J Yuk
Waters Corporation
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Featured researches published by J Yuk.
Analytical and Bioanalytical Chemistry | 2013
J Yuk; Kristina L. McIntyre; Christian Fischer; Joshua M. Hicks; Kl Colson; Ed Lui; Daniel C. W. Brown; John T. Arnason
AbstractThe use of 1H-NMR-based metabolomics to distinguish and identify unique markers of five Ontario ginseng (Panax quinquefolius L.) landraces and two ginseng species (P. quinquefolius and P. ginseng) was evaluated. Three landraces (2, 3, and 5) were distinguished from one another in the principal component analysis (PCA) scores plot. Further analysis was conducted and specific discriminating metabolites from the PCA loadings were determined. Landraces 3 and 5 were distinguishable on the basis of a decreased NMR intensity in the methyl ginsenoside region, indicating decreased overall ginsenoside levels. In addition, landrace 5 was separated by an increased amount of sucrose relative to the rest of the landraces. Landrace 2 was separated from the rest of the landraces by the increased level of ginsenoside Rb1. The Ontario P. quinquefolius was also compared with Asian P. ginseng by PCA, and clear separation between the two groups was detected in the PCA scores plot. The PCA loadings plot and a t-test NMR difference plot were able to identify an increased level of maltose and a decreased level of sucrose in the Asian ginseng compared with the Ontario ginseng. An overall decrease of ginsenoside content, especially ginsenoside Rb1, was also detected in the Asian ginseng’s metabolic profile. This study demonstrates the potential of NMR-based metabolomics as a powerful high-throughput technique in distinguishing various closely related ginseng landraces and its ability to identify metabolic differences from Ontario and Asian ginseng. The results from this study will allow better understanding for quality assessment, species authentication, and the potential for developing a fully automated method for quality control. FigurePrincipal component analysis scores and loadings plot for differentiating between closely-related ginseng landraces in Ontario, Canada
Planta Medica | 2014
Michelle A. Markus; Jonathan Ferrier; Sarah M. Luchsinger; J Yuk; Alain Cuerrier; Michael J. Balick; Joshua M. Hicks; K. Brian Killday; Christopher W. Kirby; Fabrice Berrue; Russell G. Kerr; Kevin Knagge; Tanja Gödecke; Benjamin Ramirez; David C. Lankin; Guido F. Pauli; Ian W. Burton; Tobias K. Karakach; John T. Arnason; Kl Colson
A method was developed to distinguish Vaccinium species based on leaf extracts using nuclear magnetic resonance spectroscopy. Reference spectra were measured on leaf extracts from several species, including lowbush blueberry (Vaccinium angustifolium), oval leaf huckleberry (Vaccinium ovalifolium), and cranberry (Vaccinium macrocarpon). Using principal component analysis, these leaf extracts were resolved in the scores plot. Analysis of variance statistical tests demonstrated that the three groups differ significantly on PC2, establishing that the three species can be distinguished by nuclear magnetic resonance. Soft independent modeling of class analogies models for each species also showed discrimination between species. To demonstrate the robustness of nuclear magnetic resonance spectroscopy for botanical identification, spectra of a sample of lowbush blueberry leaf extract were measured at five different sites, with different field strengths (600 versus 700 MHz), different probe types (cryogenic versus room temperature probes), different sample diameters (1.7 mm versus 5 mm), and different consoles (Avance I versus Avance III). Each laboratory independently demonstrated the linearity of their NMR measurements by acquiring a standard curve for chlorogenic acid (R(2) = 0.9782 to 0.9998). Spectra acquired on different spectrometers at different sites classifed into the expected group for the Vaccinium spp., confirming the utility of the method to distinguish Vaccinium species and demonstrating nuclear magnetic resonance fingerprinting for material validation of a natural health product.
Planta Medica | 2015
James M. Harnly; Pei Chen; Jianghao Sun; Huilian Huang; Kl Colson; J Yuk; Joe-Ann McCoy; Danica T. Harbaugh Reynaud; Peter de B. Harrington; Edward J. Fletcher
Flow injection mass spectrometry and proton nuclear magnetic resonance spectrometry, two metabolic fingerprinting methods, and DNA sequencing were used to identify and authenticate Actaea species. Initially, samples of Actaea racemosa from a single source were distinguished from other Actaea species based on principal component analysis and soft independent modeling of class analogies of flow injection mass spectrometry and proton nuclear magnetic resonance spectrometry metabolic fingerprints. The chemometric results for flow injection mass spectrometry and proton nuclear magnetic resonance spectrometry agreed well and showed similar agreement throughout the study. DNA sequencing using DNA sequence data from two independent gene regions confirmed the metabolic fingerprinting results. Differences were observed between A. racemosa samples from four different sources, although the variance within species was still significantly less than the variance between species. A model based on the combined A. racemosa samples from the four sources consistently permitted distinction between species. Additionally, the combined A. racemosa samples were distinguishable from commercial root samples and from commercial supplements in tablet, capsule, or liquid form. DNA sequencing verified the lack of authenticity of the commercial roots but was unsuccessful in characterizing many of the supplements due to the lack of available DNA.
