Table 6.
The content of selected major compounds determined in propolis extracts by UHPLC-DAD (data are expressed as mg/g of extracts).
| No. | Compound | Rt [min] | Sample Number | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | |||
| 1 | Caffeic acid | 11.02 | 2.94 | 2.91 | 1.90 | 4.43 | 1.59 | 2.19 | 2.09 | 4.73 | 3.80 | 1.93 | 4.01 | 13.86 | 2.15 | 3.22 | 1.67 | 3.72 | 3.91 | 4.06 | 2.30 | 8.59 |
| 2 | Vanillin | 12.41 | 4.34 | 7.49 | 8.96 | 6.64 | 6.47 | 4.26 | 7.66 | 12.01 | 10.14 | 7.60 | 6.82 | 5.48 | 11.69 | 10.75 | 10.40 | 8.64 | 8.17 | 6.18 | 6.12 | 8.83 |
| 3 | Benzoic acid | 13.46 | 10.38 | 9.29 | 15.10 | 14.30 | 10.61 | 5.08 | 13.8 | 60.26 | 24.67 | 22.15 | 15.35 | 18.57 | 39.02 | 25.20 | 51.66 | 36.41 | 45.86 | 20.13 | 42.90 | 6.84 |
| 4 | p-Coumaric acid | 13.81 | 32.50 | 32.25 | 20.04 | 34.70 | 29.44 | 41.84 | 32.8 | 31.87 | 18.9 | 22.92 | 24.39 | 15.31 | 28.62 | 31.14 | 20.10 | 52.83 | 39.28 | 43.61 | 36.97 | 13.69 |
| 5 | Ferulic acid | 14.63 | 6.61 | 8.14 | 10.39 | 11.74 | 8.90 | 2.92 | 5.87 | 37.11 | 17.65 | 15.21 | 13.42 | 6.38 | 20.36 | 26.04 | 17.52 | 27.46 | 21.12 | 15.06 | 18.73 | 5.60 |
| 6 | Isoferulic acid | 14.74 | 2.28 | 2.32 | 1.60 | 4.00 | 1.00 | 1.15 | 1.12 | 2.58 | 2.95 | 1.11 | 4.50 | 11.55 | 1.10 | 2.14 | 0.99 | 1.57 | 1.07 | 1.10 | 1.05 | 5.40 |
| 7 | Dimethylcaffeic acid a | 16.40 | 0.15 | 0.75 | 0.49 | 2.24 | 0.20 | 0.24 | 0.22 | 0.47 | 0.17 | 0.19 | 0.11 | 9.60 | 0.17 | 0.13 | 0.13 | 0.13 | 0.27 | 0.16 | 0.16 | 0.43 |
| 8 | Cinnamic acid | 16.75 | 4.34 | 4.52 | 4.42 | 5.88 | 4.21 | 4.65 | 4.44 | 5.71 | 4.95 | 4.30 | 4.79 | 5.40 | 5.10 | 4.76 | 5.67 | 5.20 | 5.31 | 4.83 | 4.95 | 4.54 |
| 9 | Pinobanksin 5-methylether c | 17.32 | 3.55 | 3.80 | 1.09 | 6.01 | 0.05 | 0.35 | 0.25 | 4.23 | 6.33 | 0.72 | 8.06 | 19.33 | 0.37 | 2.96 | 0.11 | 0.22 | 0.53 | 0.54 | 0.14 | 12.66 |
| 10 | Quercetin | 17.89 | 1.12 | 1.56 | 0.73 | 1.13 | 0.78 | 0.86 | 0.80 | 1.89 | 1.37 | 0.86 | 1.21 | 3.52 | 0.66 | 1,00 | 0.67 | 0.69 | 0.81 | 0.92 | 0.64 | 2.46 |
| 11 | Pinobanksin | 18.44 | 7.49 | 7.33 | 3.64 | 8.81 | 3.36 | 5.77 | 5.82 | 2.50 | 8.98 | 2.52 | 8.76 | 23.19 | 2.09 | 2.93 | tr | 1.97 | 3.49 | 5.47 | 1.43 | 24.63 |
| 12 | Naringenin | 18.92 | 1.15 | 1.26 | 0.51 | 0.85 | 1.54 | 1.21 | 1.30 | 1.43 | 0.73 | 1.34 | 0.80 | 1.55 | 0.61 | 0.72 | 1.54 | 1.00 | 1.36 | 1.85 | 0.72 | 0.79 |
| 13 | Apigenin | 19.26 | 3.24 | 3.74 | 1.65 | 3.55 | 2.87 | 2.20 | 2.04 | 3.70 | 3.97 | 3.57 | 4.52 | 6.36 | 1.63 | 2.83 | 3.34 | 1.57 | 2.90 | 2.84 | 2.06 | 4.90 |
| 14 | Kaempferol | 19.44 | 4.40 | 5.30 | 2.03 | 4.70 | 4.65 | 4.74 | 4.53 | 1.80 | 2.84 | 5.02 | 4.28 | 9.80 | 1.85 | 1.98 | 3.83 | 2.05 | 3.78 | 6.24 | 1.54 | 5.65 |
| 15 | Isorhamnetin | 19.72 | 0.81 | 1.40 | 0.39 | 0.48 | 1.50 | 0.19 | 0.15 | 1.09 | 0.94 | 2.98 | 1.61 | 3.21 | 0.37 | 0.87 | 2.73 | 0.31 | 0.67 | 0.60 | 0.70 | 2.20 |
