Fmoc Amino Acids & Peptides - Omizzur

03/12/2024

Fmoc-His-Aib-OH.TFA | Semaglutide Intermediate Supply
Fmoc-His-Aib-OH.TFA is an amino acid derivative that can be used for the synthesis of semaglutide. In addition, Fmoc-His-Aib-OH.TFA is a side chain dipeptide of semaglutide, and the N-terminus of the peptide is blocked by an fmoc group to enhance its stability.

Fmoc-His-Aib-OH.TFA is an important intermediate in the chemical synthesis of semaglutide dipeptides.

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28/11/2024

Long Peptide Synthesis Guideline:
In protein chemical synthesis research, solid-phase synthesis method is the most commonly used and simplest synthesis method. This method is also effective in synthesizing long-chain peptides, but as the peptide chain lengthens, the reaction gradually becomes more difficult (such as greater than 150 amino acids), and some target peptides with missing residues are produced. These peptide chains with missing residues are also the main impurities generated during the synthesis of long peptides.

Therefore, the main difficulty we need to overcome in the synthesis of long peptides is to explore better reaction conditions and methods, so as to make the amino acid condensation reaction more complete and thorough. At the same time, shorten the reaction time, because the longer the reaction time, the more uncontrollable side reactions there will be, and the more complex the by-products will be. These by-products are also important components of the impurities produced by the entire reaction.

In order to solve the many problems in the synthesis of long peptides, Omizzur Biotech has adopted a series of effective measures and methods:

(1) Microwave Synthesis Method:
For some amino acids that are difficult to condense during the synthesis process, we use microwave method for synthesis. This method has significant effects, greatly shortens the reaction time, and reduces the production of two main by-products.

Omizzur's microwave technology support: It is a peptide synthesis method under microwave administration.

Greatly improve reaction speed. Shorten the synthesis cycle of peptides and improve synthesis efficiency.

Under microwave radiation, the synthesis of disulfide bonds was carried out, which shortened the reaction time and improved the purity and yield of the product.

Based on microwave technology support, Omizzur Biotech has launched a rapid peptide synthesis business, with delivery within 4 days faster than 10aa.

Full article of long peptide synthesis method you can click:
https://www.omizzur.com/long-peptide-synthesis.html

25/11/2024

Methods for Removing TFA Salt from Peptide: HPLC

The following is a detailed description of the steps:

I. Basic Principles
TFA (trifluoroacetic acid) is a strong organic acid that is often used in the deprotection step after peptide synthesis, but due to its strong acidity, it may cause unwanted side effects in some applications.

Acetate is a weaker organic acid salt that usually has better biocompatibility, so in some pharmaceutical preparations or biological experiments, the acetate form is more suitable.

II. Conversion Process
1. Choose a suitable column:
For ion exchange, columns filled with ion exchange resins are usually used. These columns can selectively exchange ions based on the charge and size of the ions.

2. Sample Preparation:
Prepare the peptide solution containing TFA salt to ensure that the concentration and purity of the solution meet the experimental requirements.

3. Loading:
Inject the prepared sample into the HPLC system. The HPLC system can accurately control the speed, pressure and temperature of the mobile phase to ensure efficient ion exchange.

4. Mobile Phase Selection:
Use an appropriate buffer as the mobile phase, such as ammonium acetate solution. Ammonium acetate can provide acetate ions to exchange with cations in TFA salts.

5. Elution:
When the sample passes through the column, the TFA salt will undergo an ion exchange reaction with ammonium acetate to form peptides in the form of acetate.

During this process, the HPLC system can monitor the composition and concentration of the eluent in real time to ensure the completeness of the conversion.

6. Collection:
Collect the eluted peptides in the form of acetate. If necessary, the collected peptides can be further purified and concentrated.

7. Post-treatment:
According to the experimental requirements, the collected peptides in the form of acetate are subjected to necessary post-treatment, such as removing the solvent, adjusting the pH value, etc.

Full guidelines here:

If you need to do cell experiments in peptide R&D, removing TFA salt in peptide is an important step in peptide research. TFA may have direct effects on cells, such as anti-tumor, anti-angiogenic, and induction of apoptosis.

