Cynanchum auriculatum Royle ex Wight., Cynanchum bungei Decne. and Cynanchum wilfordii (Maxim.) Hemsl.: Current Research and Prospects.

Cynanchum auriculatum Royle ex Wight. (CA), Cynanchum bungei Decne. (CB) and Cynanchum wilfordii (Maxim.) Hemsl. (CW) are three close species belonging to the Asclepiadaceous family, and their dry roots as the bioactive part have been revealed to exhibit anti-tumor, neuroprotection, organ protection, reducing liver lipid and blood lipid, immunomodulatory, anti-inflammatory, and other activities. Until 2021, phytochemistry investigations have uncovered 232 compounds isolated from three species, which could be classified into C21-steroids, acetophenones, terpenoids, and alkaloids. In this review, the morphology characteristics, species identification, and the relationship of botany, extraction, and the separation of chemical constituents, along with the molecular mechanism and pharmacokinetics of bioactive constituents of three species, are summarized for the first time, and their phytochemistry, pharmacology, and clinical safety are also updated. Moreover, the direction and limitation of current research on three species is also discussed.

Mitochondrial plastid DNA can cause DNA barcoding paradox in plants.

The transfer of ancestral plastid genomes into mitochondrial genomes to generate mitochondrial plastid DNA (MTPT) is known to occur in plants, but its impacts on mitochondrial genome complexity and the potential for causing a false-positive DNA barcoding paradox have been underestimated. Here, we assembled the organelle genomes of Cynanchum wilfordii and C. auriculatum, which are indigenous medicinal herbs in Korea and China, respectively. In both species, it is estimated that 35% of the ancestral plastid genomes were transferred to mitochondrial genomes over the past 10 million years and remain conserved in these genomes. Some plastid barcoding markers co-amplified the conserved MTPTs and caused a barcoding paradox, resulting in mis-authentication of botanical ingredients and/or taxonomic mis-positioning. We identified dynamic and lineage-specific MTPTs that have contributed to mitochondrial genome complexity and might cause a putative barcoding paradox across 81 plant species. We suggest that a DNA barcoding guidelines should be developed involving the use of multiple markers to help regulate economically motivated adulteration.

Ethnobotany, Phytochemistry and Pharmacological Effects of Plants in Genus Cynanchum Linn. (Asclepiadaceae).

Genus Cynanchum L. belongs to the family Asclepiadaceae, which comprise more than 200 species distributed worldwide. In Chinese medical practice, numerous drugs (such as tablets and powders) containing different parts of plants of this genus are used to treat snake bites, bruises, osteoblasts, rheumatoid arthritis and tumors. A search for original articles published on the cynanchum genus was performed by using several resources, including Flora of China Official Website and various scientific databases, such as PubMed, SciFinder, the Web of Science, Science Direct, and China Knowledge Resource Integrated (CNKI). Advances in the botanical, ethnomedicinal, phytochemical, and pharmacological studies of this genus are reviewed in this paper. Results showed that more than 440 compounds, including C21 steroids, steroidal saponins, alkaloids, flavonoids and terpene, have been isolated and identified from Cynanchum plants up to now. In vivo and in vitro studies have shown that plants possess an array of biological activities, including anti-tumor, neuroprotective and anti-fungal effects. Popular traditional prescription of Cynanchum sp. was also summed up in this paper. However, many Cynanchum species have received little or no attention. Moreover, few reports on the clinical use and toxic effects of Cynanchum sp. are available. Further attention should be focused on the study of these species to gather information on their respective toxicology data and relevant quality-control measures and clinical value of the crude extracts, active compounds, and bioactive metabolites from this genus. Further research on Cynanchum sp. should be conducted, and bioactivity-guided isolation strategies should be emphasized. In addition, systematic studies of the chemical composition of plants should be enhanced.

Discrimination of Cynanchum wilfordii and Cynanchum auriculatum by terahertz spectroscopic analysis.

INTRODUCTION: Precise identification of botanical origin of plant species is crucial for the quality control of herbal medicine. In Korea, the root part of Cynanchum auriculatum has been misused for C. wilfordii in the herbal drug market due to their morphological similarities. Currently, DNA analysis using the polymerase chain reaction (PCR) method is employed to discriminate between these species. OBJECTIVE: In order to develop a new analytical tool for the rapid discrimination of C. wilfordii and C. auriculatum, terahertz (THz) spectroscopy was employed. METHODOLOGY: Authentic samples of C. wilfordii and C. auriculatum were provided from the National Institute and standardized pellets for each species were prepared to get optimum results with terahertz time-domain spectroscopy (THz-TDS) in frequency range 0.2-1.20 THz. RESULTS: The C. wilfordii pellet showed longer time delay compare to the sample of C. auriculatum and this was due to the difference in permittivity. The pellet samples of C. wilfordii and C. auriculatum showed a permittivity difference of about 0.08 at 0.2-1.20 THz. CONCLUSION: The experimental results indicated that THz-TDS analysis can be an effective and rapid method for the discrimination of C. wilfordii and C. auriculatum, and this application can be expanded for the discrimination of other similar herbal medicines.

