Agilent 6890n series gc system

Commercially available food-grade RBTs (Oryza triterpenoid – PK) were purchased from the Oryza Oil & Fat Chemical Company (Aichi, Japan). The triterpenoid composition was determined using gas chromatography (Agilent 6890N series GC System; Agilent Technologies Inc., Santa Clara, CA, USA). This composition included cycloartenol, 24-methylene cycloartenol, β-sitosterol, and campesterol in mass ratios of 57/38/1/2% (w/w) (Lot Q-404). Rice (Sato No Gohan^®; energy 294 kcal, carbohydrate 67.8 g, protein 4.2 g, fat 0 g) was obtained from Sato Foods (Niigata, Japan).

HEO was extracted and determined according to the reported method in reference [26 ]. Briefly, fresh Houttuynia cordata was cut into 1 cm lengths, soaked with ethyl acetate (the ratio of solid to liquid was 1:1.5), extracted by ultrasonication for 30 min, sealed, placed in a sunless place for 3 days, and concentrated to obtain crude HEO. After ethanol sinking, n-hexane extraction, and macroporous resin column chromatography, the HEO for pharmacokinetic and pharmacodynamic studies was obtained and analyzed by an Agilent 6890N series GC system with an Agilent DB-5 capillary column GC (30 m × 0.25 mm, 0.25 µm, Agilent Technologies, Santa Clara, CA, USA) for separation, and a hydrogen flame ionization detector (FID) was used for quantitative analysis [16 (link)].