This topic studies the structural characteristics and functions of antibacterial drugs. Clavulanic acid is a β -lactam antibiotic of penicillamine. Clavulanic acid is composed of β -lactam ring and hydrogenated isoxazole ring, and its tension is much greater than that of penicillin. Therefore, it is easy to accept the attack of nucleophilic groups (such as hydroxyl and amino) in β -lactamase and carry out irreversible alkylation to completely inactivate β -lactamase So clavulanic acid is a "suicidal" enzyme inhibitor. The clinical application of the compound preparation composed of clavulanic acid and amoxicillin can improve the curative effect of amoxicillin by 65438 0.30 times, and can be used to treat the infection caused by amoxicillin-resistant bacteria. Clavulanic acid can also be combined with other β -lactam antibiotics, which can improve the curative effect of cephalosporins by 2~8 times. Clavulanic acid alone has no antibacterial effect, so option C is wrong and the answer is C.