Valerian (herb) particular binding site. Hydrophilic extractions of the herb commonly sold over the counter, however, probably do not contain significant amounts of isovaltrate. Valerenic acid in valerian stimulates serotonin receptors as a partial agonist, including 5-HT which is implicated in the sleep-wake cycle. The chief constituent of valerian is a yellowish-green to brownish-yellow oil present in the dried root, varying in content from 0.5 to 2.0%. This variation in quantity may be determined by location; a dry, stony soil yields a root richer in oil than moist, fertile soil. The volatile oils that form the active ingredient are pungent, somewhat reminiscent
Valerian (emperor) "The Hard Hours". He is referenced in Evelyn Waugh's "Helena": "Do you know what has happened to the Immortal Valerian?...They have him on show in Persia, stuffed." Valerian (emperor) Valerian (; ; 193/195/200260 or 264), also known as Valerian the Elder, was Roman Emperor from 22 October 253 AD to spring 260 AD. He was taken captive by the Persian Emperor, Shapur I, after the Battle of Edessa, becoming the first Roman emperor to be captured as a prisoner of war, causing shock and instability throughout the empire. Unlike many of the would-be emperors and rebels who vied for imperial