Original Paper Ultra-performance LC/TOF MS analysis of medicinal Panax herbs for metabolomic researchIn this study, metabolite profiling of five medicinal Panax herbs including Panax ginseng (Chinese ginseng), Panax notoginseng (Sanchi), Panax japonicus (Rhizoma Panacis Majoris), Panax quinquefolium L. (American ginseng), and P. ginseng (Korean ginseng) were performed using ultra-performance LC-quadrupole TOF MS (UPLC-QTOFMS) and multivariate statistical analysis technique. Principal component analysis (PCA) of the analytical data showed that the five Panax herbs could be separated into five different groups of phytochemicals. The chemical markers such as ginsenoside Rf, 20(S)-pseudoginsenoside F11, malonyl gisenoside Rb1, and gisenoside Rb2 accountable for such variations were identified through the loadings plot of PCA, and were identified tentatively by the accurate mass of TOFMS and partially verified by the available reference standards. Results from this study indicate that the proposed method is reliable for the rapid analysis of a group of metabolites present in herbal medicines and other natural products and applicable in the differentiation of complex samples that share similar chemical ingredients. IntroductionMetabolomics aims to identify and quantify the full complement of low-molecular-weight, soluble metabolites in actively metabolizing tissues [1 -4], which has aroused extensive awareness and interests, especially in the botanical studies such as quality control of plants [5 -9], plant engineering [10, 11] using a number of techniques including NMR or different combinations of LC, GC, and MS. Also, based on the multivariate analysis of complex biological profiles, metabolomics has been successfully applied to plant genotype discrimination and differentiation [1, 12 -14]. Plants are rich in chemically diverse metabolites, which cannot be completely detected by a single analytical method currently available in phytochemical laboratories. Over the past 20 years, HPLC/MS (LC/MS) has become one of the main analytical techniques used in controlling the quality and consistency of both the chemical markers and active substances of traditional Chinese medicines (TCMs). Despite early claims that MS, and particularly MS/MS, is able to remove the need for good chromatographic separation in the analysis of low abundance samples, a poor LC run prior to MS analysis will lead to issues of ion suppression and isobaric interferences that cannot be overcome by a spectrometer alone. More recently, the desire for significantly reduced analysis time with increased sample throughput, resolution, and sensitivity has resulted in the development of ultrafast separation and identification using LC-MS techniques [15,16]. Among the various LC platforms, ultra-performance LC (UPLC) is considered suitable for metabolite profiling and metabolomics [17 -28], especially, for large-scale untargeted metabolic profiling due to its enhanced reproducibility in retention time [24]. The ability to generate high peak capacities in short...

In this study, the chemical constituents of pu-erh tea, black tea, and green tea, as well as those of pu-erh tea products of different ages, were analyzed and compared using a chemical profiling approach. Differences in tea processing resulted in differences in the chemical constituents and the color of tea infusions. Human biological responses to pu-erh tea ingestion were also studied by using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) in conjunction with multivariate statistical techniques. Metabolic alterations during and after pu-erh tea ingestion were characterized by increased urinary excretion of 5-hydroxytryptophan, inositol, and 4-methoxyphenylacetic acid, along with reduced excretion of 3-chlorotyrosine and creatinine. This study highlights the potential for metabonomic technology to assess nutritional interventions and is an important step toward a full understanding of pu-erh tea and its influence on human metabolism.