Selective extraction of plant bioactive compounds with deep eutectic solvents: Iris sibirica L. as example.

INTRODUCTION: Deep eutectic solvents (DESs) are promising extractants with tuneable properties. However, there is a lack of reports about the influence of the nature of the original DES on obtaining the metabolomic profile of a plant. OBJECTIVE: The aim of this study is to investigate the possibility of obtaining Iris sibirica L. chromatographical profiles with DESs based on various hydrogen bond donors and acceptors as extraction solvents. METHODOLOGY: DESs were prepared by mixing choline chloride or tetrabutylammonium bromide with various hydrogen bond donors and investigated for the extraction of bioactive substances from biotechnological raw materials of I. sibirica L. The obtained extracts were analysed by HPLC with diode array detector (DAD) and Q-MS. RESULTS: Chromatographic profiles for I. sibirica L. extracts by eight choline chloride DESs and six tetrabutylammonium DESs have been obtained. It has been found that selective recovery of bioactive substances can be achieved by varying the composition of DESs. Eleven phenolic compounds were identified in I. sibirica L. using HPLC-MS. Phase separation was observed with acetonitrile for four DESs. New flavonoid derivatives have been found in DES extracts compared with methanol extracts. CONCLUSION: The results showed the possibility of DES usage for extraction without water addition. Selectivity of DESs varies depending on the chemical composition of hydrogen bond donors and acceptors. Choline chloride is a more suitable hydrogen bond acceptor for the flavonoid extraction. Choline chloride-lactic acid (1:1) DES has demonstrated a metabolic profile that was the closest to the methanol one and enhanced the extraction up to 2.6-fold.

Development of approach for flavonoid profiling of biotechnological raw materials Iris sibirica L. by HPLC with high-resolution tandem mass spectrometry.

INTRODUCTION: Iris L. are promising in medicine due to the biological activity of extracts. Iris sibirica L. is spread in Russia but its phytochemical composition has not been studied in detail though it is included in the Red Book. For this reason, I. sibirica L. biotechnology is in high demand. One of the key points in biotechnology is the regulation of plant metabolism using phytohormones. Obtaining of chromatographic metabolite profiles allows to control this process. OBJECTIVE: The aim of this study was to develop an approach for effective control of biotechnological raw materials of I. sibirica L. by flavonoid profiles using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and to investigate the influence of phytohormones in nutrient media on content of flavonoids. METHODOLOGY: Iris sibirica L. regenerated plants were grown on Murashige-Skoog media with 6-benzylaminopurine (6-BAP) and α-naphtylacetic acid (NAA) additives. To optimise extraction conditions, the design of the experiment was used. Profiles of polyphenols were obtained by HPLC-MS/MS in the positive and negative ionisation modes. RESULTS: The process for efficient extraction from leaves of I. sibirica L. were developed. The factors influencing the extraction efficiency of flavonoids have been determined. A total of 36 compounds were identified by HPLC-MS/MS. Among them isoflavones and their glycosides are the main classes. Addition of an auxin-like hormone increased the non-polar flavonoid levels, but decreased the polar ones. The variation in concentration of cytokinin (6-BAP) affected almost all of the analytes. CONCLUSION: The methodology for effective control of I. sibirica L. raw plant material biotechnology was developed by analysing obtained chromatographic polyphenol profiles.