You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
Give me a molecule that satisfies the conditions outlined in the description: The molecule is a proteasome inhibitor.
user
O=C(NC1CCCC1)C1CCCCOc2cccc(c2)CC(N2CCCC2=O)C(=O)NC(CCN2CCOCC2)C(=O)N1
assistant