Metabolic Alterations in Two Cirsium Species Identified at Distinct Phenological Stages using UPLC-QTOF/MS.

INTRODUCTION: Cirsium chanroenicum and C. setidens are commonly used both in traditional folk medicine and as a food source. The quality of different species of Cirsium at different harvest times is a function of their metabolite composition, which is determined by the phenological stage. OBJECTIVE: We sought to determine the differences in the metabolite composition of two species of Cirsium during different phenological stages using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight (QTOF) mass spectrometry (MS). METHODOLOGY: Cirsium chanroenicum and C. setidens plants were collected at the floral budding and full flowering stages. Metabolic profiles of Cirsium extracts were determined using UPLC-QTOF/MS to characterise the differences between phenological stages, and the major metabolites were quantified using UPLC-QTOF/MS-multiple reaction monitoring (MRM). RESULTS: At the full flowering stage, the levels of phenolic acids as well as components of the phenylpropanoid pathway were increased. Flavonoids predominated at the full flowering stage in both species. The levels of coumaric acid, kaempferol, and pectolinarigenin differed between the two species of Cirsium. Overall, these results suggest that components of the phenylpropanoid metabolic pathway are upregulated in the full flowering stage in Cirsium, although we did observe some variation between the species. CONCLUSION: These results will help elucidate the metabolic pathways related to the different phases of the vegetative cycle, and may help determine the optimal season for the harvest of Cirsium with the highest levels of bioactive compounds. Copyright © 2017 John Wiley & Sons, Ltd.

TLC Profiles of Selected Cirsium Species with Chemometrics in Construction of Their Fingerprints.

The dried aerial parts of 12 plants of Cirsium species were extracted with the Soxhlet apparatus using dichloromethane and methanol as solvents. Next, the extracts were separated by TLC methods to obtain the fingerprint chromatograms. The analysis was performed on silica gel or RP-18 layers as stationary phases using the following eluents: ethyl acetate/formic acid/acetic acid/water (12/1.5/1.5/4; v/v) for silica gel, and 5% (v/v) aqueous solution of formic acid/methanol (70/30; v/v) for the first development and the same system in the proportion of 50/50 (v/v) for the second development for RP-18. The double development was applied in the case of RP-18 plates. The analysis was performed for all Cirsium methanolic extracts and five selected standards (naringin, apigenin, rutin, caffeic acid and chlorogenic acid). The results were analyzed using chemometrics. The comparison of individual Cirsium species and the identification of unknown species were performed using the similarity indices (Pearson's correlation coefficient, determination coefficient and congruence coefficient), distance indices (Euclidean distance, Manhattan distance and Chebyshev's distance) and Multi-Scale Structural SIMilarity. Based on chemometric analysis, the first extract of the widely grown species is identified as Cirsium arvense and the second one as Cirsium rivulare.

Fatty acid composition of achenes of Cirsium taxa (Asteraceae, Carduoideae) from Turkey.

The fatty acid compositions and total oil contents in achenes of 22 Cirsium taxa collected from different natural habitats in Turkey were investigated. The range of total fat in the taxa varied from 1.7% to 13.3%. The taxa contained palmitic (C16:0), stearic (C18:0), oleic (C18:1n-9), linoleic (C18:2n-6), and α-linolenic (C18:3n-3) acid. Polyunsaturated fatty acids had the highest level, ranging from 52.1% to 75.2% (C18:2n-6) and 0.5%-17.3% (C18:3n-3). Total saturated (6.9%-17.4%), monounsaturated (11.7%-28.9%), and polyunsaturated (57.4%-79.9%) fatty acids varied substantially, whereas total unsaturated fatty acids ranged from 70.6% to 91.3%. Considerable variation was observed (P<0.05) within each taxon for these fatty acids, especially α-linolenic acid (C18:3n-3). Fatty acid compositions of the 22 taxa were compared by cluster analysis (UPGMA) and principle component analysis (PCA) based on six major fatty acids. This is the first report on the lipid content and fatty acid composition of achenes of Cirsium taxa growing in different areas of Turkey. Fatty acid profiles, relative proportions and levels of fatty acids can be used as additional biochemical markers in the taxonomy of Cirsium.

Chemical constituents and biological activities of Cirsium leucopsis, C. sipyleum, and C. eriophorum.

Two endemic Cirsium species, C. leucopsis DC. and C. sipyleum O. Schwarz, and C. eriophorum (L.) Scop. growing in Turkey were investigated to establish their secondary metabolites, fatty acid compositions, and antioxidant and anticholinesterase potentials. Spectroscopic methods were used to elucidate the structures of thirteen known compounds (p-hydroxy-benzoic acid, vanillic acid, cis-epoxyconiferyl alcohol, syringin, balanophonin, 1'-O-methyl-balanophonin, apigenin, kaempferol-3- O-ß-D-glucopyranoside, kaempferol-3-O-α-L-rhamnopyranoside, taraxasterol, taraxasterol acetate, ß-sitosterol, ß-sitosterol-3-O-ß-D-glucopyranoside). cis-Epoxyconiferyl alcohol and 1'-O-methyl- balanophonin were isolated for the first time from Cirsium species. Palmitic acid (47.1%) was found to be the main fatty acid of C. leucopsis, linoleic acid in both C. sipyleum (42.1%) and C. eriophorum (37.8 %). Assays of ß-carotene bleaching, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS) cation radicals, and superoxide anion radicals, as well as cupric reducing antioxidant capacity (CUPRAC) were used to determine the antioxidant activities of the extracts and isolated compounds. Vanillic acid, balanohonin, and kaempferol-3-O-aαL-rhamnopyranoside exhibited strong antioxidant activity. Taraxa-terol was a potent inhibitor of acetyl- and butyrylcholinesterase activity, respectively.

Differentiation of Cirsium japonicum and C. setosum by TLC and HPLC-MS.

The Chinese Pharmacopoeia indicates the use of field thistle (Cirsium setosum) and Japanese field thistle (C. japonicum) in the treatment of bleeding and inflammation. In the absence of an analytical method for the differentiation and analysis of these two species, TLC and HPLC-MS methods have been developed for this purpose. Both species could be readily distinguished by their flavonoid pattern as revealed by TLC on silica gel layers eluted with ethyl acetate:formic acid:acetic acid:water. The quantitative determination of four flavonoids, namely hispidulin-7-neohesperidoside, linarin, pectolinarin and luteolin, was possible using HPLC. Their optimum separation was achieved on a C12 column eluted with water and 0.025% trifluoroacetic acid in acetonitrile. HPLC-MS experiments were performed to confirm peak identity. In samples of C. japonicum, pectolinarin was the major flavonoid (0.32-2.00%), followed by linarin, hispidulin-7-neohesperidoside and luteolin; the total flavonoid content varied from 0.81 to 3.67%. In C. setosum only one flavonoid (linarin; 1.36-2.83%) was assignable. The HPLC method was validated for linearity, limit of detection (< or = 1.7 ng on-column), peak purity, repeatability (< or = 2.3%) and accuracy (recovery rates of spiked samples were between 99.2 and 101.6%).