Cephalexin hydrate

Cephalexin is a first generation cephalosporin antibiotic most effective against gram-positive cocci. However, it also exhibits efficacy against some gram-negative bacilli. In addition, cephalexin has been used to study the penicillin binding proteins, especially PBP3. Cephalexin hydrate is slightly soluble in aqueous solution.

Cephalosporins are a type of β-lactam antibiotic consisting of a four-membered β-lactam ring bound to a six-membered dihydrothiazine ring. This two-ring system causes distortion of the β-lactam amide bond, resulting in decreased resonance stabilization and increased reactivity. β-lactams inhibit the formation of peptidoglycan cross-links within bacterial cell walls by targeting penicillin-binding proteins or PBPs. Consequently, the bacterial cell wall becomes weak and cytolysis occurs. Cephalosporins are less susceptible to β-lactamases than the penicillin β-lactam antibiotics.

Antibiotics are often used in clinical in vitro tests known as antimicrobial susceptibility tests or ASTs to determine their efficacy against certain bacterial species. They are tested against gram-negative and gram-positive bacteria using panels, discs, and MIC strips by medical microbiologists. ASTs decrease the risk of using an antibiotic against bacteria exhibiting resistance to it, and the results are used in clinical settings to determine which antibiotic(s) to prescribe for various infections.

Product Specifications
Cephalexin hydrate

Formula: C₁₆H₁₇N₃O₄S · H₂O

MW: 365.40 g/mol

Storage/Handling: Store at 4°C.

PubChem Chemical ID: 27447