In recent years, there have been major strides towards making peptide synthesis greener. CPC Scientific is a peptide CDMO specialising in solid-phase peptide synthesis (SPPS). Chris Gothard, Director of Technical Marketing at CPC Scientific explained that the main advantage of SPPS over solution phase is the ability to easily wash away excess reagents and use multiple equivalents to force the reaction to completion. Furthermore, intermediates do not need to be isolated, purified, or characterised. However, SPPS also generates a lot of chemical waste due to solvent use.
Gothard explained that the main goal of CPC Scientific’s M peptide case study: To mitigate the use of DMF, diethyl ether, and TFA in the SPPS process. These solvents are highly hazardous, so Gothard investigated the possibility of replacing them with environmentally friendly solvents like aqueous ethanol and isopropanol. Gothard said: “We can introduce co-solvents like isopropanol in the washing steps, but not in the removal or coupling steps.” DMF cannot be fully replaced by isopropanol because the DMF is needed to swell the resin.
Within SPPS it is important to protect the hydroxy groups, but this usually requires large amounts of TFA. Since the M peptide molecule is acid sensitive TFA cannot be used. So, the strategy involved using DDE to protect lysine, allowing the removal of protection groups with dilute hydrazine instead of strong acids, thus reducing the need for strong acids like TFA and diethyl ether.
Although CPC Scientific is primarily focused on SPPS, the company also works on hybrid approaches that combine solid phase and solution phase. Diego Silva, Director of International Sales at CPC Scientific introduced their FTE (full-time-equivalent) services. This model allocates a team of peptide chemists to their customers' projects at a fixed rate per employee over a period of time. Services like these demonstrate a strong commitment to R&D and CPC Scientific supports its clients at every step of the way from proof of principle discovery to commercialisation.
Additionally, Silva mentioned other services on offer such as neoantigen peptides and facilities dedicated to immunotherapy. The company has a broad generics portfolio, with Luprolite as their flagship compound, which is offered in commercial batches for prostate cancer. To foster engagement and a sense of community amongst peptide chemists, CPC Scientific hosts and organises a three-day symposium that invites customers, regulatory personnel, and venture capitalists to discuss the latest innovations, challenges, and potential collaborations in peptide chemistry.
