Anhydroicaritin Chemical Identity
Anhydroicaritin has the molecular formula C21H20O6 and a molecular weight of 368.4. The skeleton is a flavonol with a 4′-methoxy group on the B-ring and hydroxyl groups at positions 3 and 5. Where icaritin carries a free prenyl chain at position 8 and a hydroxyl at position 7, anhydroicaritin has lost one molecule of water, which is the meaning of anhydro, and the prenyl group has closed onto the 7-oxygen to form a dihydropyran ring. The result is a more compact, more lipophilic molecule with one fewer free hydroxyl.
The line of compounds is easy to describe. Icariin is the glycoside, with a sugar at position 3 and another at position 7. Removing the sugars gives icaritin, the aglycone, and cyclizing its prenyl group gives anhydroicaritin. The natural source is the leaf of Epimedium brevicornum Maxim., which GBIF lists under the spelling brevicornu, a plant of the family Berberidaceae often called horny goat weed. Related products are Epimedium Extract 5–50% Icariin, the 10:1 Epimedium Extract Powder and Baohuoside I 98%. The extracts are mixtures defined by a different marker, while anhydroicaritin here is a single aglycone.
Because the Epimedium family of flavonols uses names that look alike, the formula, the CAS number and the retention time are the dependable identifiers.












