Ginger Compounds Quantification Protocol

The ginger capsules and the corresponding placebos were a gift provided and manufactured by Pure Encapsulations LLC (Sudbury, MA). The ginger capsules contain 6.55% 6G, 0.94% 8G, 1.88% 10G, 2.21% 6S, 0.37% 8S, and 0.95% 10S. β-Glucuronidase from bovine liver, sulfatase from Helix pomatia, d-saccharic acid 1,4-lactone monohydrate (β-glucuronidase inhibitor), ascorbic acid, and N-vanillylnonanamide (internal standard, IS) were purchased from Sigma-Aldrich Inc. (St Louis, MO, USA). Sodium acetate was purchased from Fisher Scientific. All ginger standard compounds were previously purified or synthesized in our lab.^{27 (link),28 (link)} Their purities were as follows: 6G, 97.0%; 8G, 96.2%; 10G, 97.0%; 6S, 97.6%; 8S, 96.3%; 10S, 95.5%; 6G-diol-2, 95.7%; M2, 99.1%; M9, 99.1%; M11, 96.2%. Acetonitrile, methanol, and water (LC–MS grade) were purchased from Thermo Fisher Scientific (Waltham, MA). Other general chemicals were purchased from VWR (Radnor, PA).