Camptothecin yield and distribution within Camptotheca acuminata trees cultivated in Louisiana

Camptotheca acuminata plantations were established in southern Louisiana in an effort to provide raw plant materials for deriving camptothecins, compounds having antitumor activity. This study was conducted to evaluate the growth and camptothecin distribution within the trees. It was found that all plant parts contained camptothecins following 1 year of growth in the field. Branches, roots, and stems accumulated significantly higher concentrations of camptothecins than leaves. Bark was significantly higher in camptothecin concentration than wood. Younger and older tissues within a growing season were not significantly different in camptothecin concentrations. High correlation in camptothecin concentration was found between branch and stem, root and stem, and root and branch, whereas little correlation was observed between bark and wood, and leaf and any other plant component. Field-grown C. acuminata has the observed characteristic of multiple current-year branching. The proportion of bark in term of dry weight and dimension decreased as trees increased in diameter. Dried shoots (bulk) contained 0.042% camptothecin, and dried roots (bulk) contained 0.051% camptothecin.