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DIFFERENT CLASSES OF ANTIBIOTICS - AN OVERVIEW
BY NC ND
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1930 1940 1970 1980
ß-LACTAMS
N
H
O
R
OS
OOH
AMINOGLYCOSIDES chloramphenicol glycopeptides ansamycins streptogramins
sulfonamides tetracyclines macrolides quinolones lipopeptides
EXAMPLES Penicillins (shown) such as
amoxicillin and flucloxacillin;Cephalosporins such as cefalexin.
MODE OF ACTIONInhibit bacteria cell wall biosynthesis.
S
O
O
NH2NH
H
All contain a beta-lactam ring
MOST WIDELY USED ANTIBIOTICSIN THE NHS
EXAMPLES Prontosil, sulfanilamide (shown),
sulfadiazine, sulfisoxazole.
MODE OF ACTIONDo not kill bacteria but prevent their
growth and multiplication. Cause allergic reactions in some patients.
All contain the sulfonamide group
FIRST COMMERCIAL ANTIBIOTICS WERE SULFONAMIDES
EXAMPLES Streptomycin (shown), neomycin,
kanamycin, paromomycin.
MODE OF ACTIONInhibit the synthesis of proteins by
bacteria, leading to cell death.
All contain aminosugar substructures
FAMILY OF OVER 20 ANTIBIOTICS
O
OOOHO
HO
OH
OH
N
N
HO
HO
HN
HO
H2N NH2
NH2
NH2
O
EXAMPLES Tetracycline (shown), doxycycline,
limecycline, oxytetracycline.
MODE OF ACTIONInhibit synthesis of proteins by
bacteria, preventing growth.
All contain 4 adjacent cyclic hydrocarbon rings
BECOMING LESS POPULAR DUE TO DEVELOPMENT OF RESISTANCE
O O
NH2
O
OH
OHOH
HO N
OH
COMMONLY USED IN LOW INCOME COUNTRIES
MODE OF ACTIONInhibit synthesis of proteins,
preventing growth.
No longer a first line drug in any developed nation due to increased
resistance and worries about safety.
Distinct individual compound
OH
NH
Cl
Cl
ON+
O-
O
OH
EXAMPLES Erythromycin (shown),
clarithromycin, azithromycin.
MODE OF ACTIONInhibit protein synthesis by bacteria,
occasionally leading to cell death.
All contain a 14-, 15-, or 16-membered macrolide ring
SECOND MOST PRESCRIBED ANTIBIOTICS IN THE NHS
O
O
OHHO
CH3
OH
C2H5
O
O
O
O OH
OCH3
OHO
N
CH3
COMMON ‘DRUGS OF LAST RESORT’
Consist of carbohydrate linked to a peptide formed of amino acids
EXAMPLES Vancomycin (shown), teicoplanin.
MODE OF ACTIONInhibit bacteria cell wall biosynthesis.
NH
O
O
Cl
HN
O
O
NH
O
HN
O
O
NH
NH
O
HNH2N
O
OHOHHO
O
HO
HO
ClOO
O
OOH
NH2
OH
HO
HO
OH
EXAMPLES Linezolid (shown), posizolid,
tedizolid, cycloserine.
MODE OF ACTIONInhibit synthesis of proteins by
bacteria, preventing growth.
All contain 2-oxazolidone somewhere in their structure
POTENT ANTIBIOTICS COMMONLY USED AS ‘DRUGS OF LAST RESORT’
O
HN
ON
O
N O
F
EXAMPLES Geldanamycin (shown), rifamycin,
naphthomycin.
MODE OF ACTIONInhibit the synthesis of RNA by bacteria, leading to cell death.
All contain an aromatic ring bridged by an aliphatic chain.
CAN ALSO DEMONSTRATE ANTIVIRAL ACTIVITY
NH2O
OHN
OOO
H3CO
OCH3
H3CO
OH
EXAMPLES Ciprofloxacin (shown), levofloxacin,
trovafloxacin.
MODE OF ACTIONInterfere with bacteria DNA
replication and transcription.
All contain fused aromatic rings with a carboxylic acid group attached
RESISTANCE EVOLVES RAPIDLY
1960
HN
N N
F
O O
OH
EXAMPLES Pristinamycin IIA (shown),
Pristinamycin IA.
MODE OF ACTIONInhibit the synthesis of proteins by
bacteria, leading to cell death.
Combination of two structurally differing compounds, from groups denoted A & B
TWO GROUPS OF ANTIBIOTICS THAT ACT SYNERGISTICALLY
N
O
NH
O
NOO
O
O
OH
EXAMPLES Daptomycin (shown), surfactin.
MODE OF ACTIONDisrupt multiple cell membrane functions, leading to cell death.
All contain a lipid bonded to a peptide
INSTANCES OF RESISTANCE RARE
O
OHO
HN
O
NH
NH
C9H19
O
HN
NH2
O
NH
O
O
NH
HN
HN
NH
HN
NH
NH
NH
HN O
O
O
O
O
O
O
OOO
OH
O
OH
OHO
O
OH
H2N
O
NH2
Key: COMMONLY ACT AS BACTERIOSTATIC AGENTS, RESTRICTING GROWTH & REPRODUCTION COMMONLY ACT AS BACTERICIDAL AGENTS, CAUSING BACTERIAL CELL DEATH
1950
oxazolidinones
DISCOVERY