Kiralna separacija beta-blokatora tekućinskom kromatografijom visoke djelotvornosti i određivanje enantiomera bisoprolola u površinskim vodama

Beta-blockers are chiral compounds with enantiomers that have different bioactivity, which means that while one is active, the other can be inactive or even harmful. Due to their high consumption and incomplete degradation in waste water, they may reach surface waters and affect aquatic organisms. To address this issue we developed a chromatographic method suitable for determining beta-blocker enantiomers in surface waters. It was tested on five beta-blockers (acebutolol, atenolol, bisoprolol, labetalol and metoprolol) and validated on bisoprolol enantiomers. Good enantioseparation of all analysed beta-blockers was achieved on the Chirobiotic V column with the mobile phase composed of methanol/acetic acid/triethylamine (100/0.20/0.15 v/v/v) at a flow rate of 0.5 mL/min and column temperature of 45 °C. Method proved to be linear in the concentration range from 0.075 μg/mL to 5 μg/mL, and showed good recovery. The limits of bisoprolol enantiomer detection were 0.025 μg/mL and 0.026 μg/mL and of quantification 0.075 μg/mL and 0.075 μg/mL. Despite its limitations, it seems to be a promising method for bisoprolol enantiomer analysis in surface water samples. Further research could focus on waste water analysis, where enantiomer concentrations may be high. Furthermore, transferring the method to a more sensitive one such as liquid chromatography coupled with tandem mass spectrometry and using ammonium acetate as the mobile phase additive instead of acetic acid and triethylamine would perhaps yield much lower limits of detection and quantification.Beta-blokatori su kiralni spojevi s enantiomerima različite bioaktivnosti, dakle, dok je jedan enantiomer aktivan, drugi može biti neaktivan ili čak štetan za organizam. Zbog njihove visoke potrošnje i nepotpune razgradnje u pogonima za preradu otpadnih voda, postoji mogućnost da se pojave u prirodnim vodama i negativno utječu na vodene organizme. Stoga je u ovom radu razvijena kromatografska metoda za određivanje enantiomera beta-blokatora u prirodnim vodama. Metoda je testirana na pet beta-blokatora (acebutolol, atenolol, bisoprolol, labetalol i metoprolol) te validirana za enantiomere bisoprolola. Dobra enantioseparacija svih analiziranih beta-blokatora postignuta je na koloni Chirobiotic V sastava mobilne faze metanol/octena kiselina/trietilamin (100:0,2:0,15 v/v/v) pri protoku od 0,5 mL/min i temperaturi od 45 °C. Metodom je postignuta dobra linearnost u području od 0,075 μg/mL do 5 μg/mL s dobrim analitičkim povratom. Granice detekcije pojedinih enantiomera bisoprolola bile su 0,025 μg/mL i 0,026 μg/mL, a granice kvantifikacije 0,075 μg/ mL za oba enantiomera. Unatoč ograničenjima metode, pokazala se kao obećavajuća metoda analize enantiomera bisoprolola u površinskim vodama. Daljnja istraživanja mogla bi se izvoditi na otpadnim vodama, gdje bi koncentracije enantiomera mogle biti više. Također, korištenjem osjetljivije metode, primjerice vezanoga sustava tekućinske kromatografije i tandemne spektrometrije masa, te korištenjem amonijeva acetata kao aditiva mobilnoj fazi umjesto octene kiseline i trietilamina, mogle bi se postići znatno niže granice detekcije i kvantifikacije

<i>Teucrium montanum</i> L.—Unrecognized Source of Phenylethanoid Glycosides: Green Extraction Approach and Elucidation of Phenolic Compounds via NMR and UHPLC-HR MS/MS

Health-oriented preferences, a demand for innovative food concepts, and technological advances have greatly influenced changes in the food industry and led to remarkable development of the functional food market. Incorporating herbal extracts as a rich source of bioactive compounds (BC) could be an effective solution to meet the high demand of consumers in terms of expanding the high-quality range of functional foods. The aim of this study is the valorization of the bioactive potential of T. montanum L., an understudied Mediterranean plant species, and the in-depth elucidation of a polyphenolic profile with a UHPLC-HR MS/MS and NMR analysis. The total phenolic content (TPC) and antioxidant capacity (AC) were determined on heat-assisted (HAE), microwave-assisted (MAE) and subcritical water (SWE) extracts. In terms of antioxidant capacity, SWE extracts showed the most notable potential (ABTS: 0.402–0.547 mmol eq Trolox g−1 dw, DPPH: 0.336–0.427 mmol eq Trolox g−1 dw). 12 phenolic compounds were identified in the samples of T. montanum from six microlocations in Croatia, including nine phenylethanoid glycosides (PGs) with total yields of 30.36–68.06 mg g−1 dw and 25.88–58.88 mg g−1 dw in HAE and MAE extracts, respectively. Echinacoside, teupolioside, stachysoside A, and poliumoside were the most abundant compounds HAE and MAE extracts, making T. montanum an emerging source of PGs