Clavam

Clavams are a class of β-lactam antibiotics.^[1] These antibiotics are derived from Streptomyces clavuligerus NRRL 3585.^[1] This class is divided into the clavulanic acid class and the 5S clavams class. Both groups are the outcomes of the fermentation process produced by Streptomyces spp.^[2] Clavulanic acid is a broad-spectrum antibiotic and 5S clavams may have anti-fungal properties. They are similar to penams, but with an oxygen substituted for the sulfur.^[3] Thus, they are also known as oxapenams.

An example is clavulanic acid,^[4] from which this compound class receives its name.

Clavulanic acid, a type of clavam, has antibiotic properties. It can be used as a medication to treat a variety of bacterial infections. Clavam tablets may be effective for short-term treatment of bronchitis, cystitis, sinusitis, otitis media, or skin infections.^[5][6] Clavams are commonly used in conjunction with other antibiotics such as amoxicillin to produce a broader therapeutic effect. "One of the most valuable multipurpose and incredible trade of antibiotics is the β-lactams group.^[7]

Clavulanic acid strongly inhibits β-lactamase in bacteria, which is associated with its antibiotic properties. β-Lactam antibiotics generally have a common feature which is the 3-carbon and 1-nitrogen ring (β-lactam ring) that is highly reactive.^[8] Different molecules of the Clavam class have been shown to inhibit the action of several fungal species. 5S clavams do not have an inhibitory effect on β-lactamase, but are involved in methionine biosynthesis inhibition, making them bacteriostatic agents.^[9] Additionally, 5S Clavams may have inhibitory effects on RNA synthesis, which is a common property of anti-fungal medications.^[10] Clavams have wide-ranging bioactivity, and may have greater therapeutic use than current research indicates.^[11] Because of their activity on β-lactamase, this class of antibiotics can evade antibiotic resistance in bacteria, which is a risk associated with other antibiotics such as penicillins.

In S. Clavuligerus infection, a Streptomyces antibiotic regulatory protein known as cephamycin and clavulanic acid regulator (CcaR) is encoded into the cephamycin gene cluster. This is essential for the cephamycin C and clavulanic acid, but not the 5S claims. CcaR is important for the expression of polycistronic transcripts, which are early genes for clavulanic acid biosynthesis. This is also a key factor for activating its own transcription by binding to its own promoting region.^[12]