ABSTRACT
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.
ABSTRACT
Molecular pharmacognosy( MP) is a new interdisciplinary science,which integrates the pharmacognosy and molecular biology,and focuses on the crude drugs' classification and identification,cultivation and protection,and production of active ingredients at the molecular level. Pogostemon cablin is one of the ten major southern medicines in China,MP research on this famous herb has developed on the basis of traditional research methods,and achieved certain results. This article summarized the MP research achievements of P. cablin in recent years,the prospect of this field is also discussed to provide references for the protection,development and utilization of P. cablin resources.
Subject(s)
China , Lamiaceae , Molecular Biology , Pharmacognosy , PogostemonABSTRACT
Dendrobium officinale is not only an ornamental plant, but also a valuable medicinal herb that is widely used in traditional Chinese medicine. However, distinguishing D. officinale from other Dendrobium species is usually a difficult task. In this study, we developed a rapid identification protocol for D. officinale using the loop-mediated isothermal amplification (LAMP) method. A set of primers were specifically designed to detect a modified internal transcribed spacer region of D. officinale at 65 °C within 40 min after adding SYBR Green I, which was used for the detection of D. officinale. Unlike commonly used adulterants, reaction mixtures containing D. officinale DNA changed from orange to green, and this color change was easily observed with the naked eye. Thus, this methodology can be used to accurately differentiate D. officinale from other Dendrobium species, is quick as all D. officinale samples were amplified within 40 min, and specific as samples of the adulterants were not amplified. The specificity of this LAMP-based method was confirmed by testing 17 samples of D. officinale and 32 adulterant samples from other Dendrobium species. This LAMP-based rapid identification method does not require expensive equipment or specialized techniques and can be used in field surveys for accurate and fast on-site identification.
ABSTRACT
Accurate identification of varieties is the most important part of quality control of Chinese materia medica (CMM). To find an efficient, convenient, and accurate identification method is the development trend of identification technology of CMM. Compared with the traditional identification method based on phenotypic markers, DNA molecular marker technology is more accurate and reliable, suitable for the identification of closely related species and sample with confusion and multiple sources, but unable to realize the rapid identification due to the limits of the PCR technology, such as high cost, complex procedures, and the drawback of long time. Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid amplification technology, with the advantages of high specificity, high sensitivity, simple, rapid, low cost, etc., become another new technology after PCR to realize the rapid molecular identification of CMM successfully. In this paper, the common isothermal amplification of nucleic acid technology and its application in the study of molecular identification of Chinese herbal medicines were reviewed analysis, to provide a reference for the study of rapid molecular identification system of Chinese herbal medicines.
ABSTRACT
Objective: To establish a method for discovering single nucleotide polymorphisms (SNPs) in the cDNA sequence of dammaranediol synthase (DS) gene, a key enzyme in the ginsenoside biosynthesis pathway of Panax ginseng, thus to provide reference for the SNP analysis of DS gene and authentication of ginseng medicinal materials. Methods: P. ginseng samples from various cultivars, production regions, and growth years were collected. Total RNA was extracted and reversely transcribed into cDNA. The cDNA was amplified by nested PCR method to prepare the products for directly sequencing. The sequences were analyzed by BLAST for homology alignment and then by DNAMAN for multiple sequence alignment to explore different loci among different samples, which was regarded as candidate SNP. Results: One hundred and eleven amplicons of the upper or lower half part of DS gene were obtained from 57 samples after nested PCR, and 103 amplicons were successfully sequenced. All of these sequences were confirmed to be the P. ginseng DS gene by BLAST analysis. Seven SNPs from six samples were discovered by multiple sequence alignment analysis. Conclusion: We have developed a method to discover the unknown SNPs from the cDNA sequence of DS gene in P. ginseng with the advantages of good specificity, simple operation, and accurate result. This method can be used to detect if P. ginseng samples contain SNP and its type, and it also provides a valuable tool for the genetic research and molecular markers resources for establishing a new quality evaluation method for P. ginseng and related Chinese matereia medica and its products.