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Chemotherapeutic Agents, chapter 34-39 •Antibacterial compounds (procaryotes) •Antifungal compounds (eucarytotes) •Antiparasitic agents (eucarytotes) • •Antiviral compounds •Anticancer compounds Different living organisms Eucaryotes Mono or polycellular Cell nucleus; DNA May have cell wall sexual and / or asexual replication Animals Plants Fungi Protocista: - Protozoea - Algea Procaryotes Bakteriea: Monocellular, no nucleus - DNA single strand, cell wall, asex. replic. Virus RNA or DNA + protein coating (not really a cell) Use other oramisms ribosomes for protein synth Antibacterial compounds, chapter 34 (- antimycobacterials) •Synthitic antibacterials (chemotherapeutica) •Antibiotics Antibiotics Product from metabolism (natural product) (also applies if compd is prepared synthetically, or is a synthetic analog of a naturally occuring antibiotic/ semisynthetic compd) Inhibit growth (bacteriostatic) or kill (bacteriocide) microorg. Effective in low conc. Antimicrobial chemotherapeutics: Antimicrobial comp ≠ Antibiotics G+ and G- bacteria Grampositive bakterier: Gramnegative bakterier: F. eks. F. eks. Streptococcus Staphylococcus Bacillus - causes anthrax and gastroenteritis Clostridium - causes botulism, tetanus, gas gangrene, and pseudomembranous colitis Corynebacterium - causes diphtheria Listeria - causes meningitis Spirochetes - causes syphilis, lyme disease Neisseria- causes meningococcus, gonorrhea The cell walls of gram-positive bacteria are made up of twenty times as much murein or peptidoglycan than gram-negative bacteria. These complex polymers of sugars and amino acids cross-link and layer the cell wall. The thick outer matrix of peptidoglycan, teichoic acid, polysaccharides, and other proteins serve a number of purposes, including membrane transport regulation, cell expansion, and shape formation Gram-negative bacteria have a unique outer membrane, a thinner layer of peptidoglycan, an d a periplasmic space between the cell wall and the membrane. In the outer membrane, gram-negative b acte ria ha ve lipopolysaccharides (LPS), porin channels, and murein lipoprotein all of which gram-positive bacteria lack. The gram-negative outer membrane which contains LPS, an endotoxin, blocks antibiotics, dyes, and detergents protecting the sensitive inner membrane and cell wall. Synthetic antibacterials (chemotherapeutica) Salvarsan 1. antisyphilis drug 1912 Antibacterial sulfonamides H2N HO Azo dyes Bayer etc Late 1800-century, ex. HO3S As N N Metylorange HO Pararødt OH NH2 N O2N As Screening of dyes as antibacterials N N 1932: Prontocil active against Streptoccocces infection no activity on bacterial cultures O H2N S O H2N N N NH2 1935: Prontocil metabilized (azoreductase) to Sulfanilamid in vivo O H2N S O NH2 Modern sulfa drugsr O H R N S O NH2 R: Aryl or hetroaryl (rel. toxisk) Sulfonamides are acidic O H2N S O - H+ O HN S O NH2 NH2 O HN S O NH2 O HN S O NH2 Sulfanilamid pKa 10.4 Nøytral sulfonilamid dårlig vannløselig. Urine pH ca 6: Crystallization neutral form, kidney damage Modern sulfa drugs pKa 5 – 7; better solubility Sulfametoxazol O N O O - H+ HN S Ar O Sulfametoksasol pKa 6.1 