Glenthmycin L is a member of the C-20 nortetromycin family of spirotetronate polyketides reported by Khalil and co-workers, University of Queensland, Australia in 2022. Structurally, glenthmycin L is the desmethyl analogue of tetromycin A reported by Tomio and colleagues at Microbial Chemical Research Foundation (Institute of Microbial Chemistry, Japan) in 1996. Glenthmycin L is a potent antibacterial with activity against Gram-positive antibiotic-susceptible and -resistant strains of S. aureus and E. faecalis.