Jonathan Pease, Ph.D.

Senior Scientist

Jonathan helps oversee the research & development projects for Cedarburg Hauser Pharmaceuticals and our clients to ensure their successful outcomes. Jonathan evaluates the needs and requirements of new projects to ensure that our clients' expectations align with our capabilities in contract process research and development.  He also uses his experience and expertise in API process development to assist our clients with scaling and transferring their processes from bench scale to plant production within GMP manufacturing requirements.

Past Experience

• Custom Synthesis, process development and scale up work on gram to kilogram scale.

• Developed kilogram scale production route for poly lysine & poly ornithine for use as controlled release matrices in mammalian cell culture. 
• Prepared a series of experimental polyamino acids for other controlled release applications.

Education

• Synthesized resorcinol analogs of dopamine
• Conformationally restrained benzocycloheptene analogs of dopamine  examined  SAR requirements of  central dopaminergic receptors.

• Prepared platinum (II) cyclopropane complexes as potential anti-cancer compounds.
• Prepared  key organometallic intermediates for a variety of ongoing  research projects.

The interactions of poly(L-ornithine) and poly(L-2,4-diaminobutyric acid) with copper(II) in aqueous solution have been investigated by using ERP and electronic spectroscopy and potentiometric titration as a function of pH between 2 and 13.  As with the copper(II)-poly(L-lysine) system, many more complexes are found to be in pH-dependent equilibrium than previous reports for these systems have indicated. 

The complexes correspond to progressive replacement of the inner-sphere water molecules of the Cu(II) ion as the pH is raised, first by side-chain amines, then by deprotonated peptide nitrogens, and finally by hydroxide ligands.  The length of the side chain strongly affects these equilibria.  This is most noticeable in the unusual stability of the chelate of poly(L-2,4-diaminobutyric acid), where two amine and two deprotonated peptide ligands are bound to the copper even at pH values as low as 5. 

This provides evidence for a chelate effect indicating that adjacent Cu(II) ligands are nitrogen atoms from amine and peptide groups of the same amino acid residue, binding to form a six-membered ring.  The similarity between the ERP parameters for the three systems indicates similar ligand environments in contrast to previous suggestions that deprotonated peptide nitrogens are adjacent ligands in the copper(II)-poly(ornithine) system.