A novel comparative chromatographic research of secoiridoid glycosides in two species of centaury herb

The aim: A novel comparative analysis of the secoiridoid glycosides composition in Centaurium erythraea Rafn. and Cеntaurium pulchellum (Sw.) Druce has being described. Swertiamarin has been chosen as an active marker and its comparative quantitative estimation in two species of the raw material has been carried out by HPLC method. Materials and methods: The quantitative HPLC analysis of swertiamarin was conducted using a chromatographic column ACE 5 C18. Methanol and 0,5 % acetic acid aqueous solution were used as mobile phases; the chromatographic procedure was carried out in a gradient mode. Results: The content of swertiamarin in the C. pulchellum herb ranges from 2.51 to 3.07 mg/100 mg. In that time swertiamarin content in C. erythraea herb varies and depends from 3.83 to 8.94 mg/100 mg. The content of swertiamarin in C. pulchellum herb is much lower than in C. erythraea herb. Taking into account this fact the possibility of using of C. pulchellum herb for medicine instead of C. erythraea herb must be proven additionally by biological experiments. Also it could be preliminary concluded that the most appropriate climate for swertiamarin accumulation in C. erythraea herb is located in Central and Eastern parts of Ukraine. Conclusions: It was discovered that the main representative of secoiridoid glycosides in C. erythraea is swertiamarin when in C. pulchellum Druce that are represented by both sweroside and swertiamarin. A more perspective raw material – C. erythraea herb, according to the content of swertiamarin, was chosen

Diversity of secoiridoid glycosides in leaves of UK and Danish ash provide new insight for ash dieback management

Secoiridoid glycosides are anti-feeding deterrents of the Oleaceae family recently highlighted as potential biomarkers in Danish ash trees to differentiate between those tolerant and susceptible to the fungal disease ash dieback. With the knowledge that emerald ash borer has recently entered Europe from Russia, and that extensive selection trials are ongoing in Europe for ash dieback tolerant European ash (Fraxinus excelsior), we undertook comprehensive screening of secoiridoid glycosides in leaf extracts of trees tolerant and susceptible to ash dieback sampled from sites in the UK and Denmark. Here we report an unexpected diversity of secoiridoid glycosides in UK trees and higher levels of secoiridoid glycosides in the UK sample group. While it is unlikely that secoiridoid glycosides generally can serve as reliable markers for ash dieback susceptibility, there are differences between tolerant and susceptible groups for specific secoiridoids. We predict that the high levels—and structural diversity—of secoiridoids present in the UK group may provide a robust reservoir of anti-feeding deterrents to mitigate future herbivore threats such as the Emerald ash borer.

Preparative Separation of Phenylethanoid and Secoiridoid Glycosides from Ligustri Lucidi Fructus by High-Speed Counter-Current Chromatography Coupled with Ultrahigh Pressure Extraction

Three phenylethanoid glycosides, echinacoside (1), salidroside (3), and acteoside (6), and three secoiridoid glycosides, isonuezhenide (2), nuezhenoside G13 (4), and specnuezhenide (5), have been extracted and separated by a combined method of ultrahigh pressure extraction (UPE) and high-speed counter-current chromatography (HSCCC) from Ligustri Lucidi Fructus. For the UPE, the optimal extraction was developed with conditions including solvent of 90% ethanol, sample to solvent ratio of 1:20 g/mL, pressure of 200 MPa, and time of 2 min, which rendered the yields of compounds 4 and 5 were 15.0 and 78.0 mg/g, respectively. For the HSCCC separation, the strategy of changing flow rates between 1.0 and 2.0 mL/min allowed the acquisition for 2.7 mg of compound 1, 4.5 mg of compound 2, 6.8 mg of compound 3, 5.9 mg of compound 4, 11.2 mg of compound 5, and 2.2 mg of compound 6 in one separation run under the solvent system of ethyl acetate:n-butanol:water (2:1:3, v/v) from 200 mg of the UPE extract. The structures of these phenylethanoid and secoiridoid glycosides were elucidated by extensive spectroscopic methods.