Loracarbef

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Cat Number

API0231506

CAS Number

76470-66-1

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Product Detail Description Scientific Support Customer Q&A

CAS Number

76470-66-1

Storage

Store at 2-8℃

Synonyms

Lorabid; Loracarbefum; loracarbef anhydrous; Anhydrous loracarbef; Lorbef; LORACARBEF, ANHYDROUS; KT-3777; W72I5ZT78Z

Molecular Formula

C16H16ClN3O4

Molecular Weight

349.77

Smiles

C1CC(=C(N2[C@H]1[C@@H](C2=O)NC(=O)[C@@H](C3=CC=CC=C3)N)C(=O)O)Cl

Boiling Point

662.2℃

General Description

Loracarbef is a synthetic carbacephem antibiotic, structurally analogous to cephalosporins but with a carbon atom replacing the sulfur in the dihydrothiazine ring. This structural modification confers enhanced chemical stability and a pharmacokinetic profile suitable for oral administration. It is classified as a second-generation beta-lactam agent with activity similar to cefaclor.

Mechanism of Action

Similar to other beta-lactams, loracarbef exerts bactericidal activity by binding to penicillin-binding proteins (PBPs) located on the bacterial cell membrane. This binding inhibits the final transpeptidation step of peptidoglycan synthesis, disrupting cell wall formation. The resulting cell wall instability leads to bacterial lysis, particularly in actively dividing organisms.

Application

It was indicated for the treatment of mild to moderate upper respiratory tract infections, including acute otitis media, pharyngitis, and sinusitis, as well as uncomplicated urinary tract infections and skin infections. While effective, its use has largely declined following the introduction of broader-spectrum, more cost-effective generic alternatives. It remains a representative agent of the carbacephem class.

This structure‑function analysis examined the role of isoleucine at position 35 in the carbapenem‑resistance enzyme NDM‑1 metallo‑β‑lactamase. Laboratory mutants replacing I35 with threonine (I35T) or serine (I35S) were generated and kinetically characterized. Although overall catalytic parameters changed modestly, the I35S mutant showed roughly 14‑fold higher catalytic efficiency (kcat/Km) toward the carbacephem loracarbef than wild‑type NDM‑1. Circular dichroism spectroscopy revealed local structural rearrangements with a marked drop in α‑helix content in both mutants. Thus, position 35 influences substrate specificity and secondary structure, contributing to understanding NDM‑1’s catalytic mechanism and potential for resistance evolution.

Fig. 1 Molecular modeling of the NDM-1 in complex with hydrolyzed loracarbef. (Marcoccia F, et al., 2016)

References

Marcoccia F, et al. Kinetic Study of Laboratory Mutants of NDM-1 Metallo-β-Lactamase and the Importance of an Isoleucine at Position 35. Antimicrob Agents Chemother. 2016; 60(4):2366-2372.

Does Loracarbef require refrigerated storage as a carbacephem antibiotic?

Yes, it must be stored at 2-8°C. The carbacephem core is susceptible to hydrolysis at room temperature, leading to rapid loss of potency.

Is Loracarbef sensitive to moisture during handling and storage?

Absolutely. It is highly hygroscopic and readily absorbs moisture, which triggers beta-lactam ring opening.

What visual changes indicate degradation of Loracarbef?

Degradation may manifest as yellowing of the powder or clumping due to moisture absorption. If observed, the material should be tested for potency before use.

How is the impurity profile of Loracarbef monitored for parenteral-grade quality?

We use a stability-indicating HPLC method to monitor for related compounds, including degradation products formed via hydrolysis of the beta-lactam ring.