Ducrey B Marston A Göhring S Hartmann RW Hostettmann K 1997 Species of the genus Epilobium (Onagraceae) have been investigated for their activity against 5 alpha-reductase and aromatase, two enzymes which are involved in the aetiology of benign prostatic hyperplasia (BPH). Activity-guided fractionation has led to the identification of two macrocyclic ellagitannins, oenothein A (1) and oenothein B (2), as the main constituents responsible for the inhibition of the two enzymes. Quantitation of oenothein B in 10 different species of Epilobium has shown that amounts of up to 14% in the crude plant extracts are possible. https://sonar.ch/global/documents/137059 eng info:eu-repo/semantics/altIdentifier/doi/10.1055/s-2006-957624 info:eu-repo/semantics/altIdentifier/pmid/9140222 Planta medica. - 1997 5-alpha Reductase Inhibitors Antineoplastic Agents, Phytogenic Aromatase Inhibitors Hydrolyzable Tannins Plants, Medicinal Tannins Inhibition of 5 alpha-reductase and aromatase by the ellagitannins oenothein A and oenothein B from Epilobium species. http://purl.org/coar/resource_type/c_6501