| 16 | Rhamnetin | 20.91 | 0.67 | 0.67 | 0.34 | 0.70 | 0.33 | 0.34 | 0.36 | 0.98 | 0.95 | 0.50 | 0.88 | 2.88 | 0.29 | 0.64 | 0.27 | 0.18 | 0.34 | 0.43 | 0.20 | 1.57 |
| 17 | Caffeic acid prenyl or isoprenyl ester II a | 21.23 | 2.35 | 2.42 | 1.43 | 2.52 | 0.69 | 0.51 | 0.52 | 6.63 | 3.28 | 1.71 | 5.28 | 10.51 | 1.83 | 3.67 | 1.25 | 2.74 | 3.43 | 1.32 | 2.31 | 18.40 |
| 18 | Caffeic acid prenyl or isoprenyl ester III a | 21.33 | 0.87 | 0.67 | 0.47 | 1.12 | 0.49 | 1.06 | 0.74 | 0.13 | 0.32 | 0.54 | 0.65 | 0.99 | 0.41 | 0.47 | 0.18 | 0.58 | 0.81 | 1.13 | 0.62 | 0.43 |
| 19 | Caffeic acid benzyl ester a | 21.64 | 1.69 | 2.27 | 1.35 | 5.45 | 0.50 | 0.60 | 0.58 | 4.02 | 4.29 | 0.95 | 4.61 | 19.62 | 0.86 | 1.73 | 0.27 | 1.06 | 1.26 | 1.45 | 0.76 | 11.53 |
| 20 | Chrysin | 21.93 | 11.08 | 11.13 | 4.64 | 16.30 | 2.73 | 6.90 | 6.26 | 14.23 | 20.34 | 4.38 | 15.66 | 43.00 | 3.34 | 7.45 | 0.58 | 1.78 | 3.82 | 6.69 | 1.74 | 35.76 |
| 21 | Pinocembrin | 22.12 | 58.34 | 53.84 | 24.65 | 72.76 | 29.38 | 53,00 | 52.69 | 47.57 | 60.38 | 28.22 | 48.17 | 167.71 | 15.95 | 23.92 | 2.35 | 11.94 | 24.49 | 49.26 | 14.44 | 164.32 |
| 22 | Sakuranetin | 22.38 | 20.85 | 20.54 | 9.47 | 17.46 | 22.69 | 19.85 | 18.65 | 7.00 | 14.19 | 29.03 | 17.54 | tr | 8.17 | 7.86 | 33.03 | 9.61 | 17.76 | 25.68 | 11.33 | tr |
| 23 | Galangin | 22.43 | 11.24 | 9.25 | 4.03 | 10.35 | 7.91 | 8.08 | 7.44 | 3.27 | 9.23 | 8.61 | 11.57 | 27.29 | 2.65 | 3.72 | 7.25 | 2.47 | 5.84 | 9.35 | 3.90 | 38.39 |
| 24 | Pinobanksin-3-O-acetate c | 22.80 | 23.56 | 25.31 | 18.77 | 33.94 | 17.77 | 18.54 | 17.64 | 54.57 | 35.81 | 22.08 | 41.55 | 41.77 | 23.78 | 38.96 | 10.80 | 37.08 | 35.17 | 24.17 | 29.94 | 78.99 |
| 25 | p-Coumaric acid benzyl ester b | 23.88 | 4.40 | 4.26 | 1.94 | 4.08 | 3.64 | 6.84 | 5.63 | 0.58 | 2.03 | 2.39 | 0.68 | 2.82 | 1.85 | 0.57 | 0.43 | 2.41 | 3.29 | 6.12 | 1.90 | 2.69 |
| 26 | p-Coumaric acid phenethyl ester b | 25.06 | 1.99 | 1.72 | 0.10 | 1.18 | 1.69 | 3.44 | 2.16 | 0.10 | 0.79 | 1.32 | 0.06 | 0.75 | 0.09 | 0.08 | 0.02 | 1.25 | 1.75 | 3.30 | 0.78 | 0.73 |
| 27 | p-Coumaric acid pentyl or isopentyl ester II b | 25.26 | 2.20 | 2.08 | 0.99 | 1.57 | 1.96 | 3.80 | 2.62 | tr | 0.65 | 1.29 | 0.02 | 0.65 | 0.90 | 0.03 | tr | 1.26 | 1.81 | 3.37 | 0.91 | 0.80 |
| 28 | p-Coumaric acid cinnamyl ester b | 26.83 | 10.42 | 10.17 | 4.63 | 8.50 | 7.54 | 16.60 | 12.69 | 1.48 | 4.25 | 6.05 | 0.65 | 5.86 | 6.02 | 1.66 | 0.68 | 5.46 | 8.59 | 9.52 | 4.79 | 3.82 |
| 29 | Pinostrobin | 27.20 | 9.17 | 7.74 | 6.33 | 6.75 | 7.73 | 13.12 | 10.62 | 0.14 | 5.51 | 9.00 | 5.86 | 5.62 | 4.73 | 1.91 | 2.04 | 3.83 | 5.49 | 8.59 | 4.21 | 13.60 |
| Sum | 244.5 | 244.5 | 152.3 | 292.5 | 182.6 | 230.9 | 221.9 | 312.2 | 270.6 | 208.7 | 255.9 | 482.8 | 186.8 | 209.5 | 179.7 | 225.7 | 252.7 | 264.5 | 198.5 | 478.5 | ||
tr—Found in traces; a Calculated as caffeic acid equivalent; b Calculated as p-coumaric acid equivalent; c Calculated as pinobanksin equivalent.