(3-hydroxy-4-methoxybenzyl)-L-proline

(2-hydroxy-3-methoxybenzyl)-L-proline

(4-hydroxy-2-methoxybenzyl)-L-proline

(2-nitrobenzyl)-L-proline

(4-nitrobenzyl)-L-proline

(4-ethoxybenzyl)-L-proline

(4-hydroxy-3,5-dimethylbenzyl)-L-proline

(4-carboxybenzyl)-L-proline

((2,3-dihydrobenzofuran-5-yl)methyl)-L-proline

((5-chlorothiophen-2-yl)methyl)-L-proline

((1H-pyrrolo[2,3-b]pyridin-3-yl)methyl)-L-proline

(2-chlorobenzyl)-L-proline

(4-chlorobenzyl)-L-proline

(3-chlorobenzyl)-L-proline

(4-fluoro-3-methylbenzyl)-L-proline

cinnamyl-L-proline