Assay of phenolic compounds distribution in different fractions of linden flower (Flos Tiliae) teas.

The aim: To determine qualitative and quantitative composition of phenolic compounds and extraction with water kinetics in different fractions of linden flowers. Object and methods: Object – linden flower teas bought in pharmacy. Total amount of phenolic compounds were determined by spectrofotometric Folin-Ciocalteu method. Total flavonoids and proanthocyanidins amount were determined by spectrofotometric methods. Individual phenolic compounds were identified and quantified by high-performance liquid chromatography (HPLC). Results: The largest amounts of phenolic compounds and proanthocyanidins but lower amount of flavonoids were determined in the largest fractions (>2,5 mm, 2 – 2,5 mm, 1,6 – 2 mm). Optimal extraction time of phenolic compounds and proanthocyanidins for this fractions is 45 minutes, but for the fractions of smaller particle size extraction time is shorter. The biggest amount of flavonoids were determined in fractions, which particle size is smaller than 0.9 mm. Optimal extraction time of flavonoids very different among the fractions, it ranges between 5 and 45 minutes. In fractions, which particle size is bigger than 2.5 mm, determined better amounts of quercitrin, hyperoside, kaempferol, astragalin, catechin and epicatechin. In particles, which size is between 1.6 mm and 2 mm and so between 2 mm and 2.5 mm, determined more catechin, epicatechin and trans- tiliroside than other particles, but also lower amounts of gallic acid and almost all flavonoids: quercitrin, hyperoside, astragalin, kaempferol. The smallest particles (<0.9 mm) stands for the biggest amounts of flavonoids (qercitrin, hyperoside, all derivatives of kaempferol). All investigated compounds of almost all fractions better extract with water than 70 percent ethanol, except kaempferol, which from all fractions better extract with ethanol that water (