06/03/2024

Semaglutide Impurities
Semaglutide is a glucagon-like peptide-1 (GLP-1) analog. This type of drug can delay gastric emptying and suppress appetite. It has obvious weight loss effects and has few side effects. It also has the effects of lowering blood sugar and improving metabolism in the body.

Semaglutide increases insulin secretion and inhibits glucagon secretion. It can improve blood sugar levels in patients with type 2 diabetes and has a low risk of hypoglycemia.

Peptide Synthesis & Impurities - Omizzur
More than 90% of the peptide drugs currently on the market can be produced through chemical synthesis method. Peptide drugs are composed of amino acids. They are formed through the connection of amino acids step by step. For now chemical synthesis methods include liquid phase method, solid phase method, and combination of liquid phase and solid phase method.

Semaglutide Impurities
Omizzur lab supply various peptide impurities, such as exenatide , semaglutide impurities etc for R&D use. Some products are in stock and some need custom-made.(delivery within 2-4 weeks). Please contact us to get the product details.

Product link:
https://www.omizzur.com/semaglutide-impurities/
Inquiry: [email protected]

Omizzur custom synthesizes semaglutide impurities with guaranteed quality and can reduce your R&D costs . contact us for product quotation & delivery date.

17/04/2023

Specific steps of Edman degradation
Edman degradation is a very important reaction step in protein sequencing, because the ordered amino acid composition of protein can be analyzed through this reaction. Automated Edman sequencing machines are now widely used, capable of sequencing peptides that are approximately 50 amino acids long. The steps of protein sequencing using Edman degradation are summarized below, and some of the important steps will be described in detail later.

1. Use a reducing agent such as 2-mercaptoethanol to destroy any disulfide bond in the protein, and a protective group (such as iodoacetic acid) may be required in the process to prevent the chemical bond from re forming;

2. If there is more than one protein, it is necessary to separate and purify each peptide chain in the protein mixture;

3. Determine the amino acid composition in each chain;

4. Determine the amino acids at the end of each chain;

5. Break each chain into fragments of less than 50 amino acids;

6. Isolation and purification of peptide fragments;

7. Determine the sequence of each peptide fragment;

8. Repeat the above steps using other cracking methods;

9. Construct the entire protein sequence

Specific steps of Edman degradation:
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For inquiry about peptide: [email protected]

10/04/2023

6 peptide impurities that appear in the synthesis & storage of peptides:
1. Amino acid deletion/ insertion
2. Protective group residues
3. Oxidation / reduction
4. Diastereomers
5. Side chain / terminal modification impurities
6. Peptide aggregates

Sources of Peptide Impurities & Peptide Characterization:
The solid-phase synthesis of peptides has been widely used nowadays. In the process of peptide synthesis and storage, related structural impurities are easily formed, such as amino acid loss, amino acid insertion, deamination, degradation products, etc. Many related structural impurities not only have no medicinal effect, but have certain toxic and side effects. Therefore, the European Pharmacopoeia requires qualitative analysis of related structural impurities with a content of more than 0.5%, quantitative analysis of related structural impurities with a content of more than 1%, and investigation of their toxic and side effects.
Learn more about peptide impurities synthesis:

Omizzur ltd provides custom peptide impurity synthesis for India,USA ,Europe etc. Imp: Exenatide,Salmon calcitonin,Octreotide,Teriparatide.

06/04/2023

How To Choose The Purity Levels of Peptide In Experiment?
The purity of the peptide is a very important indicator, and the choice of purity depends on the purpose of the experiment. For less sensitive screening experiments, it is recommended to use the crude product or >75%, and for the immune level, it is recommended to use >85%.

For studies on the interaction of receptors with LIGAND, biological ASSAY studies, or studies at the cellular level, >95% is recommended, and for structural studies, 98% is recommended.

Omizzur does not recommend crude peptides for use in biological experiments. Crude peptides may contain significant amounts of non-peptide impurities such as residual organic solvents, scavengers, TFA, and other incomplete peptides.

TFA cannot be completely eliminated and usually delivered peptides are in the form of TFA salts. If residual TFA interferes with your experiments, we recommend other salt forms such as acetate ,hydrochloride.
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Omizzur ltd is a custom peptide synthesis & impurities company,ship to India,Europe,USA. Hot: Exenatide,Calcitonin,Octreotide. Quotation in 1h.

