Experiments on the origin and function of berberine in Berberis Darwinii

THE classical researches of Pictet [1905;1907] led him to conclude that alkaloids were waste products of the metabolic activity of the plant, analogous to urea, ethereal sulphates etc. of the animal body, and he supposed that they were produced in two stages (a) by the resolution of nitrogenous bodies such as proteins or chlorophyll into more simple basic substances, and (b) subsequent condensation of these simple bodies with the active products of metabolism, e.g.aldehydes, with the formation of the alkaloid nucleus.Research on these lines in recent years has been sporadic, and the results are difficult to correlate because of diversity in the nature and origin of the alkaloids studied.Thus Annett [1920] studied the effect of sodium nitrate on the production of latex by Papaver somniferum and found a large increase with but little variation in its morphine content.Mothes [1928] showed that the concentration of nicotine in the leaves of Nicotiana increased as the leaf developed, while Koenig [1931] found an increased production of alkaloid if nitrogenous fertilisers were applied.Ripert [1921] studied the effect of etiolation on the atropine and hyoscyamine content of young shoots of Atropa and found a considerable increase in both leaves and stalks.In addition, Sabalitschka [1923] and Sabalitschka and Junger- mann [1925] observed no decrease in the alkaloid content of the seeds of Lupinus and Strychnos on germination.All these results tend to confirm Pictet's assertion that alkaloids are waste products, but throw very little extra light on the question of a possible connection between alkaloid production and protein metabolism.In the present research an attempt has been made to unify some of these earlier findings by studying the metabolism of berberine in Berberis Darwinii.The experiments have been continued throughout two seasons, and have been planned to throw light on (1) the variation in berberine content with age, (2) the effect of applying nitrogenous fertilisers and of the withdrawal of essential elements, (3) the changes brought about by etiolation, (4) disturbances in the normal distribution of berberine brought about by ringing of the bark.The results obtained establish in certain cases an undoubted connection between protein breakdown and berberine synthesis. EXPERIMENTAL.Materials used.The plants were obtained as required from nurseries and the ages are calculated from the time of the first transplantation.The various plant members were cut into small pieces and dried at 105-110' for one day, finely powdered in a coffee mill and dried for the further period of one day.