Anthraquinones from Ophiorrhiza pumila tissue and cell cultures

Tissue and cell cultures of a Rubiaceous plant, Ophiorrhiza pumila, were established. The well growing callus cultures produced only anthraquinones but none of the camptothecin-related alkaloids. We have succeeded in initiating and establishing systems of tissue and cell cultures of Ophiorrhiza pumila. Examination of the constituents of the methanol extract of the cultured calli revealed the presence of 11 anthraquinones including two new ones whose structures have been rigorously proved using advanced spectroscopic methods. These findings demonstrated a remarkable difference in the constituents between the wild plants and the callus tissue or cultured cells; the former is devoid of anthraquinones and contains a variety of camptothecin-related alkaloids whereas the latter contains a significant amount of anthraquinones and shows no indication of the presence of alkaloids after several sub-culturings or final establishment of well growing cell suspensions.