Green process for synthesis of
peptide and oligonucleotide



We have made significant strides in minimizing the environmental impact of two key processes for synthesizing peptides and oligonucleotides. These “green processes” aim to (1) avoid using DMF as solvent, and (2) reduce the consumption of solvent and reagents for efficient and sustainable large-scale production.


Amino-Li-Resin, the second generation of polyacrylamide solid support, has afforded superior results in standard peptide synthesis.[1,2] More significantly, this new resin is suitable for water-based solid phase peptide synthesis by applying the Smoc-protecting group strategy, paving one way to omitting DMF as a solvent.[3]

​

In contrast to solid phase synthesis, liquid phase synthesis is advantageous as all reactions take place in solution and solvent selection is more flexible. Molecular Hiving (A, see below) and Ajiphase (B) have been successfully used for synthesis of peptide and PMO. To meet the demand from the TIDES community, we have also developed a soluble tag, Cyclover (C), which is a lipophilic anchor assembled from a triazine core and functionalized with an amino group.[4] In contrast to its two counterparts, Cyclover contains FOUR long alkyl chains that may enhance its performance in (a) achieving complete purification and (b) making longer peptide or oligomers.





Methodology



Cyclover and its derivatives are soluble in one solvent such as THF. After completion of a desired reaction, the resultant product anchored to Cyclover can be isolated as a pure solid by adding a miscible poor solvent (e.g. methanol or acetonitrile), leaving excess reagents and side-products in solution.





TLC analysis indicates excellent purification and no loss of the product through the precipitation method:





The left lane is the reaction mixture:

Upper spot: Cyclover derivative

Middle spot: excess reagent

Bottom spot: side product.


The center lane shows the pure product isolated:

After adding methanol (5 fold volume), Cyclover derivative precipitated

and was collected by filtration.


The right lane is the filtrate after collecting the solid:

The excess reagent and side product stayed in the filtrate

with no Cyclover derivative detected.



Results



Peptide can thus be manufactured through CYCLOPHASE (commonly known as Liquid Phase) SYNTHESIS wherein each cycle involves the following steps:





(a) DISSOLVE the reactants in one volume of solvent

(b) REACT until the reaction completes

(c) PRECIPITATE the product by adding 4 to 5 fold volume of a miscible poor solvent
(d) FILTER to collect the solid.



To showcase the methodology, we synthesized Acetyl Tetrapeptide 2 (an essential skincare ingredient) in a gram scale, which resulted a 92% total yield. Steps involving elongation, deprotection and separation can be easily standardized which makes the peptide synthesis process broadly applicable. General procedures are detailed in our website.[5]





Synthesis of this model peptide has demonstrated that anchoring peptide intermediates to Cyclover can expedite the isolation of pure solid product of each cycle with ease and certainty, significantly reducing the use of solvents and related reagents.



Perspective



In comparison with Molecular Hiving and Ajiphase, Cyclover has a more stable core structure and may be more efficient in its lipophilic power. Readily available Cyclover may find its widespread use as a universal lipophilic tag for sustainable synthesis of therapeutic biomolecules including peptides and oligonucleotides on an industrial scale.





Reference



[1] Damilola C. Akintayo, Srinivasa R. Manne, Beatriz G. de la Torre, Yongfu Li and Fernando Albericio: Methods and Protocols 2022, 5(5), 72
https://doi.org/10.3390/mps5050072.
[2] Damilola C. Akintayo, Beatriz G. de la Torre, Yongfu Li and Fernando Albericio:

Polymers 2022, 14(5), 28
https://doi.org/10.3390/polym14050928.
[3] Christina Uth, Simon Englert, Olga Avrutina, Harald Kolmar and Sascha Knauer:
Journal of Peptide Science 2023, 29(12), e3527.
https://doi.org/10.1002/psc.3527.
[4] Yongfu Li:
Composition of a lipophilic agent for solution phase synthesis of biomolecules

US2023/0373936A1 and WO2023/244274A2.
[5] Cyclophase Synthesis: Practical guidance for solution phase peptide synthesis using Cyclover-Amine: www.biotide-core.com


Phone: 1-503-334-2820
Fax: 1-503-334-2230

biotide core, llc



33815 SE Eastgate Circle
corvallis, oregon 97333, usa