Antibacterial chemoterapeutics 2 1.β-lactame antibiotics 1.1Penicillins 1.2 Cephalosporins 2. Macrolide antibiotics 3.(Poly)peptide antibiotics 4. Aminoglycoside antibiotics ©assoc. prof. PharmDr. Oldřich Farsa, Ph.D. 2012 β-lactame antibiotics Lactams = internal amides of amino acids OH O NH2 N H O N H O NH ON H O t + H2O αβ α α β β β α γ γ γ δ δ ε ε α β γ δ 6-aminohexanoic acid ε-aminocaproic acid azepan-2-on ε-caprolactam 6-hexanlactam piperidin-2-on δ-valerolactam 5-pentanlactam pyrrolidin-2-on γ-butyrolactam 4-butanlactam azetidin-2-on β-propiolactam 3-propanlactam β-lactame antibiotics N S O N H CH3 CH3 OH O H H H R O N S O N H O OH HH O CH3 O R O Penicillins N-acyl-6-aminopenicillanic acids Cephalosporins N-acyl-7-aminocephalosporanic acids Mechanism of action • inhibition of cell wall synthesis by binding to specific proteins Penicilins History World 1928(9) – Alexander Fleming – isolated a liquid concentrate inhibiting growth of bacteria from a mould of Penicillium species 1939 - 1943 Fleming, Florey, Chain & Johnson – isolation and constitution of penicillins 1945-Nobel prize for Fleming, Florey and Chain Czech territory 1943 – Málek, Fragner, Herold, Hais etc. – Mykoin BF 510 Penicillins The initial „amorphous penicillin“ was a mixture of several compounds: N S O N H CH3 CH3 OH O R O H H H CH3 C H2 C H2 C H C H C H2 C H2 OH CH3 C H2 C H2 C H2 C H2 C H2 CH3 C H2 C H2 C H2 C H2 R Penicillin pentenyl- F benzyl- G p-hydroxybenzyl- X heptyl- K amyl- dihydro-F Penicillins Benzylpenicillin and its problems N S O N H CH3 CH3 OH O O H H H benzylpenicillin syn. penilcilin G • production of benzylpenicillin by the mould ↑ by addition of phenylacetic acid into its broth Problems: • weak binding to plasmatic proteins ⇒ fast excretion ⇒ frequent administration is necessary • instability in acid media of stomach (see reaction scheme) ⇒ impossibility of p.o. application N S O N H CH3 CH3 OH O O H H H H + NH S CH3 CH3 OH O H H N OO S CH3 CH3 OH O H H N N OOH benzylpenicillin penillic acid Penicillins Benzylpenicillin and its problems 3. Sensitivity to penicillinases (β-lactamases – enzymes catalysing hydrolytic cleavage of the β-lactame ring ) – see the scheme N S O N H CH3 CH3 OH O O H H H NH S O N H CH3 CH3 OH O O H H H OH β − lactamase H2O benzylpenicillinic acid 4. Rel. narrow spectrum – only G+ strains (Streptococcus, Staphylococcus, Clostridium, Neisseria, Corynebacteriun, Bacilus anthracis …) 5. Inducing allergies – anaphylactic shock – caused by 6-aminopenicillanic acid as the impurity – resolved by better purification (chromatography) Penicillins Resolving of benzylpenicillin problems Ad 1. (necessity of frequent application) – poorly soluble salts with organic bases N S O N H CH3 CH3 O OO H H H N S O N H CH3 CH3 O OO H H H NH2 + NH2 + N S O N H CH3 CH3 O OO H H H CH3 N + CH3 O NH2 O benzathine benzylpenicillin Pendepon® inj. sic. procaine benzylpenicillin Prokain Penicilin G® Biotika inj. sic. •depot (= long acting) forms for i.m. injections Penicillins Resolving of benzylpenicillin problems Ad 2. – ↑ of stability in acid media N S O N H CH3 CH3 OH O O O H H H phenoxymethylpenicillin syn. penicillin V • acquired by addition of phenoxyacetic acid into the broth of the production strain • suitable for p.o. administration V-Penicilin® , Ospen® Penicillins Overall resolving of benzylpenicililn problems – semi-synthetic penicillins •penicillinamidase (penicillinacylase) – hydrolyzes acyclic amide bond, not βlactame ring •used a microbe which produces it (e.g. E. coli) N S O N H CH3 CH3 OH O O H H H N S O NH2 CH3 CH3 OH O H H H O OH N S O NH2 CH3 CH3 OH O H H H R Cl O R O R O O N S O N H CH3 CH3 OH O H H H R O penicillinamidase (H2O) + 6-aminopenicillanic acid phenylacetic acid a semi-synthetic penicillin Penicillins Mostly semi-synthetic penicillins stable in acid media •stability against acids is increased by electron-donor substituents in N-acyl side chain (I+ or M+ efekt) N S O N H CH3 CH3 OH O O H H H NH2 N S O N H CH3 CH3 OH O O O H H HR ampicillin Ampicilin ® cps., inj sic. R = -H phenoxymethylpenicillin V-Penicilin® tbl., Ospen tbl. obd. R = -CH3 phenethicillin R = -CH2CH3 propicillin Penicillins Semi-synthetic penicillins resistant to β-lactamases •formed by acylation of amino group of 6-aminopenicillanic acid with bulky acyl rest; the lactame ring is then sterically hindered (⇒ protected) O CH3 O CH3 N S O N H CH3 CH3 OH O O H H H N S O N H CH3 CH3 OH O O H H H O N CH3 R 1R 2 meticillin R1 = R2 = -H oxacillin Prostaphlin® cps., inj. sic. R1 = -Cl, R2 = -H cloxacillin R1 = R2 = -Cl dicloxacillin R1 = -Cl, R2 = -F flucloxacillin syn. floxacillin [USAN] ●resistant also to acid media; the resistance increases oxacillin < cloxacillin < dicloxacillin = flucloxacillin Penicillins An alternative approach to ↑ of resistance to β-lactamases: β-lactamases inhibitors ● compounds with β-lactam ring which binds to the enzyme active site with greater affinity and block this site ●used in combination with penicillins N O O OH O OH H N S O O O CH3 CH3 OH O H N S O O O CH3 OH O H N N N clavulanic acid ●isolated from Streptomyces clavuligerus + amoxicillin (= Amoxiklav® , Augmentin® ) + ticarcillin (= Timentin® inj. sic.) 4,4-dioxopenicillanic acid sulbactam Betrion® + ampicillin (= Ampisucillin® inj. plv. sol.) tazobactam + piperacillin (= Tazocin® inj. sic.) Penicillins A combination of a penicilline with a β-lactamase inhibitor in one molecule N S O NH CH3 CH3 O O O O NH2 O N S CH3 CH3 O O O •a mixed ester of ampicillin and sulbactam with methanediol •a prodrug of both components sultamicillin Bitamon® inj. sic., Unasyn® tbl. obd. Penicillins Penicillins with broadened spectrum Ad 4. – introduction of a hydrophilic substituent to α-position of the acyl attached to amino group of 6-aminopenicillanic acid ⇒ broadening of the antibacterial spectrum of penicillins also to G- strains Compouns with free primary amino group N S O N H CH3 CH3 OH O O H H HNH2 R N S O N H CH3 CH3 OH O O H H HNH2 R = -H ampicillin R= -OH amoxycillin Amoclen® , Amopen® epicillin Penicillins with broadened spectrum Ampicillin prodrugs H NH