Gastrodia elata

Gastrodia elata (family Orchidaceae) is a leaf‑less, myco‑heterotrophic orchid native to East Asia, cultivated primarily for its rhizome (often called “tian ma”). The dried rhizome has been used for centuries in Traditional Chinese Medicine (TCM) as a neuro‑protective and anti‑inflammatory agent, and modern supplements aim to harness these properties for modern health‑support applications.

• The primary active compound is gastrodin (IUPAC: 4‑hydroxy‑benzyl β‑D‑glucoside, C₁₃H₁₈O⁶, molecular weight 258.27 g·mol⁻¹).
• It is a phenolic glucoside featuring a β‑D‑glucose moiety attached to a p‑hydroxy‑benzyl core via a glycosidic bond.
• The rhizome also contains p‑hydroxybenzyl alcohol, vanillin, and various polysaccharides.
• Gastrodin is water‑soluble (≈ 30 mg mL⁻¹ at 25 °C) and stable under acidic conditions, but hydrolyzes to p‑hydroxybenzyl alcohol in alkaline environments.
• The extract’s “standardized” form typically contains 10–20 % gastrodin, measured by HPLC with a detection limit of 0.1 % w/w.
• Other minor constituents include p‑hydroxybenzaldehyde, saponins, and polysaccharides (β‑glucans), which contribute to immunomodulatory activity.

• Wild G. elata grows in temperate forests of China (Sichuan, Yunnan), Japan, Korea, and parts of Russia.
• Commercial production relies on cultivated, mycorrhizal‑grown plants in controlled greenhouse settings to ensure consistent gastrodin levels.
• The rhizome is harvested, cleaned, and dried at ≤45 °C to preserve heat‑labile constituents.
• Extraction typically uses aqueous‑ethanol (70 %) extraction followed by spray‑drying, yielding a powder standardized to 10–20 % gastrodin.
• High‑quality supplements confirm identity via DNA barcoding and HPLC‑UV or LC‑MS fingerprinting.
• Quality markers include gastrodin content, absence of heavy metals (<5 ppm Pb, As, Cd), and microbial limits (≤10³ CFU/g total aerobic count).
• Look for third‑party certifications (USP, GMP) to ensure authenticity and minimal contamination.