N O N S Ar O O O N O N S Ar O N O N S Ar O Bactrim®, Trimetoprim-Sulfa ® Urine infections Combi. with trimethoprime O O N N O N S Ar O O HN S O NH 2 O NH OH N N H2N N CO2H N H N CO2H Antibact. sulfonamide O R S NH O H2N H2N H2N OH OH OH N N O Folic acid O N N H From diet, humans N H Dehydropteridinsyre PABA O O OH N H2N N H N NH N H N H H2N NH2 Essential processes bacteria and animals ex. Thymin synthesis (Metab. CH3OH) Inhib. of folate reductase H2N OCH3 OCH3 N OCH3 Trimetoprim N N H N H Dihydrofolic acid Trimetoprim N N N CO2H Tetrahydrofolic acide NH OH CO2H Folatereduktase CO2H CO2H Quinolones Inhib DNA-synthesis; DNA-gyrase (prokaryoter) uwounding DNA before replic.. DNA-topoisomerase (humans), anticancer compds. ex. doxorubicin Unique mecanism, no cross resistance Broad spectrum: G+ and G- ; also mycobactria, clamydia Parent comp. Nalidixic acid Moderne quinolones must be oxo O F increase activity CO2H N R O F N CO2H R Urinary tract infect. earlier effect on Gram-negative bacteria (ex. E. coli) R N R Essentialt Preferably H Must have aromatic ring condenced with the pyridine Intramolek. H-bond O H Chelater with Ca2+, Mg2+, Zn2+, Fe2+, Fe3+, Bi3+ N O O O O N pKa ca 5.5 - 6.5 (Benzoic acid pKa 4.2) O Met2+ O O O N R O F CO2H R N R R Ciprofloksacin Ofloksacin Ciprox®, Ciprofloxacin® Tarivid® Cilox® O F O F O CO2H N N Trovafloxacin NH2 O F O F CO2H N F CO2H N N H2N N F F F Better effect on G+ CO2H O (±) Sparfloxacin F N N N HN HN Levofloxacin, 2x active CO2H N N N O Oxazolidones Linesolid Reg. Norge 2002, Zyvoxid® 1. antibact. drug with new mechaanism of action in 35 years O Inhib. protein synthesis early O No cross resist.. G+ and some G-. N N F Resistant strains O NH O CH3 O, CH3SO, Aryl, Hetroaryl, Mettet Hetrosykel Essencial O 'R: H, F 'R N O H N R O New drugs? (S)-Konfig. O O HO S N F N F OH O O N F O H N PNU 177553 (Pharmacia&Upjohn) S N AZD 2563 (AstraZeneca) O O N O R: H, CH3, OCH3 , CHCl2 AA'-O NHCHO O-AA-FMet AA-O O-fMet 5' 3' 50S NH3 + 70S Protein 30S CO2- mRNA Other antibiotics b-Lactam-antibiotics Antibiotics b-Laktam Lactam = cyclic amide O R N O R N Penicillins CO2H O R' N R b-Laktamase- Karbapenems inhibitors O CO2H O N N R'' N S R S H H H H R' b Cefalosporines O R' N R N H H CO2H R'' S Monobaktames O SO3H R' N N R H H + Cilastatin Penicillines Gen. struct 7 CO2H O R' N R N 6 1 2 N 5 1-Aza-4-tiabicykco[3.2.0]heptane 3 S 4 S N S tot. 7atoms in ring H H b-lactam (2S, 5R, 6R) X atomsr [x.y.z]alkane z atomsr tot no. of atomes y atoms Mechanism Peptidoglycane detail HInhib. cell wall synth. - peptidoglycane - ala-ala CO2H O R N H O N H X Y Y S H Pentapeptide: gly-gly-gly-gly-gly CO2H O R X N O G+ X: N-acetylglucosamin Y: N-acetylmuraminsyre X N H Y X Y Tetrapeptide: L-alaD-gluL-lysL-ala ala-ala G- Peptidoglycane synth. -cross linking X penicillin (- ala-ala)irreversible binding to trans peptidase Cross linking inhibited Y X Y enzyme enzyme trans peptidase HN H O + X Y X H Y O O O R OH N H HN O S H O O N O N H H R N H S H OH Semi synthesis two amide func. Hydrolysis CO2H O N O R Penicillin amidase R'COCl etc. N S N H CO2H O H N O R' S H2N CO2H O H S N H H 6-aminopenicillansyre R=Ph: Benzylpenicillin R=OPh: Fenoksymetylpenicillin