Synthesis of peptide aldehydes2016-06-15
The functionalization of peptides by aldehyde groups has the inhibition properties towards various enzymes which could cause diseases, such as Parkinson's disease, Alzheimer's disease, and so on. There are lots of commercial peptide aldehydes inhibitors in the market today. For example, Z-DEVD-CHO, Ac-DEVD-CHO, and etc., which have good inhibitory action against Caspase-3. Ontores focuses upon peptide aldehydes synthesis for several years. We are able to synthesize a length of 50-60aa peptide aldehydes with >99% purity.
Here we take Decanoyl-PTANA-aldehyde for example:
The Improved Method of Chloromethylketone (CMK) Modification2016-06-08
Chloromethylketone peptide is a kind of kinase inhibitor. There are some commercialized Chloromethylketone peptides such as Z-IETD-CMK, Z-DEVD-CMK, etc on the market at present.
Currently, diazomethane method is widely used for CMK peptide synthesis. Diazomethane ether solution has very strong excitant smell, and it is very explosive if it is heated, burned, disturbed by the friction and collision. Therefore, there is a great potential safety hazard exists during the production. Depending on the literatures, Ontores chemists found another alternative reagent, (trimethylsilyl) diazomethane solution, which can reduce the risk during the experiment. Lots of experiments prove that the results are consistent with both methods.
The Conventional Method:
The improved method:
The data of HPLC and MS：
The Improvement of Inter-Disulfide Bridge Modification2016-05-31
In chemistry and biology a disulfide bond refers to a functional group with the general structure R–S–S–R. The linkage is also called an SS-bond and is usually derived by the coupling of two thiol groups.
Disulfide bonds are usually formed from the oxidation of sulfhydryl (–SH) groups, especially present in one peptide or protein. With the peptide drugs develop, inter-disulfide bridge between different molecular are widely used.
DTNP (2,2 '- dithiobis (5 - Nitro pyridine) is commonly employed to oxidize thiols to disulfides in the laboratory at present. Due to the shortage in Chinese marked, most of DTNP depends on imports. It makes the price of DTNP is relatively high.
By optimizing and comparing different experimental conditions, Ontores found another reagent, 2,2' - dipyridyl disulfide reagents, which has the same function as DTNP. The price of 2,2-Dipyridyl disulfide reagent is lower than DTNP, and it is easier to get. Additionally, 2,2-Dipyridyl disulfide reagent helped to increase the purity of crude peptide by more than 20 percent. Therefore, 2,2-Dipyridyl disulfide reagent will be a better choice for inter-disulfide bridge modification.
Peptide 1: Ac-Cys-Phe-Arg-Arg-Arg-Arg-Arg-Arg-Arg-Arg-Arg-Lys-NH2
Peptide 2: Ac-Gly-Arg-Asn-Gly-Gln-Cys(Bzl)-Gln-Arg-Lys-Lys-Cys-NH2
The conventional method:
The improved method: