Figure 1.

Polyphenolic profile of seasonal samples of Caborca propolis (CP) recorded at 280 nm. All seasonal samples were prepared at 1 mg/mL in MeOH. CP poplar-type compounds are enlisted within the figure. Pinocembrin (1), pinobanksin-3-O-acetate (2), chrysin (3) and galangin (4) were identified and assigned in the chromatogram of each seasonal sample, according to retention time (R_t) and UV_max absorption spectra of analyzed chemical standards. A calibration curve of each of the chemical standards was prepared from 80 to 0 µg/mL. All values represent the mean of a least three independent determinations ± standard deviation. Chromatograms of seasonal samples of CP and compounds were recorded at 280 nm.