Seasonal variation in hypericin content of Hypericum perforatum L. (St. John’s Wort)

• Published in: Phytochemistry (Oxford) Vol. 56; no. 5; pp. 437 - 441
• Main Authors: Southwell, Ian A, Bourke, Christopher A
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-03-2001; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Clusiaceae; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Hypericin; Hypericum - metabolism; Hypericum perforatum; Metabolism; Metabolism. Physicochemical requirements; Nitrogen metabolism and other ones (excepting carbon metabolism); Nutrition. Photosynthesis. Respiration. Metabolism; Pasture; Perylene - analogs & derivatives; Perylene - metabolism; Plant Leaves - metabolism; Plant physiology and development; Plants, Medicinal; Pseudohypericin; Seasonal variation; Seasons; Soxhlet extraction; Spectrophotometry; St. John’s Wort; Toxicity; UV-Vis spectrometry; Hypericum perforatum; St. John’s Wort; Soxhlet extraction; Hypericin; Pseudohypericin; Seasonal variation; Toxicity; Pasture; Clusiaceae; UV-Vis spectrometry; Toxin; Dicotyledones; Guttiferae; Angiospermae; Spermatophyta; Livestock; Plant leaf; Biological accumulation; Grazing; Medicinal plant
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/S0031-9422(00)00411-8

Hypericin and pseudohypericin, bioactive constituents in St. John’s Wort (
Hypericum perforatum), have been determined in the soft tops of the plant that are most likely to be browsed by foraging livestock. In two consecutive seasons, the hypericin/pseudohypericin concentration in a broad leaf biotype varied from a winter minimum of less than 100 ppm to a summer maximum approaching 3000 ppm. In contrast the narrow leaf biotype increased from similar winter values to summer maxima approaching 5000 ppm. The latter biotype was slower in returning to low levels of hypericin/pseudohypericin.