Development of molecular markers, based on chloroplast and ribosomal DNA regions, to discriminate three popular medicinal plant species, Cynanchum wilfordii, Cynanchum auriculatum, and Polygonum multiflorum.

Identification of plant species is important for standardizing herbal medicine. Cynanchum wilfordii (Baekshuoh in Korean) and Polygonum multiflorum (Hashuoh in Korean) are important oriental medicinal herbs in Korea, Japan, and China. Cynanchum auriculatum is a faster growing and more productive plant than C. wilfordii; and, it is not recognized as a medicinal plant in the Korean Pharmacopoeia. C. wilfordii, P. multiflorum, and C. auriculatum are often misidentified in the Korean herbal medicine marketplace due to their morphological similarities and similar names. In this study, we investigated molecular authentication of these three medicinal plants using DNA sequences in the TrnL-F chloroplast intergenic region. Specific species identification was achieved by detecting allelic variations of single nucleotide polymorphisms (SNPs) using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and high resolution melting curve analysis. Our results demonstrate that the intraspecific genetic distance between C. wilfordii and C. auriculatum is relatively low. We also developed a quantitative PCR assay using species-specific TrnL-F primers, which allowed us to estimate the ratio of C. wilfordii and C. auriculatum using varying ratios of mixed genomic DNA template from the two species. Additionally, to identify species in hybrid plants produced by cross-fertilization, we analyzed nuclear ribosomal DNA internal transcribed spacer regions in C. wilfordii and C. auriculatum by ARMS-PCR. Our results indicate that SNP-based molecular markers, usable to barcode tools could provide efficient and rapid authentication of these closely related medicinal plant species, and will be useful for preventing the distribution of products contaminated with adulterants.

Chemical constituents of Cynanchum wilfordii and the chemotaxonomy of two species of the family Asclepiadacease, C. wilfordii and C. auriculatum.

Definitive identification of original plant species is important for standardizing herbal medicine. Although only the dried roots of Cynanchum wilfordii (Asclepiadaceae) are prescribed as Cynanchi Wilfordii Radix in Korean Pharmacopoeia, the roots of C. wilfordii and C. auriculatum are often misused in the Korean herbal market due to their morphological similarity and similar name. Therefore, it would be very useful to discover an effective chemical marker for the identification of the two species. To this end, we carried out a phytochemical study on the roots of C. wilfordii. As a result, twenty compounds were isolated from the roots of C. wilfordii and their chemical structures were identified as ß-sitosterol (1), wilfoside C1N (2), wilfoside C3N (3), wilfoside K1N (4), methyleugenol (5), wilfoside C1G (6), cynauriculoside A (7), daucosterol (8), 2,4-dihydroxyacetophenone (9), cynandione A (10), 2,5-dihydroxyacetophenone (11), acetovanillone (12), p-hydroxyacetophenone (13), sucrose (14), conduritol F (15), geniposide (16), succinic acid (17), 3-(ß-D-ribofuranosyl)-2,3-dihydro-6H-1,3-oxazine-2,6-dione (18), bungeiside A (19), cynanoneside B (20). Among them, compounds 15, 16, 18, 19, and 20 were isolated for the first time from this species. Furthermore, conduritol F (15) was demonstrated to be contained only in C. wilfordii. Therefore, it may be useful as a chemical marker to identify the two species C. wilfordii and C. auriculatum.

[Sequence analysis of rDNA-ITS of Bai Shouwu from different species].

OBJECTIVE: To study the genetic diversity of rDNA ITS sequences in different species of Bai Shouwu, utilize the molecular diversity of ITS sequences to authenticate the different species of Bai Shouwu. METHOD: Firstly, total DNA was extracted from the different species of Bai Shouwu. Secondly, the ITS sequence was amplified by PCR with universal primer of ITS and sequenced after cloning and purification. RESULT: From four species the complete sequence of ITS and 5.8 S rDNA, the partial sequences of 18S rDNA and 26S rDNA were obtained. The rDNA ITS sequences of Cynanchum bungei (sign in No. GU198970 and No. GU479037) were obtained. Ten variable sites among the sequences were found. CONCLUSION: ITS sequence could be used to authenticate the species. The method could be used to identify germplasm resources and authenticate.

[The connotation investigation of "female-male" in Chinese traditional medicine nomenclature].

The connotation investigation of "female-male" in nomenclature of Polygonum multiflorum Thunb, suggests that the female-male" in Chinese medicine nomenclature is generalized concept. It has three connotation, including correlation, relativity identity. It's concrete use of materialist dialectics in Chinese medicine.