Relying on advanced instruments and detection systems, a professional technical team, profound theoretical knowledge, and rich practical experience, BOC Sciences can provide customers with the highest quality amino acid membrane resolution service.
Chirality is one of the essential properties of nature. Basic substances that are important foundations of life activities, such as amino acids and sugars, are chiral. The natural amino acids existing in nature are all L-type, which are closely related to people's survival. Most unnatural amino acids are racemates. And the physiological effects of D and L enantiomers are very different. L-type amino acids can be directly used by the human body. D-type must be converted into L-type in the body to be absorbed and utilized by the body. Certain D-type amino acids have a wide range of medical application prospects. Therefore, it is of great significance to efficiently obtain highly optically pure amino acid enantiomers for the production of related drugs and foods. Currently, the resolution of racemates is the most effective way to obtain single enantiomers. The methods used for racemate resolution mainly include crystallization, chemical resolution, biological enzyme method, extraction, chromatography, chiral membrane resolution and so on.
Membrane resolution is an energy-saving technology. Membrane technology has unique advantages such as low energy consumption, large batch capacity, good stability, and continuous operation, and has good potential application prospects in the field of large-scale chiral resolution. We employ a variety of liquid and solid membranes to achieve membrane resolution of amino acid racemates.
The liquid membrane has a stronger affinity for a certain enantiomer of amino acids, and the resolution can be achieved based on the principle of selective extraction. Commonly used liquid membranes include supported liquid membrane, bulk liquid membrane, and emulsified liquid membrane.
Supported liquid membrane (SLM) apparatus
U-tube bulk liquid membrane
Emulsified liquid membrane apparatus
Solid membrane resolution is based on differences in affinity between enantiomers. Using the selector with chiral recognition function to interact with the enantiomers to be separated, the isomer with strong interaction is preferentially and selectively adsorbed on the membrane, and most of the isomers with weak interaction remain in the mother liquor. Commonly used chiral selectors include cyclodextrins and crown ethers. Compared with liquid film resolution, solid film resolution is more stable and the resolution rate of amino acids is higher (up to 98%)
The mechanism of the membrane resolution method is similar to the mechanism of the separation of racemic amino acids by chiral ligand exchange chromatography, which mainly relies on the formation of three phases between the amino acid enantiomers and the metal cations in the solution and the stationary phase loaded with chiral selectors. Stability differences of metacomplexes. Generally, the complexes formed by L-amino acids are more stable than those formed by D-amino acids. The racemic amino acid to be resolved can be selectively adsorbed on the chiral permeable membrane, then desorbed by the adsorbed amino acid, and diffused into the solution driven by the concentration difference. Affected by the selectivity of the membrane, the migration rates of the two enantiomers are inconsistent, thereby achieving the purpose of chiral resolution.