O H NH2 H S H N O H CH3 O O CH3 O O CH3 CH3 O H NH O H NH2 H S H N O H O CH3 O O CH3 CH3 O H CH3 CH3 bacampicillin ampicillin 1- (ethoxycarbonyloxy)ethylester pivampicillin ampicillin pivaloyloxymethylester •successful in acute exacerbations of chronic bronchitis •hydrolyzed in vivo to ampicillin •achieve significantly higher blood and tissue levels and attains peak blood levels more rapidly than equimolar doses of oral ampicillin •more frequently used in veterinary (horses) than in human medicine •models for design of prodrugs of cephalosporins Penicillins with broadened spectrum: ureidopenicillins Compounds in which the amino group in α-position of the acyl is a part of urea moiety = ureidopenicillins = „anti-pseudomonas“ penicillins ●their spectrum includes Pseudomonas aeruginosa N S N H O CH3 CH3 OH O O N H N O O N O CH3 HH N S N H O CH3 CH3 OH O O N H N O N O HH R piperacillin Tazocin ® inj. plv. sol.(+ tazobactam) R = H- azlocillin R= CH3SO2- mezlocillin •serious infections including otitis media, CNS infections … Penicillins with broadened spectrum: •compounds with the additional carboxyl in α-position of the acyl attached to amino group in position 6 •in fact substituted malonic acids monoamides N S O N H CH3 CH3 OH O O H H HO OH N S O N H CH3 CH3 OH O O H H HO OH S carbenicillin ticarcillin Timentin® inj. sic. (+ clavulanic acid) •infections of bones and junctures (Staphylococcus aureus ), gynecological & abdominal infections … •ring analogy (benzene – thiophene) Cephalosporins • fungi Cephalosporium spp. (1948) H CH3 CH3 CH3 CH3 CH3 O OH OHOH O O CH3 O O CH3 CH3 H H S N N H O OH O H O NH2 OH O H O CH3 O N S O OHO CH3 CH3 HH N H O OH ONH2 cephalosporin P1 cephalosporin C cephalosporin N … and other various structures Cephalosporins General structure S N N H O OH O H O NH2 OH O H O CH3 O N SN H O O O O O NH2 OH CH3 O NH2 OH O S N N H R 3 OH O R 8 O H O R 7 1 2 3 45 6 7 8 cephalosporin C •isolated from Cephalosporium spp. cephamycin C •isolated from Streptomyces lactadurans S N N H R 3 OH O R 8 O H O R 7 S N N H R 3 OH O R 8 O H O R 7 Cephalosporins Properties ● electron pair on N5 is linked to conjugation with double bond ⇒ ↓ of electron density on N5 ⇒ ↓ of nucleophilicity of N5 ⇒ stability in acid media ● also ↑ resistance to β-lactamases (cefalosporinases) Cephalosporins Compounds related to cephalosporin C, i.e. N-acylderivatives of 7aminocephalosporanic acid. S N N H O OH O H O NH2 OH O H O CH3 O S N NH2 O OH O H H O CH3 O S N NH2 O OH O H H O CH3 O R Cl O S N N H O OH O H H O CH3 O R O NOCl or enzymes* cephalosporin C 7-aminocefalosporanic acid a semi-synthetic cephalosporin, or an intermediate * glutarylacylase + D-amino acid oxidase Cephalosporins Compounds related to cephalosporin C, i.e. N-acylderivatives of 7aminocephalosporanic acid 1st generation: for parenteral administration only (not absorbed from GIT) S S N OH O CH3 O O HH O N H O N S O N H O O N + OS HH cephalotin Cefalotin® Biotika inj. sic. cefaloridin Cephalosporins Compounds related to cephalosporin C, i.e. N-acylderivatives