05/04/2023

What is included in Peptide Characterization？
1. Precise molecular weight determination
2. Primary sequence confirmation: sequence coverage/peptide mapping analysis, N and C-terminal sequence confirmation
3. Confirmation of multiple modification sites
4. Glycosylation modification analysis: glycosylation site and glycoform analysis, oligosaccharide profile analysis
5. Disulfide bond analysis
6. Biosimilar drug analysis
7. Charge Heterogeneity Analysis
8. Peptide Mapping Analysis of Bioactive Extracts
9. Analysis of amino acid content
10. Drug target confirmation

25/03/2023

4 kind of salmon calcitonin impurities：
1.Amino acid deficient salmon calcitonin impurity. Salmon calcitonin lacks a peptide impurity of one amino acid, and there are 32 possible impurities ranging from the deletion of N-terminal cysteine to the C-terminal proline. For example:
Des2-Ser Calcitonin Salmon in the European Pharmacopoeia 7.0

2.Chiral racemic isomers are produced due to the chiral racemization of certain amino acids such as cysteine, serine, lysine, histidine, proline, and arginine during the condensation process during solid-state synthesis. As impurity B, 9-D leucine salmon calcitonin in European Pharmacopoeia 7.0

3.Degradation impurities, such as hydrolytic impurities, some amino acids are relatively easy to hydrolyze, such as asparagine, glutamine, and the amide structure formed by terminal proline is also easy to hydrolyze; Oxidizing impurities, impurities that are oxidized by cysteine, such as impurity D in European Pharmacopoeia 7.0

4.Recombinant salmon calcitonin impurity
Salmon calcitonin impurities from recombinant sources are given in European Pharmacopoeia 7.0

22/03/2023

Salmon calcitonin impurities
Salmon calcitonin is a peptide medicinal hormone composed of 32 amino acids, and is one of the first choice drugs for the treatment of osteoporosis in clinical practice. It has multiple effects such as reducing blood calcium, expanding blood vessels, and neurotransmitters in the central system. It is mainly used in clinical practice for the treatment of elderly osteoporosis, postmenopausal osteoporosis, migraine, and hypercalcemia, especially in the treatment of combined fractures. It also has a good analgesic effect.

Salmon calcitonin was first approved by the US FDA in March 1991 by Novartis AG in Switzerland under the trade name Miacalcin.The drug is still widely used today. However, due to the early use of salmon calcitonin, the research on its impurities was not carried out in the early stage, and there were few reports on its related substances. The impurity spectra of different manufacturers are even different. Whether these impurities have activity, and whether their activities in vitro and in vivo are related are issues that need to be explored

The production process of salmon calcitonin mainly adopts a solid-state synthesis method, which fixes the C-terminal of amino acids on an insoluble resin, and then condenses amino acids on this resin in turn. After repeated operations of condensation, washing, deprotection, neutralization, washing, and the next round of condensation, the desired length of the peptide chain is reached. Finally, the peptide chain is split off the resin, and preliminary purification treatment is conducted to obtain a crude salmon calcitonin product, which is then purified and refined, Obtain salmon calcitonin raw material. Salmon calcitonin can be made into injection or powder injection by adding appropriate auxiliary materials. Clinically used calcitonin injections include injection, powder injection, and nasal spray. Due to its complex amino acid composition and many synthesis steps, the drug has the characteristics of instability and easy degradation, and the composition of impurities is relatively complex.
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Article from Omizzur Ltd - custom peptide impurity synthesis
www.omizzur.com

09/03/2023

RGD Peptide
RGD sequence peptide can be used for the treatment of cardiovascular diseases, osteoporosis, inflammation and other diseases, and can also prevent and treat tumors caused by abnormal cell adhesion, especially the metastasis of developmental tumors; On the other hand, RGD sequence peptide can also be used as a stimulant to promote the regeneration of injured organs and tissues, wound healing, etc., and has a wide range of biological functions. Therefore, the adhesion of these peptides has become a new target for drug design.

Omizzur is a company provide custom peptide synthesis,peptide impurities & API, fmoc-amino acids ,peptide reagents in China. Mail us for technical help.