What's in your “natural” supplement? Application of NMR spectroscopy in nutraceuticals

There has been a significant increase worldwide in the usage of natural products such as plant extracts for herbal remedies or nutraceuticals. This has raised many concerns as increases in the adulteration of natural products with other materials have been detected in the market. In some cases, this is due to accidental species misidentification but in other cases, this is due to intentional substitution based on financial incentive. With the wide diversity and complexity of chemical compounds within botanical materials, a demand exists for methods to understand the composition of natural products for proper quality control and authentication. In this study, the application of a NMR-based screening tool for nutraceuticals was evaluated for the detection of adulteration and product authenticity. Both targeted and non-targeted NMR approaches for various botanical materials and adulterated dietary supplements were evaluated. This work demonstrated the potential of simultaneous analysis of nutraceuticals which involves 1) chemometric modeling for classification, 2) identification of each component through a spectral match, 3) screening check for any potential unknowns in the mixture and 4) absolute quantification using a calibrated NMR spectrometer. Utilizing the qualitative and quantitative nature of NMR spectroscopy, the NMR spectrum of a natural product contains vast information about its chemical constituents to even its species or origin. With the increasing demand for robust high-throughput analytical methods, an automated NMR-based screening tool was tested as an approach for determining the identity, purity, strength, and composition of nutraceuticals.