Journal of the Brazilian Chemical Society | 2016
J Yuk; Dhavalkumar N. Patel; Giorgis Isaac; Kerri Smith; M Wrona; Hernando J. Olivos; K Yu
The chemical profiles of four ginseng roots samples from three species of ginseng (Panax quinquefolius, Panax ginseng and Panax notoginseng) and two commercial ginseng products containing P. quinquefolius and red P. ginseng were compared using ultra-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC/QTOF-MS). Principal component analysis allowed a holistic approach in showing distinct chemical differences between the three ginseng species and correct classification of the two commercial products to their respective species. Further investigation of the chemical profile variations yielded ten main markers that were distinct for the three species. This study shows the potential of chemical profiling for the classification of complex natural product samples, such as ginseng, and application to commercial products sold in the market. This methodology can assist the industry in authenticating the various species of ginseng and providing a quick assessment of the quality of commercial ginseng products.
Planta Medica | 2017
Bharathi Avula; Yan-Hong Wang; Giorgis Isaac; J Yuk; M Wrona; K Yu; Ikhlas A. Khan
Ultrahigh-performance liquid chromatography quadrupole-time-of-flight mass spectrometry (UHPLC-QToF-MS) profiling was used for the identification of marker compounds and generation of metabolic patterns that could be interrogated using chemometric modeling software. UHPLC-QToF-MS was used to generate comprehensive fingerprints of three botanicals (Hoodia, Terminalia, and chamomile), each having different classes of compounds. Detection of a broad range of ions was carried out in full scan mode in both positive and negative modes over the range m/z 100-1700 using high-resolution mass spectrometry. Multivariate statistical analysis was used to extract relevant chemical information from the data to easily differentiate between Terminalia species, chamomile varieties, and quality control of Hoodia products. Using nontargeted analysis, identification of 37 compounds contributed to the differences between Terminalia species, 26 flavonoids were identified to show the differences between German and Roman chamomile, and 43 pregnane glycosides were identified from Hoodia gordonii samples. The UHPLC-QToF-MS-based chemical fingerprinting with principal component analysis was able to correctly distinguish botanicals and their commercial products. This work can be used as a basis to assure the quality of botanicals and commercial products.
Archive | 2015
Kl Colson; J Yuk; Christian Fischer
Nutraceuticals constitute a wide range of products that include dietary supplements, herbal products, functional foods and beverages, and isolated nutrients. These products are utilized for a wide range of health benefits from general wellness to cures for specific diseases. The global market for nutraceutical products is significant at US
Planta Medica | 2016
J Yuk; D Narendrabhai Patel; L Qiao; Giorgis Isaac; K Yu
142.1 billion in 2011. With the further expanded trade, issues related to identity and quality have grown as a concern and enhanced regulation of nutraceutical products has resulted. Direct comparisons with botanical standards are challenged by the variability of material that results from different growing conditions, different local cultivars and landraces, and different harvest and processing techniques. Additionally, the high cost, and often instability, of purified botanical metabolites as standards makes the comparison of metabolites present in botanical material non-trivial. Recently, NMR has emerged as an important technology in the nutraceutical analysis toolbox, resulting from the need for high reproducibility, precision quantitation, and high compound specificity to meet the demands of the new regulations. Using a metabolomics approach, NMR employs both targeted and non-targeted screening approaches, which may be conducted simultaneously from a single NMR spectrum, to provide valuable insight to the identity, purity, strength, and composition of the nutraceutical product.
Planta Medica | 2016
Yh Wang; Bharathi Avula; Giorgis Isaac; J Yuk; M Wrona; K Yu; Ikhlas A. Khan
Planta Medica | 2016
Bharathi Avula; Yh Wang; Giorgis Isaac; J Yuk; M Wrona; K Yu; Ikhlas A. Khan
Planta Medica | 2015
Ma Markus; J Yuk; Pm Le; Kl Colson