title: Reversed-phase high-performance liquid chromatography determination of selected phenolic acids in propolis concentrates in terms of standardization for drug manufacturing purposes.
abstract: A reversed-phase high-performance liquid chromatography method with gradient elution was developed for the determination of the caffeic, p-coumaric, and ferulic acids in propolis concentrates. Solid-phase extraction on an RP18 column was applied for preliminary purification, and chromatographic separation was performed on 100 RP18e Lichrospher column of particle size 5 microm. The mobile phase was obtained by mixing in appropriate ratios 0.03 mM NaH2PO4, acidified with H3PO4 up to pH = 3.0, with acetonitrile to obtain a gradient in the elution process. Spectrophotometric detection was conducted at 320 nm. Under the established conditions, the method featured high sensitivity, good precision, and comparability of results, as proven by method validation and statistical analysis of the obtained results. The limits of detection were 0.315, 0.325, and 0.695 microg/mL for caffeic, p-coumaric, and ferulic acids, respectively. The corresponding recovery values were 98.14, 101.05, and 99.42% and the linearity ranges from 1.31 to 99.18 microg/mL, 1.52 to 119.16 microg/mL, and 2.42 to 184.14 microg/mL. The precision of the method was expresed by relative standard deviation values that did not exceed 3%. It was also shown that the propolis concentrates under examination had similar antibacterial activity against Staphylococcus aureus ranging from 119.8 to 124.3 microg/mL, contrary to model mixtures that showed no antibacterial activity.
authors.affiliation: Jagiellonian University, Collegium Medicum, Department of Inorganic and Analytical Chemistry, Medyczna 9, 30-688 Cracow, Poland. jankrzek@cm-uj.krakow.pl
authors.forename: Jan
authors.initials: J
authors.lastname: Krzek
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kaleta
authors.forename: Urszula
authors.initials: U
authors.lastname: Hubicka
authors.forename: Aneta
authors.initials: A
authors.lastname: Niedzwiedz
mesh_terms: D000900:Anti-Bacterial Agents; D001419:Bacteria / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004339:Drug Compounding; D004345:Drug Industry / Q000592:standards; D062385:Hydroxybenzoates / Q000032:analysis*; D007202:Indicators and Reagents; D008826:Microbial Sensitivity Tests; D011429:Propolis / Q000032:analysis* / Q000494:pharmacology; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D000900:Anti-Bacterial Agents; D062385:Hydroxybenzoates; D007202:Indicators and Reagents; D011429:Propolis; C017616:phenolic acid