Benzyl Penicillanate 1,1-Dioxide-d5 is a deuterated form of its unlabeled, cas# 69388-78-9, which is reported as human leukocyte elastase (HLE) inhibitors;Also, it is an intermediate used in the synthesis of Sulbactam-d5 Sodium Salt (Major), which is a labeled Sulbactam (S699185), a semi-synthetic β-lactamase inhibitor. It is used in combination with β-lactam antibiotics as antibacterial.