The Effect of Nutritional Factors on Alkaloid Metabolism in Cephalotaxus harringtonia Tissue Cultures

Abstract

In an earlier study callus cultures of the Japanese plumyew, Cephalotaxus harringtonia, produced the same alkaloids and antitumor alkaloids as the parent tree, but in the present study a second line of callus tissue isolated and maintained under practically identical conditions produced instead a series of novel compounds in the alkaloid fraction. These compounds are closely related to one another by three separate criteria: Characteristic differences in GLC data on two different liquid phases, mass spectral similarities and correlation of amounts produced on 32 different media. The new compounds appear to be intermediates in from one to perhaps three different biosynthetic pathways. At least three of these compounds were also found in callus tissues that produced the normal Cephalotaxus alkaloids and in a stressed laboratory tree that no longer contained the normal alkaloids.

In a 2⁵ factorial experiment the effect of NH4NO3, protein hydrolysate, sucrose, kinetin and minor salts on product formation was measured. None of the various media tested restored normal alkaloid production.

Key Word Index

Cephalotaxus harringtonia - Tissue Culture - Secondary Metabolism - Medium Effects - Novel Alkaloids.