Natural Product Extraction and Isolation

Classical solvent procedures

It includes maceration, percolation, Soxhlet extraction, ultrasound-assisted extraction and turbo-extraction.

Ultrasound-assisted extraction (UAE)

It uses ultrasound energy and solvents to extract target compounds from various plant matrices.

Microwave-assisted extraction (MAE)

It uses microwave energy to heat solvents in contact with a sample in order to partition analytes from the sample matrix into the solvent.

Extraction with ionic liquids

Ionic liquids are able to dissolve a wide range of polar to non-polar compounds, have a low vapor pressure, show a high thermal stability and low combustibility.

Accelerated solvent extraction (ASE)

It uses high temperature and pressure, which results in the extraction taking less time and requiring less solvent, and possibly also giving better analyte recovery.

Supercritical fluid extraction (SFE)

It is presented as an efficient, environmentally clean, and selective alternative to conventional extraction methods.

Extraction on solid phases

This sample preparation technique enables the extraction, cleanup and concentration of analytes prior to their quantification.

Distillation methods

Recent developments in distillation methodology include microwave steam distillation.

Isolation based on adsorption properties

It is based on the difference between the adsorption affinities of natural products to the adsorbent surface.

Silica gel, alumina, and adsorptive microporous resin are three common adsorbents. Of these, silica gel is the most widely used; alumina is used for the separation of natural products, especially alkaloids; and adsorptive microporous resin can selectively adsorb almost any type of natural products.

Isolation based on partition coefficient

Partition chromatography (PC) follows the principle of liquid-liquid extraction, based on the relative solubility of two different immiscible liquids.

HSCCC, HPCCC  and CPC *attracted great attention in separation science and have been widely used in the separation of natural products.

Isolation based on molecular size

The isolation of natural products can be abtained by membrane filtration (MF) or gel filtration chromatography (GFC).

In MF, the semipermeable membrane allows smaller molecules to pass through and retains the larger molecules.

GFC is a versatile method that permits the effective separation of biological molecules in high yield.

Other isolation methods

Ion-exchange chromatography (IEC), molecular distillation, preparative gas chromatography (Prep-GC), supercritical fluid chromatography (SFC), molecular imprinted technology, simulated moving bed chromatography, multi-dimensional chromatographic separation, etc.