Valepotriol

Valepotriol is a natural product identified in valerian species, most notably Valeriana officinalis. It is related to the valepotriates, a group of iridoid-like esters found in valerian roots and rhizomes.

Chemically, valepotriol is characterized by multiple hydroxyl groups and a labile structure that renders it unstable in solution, especially when exposed to heat, light, or alkaline conditions. As a result, valepotriol is typically isolated and studied in crude plant material or after immediate stabilization, and analytical methods often detect it alongside other valepotriates and degradation products.

Occurrence and isolation: Valepotriol occurs in valerian roots and rhizomes, with concentrations varying by species, origin, and harvest conditions. It is usually detected by chromatographic techniques such as HPLC or GC-MS.

Pharmacology and uses: Valepotriol does not have an established pharmaceutical role on its own; valerian root preparations containing valepotriates are used as traditional sedatives and anxiolytics. Proposed mechanisms include interactions with gamma-aminobutyric acid (GABA) receptors, but evidence is inconsistent. Valepotriates are thought to contribute to activity, though instability complicates standardization.

Safety and regulation: Overall valerian extracts are considered safe for short-term use; rare adverse effects include headaches and dizziness. There have been reports of hepatotoxicity, but causality linking valepotriates or valepotriol to liver injury remains unclear. Regulatory guidelines emphasize careful standardization of valerian preparations, and some products aim to minimize or remove valepotriates to improve stability.