of 7aminocephalosporanic acid 2nd generation: for oral administration S N O R 2 O N H OH H O NH2 R 1 R1 = -H, R2 = -CH3 cefalexin Cefaclen® cps. R1 = -OH, R2 = -CH3 cefadroxil Biodroxil® tbl. obd. R1 = -H, R2 =Cl cefaklor Ceclor® cps. Cephalosporins Compounds related to cephalosporin C, i.e. N-acylderivatives of 7aminocephalosporanic acid 2nd generation: for parenteral use but with ↑ effect to G, ↑ resistance to β-lactamases N S O N H S O N S N N N N N CH3 HH OHO N S O N H O OH N + O HH S O O O NH2 O cefazolin Kefzol® inj. sic. cefsulodin •Pseudomonas Cephalosporins Compounds related to cephalosporin C, i.e. N-acylderivatives of 7aminocephalosporanic acid 2nd generation: for both parenteral and p.o. administration, very resistant to β- lactamase N S O N H OH O S O OH N N N CH3 N HH O S N O O NH2 O O HH O N H O N O CH3 Rcefamandole R = H- cefuroxime Ceroxim® tbl. R = cefuroxime axetil Zinnat® tbl. obd. CH3 CH O CH3 O Cephalosporins Compounds related to cephalosporin C, i.e. N-acylderivatives of 7aminocephalosporanic acid 3rd generation: for both parenteral and p.o. administration, very resistant to β- lactamase cefpodoxime proxetil Orelox® tbl. obd. N S O N H OOH O O N CH3 O N O S CH3 NH2 H H N S O N H OO O O CH3 N N O S CH3 NH2 R OCH3 O O CH3 CH3 cefotaxime Claforan® inj. sic. R = H- cefpodoxime R = Cephalosporins Compounds related to cephamycin C, i.e. N-acylderivatives of 7-methoxy-7aminocephalosporanic acid „New class = 4th generation“ – for both parenteral and p.o administration – resistant to β-lactamase NH O N S O CH3 O OH O O S NH2 O H S N OOH S N N N N O O CH3 NH O H S CH3 NH2 OH O cefoxitin Mefoxin® inj. sic. cefminox Cephalosporin analogues N H O N O O CH3O OH O OH O S N N OH N CH3 N H moxalactam ● dihydrooxazine derivative related to 4th generation of cephalosporins ●developed especially for treatment of meningitis (crosses the blood-brain barrier) and anaerobic infections Macrolides •makrocyclic lactones with 10 – 40membered ring with 1 aminomonosaccharide and 1 „neutral“ monosacharide which can have an additional aminosaccharide attached •1st group (with larger ring)- natamycine, nystatine, amphothericine B – see antimycotics •2nd group – erythromycine group (erythromycine and its analogues, spiramycine, tylosine) O CH3 CH3 O O O CH3 OH R 4 O O O N CH3 CH3 CH3 CH3 O CH3 CH3 OH OH CH3 CH3 R 1 CH3 z R 2 R 3 desosamine kladinose R1 = -OH, -H Z = 〉C=O, −CH2 N(CH3)-,〉C=N-O-CH3, 〉C=NOCH2OCH2CH2OCH3 R2 = -H, -F R3 = -H, -CH3 R4 = -CH3 or R2 + R4 = oxirane Common structure of narrower group of erythromycine (14 -15membered lakctone ring - erythromycine and analogues) Macrolides Site & mechanism of action Macrolides Site and mechanism of action •Proteosynthesis inhibition •act at 50S ribosome subunit •inhibit the translocation of growing peptide from acceptor (A) to peptide (P) site •bacteriostatic effect Spectrum: •both G+ and GNeisseria, Haemophillus, Brahmanella, Legionella … Macrolides Erythromycine and its analogues O CH3 CH3 OH O O CH3 OH CH3 O O O N CH3 O CH3 CH3 CH3 O CH3 CH3 OH OH CH3 CH3 