Identification of Species in <i>Tripterygium</i> (Celastraceae) Based on DNA Barcoding

Abstract

Species of genus Tripterygium (Celastraceae) have attracted much attention owing to their excellent effect on treating autoimmune and inflammatory diseases. However, due to high market demand causing overexploitation, natural populations of genus Tripterygium have rapidly declined. Tripterygium medicinal materials are mainly collected from the wild, making the quality of medicinal materials unstable. Additionally, identification of herbal materials from Tripterygium species and their adulterants is difficult based on morphological characters. Therefore, an accurate, convenient, and stability method is urgently needed. In this wok, we developed a DNA barcoding technique to distinguish T. wilfordii HOOK. f., T. hypoglaucum (LÉVL.) HUTCH, and T. regelii SPRAGUE et TAKEDA and their adulterants based on four uniform and standard DNA regions (internal transcribed spacer 2 (ITS2), matK, rbcL, and psbA-trnH). DNA was extracted from 26 locations of fresh leaves. Phylogenetic tree was constructed with Neighbor-Joining (NJ) method, while barcoding gap was analyzed to assess identification efficiency. Compared with the other DNA barcodes applied individually or in combination, ITS2 psbA-trnH was demonstrated as the optimal barcode. T. hypoglaucum and T. wilfordii can be considered as conspecific, while T. regelii was recognized as a separate species. Furthermore, identification of commercial Tripterygium samples was conducted using BLAST against GenBank and Species Identification System for Traditional Chinese Medicine. Our results indicated that DNA barcoding is a convenient, effective, and stability method to identify and distinguish Tripterygium and its adulterants, and could be applied as the quality control for Tripterygium medicinal preparations and monitoring of the medicinal herb trade in markets.

Molecular Identification of Three <i>Aquilaria</i> (Thymelaeaceae) Species through DNA Barcoding

“…5,9) A combination of both nuclear and cpDNA barcodes have shown to result in better species discrimination than cpDNA or nuclear barcodes alone. 19) Higher species discrimination using this pattern of DNA barcoding has been recorded in many studies that have focused on closely related genera or species, such as Dalbergia (ITS+matK+rbcL), 10) Gossypium (ITS2+matK+rbcL) 20) and Tripterygium (ITS2+psbA-trnH). 21) In this study, the trees of two combination barcodes ITS+matK and ITS+trnL-trnF shared a similar topology: each species clustered into three monophyletic clades.…”

“…19) Higher species discrimination using this pattern of DNA barcoding has been recorded in many studies that have focused on closely related genera or species, such as Dalbergia (ITS+matK+rbcL), 10) Gossypium (ITS2+matK+rbcL) 20) and Tripterygium (ITS2+psbA-trnH). 21) In this study, the trees of two combination barcodes ITS+matK and ITS+trnL-trnF shared a similar topology: each species clustered into three monophyletic clades. A. sinensis and A. crassna clustered closely with high support rates (Fig.…”

Phylogeographic and phylogenetic analysis for Tripterygium species delimitation

“…These experiments showed that five T. regelii individuals gathered closely to form a single branch that was separated from the other populations, and that T. wilfordii and T. hypoglaucum could be combined into the same species. Further analyses using four DNA regions (i.e., ITS2, matK, rbcL, and psbA-trnH) for species identification in Tripterygium showed that T. regelii clustered alone, whereas T. hypoglaucum clustered with T. wilfordii, suggesting that T. hypoglaucum and T. wilfordii are potentially conspecific or that the limited barcode did not provide enough variation for their differentiation (Zhang et al, 2016).…”

“…Further analyses using four DNA regions (i.e., ITS2, mat K, rbc L, and psb A ‐trn H) for species identification in Tripterygium showed that T . regelii clustered alone, whereas T. hypoglaucum clustered with T. wilfordii , suggesting that T. hypoglaucum and T. wilfordii are potentially conspecific or that the limited barcode did not provide enough variation for their differentiation (Zhang et al., ).…”

Structure elucidation and NMR assignment of two new hydroxywilfordate‐type alkaloids from the stems of Tripterygium hypoglaucum and activity evaluation

“…Hutch (THH) is an endemic liana shrub (Celastraceae) indigenous in southwest China and distributed mainly in Yunnan, Sichuan, and Guizhou Provinces. [ 1–4 ] Previously published research results suggest that a broad variation of dihydroagarofuran sesquiterpene derivatives appears to be the most common and representative of the bioactive metabolites found in Celastraceae species, [ 5–7 ] and many are considered to be important as chemotaxonomic indicators. [ 8 ] The macrolide sesquiterpene pyridine alkaloids (MSPASs) represent a structurally specific class of macrolactone alkaloids that contain a pyridine dicarboxylic acid substructure, including wilfordic, hydroxywilfordic, evoninic, cassinic, and edulic, which bridge the C 3 and C 15 positions of the highly functionalized sesquiterpenoid core, for example, evoninol, euonyminol, or isoeuonyminol.…”