[Study on content of two sesquiterpenes in Alpinia oxyphylla]

To develop an HPLC method for determining oxyphyllenodiol A (1) and teuhetenone A (2) contained in Alpinia oxyphylla and to compare the contents of the two components contained in medicinal materials and prepared herbal medicines in pieces sold in the market and different fractions.

HPLC and Waters sunfire C18 column (4. 6 mm x 250 mm, 5 microm) were adopted for gradient elute with the mobile phase of acetonitrile and water. The flow rate was 1.0 mL x min(-1) and the detection wavelength was 250 nm.

1 and 2 showed a good linear relationship within the range of 0.1296 - 0.8640 microg and 0.1635 - 1.0900 microg respectively, with the average recoveries of 99.08% and 97.80%. Their content ranges were 0.0059% - 0.0149% and 0.0080% - 0.0164% in different samples. The mean value of 1 and 2 were 0.0085% and 0.0104% in the whole fruits, and 0.0137% and 0.0157% in the seeds. They were undetected in the nutshells.

The method is so precise, accurate and highly reproducible that it can be used to determine the contents of oxyphyllenodiol A and teuhetenone A in A. oxyphylla. The contents of the two components are mainly extracted from the seeds, with certain difference among different samples. There are a higher contents and no significant difference in the salted and raw seeds.