The Untargeted Capability of NMR Helps Recognizing Nefarious Adulteration in Natural Products.

Curcuma longa (turmeric) has an extensive history of ethnomedical use for common ailments, and "curcumin"-containing dietary supplements (CDS) are a highly visible portion of today's self-medication market. Owing to raw material cost pressure, CDS products are affected by economically motivated, nefarious adulteration with synthetic curcumin ("syncumin"), possibly leading to unexpected toxicological issues due to "residual" impurities. Using a combination of targeted and untargeted (phyto)chemical analysis, this study investigated the botanical integrity of two commercial "turmeric" CDS with vitamin and other additives that were associated with reported clinical cases of hepatotoxicity. Analyzing multisolvent extracts of the CDS by 100% quantitative 1H NMR (qHNMR), alone and in combination with countercurrent separation (CCS), provided chemical fingerprints that allowed both the targeted identification and quantification of declared components and the untargeted recognition of adulteration. While confirming the presence of curcumin as a major constituent, the universal detection capability of NMR spectroscopy identification of significant residual impurities, including potentially toxic components. While the loss-free nature of CCS captured a wide polarity range of declared and unwanted chemical components, and also increased the dynamic range of the analysis, (q)HNMR determined their mass proportions and chemical constitutions. The results demonstrate that NMR spectroscopy can recognize undeclared constituents even if they represent only a fraction of the mass balance of a dietary supplement product. The chemical information associated with the missing 4.8% and 7.4% (m/m) in the two commercial samples, exhibiting an otherwise adequate curcumin content of 95.2% and 92.6%, respectively, pointed to a product integrity issue and adulteration with undeclared synthetic curcumin. Impurities from synthesis are most plausibly the cause of the observed adverse clinical effects. The study exemplifies how the simultaneously targeted and untargeted analytical principle of the 100% qHNMR method, performed with entry-level high-field instrumentation (400 MHz), can enhance the safety of dietary supplements by identifying adulterated, non-natural "natural" products.

The PlantLIBRA project: how we intend to innovate the science of botanicals.

The main aim of the EC-financed R&D project PlantLIBRA (PLANT food supplements: Levels of Intake, Benefit and Risk Assessment) is to foster the safe use of food supplements containing plants or botanical preparations, by enabling science-based decision making by regulators and stakeholders. To make informed decisions, competent authorities and industry need more accessible and quality-assured information, as well as better tools (e.g., databases) and procedures for safety and benefit assessments, supported by broadly accepted methodologies. Consequently, PlantLIBRA is working to develop, validate and disseminate data and methodologies for risk and benefit assessment of plant food supplements, and to implement sustainable international cooperation. International cooperation will help ensure the quality of botanicals imported in the EU. Moreover, the project will provide data on intake by conducting a harmonized consumption survey. Existing composition and safety data will be collated into a meta-database. New analytical data and methods will be investigated and validated. The consortium is working closely with competent authorities and stakeholders.