Cell Suspension Cultures of Cinchona ledgeriana; I. Growth and Quinoline Alkaloid Production

Abstract

Callus and suspension cultures of Cinchona ledgeriana were established from sterile shoot segments in a medium containing 2.0 mg 1^-1 dichlorophenoxyacetic acid (2, 4-D) and 0.5 mg 1^-1 benzyladenine (BA). The production of alkaloids in these suspension cultures growing under standard conditions was stimulated from 0.01 to 4 mg 1^-1 by lowering the concentrations of 2, 4-D and BA in the medium to 0.5 and 0.1 mg 1^-1, respectively. Cell suspension cultures of C. ledgeriana adapted to the low hormone medium released up to 75% of their total alkaloid into the culture medium. The qualitative composition of the alkaloid mixture produced by the initial cultures resembled the explant tissue from which it was derived in having cinchonine, the precursor of quinidine as the major alkaloid constituent. Manipulation of the culture led not only to an increase in the total alkaloid formed but also to a relative increase in the formation of cinchonidine, the precursor having the stereochemical structure of quinine.