In polyplyptunous synthesis, the choice and removal of protection cells is a key step in ensuring the success of synthesis and the purity of the product. The following is a detailed analysis of the selection and removal of the kpc:
I. Options for the protection of the corps
The choice of kpc requires a combination of factors, including its responsiveness, selectivity, stability and ease of removal。
Common protection groups include alkyloxyethylene (e. G., tertbutyloxyethyl boc, ethylenedioxyethyl fmoc, etc.), aylyl (e. G., acetylac) and sulfylide (e. G., toth) groups。
Protection of alpha-aminos:
Fmoc-protective: fmoc-based is stable for acids, easily detached under alkaline conditions (e. G. Thallium-dmf) and not prone to volatilization, and is therefore widely used in solid polypesium synthesis。
Boc-protective: boc-based can easily be removed under acidic conditions (e. G. Tfa), but not in some acid-sensitive amino acids or aluminum-part synthesis。
The protection of the platinum:
Alkyl is generally protected by the formation of esters, with methyl, ethyl, tertbutyl and so on commonly used. These esters can be easily removed under alkaline conditions (e. G., soap reaction)。
Side chain protection:
For amino acids containing active side chains (e. G., cys, zinc, asp, glu, etc.), an appropriate protection group is needed to protect the side chains from secondary reactions during synthesis. For example, the cys base is commonly used for protection such as trt, acm and the asp and glu base chain for protection such as otbu and obzl。
Ii. Removal of protection corps
The removal of kpc is one of the key steps in the synthesis of polyplyptunium and needs to be undertaken without destroying the main chain of polyplyptunium and other protection groups. Common de-protection methods include acid de-protection and alkali de-protection。
Acid deprotection:
The kpc was largely removed using acid conditions (e. G. Tfa, hf, etc.). This approach applies to many protection missions, but needs to be used with caution in some acid-sensitive amino acid or aluminum section synthesis。
Blank deprotection:
The kpc was removed through alkaline conditions (e. G. Radon, ammonia, etc.). This method is widely applied in the synthesis of fmoc solid phase peptide because fmoc-based is easily detached under alkaline conditions and does not cause voltilization。
Iii. Optimization of removal from protection
In order to improve the efficiency and purity of polyplyptunium synthesis, the deprotection process needs to be optimized. Optimization measures include selection of appropriate deprotection methods, optimization of response conditions (e. G. Temperature, time, solvent, etc.), control of the occurrence of secondary reactions and monitoring of deprotection effects。
Select the appropriate deprotective method:
Select the appropriate deprotection method based on the nature of the polyplyptunium sequence and the protection umbrella. For example, alkaline deprotective methods are often used in fmoc solid phase polyplyptunium synthesis。
Optimizing response conditions:
Optimizing deprotective effects by adjusting conditions such as response time, temperature and solvent. In general, extended response times, increased response temperatures and use of organic solvents can increase de-protection efficiency, but care needs to be taken to avoid degradation and side reactions from the peptide chain。
Control the occurrence of secondary reactions:
Secondary reactions may occur during de-protection, such as removal of the side chain protection cell or partial contraction of the pelican chain. In order to reduce the occurrence of these secondary reactions, it is possible to protect the side chain or optimize the response conditions (e. G. Control ph, buffers, etc.) by adding appropriate reagents。
Monitor deprotective effects:
The degree of deprotective reaction and the purity of the product are monitored through mass spectrometry, efficient liquid chromatography, etc. Timely adjustment of response conditions based on monitoring results to achieve optimal deprotection effect。
It was to be hoped that the success and purity of the product of polyplyptunium synthesis would be ensured by reasonable choice to protect the corps and optimize the process of deprotection。
