highly unlikely but cannot be entirely ruled out.

Justicieae (Acanthaceae) do Semiárido do Estado da Bahia, Brasil

“…Estudos fitoquímicos com plantas do Semiárido têm revelado que algumas espécies dessa tribo também são promissoras do ponto de vista farmacológico, como Thyrsacanthus ramosissimus Moric. (Cabral et al 2012).…”