Case Study: Water-Based Synthesis of Bivalirudin Using SpheriTide® Aq-M 

Background

Bivalirudin is a 20-amino acid peptide used as an anticoagulant in medical procedures such as coronary angioplasty.  Marketed as Angiomax, traditional methods for assembling Bivalirudin involve organic solvents, which pose significant environmental and safety challenges. In response, a more sustainable and efficient method was developed using water for amino acid dissolution and SpheriTide® Aq-M, a novel macroporous microsphere support.

Objective

To demonstrate the feasibility and efficiency of synthesizing Bivalirudin in water, using SpheriTide® Aq-M as the solid support. The goal was to achieve high peptide purity while significantly reducing the use of organic solvents.

Challenges

1. Solubility: Traditional peptide synthesis relies on organic solvents to dissolve Fmoc-protected amino acids and activating agents.

2. Coupling Efficiency: Maintaining high efficiency in coupling reactions without the use of organic solvents required the development of a novel activating agent.

3. Cleavage: The peptide needed to be cleaved from the support under mild aqueous conditions without compromising purity.

Methodology

Dissolution of Fmoc-Protected Amino Acids 

We utilized novel techniques to dissolve Fmoc-protected amino acids directly in water, ensuring complete solubility without the need for organic solvents.

Coupling Using a Water-Soluble Activating Agent 

A novel water-soluble activating agent invented in-house was employed to facilitate efficient peptide bond formation in aqueous conditions. Coupling reactions proceeded effectively, matching the efficiency typically achieved with organic solvents.

Peptide Cleavage from the Support 

The fully assembled Bivalirudin peptide was deprotected on the resin then cleaved from the SpheriTide® Aq-M support using an aqueous solution of sodium hydroxide (0.1 mol/dm³).

Results

• Purity: The Bivalirudin produced via this method exhibited a crude purity of 83%, demonstrating the effectiveness of the water-based synthesis approach.

• Environmental Impact: The process reduced the need for harmful organic solvents, significantly reducing the environmental footprint of the synthesis.

• Efficiency: The method proved to be efficient, with coupling reactions and deprotection steps proceeding smoothly in water.

• Scalability: The process is scalable to industrial levels, offering a sustainable alternative for large-scale peptide production.

Conclusion

This case study highlights the successful implementation of SpheriTide® Aq-M in the water-based synthesis of Bivalirudin. By overcoming key challenges, a method was developed that not only achieves high peptide purity but also aligns with green chemistry principles. The results of this study demonstrate the potential of SpheriTide® Aq-M to revolutionize peptide synthesis, offering a sustainable, efficient, and scalable solution for the pharmaceutical industry.

Future Implications

The success of aqueous coupling chemistry suggests broader applications for SpheriTide® Aq-M in the production of other complex peptides and proteins. This method could pave the way for more environmentally friendly practices in peptide synthesis, with significant implications for the pharmaceutical, life sciences and biotechnology sectors.