Identification of phytolaccosides in biological samples from pokeweed intoxication patients using liquid chromatography-tandem mass spectrometry

In Phytolaccaceae family, Phytolacca americana L. (American pokeweed) and P. esculenta Van Houtte (Chinese pokeweed) are the two representative species among the genus. Pokeweeds have triterpenoid saponins as toxic compounds in every part of the plant. The saponins phytolaccoside A, B, D, E, and G were isolated from P. americana, and esculentoside H, J, L, K, M, I, and N were isolated from P. esculenta. Along with saponins, their aglycones (phytolaccagenin, phytolaccagenic acid, esculentic acid and jaligonic acid) were also isolated from P. americana and P. esculenta. Two people who unknowingly ate misidentified pokeweed plant roots were transferred to the emergency room. Urine and gastric content after irrigation were collected from the first patient (patient 1), and blood and urine were collected from the second patient (patient 2). The samples were analyzed to identify toxic substances with liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the blood sample, 1.9 ng/mL of esculentoside A and 1.5 ng/mL of esculentoside C were detected, while the concentration of esculentoside B and H were below the LLOQ. In gastric contents and ingested roots, esculentoside A, B, C, and H were identified. Esculentoside A, C, and H were identified in the urine of patient 1, and esculentoside A and C were identified in the urine sample of patient 2. The developed analytical method was validated for parameters such as linearity, limit of detection, precision, accuracy, matrix effect, recovery, and process efficiency, and they showed clear and unbiased results.