Chemical profiling and quantification of flavones in several Pseudognaphalium and Gnaphalium species of Mexican gordolobo using UHPLC/PDA/MS.

The inflorescences of the Mexican gordolobo are used as a folk medicine to treat various respiratory diseases. Currently, the botanical species that bear the name Mexican gordolobo belong to the genera Gnaphalium and Pseudognaphalium. Despite a long history of traditional use, most Mexican gordolobo species have never been fully chemically characterized, and the range of constituents in the species has not been comprehensively reported. To establish a quality control and chemical characterization method, a total of 49 samples belonging to 18 species of Pseudognaphalium and four species of Gnaphalium were studied. Nine flavones were quantified using a UPLC-PDA method. The method was validated in terms of linearity (R2 > 0.99), precision (intra- and inter-day: 0.1-3.9%), accuracy (96-103%), detection limit (10 ng/mL), limit of quantification (25 ng/mL) and robustness. 3-Methylquercetin, luteolin, quercetin, 3,5-dihydroxy-6,7,8-trimethoxyflavone, apigenin and gnaphaliin A were present at relatively high levels in most of the samples analyzed. The samples of P. oxyphyllum and P. liebmannii showed the highest content of the 9 compounds analyzed. Whereas the samples of the 5 species of Gnaphalium showed the lowest levels, including non-detectable, of the 9 compounds quantified. This marks an important difference with Pseudognaphalium species. Furthermore, using UHPLC-ESI-QToF data with targeted and non-targeted approaches, 57 compounds, were identified in Mexican gordolobo samples. Flavonoids were the main group of compounds found in Mexican gordolobo.

Microscopy, HPTLC, and LC-DAD-Q-ToF validation of nut-based weight-loss dietary supplements, Aleurites moluccanus (candlenut) and Bertholletia excelsa (Brazil nut).

Aleurites moluccanus (candlenut) and Bertholletia excelsa (Brazil nut) are marketed as dietary supplements for weight loss. These dietary supplements have been found to sometimes be adulterated with toxic nuts/seeds from Cascabela thevetia, commonly known as yellow oleander or lucky nut. This study emphasizes the key identification parameters to differentiate the genuine and adulterated nuts. Samples were obtained from authenticated sources of the nuts and from commercial sources of dietary supplements. This study examined 38 samples, including voucher and commercial samples. All eight commercial candlenut dietary supplement samples were adulterated. Additionally, two samples sold as Brazil nuts were also found to be adulterated. Other nuts were screened for the presence of Cardiac Glycosides, but none were found to be positive. The presence of yellow oleander was confirmed in all commercial dietary supplement samples marketed as candlenut as well as in commercial samples of Brazil nut. This study provides simple key identification characters using micro-morphology and histochemical localization of cardiac glycosides in the commercial nuts, HPTLC fingerprints, and LC-DAD-Q-ToF analytical parameters to detect and identify adulteration in commercial products.