Naslov
Optimization of extraction procedure and chemical characterization of Croatian propolis tinctures

Autori
Cvek, Josipa ; Medić-Šarić, Marica ; Jasprica, Ivona ; Zubčić, Snježana ; Vitali, Dubravka ; Mornar, Ana ; Vedrina-Dragojević, Irena ; Tomić, Siniša

Izvornik
Phytochemical Analysis (0958-0344) 18 (2007), 5; 451-459

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Polyphenols; spectrophotometric methods; validation; quality control

Sažetak
Three spectrophotometric methods for the quantitative determination of different flavonoid groups and total phenolics in Croatian propolis samples were optimized and validated. The assay based on the formation of aluminium chloride complex (with galangin as a standard) was applied for the quantification of flavones and flavonols, while 2, 4-dinitrophenylhidrazine method (with pinocembrine as a reference) was used for the quantification of flavanones. Total phenolics content was measured by the Folin-Ciocalteau method using reference solution of caffeic acid : galangin : pinocembrine (1:1:1). Through analytical validation, the most suitable extraction conditions (regarding the time, temperature, and concentration of extraction solvent) were determined, and final conditions for the extraction were established (80% ethanol, 1 hour at the room temperature). Appropriate ratio between the mass of raw propolis and extraction solvent volume was established as well. Applying developed method of extraction, ten propolis tinctures were prepared and subjected to the analysis of general pharmacopoeial parameters which are fundamental for the creation of quality specification (relative density, dry residue of extract, content of ethanol, methanol and 2-propanol). Additionally, we determined the content of waxes as the main inactive constituents in order to observe the level of their migration from crude propolis to the prepared tinctures.

Izvorni jezik
Engleski

Znanstvena područja
Farmacija

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