L-proline ethyl ester monohydrochloride, (S)-ethyl pyrrolidine-2-carboxylate hydrochloride, ethyl (2S)-2-pyrrolidinecarboxylate hydrochloride, L-proline ethyl ester hydrochloride, L-Pro-OEt*HCl, Ethyl L-prolinate hydrochloride, (S)-proline ethyl ester hydrochloride, Ethyl L-prolinate HCl