CHARACTERIZATION OF URINARY BIOACTIVE PHENOLIC METABOLITES EXCRETED AFTER CONSUMPTION OF A CUP OF MOUNTAIN TEA (Sideritis scardica) USING LIQUID CHROMATOGRAPHY – TANDEM MASS SPECTROMETRY

A nutrition experiment was performed for studying the bioavailability of polyphenols from Sideritis scardica with healthy human subjects, who consumed a standardized S. scardica decoction after which urine was collected and analyzed. Thirty five polyphenolic compounds in the ingested decoction and sixty three of their metabolites in urine collected after ingestion were identified using HPLC/MSn. It was shown that phenolic compounds present in the S. scardica decoction are extensively conjugated to glucuronides, sulfates and also transformed to methylated forms after oral administration. Thirty one different metabo-lites of hypolaetin, methylhypolaetin, isoscutellarein, methylisoscutellarein and apigenin, and 32 phenolic acids metabolites were detected in the analyzed urine samples, whereas hypolaetin and isoscutellarein me-tabolites were the most abundant. This enabled polyphenols metabolites patterns to be obtained, which is a crucial step towards revealing the bioavailability and metabolism of phenolic compounds from S. scardica in human. The identification and structure elucidation of these metabolites provided essential data for fur-ther studies of S. scardica polyphenols bioavailability