Isolation of pure pinosylvins from industrial knotwood residue with non-chlorinated solvents

Abstract

The aim of the study was to find appropriate non-chlorinated solvent systems for the extraction and separation of pure pinosylvin (PS) and pinosylvin monomethylether (PSMME) from Scots pine/Norway spruce wood residues. The extraction was performed in a pressurized solvent extractor and the purification and isolation of pure substances was done by flash chromatography. More precisely, pure PS was isolated via sequential flash chromatography in two repetitions in the gradient mode of the mobile phase, with cylcohexane (CX) and ethylacetate (EtOAc), beginning with 100% CX and ending up with 100% EtOAc. The extractives were qualitatively and quantitatively analyzed in terms of PS and PSMME contents by gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC) and proton nuclear magnetic resonance (1H-NMR) spectroscopy.

Improving Fungal Decay Resistance of Less Durable Sapwood by Impregnation with Scots Pine Knotwood and Black Locust Heartwood Hydrophilic Extractives with Antifungal or Antioxidant Properties

“…Analytical standards robinetin (HPLC assay, ≥95%) and dihydrorobinetin (HPLC assay, ≥99%) were supplied by Extrasynthese (Genay, France). Pure pinosylvin (PS) and pinosylvin monomethyl ether (PSMME) used in the in vitro antifungal assay were isolated from the acetone extract of Scots pine knotwood by the method described by Poljanšek et al [21]. Pure dihydrorobinetin (DHR) and robinetin (Rob) used for the antifungal assay were purchased from Extrasynthese (Genay, France).…”

“…The wavelength for monitoring the phenolic compounds was set at 280 nm, and UV spectra were recorded from 200 nm to 400 nm. Peak assignments were achieved by comparing the retention times and UV spectra of the separated compounds to those of analytical standards [21,62]. Quantification of identified compounds was done by comparing peak areas with calibrations made with standards and analyzed under the same conditions.…”

“…The knotwood of pines, generally treated as a residue in the wood-processing industry, has been shown to be a potential source of pinosylvins [21,22]. Both pinosylvins and crude extracts of Scots pine heartwood and knotwood have been comprehensively studied, and it has been reported that these phytochemicals possess antifungal, antimicrobial and antioxidant properties [23][24][25][26][27][28].…”

Natural Sources and Pharmacological Properties of Pinosylvin

“…These different biotechnological approaches have been applied to avoid the formation of many undesirable biproducts of high medicinal risk in the extracts obtained by chemical synthesis. These biproducts subsequently necessitate a more complicated purification process, such as sequential flash chromatography in two repetitions in gradient mode during the mobile phase with cyclohexane (CX) and ethyl acetate (EtOAc) [50].…”

“…In another study performed by Ekeberg et al [64], the quantitative identification of P. sylvestris L. heartwood extracts, including pinosylvin and its derivatives, was carried out using gas chromatography (GC) with flame ionization detection (FID). Similarly, a study on Scots pine/spruce wood residues from Norway conducted by Poljanšek et al [50], describes the qualitative and quantitative analysis of the obtained extracts in terms of pinosylvin and pinosylvin monomethyl ether performed uisng gas chromatography with a flame ionization detector (GC-FID) and gas chromatography with mass spectrometry (GC-MS).…”