Variability in the content of the constituents of Hypericum perforatum L. and some commercial extracts

Seven samples of Hypericum perforatum L. (St. John's wort) were collected t hroughout Tuscany; the dried extracts were assayed to determine the concent ration of the constituents. Total flavonol content ranged from 4.58% to 15. 90%; hypericins ranged from 0.05% to 0.11%; and hyperforins ranged from 1.3 7% to 20.80%. In addition, four commercially dried extracts were analyzed u sing the same high-performance liquid chromatographic (HPLC) method; their flavonol contents varied from 10.64% to 15.01%, hypericins varied from 0.03 % to 0.20%, and hyperforins varied from 1.18% to 6.54%. The aim of this inv estigation was to evaluate the contents of the different constituents depen ding on environmental factors and drying and storage conditions of the wild samples. In addition, the contents of the constituents of the products ava ilable to the consumer that were related to quality and the relation of thi s to safety and efficacy were also evaluated.