Green Extraction of Alkaloids and Polyphenols from Peumus boldus Leaves with Natural Deep Eutectic Solvents and Profiling by HPLC-PDA-IT-MS/MS and HPLC-QTOF-MS/MS.

Jeniffer Torres-Vega,Edgar Pastene-Navarrete,Sergio Gómez-Alonso,José Pérez-Navarro

doi:10.3390/plants9020242

Abstract

Peumus boldus Mol., is a Chilean medicinal tree used for gastrointestinal and liver diseases. Such medicinal properties are associated with the presence of bioactive flavonoids and aporphine alkaloids. In this study, a new green and efficient extraction method used seven natural deep eutectic solvents (NADES) as extraction media. The extraction efficiency of these NADES was assessed, determining the contents of boldine and total phenolic compounds (TPC). Chemical profiling of P. boldus was done by high-performance liquid chromatography coupled to photo diode array detector and electrospray ion-trap mass spectrometry (HPLC-PDA-ESI-IT/MS) and electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry (HPLC-ESI-QTOF-MS). Among the NADES tested, NADES4 (choline chloride-lactic acid) and NADES6 (proline-oxalic acid) enable better extraction of boldine with 0.427 ± 0.018 and 2.362 ± 0.055 mg of boldine g−1 of plant, respectively. Extraction of boldine with NADES4 and NADES6 was more efficient than extractions performed with methanol and water. On the other hand, the highest TPC were obtained using NADES6, 179.442 ± 3.79 mg of gallic acid equivalents (GAE g−1). Moreover, TPC in extracts obtained with methanol does not show significant differences with NADES6. The HPLC-PAD-MS/MS analysis enable the tentative identification of 9 alkaloids and 22 phenolic compounds. The results of this study demonstrate that NADES are a promising green extraction media to extract P. boldus bioactive compounds and could be a valuable alternative to classic organic solvents.

Highlights

Peumus boldus Mol., (Monimiaceae) is a Chilean medicinal tree used for gastrointestinal and liver diseases [1,2]
Peaks were numbered according to its elution order from to as well as Figures S1–S4, identification was based on UV spectra obtained by HPLC-PDA, comparison 31
The identity of main P. boldus alkaloids and phenolics compounds was confirmed by HPLC coupled to diode array detector (DAD)-IT-MS/MS and Q-ToF HRMS

Summary

Introduction

Peumus boldus Mol., (Monimiaceae) is a Chilean medicinal tree used for gastrointestinal and liver diseases [1,2]. In Chile, this tree is called Boldo, Peta, Voldu or Boldu and botanically was described for the first time by Molina in 1782. The phytochemical profiling of Boldo usually is based on its aporphine alkaloids and phenolic compounds, whose concentration varies depending on the analyzed part of the tree [3,4,5,6]. The concentration of boldine is higher in the bark than in the leaves. Certain classes of alkaloids are concentrated in other parts such. The analysis of botanical parts of Boldo tree allowed the identification of alkaloids such as boldine, isoboldine, coclaurine, N-methylcoclaurine, (−)-pronuciferine, (+)-reticuline, laurotetanin, N-methyl-laurotetanin, sinoacutin, isocorydine, isocorydine N-oxide, nor-isocorydine and laurolitsin (norboldine) (Figure 1)

Methods

Results

Conclusion