Compound Monograph
Ginkgolic acids
Alkylphenolic acids from Ginkgo biloba, regarded as allergenic contaminants that quality ginkgo extracts are processed to remove.
Classification
Ginkgolic acids are alkylphenol (anacardic-acid type), part of the phenolics class. Antioxidant compounds built around one or more phenol rings — the flavonoids, tannins, phenolic acids, coumarins, and pigments behind much of a plant's protective chemistry.
Where Does It Come From? (3)
Ginkgolic acids are naturally occurring alkylphenol (anacardic-acid type), found in Ginkgo and 2 other sources. They are flagged as moderately toxic.
Research & Evidence
Ginkgolic acids are a group of alkylphenolic (anacardic-acid-type) compounds found chiefly in the seed coats and leaves of Ginkgo biloba. Unlike the beneficial flavonoids and terpene trilactones of ginkgo, they are generally treated as undesirable constituents: standardised ginkgo leaf extracts are processed to keep ginkgolic acid content below low limits.
Toxicity & Safety
Ginkgolic acids are allergenic and potentially irritant, belonging to the same chemical family as the urushiols of poison ivy, and they show cytotoxic and mutagenic activity in laboratory assays. For this reason their concentration in ginkgo supplements is deliberately limited. Direct contact with ginkgo seed pulp, which is rich in related compounds, can cause skin reactions.