Free amino acids in botanicals and botanical preparations

Numerous studies were carried out about aminoacidic composition of vegetable proteins, but information about the free amino azid pool and the role of these substances is very Incomplete. The aim of this was to contribute to the scarce knowledge concerning the composition of free amino acids in botanicals and botanical preparations widely used vs food, in dietary supplements, and in pharmaceutical products. This work si the composition of free amino acids, Identified the major components of 19 species of plants, and evaluated the influence of different types of extraction on the amino acid profile. Amino acids were determined using an automatic precolumn derivatization with fluroenylmethyl-chloroformate and reversed-phase liquid chromatography with fluorescence and ultraviolet detection. The amounts of total free amino acids varied widely between plants, from approximately 12 g in 100 g of Echinacea pallida extract to less than 60 mg in the same amount of Coleus forskohlii, Garcinia cambogia, and Glycine max. In 13 plants arginine, asparagine, glutamine, proline, and gamma-aminobutyric acid were the free amino acids found in preponderant quantities. The levels of free amino acids above the quantification limit in 36 assayed samples of botanicals, extracts, and supplements are shown.