11-Oxomogroside III is a natural product from Siraitia grosvenorii Swingle.

A high performance liquid chromatographic method was developed for simultaneous determining the contents of mogroside V, mogroside IV A, mogroside III, 11-Oxomogroside III, mogroside II E and 11-oxomogroside II E in Siraitia grosvenorii fruits. The chromatographic analysis was carried out on a ZORBAX SB-C18 column (150 mm x 4.6 mm, 5 microm). The mobile phase was water (A) and acetonitrile (B) with gradient elution (0-3 min, 20% B - 30% B; 3-8 min, 30% B - 35% B; 8-9 min, 35% B). The flow rate was maintained at 0. 8 mL/min. The detection wavelength was set at 203 nm and the column temperature was controlled at 30 degrees C. The sample injection volume was 10 microL. The calibration curves were linear over the ranges of 0.04 - 1.0 mg/mL, 0.011 - 0.68 mg/mL, 0.010 - 0.80 mg/mL, 0.0097 - 0.58 mg/mL, 0.025 - 1.0 mg/mL and 0.013 - 0.76 mg/mL (r > 0.999 1) for the above cucurbitane triterpene glycosides, respectively. The average recoveries were 99. 65% for mogroside V , 101.6% for mogroside IV A, 97. 05% for mogroside m, 103. 1% for 11-oxomogroside I, 99. 25% for mogroside II E, and 103.0% for 11-oxomogroside II E, with the relative standard deviations of 0.83%, 3.1%, 1.9%, 3.3%, 0.59% and 2.0%, respectively.