In the paper as presented, the effect was determined of the polarity of sorbents in solid phase extraction on the contents of phenylpropanoids in extracts obtained from a pepper pericarp. Three types of sorbents were analyzed: silica gel modified with octadecyl (C18), ethylophenyl (Phe), and cyanopropyl (CN), and, in every case, the same system of solvents was applied. The extraction yield was determined using three derivatives of quercetin as the standards; those derivatives were isolated from the pepper pericarp during the preceding studies. The standards comprised: quercetin 3-O-rhamnoside-7-O-glucoside, quercetin-3-O-glucoside, and quercetin-3-O-rhamnoside. Next, the fractions of phenolic compounds were isolated from the pepper pericarp with the use of the three above indicated sorbents. In the fractions obtained, the content of quercetin derivatives was quantitatively determined by a HPLC method and with the use of the standard curves for each compound. Additionally, there were determined the total of phenolic compounds by a Folin-Ciocalteu method and their antiradical activity in the system with DPPH• radical. Of the three standards applied, the quercetin-3-O-glucoside was recognized for its highest extraction yield; it was characterized by an intermediate polarity. Among the sorbents analyzed, the most effective sorbent was the silica gel modified with cyanopropyl. Also in the case of the fraction of phenolic compounds present in the pepper fruits, the highest extraction efficiency was obtained for the same gel used. This fact was confirmed by the results of total phenolic compounds and antiradical activity.
Capsicum annuum, solid phase extraction, phenolic compounds, quercetin O-glycosides