from fermentation Mild acidic hydrol taut. CO2H O R PCl5 N OH N Cl R S N CO2H O N H S H iminochloride Stability Basic amide hydrol. - ring strain in b-lactame OH O O O N O R OH N H O S H R N H O OH N H O O S H OH R N H O OH HN S H stabile pH•7 OH Penicillo syre Acidic hydrolysis Alternative A Penicillo syre H2O H O OH O R HO N O OH O S N H R H O N H O O N O S H R OH HN HN O H N R S N H OH O H OH Penillosyre S + CO2 H O labilem acidic media H O + H N R OH H2N Penicillamin H 2N H 2N H N R O SH O Penilloaldehyde H N R OH OH O ±H SH O O OH O OH H2N S OH2 H N R O O S H2 O Acidic hydrolysis Alternative B O OH O N O R H O H S H OH HN HO S O H NH R R N N H O S NH OH O OH HN O HO O O O S N H R H2O Penicillosyre As Alternative. A Acidic hydrolysis Alternative C O OH O O N O R O HN S N H H NH O ±H O S H H O N R OH O R O HS N H R N H O S O H CO2H R N N S CO2H Penillinsyre H O O H OH O N O N R N OH HN N O R H OH HN O S O HO O OH HS N H R HS OH Structure acide stabile pennicillines O O O N O R O S N H H O HO O R N H N H OH H BensylP. acid labile HN S O OH NH H Nat. occuring P. O R N O N O OH N O O S N H H H PhenoxymethylP.acid stabile Indictive electron withdrawing effect EWG R; Olessnukleofilic Semisynthetic, increased acid stability Ampicillin O Pentrexyl®, N O NH 2 Amoxicillin OH O N H H O Pivampicillin O N O Pondocillin®, NH 2 N H H O N O O O S O NH 2 N H H O O Amoxicillin®, S HO O Piperacillin Tazocin® O N OH H N N O S O N O N H S H OH Resistant strains O OH O R b-Lactamase N O N H O O S H R N H OH HN S Kloksacillin Ekvacillin® H O O O OH N H N H N O N O R Cl O O S OH N H S CH 3 H Dikloksacillin Diclocil® Larger R; effect on b-lactamase resistant bacteria (starical hindrance) O Cl O O Cl Meticillin CH 3 O O OH N OCH 3 O N H OCH 3 N H N O S H Acid labile, last resort drug resist. strains N H S OH Semisynthetic, Broad spectrum, Imines Meticillinam Selexid® Pivmeticillinam Selexid® O O O OH O N N N N H S No nucleophilic cabronyl N N H O O S O b-Lactamase Inhibitors Combination with penicillines Clavulanic acid Enzyme O OH O X O O R' N No subst, less steric hindrance Enzyme OH O R H H O OH N R' X H H R O Tazobaktam O OH N N O H OH O N N N S HO O OH •Mechanism based irreversible enzyme inactivators Suicide substrate - kcat inhibitors - Trojan horse inhib. - latent alkylating agent ≈ Pro-drug, must be activated by the enzyme Clavulanic acid irreversibly inhibits b-lactamase OH O O OH N O O H Nu O O H O H H O O HN H OH OH OH O OH HN H O OH Nu Nu O O O OH HN HH O Nu OH Carbapenems / Carbapenins CO2H O R'' N R H H Tienamycin from Streptomyces cattleya 1976 S R' N HO Broad spectrum No S in 5-membered ring NH2 CO2H O H H Not substr. for blactamase S Labile, acidic and basic media Cleaved in vivo av DHP-I (dehydropeptidase I) R' Meropenem Meronem® Imipenem + cilastan Tienam® O NH CO2H O N HO H H HN N NH2 S Not nucleophilicm R' Imipenem CO 2H O HO O HN S O Cilastatin DHP-I inhib. HO H H N NH S R' OH O 2. Gen. Not cleaved by DHP-1 Cephalosporins Cefalosporin C from Cephalosporium acremonium 1945 O CO2H O H N O HO NH2 O N H H O CO2H O 6 5 4 R'' R' N 3 N 2 R 7 8 S H H 1 S 6- membered ring; Less ring strain than penicillins Subst in 3-pos., important for hydrolyttic stability OH O CO2H O CO2H HO2C O N RHN H H HN S RHN S O + O Good leaving group Metabolism O O N RHN H H S O O CO2H Esterase O OH O O O N OH N RHN RHN H H S H H S Inactive lactone Isolation from Cephalosporium sp or semisynth from 7-aminocefalosporic acid (7-ACA) O CO2H O O N H2N H H 7-ACA S Semisynth from penicillins HO2C H O R CO2H O mCPBA N N H R S H O (ox. av sulfid til sulfoksid) CO2H O N N H S H O C H H H O R O N N H S H OH Pummerer omleiring CO2H O R O N N H H S 1. generation: Relatively broad spectrum (G+, some G-) Cleaved by b-Lactamase Cephalexin Cefalex® Keflex® CO2H H2N O H N O N H H Cefalotin Cefalotin® Keflin® O CO2H O H N S S O O N H H S Realtively diff. to hydrolyze Only oral Ceph. 2. generation: More broad spectrum Not cleaved by b-Lactamase Cefoxitin Mefoxitin® Cefuroxim Cefuroxim® Zinacef® O CO2H H N S O Syn isomer, steric hindrance b-L Anti cleaved byb-L O O N O H NH2 S Increased stability compared to cephalotin N H N O Steric hindrance b-L O CO2H O O O O N H H S NH2 3. generation: Very broad spectrum, also Pseudomonas sp Not cleaved by b-Lactamase Acid labile Cefotaxim Cefotaxime® Claforan® O N O CO2H H N N O H2N Ceftazidim Fortum® Good leaving group Steric hindrance G- HO2C O CO2 O N O N H H S H N N O H2N S O N N H H S S Oral 3. gen (not in N): Ceftriaxon Rohephalin® R' O O H N N N CO2H O N H N N H2N O S N H H O H2N O N O H H S S S S N CO2H R N N OH R: -H, -CH=CH2, -CH2OCH3 Monobactams From Sulfacetin; weak antibacterial Not substrate forr b-lactamase O SO3H R' N N R R'' R''' O O H N O HO Only 4 membered ring N H NH2 O N SO3H O H NH 2 S Aztreonam Azactam® N O HO N O O O H N N H SO 3H Mer stabil enn Sulfacetin Bare effekt på G- Aminoglycosides Broad spectrum Toxic H2N Inhib. protein synthesis O -N o absorb. from GI, local treatment infect. GI tract. O Systhemic infections – parenteral adm. O H NH3 O Basic, water solubile salts phys. pH -Glykosides (= acetals) stabile acidic media because of protonated amino subst. Bind to mRNA read wrong Transloc. blocked NH3 + 3' 5' mRNA NH3 + 50S Protein 30S Ribosom 70S CO2- NH H2N NH H2N NH HN O OH OH HO Streptidin (sykloheksander.) First aminoglyc.: Streptomycin (ca 1944) from Streptomy O O griseus L-Streptose HO HO HO OH Toxic! O N-Metylglucosamin NH Neomycin Gentamicin Garamycin® From Micromonospora purpurea. Streptomyces fradia (1949). Maxitrol®, eyedrops Less tox. than streptomycin R NH2 O HO HO O O O NH2 H2 N OH OH O O OH NH2 HO O OH Neomycin C Netilmicin Netilyn® injek. Semisynth from Sisomicin (Micromonospora inyoensis) O NH2 OH NH2 O R' NH NH2 NH2 HO First antituberculosis drug. Streptomycin O HO HN O O NH2 NH2 O HO OH R = R' = -CH3: Gentamicin C 1 R = CH3, R' = -H: G entamicin C 2 R = R' = -H: Gentamicin C 1a HO HN O O OH NH2 O NH2 HO Tobramycin Nebcina® Tobi®, Tobrex Streptomyces tenebrarius. NH2 HO O NH2 HO HO O H2 N O NH2 OH Tobramycin N H R R = -Et: Netilmicin (R = -H: Sisomicin ) Lincomycines Sulfur cont. antibiotics from Streptomyces lincolnensis; Naturally occuring: Linkomycin (not in N), more active semisynth der. Inhib protein synth, binds to 50S part of ribosome Klindamycin Dalactin® Dalactin® Clindamy cin®. N R O Semisynth from linkomycin R= H, R'=Cl: