Seasonal Dynamics of Metabolites in Needles of Taxus wallichiana var. mairei.

Seasonal variations of the phytochemicals contents in needles of T. wallichiana var. mairei due to the effects of growth meteorological parameters were investigated in this study. The needles of T. wallichiana var. mairei were collected from different months and the contents of taxoids (paclitaxel, 10-deacetylbaccatin III (10-DAB), baccatin III, cephalomannine, 10-deacetyltaxol (10-DAT)), flavones (ginkgetin, amentoflavone, quercetin) and polysaccharides were quantified by ultra performance liquid chromatography (UPLC) and the resonance light scattering (RIL) method. The content of taxoids gave the highest level of 1.77 ± 0.38 mg·g-1 in January, and the lowest value of 0.61 ± 0.08 mg·g-1 in September. Unlike taxoids, the content of flavonoids was the highest in August. The content of polysaccharides reached peak value of 28.52 ± 0.57 mg·g-1 in September, which was two times higher than the lowest content of 9.39 ± 0.17 mg·g-1 in January. The contents of paclitaxel, 10-DAB, 10-DAT and polysaccharides significantly depended on meteorological parameters. The mean of minimum temperature (R = -0.61) and length of daylight (R = -0.60) were significantly correlated to 10-DAB content, while 10-DAT level showed significant correlation with length of daylight (R = -0.70) and relative humidity (R = 0.70). In addition, temperature had significantly negative effect on the content of paclitaxel and a significantly positive effect on that of polysaccharides. This study enriched the knowledge on the accumulation pattern of metabolites and could help us to determine the collecting time of T. wallichiana var. mairei for medicinal use.