SUSTAINABILITY
Figure 2 - Reaction scheme , substrates & reactions of KGOs .
available in kg quantities and capable of catalysing oxygenation reactions for a broad range of compounds . The first processes used the so-called P450 monooxygenase family , which in parts are still used today – albeit not for processes beyond 100 kg scale , due to the inherent instability of the biocatalyst . Today , more promising alternatives exist and Aminoverse offers two types of biocatalysts that fulfil all criteria .
UPOs & KGOs
As the name implies , unspecific peroxygenases ( UPOs ) act on a broad spectrum of substrates , which currently covers more than 400 different compounds , including steroids , terpenes and chemical building blocks like pyridines and heterocycles ( Figure 1 ). The oxygen donor is hydrogen peroxide instead of molecular oxygen , which facilitates both handling and reagent costs significantly .
Nature evolved UPOs to withstand harsh environmental conditions . This innate stability makes them ideally suitable as biocatalysts even for water-insoluble compounds , because they can resist organic solvents typically up to 20 % v / v .
As well as targeted hydroxylation , UPOs are also able to form ketones and even carboxylic acids , oxidise heteroatoms and demethylate . Recent scientific breakthroughs in the production of UPOs ensure kg-scale supply to facilitate the manufacturing of oxyfunctionalised products at tonne scale .
Fe ( II )/ α-ketoglutarate dependent oxygenases ( KGOs ) have been evolved by nature to act on metabolic compounds . As such , these biocatalysts have an inherent affinity for amino acids , nucleosides and DNA , antibiotics , alkaloids and terpenes ( Figure 2 ).
KGOs primarily catalyse siteselective C-H hydroxylation reactions , but they are also able to catalyse demethylations , ring formations , rearrangements and even halogenations using chlorine , bromine and iodine . They have already been scaled to tonne-scale biocatalytic processes .
KGOs are particularly robust biocatalysts , because they do not rely on a heme-cofactor or complex domains as , for instance , in P450 monoxygenases . Unlike UPOs , however , KGOs are not suited for low-margin products , as they require ketoglutarate as a sacrificial cofactor , which needs to be considered in each business case .
UPO-catalysed reaction
A study by Heckmann et al affords some insights into how UPOs can
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