Phenolic acids from Ginkgo biloba L. Part II. Quantitative analysis of free and liberated by hydrolysis phenolic acids.

HPLC was applied to the quantitative assay of seven free phenolic acids from the leaves, roots and seed testas of Ginkgo biloba L. (Ginkgoaceae). The concentration of the free phenolic acids amounted to: 19.693 micrograms/g of fresh leaves, 345.321 micrograms/g of roots and 2.708 micrograms/g of testas: protocatechuic acid is a dominant one. The concentration of the phenolic acids liberated by acid-mediated and alkaline hydrolysis was determined as well.