Klindamycin R' R=OH, R'=H: Linkomycin, NH HO OH O S OH Tetrasyclines OH O HO 10 9 12 11 D 6 7 1 B C 8 OH O A NHR2 3 H5 H 4 R5 N R6 Mechanism: Bindes to 30S part of ribosome, inhibits protein O 2 synth.; komplexing Mg2+ involv ed. OH Binds also to 30S-rib. mammals, but bacteria cells also have active transport mech. for T uptake. Tetracyclines: Gen. struct. (reg. in N.) The most broad spctrum antibiotic known to date. 10 9 11 12 1 10a 11a 12a D 8 7 6a 6 A B C 5a 5 4a 2 Bakteriostatic, not baktericid. 3 Attacks natural bacteria flora in GI tract (oportunistic candida 4 infect.) Naftacene Chelate N HO H R5 Acid - Base prop. R6 H Acidic enol Acidic phenol Zwitter ion (high water sol.) neutral pH R2HN N HO 2 H R5 H O R6 O OH O Metn+ R2HN O O OH O OH OH -2H OH O OH 10 Metn+ 9 O 8 O OHO Chelate: Chelos = Claw, Klo (greek) Metn+ O NHR2 Ca2+ (milk) Fen+ (iron prep.) Al3+ (antacida.) OH O HO H R6 H R5 N 11 12 OH O 1 O 2 3 7 6 R6 H5 H 4 R5 N OH O HO 1 NHR2 OH Basic amine O 2 NHR2 3 Acidic enol R6 OH OH O H 4 R5 N H O Stability; acid / base pH 2 - 6: Epimerisation C-4 OHO OHO O NHR2 A OH H N H O OHO NHR2 OH H N H H OHO Epitetracycline - inactive OH H N H N H Protonated tetracycline O NHR2 OH H N H O NHR2 OH H OHO O NHR2 Base H OHO O NHR2 H N H OH H pH Š2: Dehydratisation; Aromatisation C-ring (R6=OH) OH O D OH OH O OH OH O OH OH O OH OH O OH C 6 H H H HO Base - H2O H 2O taut. H Benzylic cation (resonanse stab.) pH •7.5: Rearrangement to isotetracyclines (R6=OH) OH O D OH OH O OH 6 H H O Base H O H OH O O H OH O H O O C O OH O H 5-ring lactone O O H Isotetracycline inactive Tetracycline R5 R6 R2 -H -OH -H -OH -H Oxytetracycline -OH OH O HO 10 9 11 D 8 7 C 6 R6 OH O 12 B 1 O 2 A H5 H 4 R5 N NHR2 3 OH Doxycycline -OH -H -H Lymecycline -H -OH -CH2NHCH2NH(CH2)4CH(NH2)CO2H Tetracyclin Isolation from Streptomyces sp, Semisynth from chlorotetracycline more effective (low bioavailability) HO OH O HO O HO OH O HO O O NH 2 Cl HO H H O H2 / kat. NH 2 OH N Klortetracyclin fra fermenter. av Streptomyces arter HO H H OH N Tetracyclin Lymecyclin More water sol., pro-drug. Semisynth from tetracycline OH HO O HO O H HO H O N H OH N Lymecyclin HO OH O HO O NH 2 N H O in vivo O CH 2O NH 2 OH HO H H NH 2 OH N Tetracyclin O H2N Lysin OH Doxycyclin Not OH i 6-pos. More stabile in water solution (also mixture). Longer t 1/2, good oral absorb. Semisynth oxytetracyclin. OH O HO OH O O O Cl N OH O O OH O OH Cl O HO H OH N OH Oxytetracyclin - H2O NCS Electrophil chrorination reag. H HO OH O H H OH N OH O O OH O NH2 H OH exocyclic double bond H OH N O NH2 H OH N OH O HO OH O Anhydrotetracyclin H H OH N OHO O OH O NH2 H NH2 OH NaHSO3 O Cl OH H2 / kat. OH O O OH HF NH2 H OH N NH2 Hemiacetal OH O HO O O O OH H OH N O OH - H2O OH O HO OH OH OH Cl NH2 NH2 H OH O H OH N OH Makrolides O O Isolated from soil-ba kteria, Streptomyces sp. Amino sugar Reletively narrow spectrum, mainly G+. Low tox. O Bindes to 50S part of ribosome, inhib. Protein synth. O Structure / Activity: Macrolaktone (14-16-ring, smaller than antimycotic polyenes) Keto function No unsat. in lactone ring (spiramycin - dien) ° an timycotic polyenes Amino sugar Erytromycin Degradation acidic media O O O N HO HO O HO HO O O O O