Influence of altitude on secondary metabolites, antioxidants, and antimicrobial activities of Himalayan yew (Taxus wallichiana)

The present study aimed to investigate the impact of altitude on the bioactive compounds, antioxidants, and antimicrobial activity of Taxus wallichiana. Plant needles were collected from three different altitudes representing different environmental conditions and investigated for secondary metabolites such as phenol, flavonoid, flavanol, taxol, and tannin along with antioxidant and antimicrobial activity. Results revealed that the investigated Taxus wallichiana populations have accumulated varied amount of studied bioactive compounds. Total phenol, flavonoid content, and bioactive compounds such as gallic acid, ascorbic acid, and quercetin showed significant positive correlation with altitude (p < 0.01) and antioxidant activity (DPPH, ABTS). By contrast, tannin, taxol, and flavanol content of the plant did not show any relation with altitude, but showed positive significant correlation with antibacterial activity. The results suggest that the accumulation of bioactive compounds in Taxus wallichiana needles depend on the edaphic and climatic conditions of the habitat and plant antimicrobial activity is mainly due to taxol, flavanol, and tannin compounds.