Quantitation of 6-, 8- and 10-gingerols and 6-shogaol in human plasma by high performance liquid chromatography with electrochemical detection

Zingiber officinale is one of the most commonly used spices. We developed a method to determine the main pungent ginger constituents, 6-, 8- and 10-gingerols and 6-shogaol in human plasma. Quantitation was achieved using a reversed-phase C₁₈ column using high-performance liquid chromatography with electrochemical detection. The assay was linear from 0.1 to 5.0 μg/mL. The within-day coefficients of variation for the assay at 5.0 μg/mL were ≤ 5% for all analytes. The recovery of all four analytes was ≥ 99% for at 5.0 μg/mL. The lower limit of quantitation was 0.1 μg/mL except for 10-gingerol which was 0.25 μg/mL. Currently, there is no analytical method for detecting pungent ginger constituents in human plasma. This HPLC method allows for the detection of all four of ginger's pungent constituents simultaneously in a relatively short run time of 25 minutes. This method should be useful for determining plasma levels of 6-, 8-, 10-gingerol and 6-shogaol in phase I clinical trials.