Ester hydrol. in vivo O OH Erytromycin H O O HO HO O O HO N O O O O O O HO HO HO HO OH Erytromycin ethylsuksinate Pro-drug (masks bad tast) O R O R' O O hemiketal H O O HO HO HO O O HO O O O -H2O O O O O O O inactive spiroketal Spiroforbindelse Azitromycin Klaritromycin Erythromycin N H N O HO HO HO HO N O O HO HO HO R MeO O OH Increased stability acidic media No intramolec. hemikatalisation OH Increased stabil., bioavail. More active G- less active G+ Increased stabil., bioavailability, less side effects Somewhat more broad spectrum N O O O Increased stability acidic media No intramolec. hemikatalisation Telitromycin O O O O O O O HO O O O R' O O HO O HO Spira mycin N N OH OH IsolatedStreptomyces ambofaciens. G+. O N N O O HO MeO O O O O No ketone O O O O O Increased stability acidic media No intramolec. hemikatalisation Improved ribosome binding, less resistans Increased ribosome affinity In N. 2002. Ketolide. O O O R N OH O O HO O HO R= H: Spiramycin I R=COCH3: Spiramycin II R=COCH2CH3: Spiramycin III Polypeptides Low oral avail.; lo cal admin. or. infusion/injektion. H Often high tox (kidneys). H2N D-amino acids and other rare AA. Vancomycin NH2 HO OH OH OH Cl N H O N H O H2N O H N O N H H N OH OH O O Cl NH O O O N H O HO N H O O OH HO O H N heptapeptide fragment Isol. Streptomyces orientalis (= Amycolatopsis orientalis). G+bakteria, Neisseria sp (G-). Inhib. Synth of mucopeptide polymer in cell wall. No oral uptake, Minimal degrad. In Gi, local treatment GI infect. Rel. tox., little resisence Severe infections few other alternatives O O HN HO2C O HO HO HO R Cl O OH O L-AA O N O H O O HN HO2C HO Cl O H N CO2H Teicoplanin O O H2N CO2H H R: O O HO R D-Amino acid HO OH HO R HO O H N N H O NH2 O heptapeptide fragment OH OH OH Isol. Actinoplanes teichomyceticus. Only G+. Mech as vanoc.m.. More lipid sol. than vancomycin, better distrib. In fat tissue Little resistance tox. Less than vancomycin; Severe infect., few alternatives D-Asp O HO 2C Bacitracin Isol. Baccilus subtilis. Mixt of struct (Bacitracin A, A1, B, C, D, E, F1, F2, F3 and G) Bacitracin A main comp. Bacimycin. Mainly G+. Inhib. Synth. mukopeptide in cell wall. Requires Zn2+ for activity NH 2 HN N O NH O Asp His N H O HN HN D-Phe O Lys 4 O O NH O HN HN Ile N H O D-Glu O Ile Orn NH SH NH 2 HO 2C NH O S H N N O Leu HO NH 2 O NH 2 Cys / Ile Colistin (Polymyxin E1) Polymixin B HN CO R-H2C CH CH CH 2CH 2NH 2 CO NH CH 2CH 2NH 2 CH 2CH 2NH 2 NH CO CH 3 H O O (H3C) 2HCH 2C CH HC N C C N C CH N C C N C C C C C C CH 2CH 3 H H O H O H H H2 H2 H2 H2 H OC CH 2 CHOHCH 3 NH CH 2 H2NH 2CH 2C CH NH R=-CH(CH 3)2: Colisin A / Polymyxin E 1 CO CO R=Ph: Polymyxin B 1 NH CH CHOHCH 3 H2NH 2CH 2C CH NH C O Cys OH O NH 2 Ile Others Chloroamfenikol Cl O O2N H H OH Cl NH OH Isol. 1.time Streptomyces venezuelae (1947), later found in several microorg. Broad spectrum. Inhib. Protein synth., mech. Not fully understood. Rel. tox. (daqmage bone marrow – an emiea, leukemi), seldom used systhemically. Simple structure – total synthesis. Stereoid H HO CO 2H OCOMe Fusidinic acid Narrow spectrum: G+; Stafylloccocus Streptococcus sp.(weak effect). Inhib. Protein synth. No cross resist. H HO aureus, H corynebakteria