Part IX: Summary of Case Study

Closing Thoughts

The results for Investigation 34 are reported as the concentration, in mg/g, of danshensu and tanshinone I in samples of Danshen roots. Despite reporting the results this way, we cannot assume these values are the actual concentrations of danshensu and tanshinone I in these sample; they are, instead, the concentration of danshensu and tanshinone I extracted using 35.0 mL of a solvent that is 80% methanol and 20% water (by volume) per 1.000 g of sample, and using a microwave oven at 800 W to heat the solvent and sample for 7.50 min at 70°C. Different methods of extracting samples of Danshen yield different extraction yields, some of which recover smaller amounts of analytes (see Table 3 and Investigation 31), and some of which recover larger amounts of analytes (see Figures 3–5 and Investigation 12).

Although our analytical method reports the concentrations in Danshen of extractible hydrophilic and lipophilic compounds instead of their total concentrations, the analysis still has value because ultimately we are interested in the concentrations of these compounds that are recovered easily from harvested plants. In addition, and as suggested by Investigation 34, our analytical method provides us with a standard method for comparing the relative potency of different sources of Danshen and as a means of evaluating how changes in cultivation practices affect the relative potency of commercially grown Danshen. These are important and useful applications.