Table 1. Alkylamide content of an Echinacea purpurea extract, chloroform layer, and column fractions from the chloroform layer.
| Sample | Concentration of alkylamide 5 ± SD (μg/mg extract) a | Estimated total alkylamide content ± SD (μg/mg extract) |
|---|---|---|
| 95% ethanol extract | 7.9 ± 0.57 | 51 ± 8.2 |
| Chloroform layer | 26 ± 1.1 | 140 ± 4.7 |
| Fraction 1 | - | - |
| Fraction 2 | Below LOQ b | Below LOQ |
| Fraction 3 | ND c | ND |
| Fraction 4 | ND | ND |
| Fraction 5 | ND | ND |
| Fraction 6 | 63 ± 12 | 310 ± 42 |
| Fraction 7 | ND | 2.2 ± 0.38 |
| Fraction 8 | ND | 0.14 ± 0.034 |
| Fraction 9 | Below LOQ | Below LOQ |
| Fraction 10 | ND | ND |
| Fraction 11 | ND | ND |
| Fraction 12 | ND | ND |
| Fraction 13 | ND | ND |
a. Concentration is reported for one of the major alkylamides in the extract, alkylamide 5 in Fig 3 (dodeca-2E,4Z-diene-8,10-diynoic acid isobutylamide). The total alkylamide concentration was estimated using the calibration curve for this compound. Reported concentrations are means+/- SD from triplicate measurements by LC-MS as described in the Materials and Methods.
b. Below LOQ (limit of quantification) indicates that alkyamides were detected but were present at concentrations below the limit of quantitation for the method.
c. ND indicates that alkylamides were not detected, i.e. not present at levels above the limit of detection (LOD).