Bioorganic research of Galactites tomentosa Moench honey extractives: enantiomeric purity of chiral marker 3-phenyllactic acid

Thistle (Galactites tomentosa Moench.) honey organic extracts were obtained by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analyzed by gas chromatography (GC-FID and GC-MS) for the first time. Most abundant headspace compounds were terpenes, particularly linalool derivatives (hotrienol was predominant with a range of 38.6–57.5%). 3-Phenyllactic acid dominated in the solvent extracts (77.4–86.4%) followed by minor percentages of other shikimate pathway derivatives. After determination of an adequate enantioseparation protocol on Chirallica PST-4 column, the honey solvent extracts were analyzed by high-performance liquid chromatography (HPLC). The chiral analysis revealed high enantiomeric excess (>95%) of (–)-3-phenyllactic acid in all samples. Therefore, previous findings of chemical markers of thistle honey were extended, providing new potential for advanced chemical fingerprinting (optical pure chemical marker).