Potential application of native lipases in the resolution of (RS) - phenylethylamine

The performance of two native lipases (lipase from Aspergillus niger and Rhizoupus oligosporus) in the resolution of (RS)-phenylethylamine (1), varying the temperature, acyl donor type (ethyl acetate, vinyl acetate, iso-propenyl acetate and acetic anhydride) and organic medium, was studied. The effect of the nature of the anion using native A. niger lipase in n-heptane with a series of imidazolium-based ILs [BMIm][X], where X = BF4, PF6, SCN and Cl, was also evaluated. Using the lipase from A. niger, the R-2b amide was obtained with conversions from 6 to > 99% and E-values from 2 to > 200, with n-heptane or n-hexane. This lipase showed better E-values in a two-phase system using n-heptane and [BMIm][PF6] or [BMIm][BF4] 9: 1 (v/v), obtaining values of 9 and 7, respectively, when vinyl acetate was used as the acyl donor, compared to the use of pure n-heptane (E = 2). The series for the anions in terms of decreasing performance was as follows: PF6->BF4->SCN->Cl-.