Differential metabolic profiles of ginsenosides in artificial gastric juice using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry.

Ginsenosides have poor oral bioavailability and undergo rapid biological transformation in the complex gastrointestinal environment. Most studies on the metabolism of ginsenosides have focused on gut bacteria, yet gastric juice remains a nonnegligible factor. Metabolic profiles of ginsenoside monomers formed in artificial gastric juice were separately investigated and qualitatively identified using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap MSn ). A common pattern of their metabolic pathways was established, showing that ginsenosides were transformed via deglycosylation, hydration, and dehydration pathways. Two major structure types, 20(S), 20(R)-protopanaxatriols and 20(S), 20(R)-protopanaxadiols, basically shared similar transformation pathways and yielded deglycosylated, hydrated, and dehydrated products. Fragmentation patterns of major ginsenosides were also discussed. Consequently, gastric juice, as the primary link in ginsenoside metabolism and as important as the intestinal flora, produces considerable amounts of degraded ginsenosides, providing a partial explanation for the low bioavailabilities of primary ginsenosides.

Metabolic Profile of Dendrobine in Rats Determined by Ultra-high-performance Liquid Chromatography/Quadrupole Time-of-flight Mass Spectrometry.

AIMS: Dendrobine is a major alkaloid present mainly in dendrobium nobile Lindl. It has been reported to have analgesic, antipyretic, lower heart rate and blood pressure and other pharmacologic activities. Despite its critical pharmacological function, its metabolite profiling is still unclear. METHODS: In this study, the in vivo metabolite profiling of dendrobine in rats was investigated using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS). The metabolites were predicted using MetabolitePilotTM software with a mass defect filter (MDF) technique. These predicted metabolites were further analyzed by MS2 spectra and compared with the detailed fragmentation pathway of the dendrobine standard and literature data. RESULTS: Total of 59 metabolites were identified for the first time in rat plasma and urine after oral administration of dendrobine. Demethylated, dehydrogenated, hydroxylated, ketonizated and glucuronide were the major metabolic pathways. CONCLUSION: This research provides scientific and reliable support for full understanding of the metabolic fate of dendrobine in vivo.

Constructing a DNA barcode reference library for southern herbs in China: A resource for authentication of southern Chinese medicine.

Southern Chinese Medicine (SCM) is an important sect of Traditional Chinese Medicine (TCM) with its own special cultural style. Species identification is essential for TCM quality control because authentic herbs are possibly substituted with adulterants that would threaten the health of the public or even cause death. Here, we provided the first local reference DNA barcode library based on the second internal transcribed spacer (ITS2) for the molecular identification of SCM. A total of 1512 specimens of southern herbs representing 359 species were collected under the instructions and identification of taxonomic experts. Genomic DNA was extracted, and the PCR reaction proceeded according to standard procedures. After Sanger sequencing, sequence assembling and annotation, a reliable ITS2 barcode library with 1276 sequences from 309 species of Southern herbs was constructed. The PCR efficiency of the whole samples was 84.39%. Characteristics of the ITS2 barcode were analyzed, including sequence lengths and GC contents in different taxa. Neighbor-joining trees based on Kimura 2-Parameter (K2P) genetic distances showed a 67.56% successful rate of species identification with ITS2 barcode. In addition, 96.57% of species could be successfully identified at the genus level by the BLAST method. Eleven plant species were discovered to be cryptic. In addition, we found that there is an incorrect sequence existing in the public database, making a reliable local DNA barcode reference more meaningful. ITS2 barcodes exhibit advantages in TCM identification. This DNA barcode reference library could be used in Southern Chinese Medicine quality control, thus contributing to protecting public health.

Chemical Analysis and Multi-Component Determination in Chinese Medicine Preparation Bupi Yishen Formula Using Ultra-High Performance Liquid Chromatography With Linear Ion Trap-Orbitrap Mass Spectrometry and Triple-Quadrupole Tandem Mass Spectrometry.

