Coumarins: Analytical and Preparative Techniques

Abstract

Coumarins are, nowadays, an important group of organic compounds from natural and synthetic sources, possessing a wide range of pharmacological activities. Coumarins comprise a large group of phenolic substances, which occur in plants as secondary metabolites. On account of the significance of this group of compounds, the development of effective methods for the extraction, separation, qualitative and quantitative analyses, and purification remains of high importance. The purpose of the chapter is to present information about methods of analysis and separation of this important group of naturally occurring compounds.

Imperatorin–pharmacological meaning and analytical clues: profound investigation

“…Rarely, there is a small addition of acid. Because acetonitrile and methanol may have different selectivity in the analysis of complex matrices, the mixture of acetonitrile, methanol, and water is sometimes ultimately determined as the mobile phase (Skalicka-Woźniak and Głowniak 2014 ). The most useful combinations of solvent systems for the HPLC analysis of imperatorin are indicated in Table 5 .…”

“…Methyl substitutions at C-5, C-7, and C-8 lead to a bathochromic shift of the 274 nm peak, but not of the 311 nm peak. Linear furanocoumarins, including imperatorin, show four areas of absorption, at 205–225, 240–255, 260–270, and 298–316 nm (Murray and Mendez 1982 ; Skalicka-Woźniak and Głowniak 2014 ). UV λ max values obtained from the HPLC–DAD analysis of imperatorin are 217.9, 248.8, 263.5, and 302.9 nm (Liu et al 2011 ), or 218.1, 248.7, and 300.9 nm (Kim et al 2011 ).…”

“…The common solvents used for the isolation of coumarins are ethanol, methanol, dichloromethane, ethyl acetate, diethyl ether, petroleum ether, and their combinations (Skalicka-Woźniak and Głowniak 2014 ). In order to select the most efficient process to obtain pure imperatorin, a variety of extraction methods were evaluated, including Soxhlet extraction (SX), ultrasound assisted extraction (UAE) at room temperature and at 60 °C, microwave assisted extraction (MAE) in open and closed systems, or accelerated solvent extraction (ASE).…”

“…On aluminum oxide (activity degree III), imperatorin can be separated using petroleum ether and chloroform (2:1), chloroform, and chloroform-ethanol mixtures (9:1, 4:1, and 2:1) as eluents, depending on the complexity of the starting matrix. When silica gel is used, mixtures of hexane-chloroform and chloroform-ethanol with increased proportions of a more hydrophilic component are used (Lozhkin and Sakanyan 2006 ; Skalicka-Woźniak and Głowniak 2014 ). For example, in the gradient elution (petroleum ether:acetone) of a 95 % ethanolic extract from the roots of A. dahurica on silica gel, imperatorin was identified in fractions eluted with petroleum ether:acetone (100:5).…”

Extraction of Cellulases Produced through Solid-State Fermentation by Trichoderma reesei CCT-2768 Using Green Coconut Fibers Pretreated by Steam Explosion Combined with Alkali

“…The first column was operated at 50 • C and eluted using 5.0 mM H 2 SO 4 at a rate of 0.6 mL/min. The second column was set at 35 • C and used a gradient of acetonitrile and acetic acid (1.0% v/v) for elution at a constant flow rate of 0.6 mL/min [35].…”