Novel SNP markers on ginsenosides biosynthesis functional gene for authentication of ginseng herbs and commercial products

Panax ginseng and Panax quinquefolius have similar bioactive components and morphological characteristics, but they are known to have different medicinal values, high-sensitive and accurate method is expected to identify the sources of ginseng products and evaluate the quality, but with a huge challenge. Our established UHPLC-TOF/MS method coupled with orthogonal partial least squares discriminant analysis (OPLS-DA) model based on 18 ginsenosides was applied to discriminate the sources of raw medicinal materials in ginseng products, and nested PCR strategy was used to discover 6 novel single nucleotide polymorphism (SNP) sites in functional dammarenediol synthase (DS) gene for genetic authentication of P. ginseng and P. quinquefolius for the first time. OPLS-DA model could identify the sources of raw ginseng materials are real or not. SNP markers were applied to identify ginseng fresh samples as well as commercial products, and proved to be successful. This established molecular method can tell exact source information of adulterants, and it was highly sensitive and specific even when total DNA amount was only 0.1 ng and the adulteration was as low as 1%. Therefore, this study made an attempt at the exploration of new type SNP marker for variety authentication and function regulation at the same time, and the combination of chemical and molecular discrimination methods provided the comprehensive evaluation and authentication for the sources of ginseng herbs and products.

Identification of blood-red color formation in edible bird's nests provides a new strategy for safety control

In order to reveal the color formation mechanism of blood-red edible bird's nests (EBNs) and develop a quick and specific strategy to distinguish the artificial fake one, multiple methods of UPLC-TOF/MS, UV, NMR, FT-IR and 2D IR were used to detect the chemical markers of the reddening reaction, the results showed that the reddening substances were C₉H₁₀N₂O₅ and C₉H₉NO₆, which were verified as products of a phenol-keto tautomerism evolved from l-tyrosine. Moreover, natural and artificial red EBNs with varying degrees of chemical fumigation also can be successfully distinguished using the chemical markers, and the protein variation in SDS-PAGE gel could also support the distinction. This work established a systematic method of chemical identification for both natural and artificial blood-red EBNs, and provided a new identification strategy for food safety control that can promote the development of a healthier market of EBNs.

Development and validation of a multi-residue and multi-class screening method of 44 antibiotics in salmon (Salmo salar) using ultra-high-performance liquid chromatography/time-of-flight mass spectrometry: Application to farmed salmon

A fast and sensitive multi-residue and multiclass screening method for the simultaneous determination of 44 antimicrobials in salmon muscle, using ultra- high-performance liquid chromatography/time-of-flight mass spectrometry (UHPLC-TOF/MS), was develop and validated. Two different procedures for the extraction step were tested, and an extraction with acetonitrile, ethylenediaminetetra acetic acid (EDTA) and n-hexane proved to be the best alternative. The method was validated, in accordance with Decision 2002/657/EC, using a qualitative approach at the CCβ level. The detection of the analytes was accomplished by retention time and accurate mass, whose maximum error should not exceed 5 ppm. All the compounds were successfully detected and identified at concentration levels corresponding to ½ maximum residue limit (MRL). The screening method was applied to 39 store bought samples of farmed salmon purchased in Portugal, originating from Norway and Denmark, and no antibiotic residues were detected.

An integrated strategy for rapid discovery and identification of quality markers in Guanxin Kangtai preparation using UHPLC-TOF/MS and multivariate statistical analysis

BACKGROUND

Guanxin Kangtai preparation (GXKT), consisting of Panax ginseng, Panax notoginseng and Ilex pubescens, is a new proprietary Chinese medicines under development for treating coronary heart disease. Like other Chinese medicines, the components of GXKT were complex and the bioactive compounds remained unclear.

PURPOSE

To discover bioactive compounds as quality markers (Q-markers) for better quality control of GXKT.

STUDY DESIGN

Chinese medicines was separated into fractions. The correlation between chemical information and bioactivity of these fractions were analyzed with multivariate statistical methods to discover bioactive compounds responsible for the actions of Chinese medicine.

METHOD

GXKT was separated into fractions by using high-performance liquid chromatography (HPLC). Ultra HPLC coupled with time-of-flight mass spectrometer (UHPLC-TOF/MS) was applied to detect compound information from these fractions to form a chemical database. The bioactivity of these fractions in protecting cardiomyocytes from ischemia/reperfusion injury was examined in H9c2 cells that were exposed to hypoxia followed by reoxygenation (H/R). Then, partial least square model and orthogonal projections to latent structures discriminant analysis were employed to discover bioactive compounds from the chemical database that were positively correlated with the bioactivity of GXKT fractions. Finally, the bioactivity of these compounds was confirmed by bioassay in H9c2 cells.

RESULTS

The chemical information of 120 fractions separated from GXKT was detected and extracted by UHPLC-TOF/MS, and a chemical database including 61 high abundance compounds were formed from all fractions. These fractions produced different extent of protective effect to H9c2 cell underwent H/R treatment with cell viability ranging from 33.43% to 74.91%, demonstrating the separation of bioactive compounds among different fractions. The multivariate analysis discovered 16 compounds from GXKT positively correlated with the bioactivity of GXKT. Of these compounds, 6 compounds, i.e.: ginsenoside Rg₁, Rb₁, Rh₁, Rc, ilexsaponin A₁, and chikusetsusaponin IVa were chemical identified and also confirmed for their responsibility to the action of GXKT by bioassay.

CONCLUSION

Ginsenoside Rg₁, Rb₁, Rh₁, Rc, ilexsaponin A₁, and chikusetsusaponin IVa were bioactive compounds and qualified as Q-markers for quality control of GXKT. This research provided a useful reference for the quality research of Chinese medicines.