OH CH3 OCH3 CH3 OH O O CH3 OH CH3 O O O N CH3 N CH3 CH3 CH3 O CH3 CH3 CH3 OH CH3 CH3 OH CH3 OH erythromycine •isolated 1952 from Streptomyces erythreus •poor biological availability ⇒ lipophilic salts (stearate, ethylsuccinate …) •external form (lotions …) – treatment of acne vulgaris Porphyrocin® tbl. azithromycine ●semi-synthetic compound Sumamed® tbl. obd. Macrolides Synthesis of azithromycine from erythromycine CH3 OH CH3 O CH3 OH CH3 OH CH3 OH CH3 N CH3 OH CH3 OH OH CH3 S O O Cl CH3 OH CH3 N CH3 OH CH3 OH O S O O CH3 CH3 OH CH3 OH N H CH3 OH CH3 O S O O CH3 CH3 OH CH3 OH N C + CH3 OH CH3 CH3 S O O O CH3 OH CH3 OH N CH3 OH CH3 O + H H CH3 OH CH3 OH N CH3 OH CH3 OH CH3 S O O Cl O CH3 NCH3 OH OH OH CH3 CH3 OH CH3 OH N H CH3 OH CH3 CH3 OH CH3 OH N CH3 OH CH3 CH3 NH2OH - H2O - H+ - H2O NaBH4 HCOH HCOOH Macrolides Erythromycine and its analogues O O CH3 CH3 CH3 O O CH3 CH3 OH O O O O N CH3 CH3 CH3 CH3OH O CH3 CH3 CH3 OH OH CH3 CH3 O CH3 CH3 O O O O CH3 OH O O CH3 CH3 OH CH3 OH CH3 CH3 OH CH3 N CH3 N OH CH3 CH3 CH3 O O O CH3 6-O-methylerythromycine clarithromycine •also some strains of Mycobacterium avium Klacid® tbl. obd. roxithromycine Rulid® tbl. Macrolides Erythromycine and its analogues O OH O CH3 H O O O CH3 CH3 CH3 CH3 CH3 CH3 F OH OHOH CH3 O O H OH CH3 N CH3 CH3 O CH3 CH3 O NOH CH3 CH3 CH3 O O O OH CH3 CH3 CH3 O O N H O O OH OH CH3 CH3 CH3 CH3 CH3 CH3 O O CH3 CH3 H H H H 8-fluoroerythromycine flurithromycine dirithromycin Macrolides Erythromycine and its analogues O O CH3 CH3 O OH CH3 CH3 O O OCH3 CH3 OH O O N CH3 CH3 CH3 O CH3 OH CH3 O CH3 CH3 O O O O CH3 OH O O CH3 CH3 OH CH3 OH CH3 CH3 OH CH3 N CH3 N OH CH3 CH3 CH3 O CH3 oleandomycine •isolated 1954 from Streptomyces antibioticus lexithromycine L-oleandrose O N N O O O N O N O O O N OHCH3 O CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 H telithromycine Ketek® tbl. „More free“ erythromycine analogues: Ketolides •2 keto-moieties on lactone ring (+ 1 ester carbonyl + 1 cabamate carbonyl) •good biological availability Macrolides Compounds with 16membered lactone ring unsaturated in positions 10 and 12 O H CH3 N CH3 CH3 OCH3 O O O CH3 O O OH N CH3 CH3 CH3 O O H OH CH3 OHCH3 CH3 O O H R O O O CH3 O CH3 O OHO O CH3 O OH N CH3 O CH3 CH3CH3 O CH3 OH CH3 O O CH3 CH3 spiramycine (syn. rovamycin) •isolated 1954 from Streptomyces ambofaciens R = HCO- spiramycine A = spiramycine I CH3CO- spiramycine B = spiramycine II CH3CH2CO- spiramycine C = spiramycine III Rovamycine® tbl. obd. josamycin •also Mycoplasma Wilprafen® tbl. obd., Alpucine® premix a.u.v. O CH3 O O CH3 O CH3 O CH3 O O O CH3 NOH CH3 CH3 O O OHCH3 O CH3 CH3 OH O O O O CH3 O CH3 O OHO O O O N CH3 CH3 O CH3 CH3 CH3 CH3 O O O CH3 CH3 O CH3 O O CH3 Macrolides Compounds with 16membered lactone ring unsaturated in positions 11 and 13 rokitamycin miokamycin (Poly)peptide antibiotics •site of action: cytoplasmic membrane •mode of action: ionophores: cause uncontrolled exchange of ions between inside and outside media of a bacterial cell and thus ionic imbalance and cell death •very toxic, external application •totally known approx. 