DIURNAL AND SEASONAL EFFECTS ON THE TAXANE CONTENT OF THE CLIPPINGS OF CERTAIN TAXUS CULTIVARS

Clippings of ornamental cultivars of Tarus were collected at different times of the day, and monthly for two growing seasons (June to Octobe r 1993 and March to October 1994), Uniformly dried samples were extrac ted and analysed for their content of six taxanes, namely 10-desacetyl baccatin III (1), baccatin III (2), 10-desacetyl taxol (3), cephaloma nnine (4), 10-desacetyl-7-epi-taxol (5) and taxol (6), Clippings harve sted between noon and 8.00 p.m. provided biomass with a high total tax ane content (0.099-0.102%) without sacrificing the yield of any of the individual taxanes, Data obtained from a seasonal study showed that t he best time to harvest Taxus clippings for the production of taxanes (especially 1 and 6) is approximately one month from the beginning of new growth (flush), The date of harvest could vary depending on the ge ographic location and weather conditions. (C) 1997 by John Wiley & Son s.