Bupi Yishen Formula (BYF), a Chinese medicine preparation, has been clinically applied for the recovery of chronic kidney disease and for delaying its progress. Nevertheless, the chemical components in BYF have yet to be fully clarified. Ultra-high performance liquid chromatography with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap-MSn) and triple-quadrupole tandem mass spectrometry (UHPLC-TQ-MS/MS) methods were developed for qualitative chemical profiling and multi-components quantitative analysis in BYF. The chromatographic separation was performed on a Phenomenex Kinetex C18 column (2.1 × 100 mm i.d., 1.7 µm) using gradient elution of water (A) and acetonitrile (B) both containing 0.1% formic acid. Eighty-six compounds, including flavones, saponins, phenolic acids, and other compounds were authenticated or temporarily deduced according to their retention behaviors, mass mensuration, and characteristic fragment ions with those elucidated reference substances or literatures. Among the herbal medicinal materials of the formula, Astragali Radix, Codonopsis Radix, Salviae Miltiorrhizae Radix Rhizoma, and Polygoni Multiflori Radix Praeparata contributed to the bulk of the dissolved metabolites of the formula extraction. In addition, seven analytes were simultaneously determined by UHPLC-TQ-MS/MS, which was validated and has managed to determine major components in BYF. The study indicated that the established qualitative and quantitative methods would be potent and dependable analytical tools for characterizing multi-constituent in complex prescriptions decoction and provided a basis for the evaluation of bioactive components in BYF.

Chemical profiles and metabolite study of raw and processed Polygoni Multiflori Radix in rats by UPLC-LTQ-Orbitrap MSn spectrometry.

The raw and processed roots of Plygonum multiflorum Thunb (PM) are used to treat different diseases in clinical practice. In order to clarify the influence of processing, a comparative study of chemical substance analysis was carried out. As the xenobiotics with a high enough exposure in target organs being considered as the potential effective or toxicity components, an in vivo study was also implemented to characterize the constitutes and metabolites, and meanwhile, the factor of compatibility with black bean were also considered. As a result, a total of 148 compounds were detected in PM extracts and more than 40 compounds were only detected in the processed products, which were probably new components produced during the steaming process. In in vivo study, 7 prototype components and 66 metabolites were detected or tentatively identified, 24 of which were reported for the first time. Our results indicated that processing greatly changed the chemical composition of PM and influenced the disposition of the compounds in vivo. To the best of our knowledge, this was the first global comparative study of raw and processed PM. These results expanded our knowledge about the influence of processing of PM and provided the essential data for further efficacy or toxicity studies.

Application of Ultra-High-Performance Liquid Chromatography Coupled with LTQ-Orbitrap Mass Spectrometry for the Qualitative and Quantitative Analysis of Polygonum multiflorum Thumb. and Its Processed Products.

In order to quickly and simultaneously obtain the chemical profiles and control the quality of the root of Polygonum multiflorum Thumb. and its processed form, a rapid qualitative and quantitative method, using ultra-high-performance liquid chromatography coupled with electrospray ionization-linear ion trap-Orbitrap hybrid mass spectrometry (UHPLC-LTQ-Orbitrap MS(n)) has been developed. The analysis was performed within 10 min on an AcQuity UPLC™ BEH C18 column with a gradient elution of 0.1% formic acid-acetonitrile at flow rate of 400 µL/min. According to the fragmentation mechanism and high resolution MS(n) data, a diagnostic ion searching strategy was used for rapid and tentative identification of main phenolic components and 23 compounds were simultaneously identified or tentatively characterized. The difference in chemical profiles between P. multiflorum and its processed preparation were observed by comparing the ions abundances of main constituents in the MS spectra and significant changes of eight metabolite biomarkers were detected in the P. multiflorum samples and their preparations. In addition, four of the representative phenols, namely gallic acid, trans-2,3,5,4'-tetra-hydroxystilbene-2-O-ß-d-glucopyranoside, emodin and emodin-8-O-ß-d-glucopyranoside were quantified by the validated UHPLC-MS/MS method. These phenols are considered to be major bioactive constituents in P. multiflorum, and are generally regarded as the index for quality assessment of this herb. The method was successfully used to quantify 10 batches of P. multiflorum and 10 batches of processed P. multiflorum. The results demonstrated that the method is simple, rapid, and suitable for the discrimination and quality control of this traditional Chinese herb.