200 ATB of polypeptid structure •homomeric peptides: contain amino acids only (often D-) •heteromeric peptides: except amino acids also other carboxylic acids •if they are cyclic, then homodets and heterodets Tyrothricin •mixture from Brevibacillus brevis H N O H NH O H CH3 CH3 NH O H NH2 NH O H NH OH OH NHH OH O O NH HNH2 O O H NH O H NH O CH3 CH3 N H N H NH OO NH N HO CH3 CH3 CH3 CH3 ON H N H O CH3 CH3 O N H NH N HO CH3 CH3 CH3 CH3 ON H CH3 N H O O N H NH N HO CH3 CH3 O CH3 CH3 N H CH3 N H O O N H N H OH O N H CH3 CH3 O H H H H H H H H H H H H H H tyrocidin A tyrocidins A – E total 80% decapeptides gramicidin A1 20 % of gramicidines A1, A2, C1 and C2 pentadecapeptides Polymyxins and colistins N O N ON N O N O H N O N N O N N O O N O N N O N O N N O O H HH H H H H H H H H H H H H H H H H H H H H CH3 D-Phe polymyxin B colistin A: D-Leu instead D-Phe Bacitracin N S NH2 CH3 Leu O CH3 Glu IleLys Asn O Asp NH His Ile Phe NH2 L-Cys L-Ile bacitracin A Framykoin® ung., Pamycon® plv. (+ neomycin B) Aminoglycosides ➔ aminosaccharide glycosides produced by strains of Streptomyces genus • Streptomycin group • Neomycin group • Kanamycin and gentamycin group Mechanism of action • protheosynthesis inhibition • they avoid accurate reading of the genetic code and binding of peptidyltRNA to the peptide binding site • effect bacteriostatic – bactericidal Spectrum G+ < GBacillus anthracis, Bordetella pertussis, Brucella, Corynebacterium diphteriae, E. coli, Enterobacter, Haemophillus, Mycobacterium tuberculosis… Aminoglycosides 1. Streptomycin group O O O OH O NH N H OH OH CH3 OH OH OH OH N H NH2 NH NH2 NH CH3 R R = -CHO streptomycin •isolated 1944 from Streptomyces fradiae •used to M. tuberculosis in combination with other tuberculostatics •bactericidal Streptomycin „Grünenthal“® inj. sic., Streptowerfft® a.u.v R = -CH2OH dihydrostreptomycin Depomycine® a.u.v. inj. (+ benzylpenicillin) streptidine = aglycone N-methyl-L-glucosamine furanose (streptose or dihydrostreptose) Aminoglycosides 2. Neomycin group O OH OHO NH2 NH2 H O OH OH O NH2 OH NH2NH2 H O O H OH R OH R= -NH2 neomycin B •mixture of neomycins isolated from Streptomyces fradiae in 1949 Framykoin® ung., Pamycon® plv. (+ bacitracin) R = -OH paromomycin •not absorbed from GIT •used for Entamoeba histolytica Humatin® cps. deoxystreptamine = aglycon Aminoglycosides 3. Group of kanamycin and gemtamycin Kanamycin subgroup O NH OH O O NH2 OH O NH2 OH OH OH OH OH NH2 R O OH NH2 O OH NH2 O O NH2 OH O NH2 NH2 OH OH OH NH2 H H R = -H kanamycin Kanacol® a.u.v. inj. R= amikacin Amikin® inj. tobramycin Tobi Nebuliser Solution® inh. sol. •treatment of chronic pulmonary infection caused by Pseudimonas in patients with cystic fibrosis Aminoglycosides 3. Group of kanamycin a gemtamycin Subgroup of gentamycin O OH OH OH NH2 O NH2 NH2 H OO O NH2 OH N H H OH N H CH3 OH CH3 R 2 R 1 O NH2 NH2 H R2 = gentamycin Garasone® gtt. opht. (+betamethason) Diagen® a.u.v. sisomycin R1 = H- H- CH3CH2- netilmycin Netromycine® inj. •serious infections, sepsis …