In the Chinese Pharmacopoeia, salidroside is chosen as a marker compound for quality control [7].
This metabolite has been proposed as an indicator compound for quality control due to its instability and rapid degradation when compared to other secondary metabolites within plant materials [9, 18].
As for linderane, a marker compound for quality control in current Chinese Pharmacopeia [6], the mean content levels (132 μg/g for SQP-1 and 266 μg/g for SQP-2) were superior to the mandatory criteria (i.e., no less than 90 μg/g) albeit the 2-fold difference between the two products.
By combining with bioactivity assays, we demonstrated that "functional compound combination (FCC)", which is the core and indispensable effective part, could be discovered from an herbal medicine and suitable as marker compounds for quality control.
High confidence in the data set was achieved by (1) blinding the contract researchers to compound properties, (2) quality control checks at all stages, (3) transparency of raw data and analysis procedures and easy access to all data, and (4) a high automation level in data acquisition and analysis.
Solid-phase synthesis, on the other hand, is compatible with a broad range of solvents, there are numerous solid-phase chemical reactions available, sample purification is trivial (washing), and each bead harbors numerous copies of the compound for synthesis quality control.
To confirm the activity of a subset of compounds based on activity profiles from the primary screening, the 50 compounds that passed quality control measures were retested in the original ARE assays and the ARE- bla-mut assay to identify promiscuous β-lactamase activators.
Although, most of studies reviewed are preliminary in nature, detailed isolation, characterization, mechanisms of actions of these of isolated compounds, safety studies, quality control as well as clinical trials on some of these herbs and their isolated compounds is far from satisfactory.
Therefore, these three kinds of components should be chosen as the bioactive marker compounds for the quality control of A. oxyphylla fruits.
Of the 63 compounds that passed quality control measures [see Supplemental Material, Figure S2 (http://dx.doi.org/10.1289/ehp.1104709)], 50 were cherry-picked from the original solutions provided by NTP.
