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Probing Nature for Antibiotics. Irosha Nayanthika Nawarathne Michigan State University 04/30/08. health.howstuffworks.com . Struggle for living. dansaper.blogspot.com, www.photos-screensaver-maker.com, tecnocientista.info.com, www.creswell-crags.org.uk .

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probing nature for antibiotics
Probing Nature for Antibiotics

Irosha Nayanthika Nawarathne

Michigan State University

04/30/08

health.howstuffworks.com

struggle for living
Struggle for living

dansaper.blogspot.com, www.photos-screensaver-maker.com,

tecnocientista.info.com, www.creswell-crags.org.uk

slide3
“History of humankind can be regarded from a medicinal point of view as a struggle against infectious diseases”

Yoneyama, H., Katsumata, R., Biosci. Biotechnol. Biochem., 2006,70,1060

survival against infectious diseases
Survival against infectious diseases

dodd.cmcvellore.ac.in, www.ayurvedicmedicine4u.com, www.rootsweb.com

what are antibiotics
What are antibiotics?

Molecules that stop the microbial growth (both bacteria and fungi) or kill them outright

Walsh, C., Antibiotics Actions origins and Resistance, 2003, 4

how do the antibiotics act against bacteria
How do the antibiotics act against bacteria?

Cell Wall Biosynthesis

β-lactams,Cyclosporins,Glycopeptides

Walsh, C., Antibiotics Actions origins and Resistance, 2003, 19

www.jacksofscience.com

how do the antibiotics act against bacteria7
How do the antibiotics act against bacteria?

Protein Biosynthesis

Aminoglycosides,Macrolides,

Tetracyclines,Oxazolidinones

Walsh, C., Antibiotics Actions origins and Resistance, 2003, 19

www.istockphoto.com

how do the antibiotics act against bacteria8
How do the antibiotics act against bacteria?

DNA Biosynthesis

Quinolones

RNA Biosynthesis

Rifampicin

Walsh, C., Antibiotics Actions origins and Resistance, 2003, 19

publications.nigms.nih.gov, www.istockphoto.com

how do the antibiotics act against bacteria9
How do the antibiotics act against bacteria?

Metabolic pathways

Folic Acid Metabolism

Trimethoprim, Sulfonamides

Fatty Acid Biosynthesis

Triclosan, Isoniazid, Ethionamide

Walsh, C., Antibiotics Actions origins and Resistance, 2003, 19

www.istockphoto.com

why do we need more antibiotics
Why do we need more antibiotics?

- Developing antimicrobial resistance

Bacterial speciesCommon types of AntimicrobialTypes ofInfectionsResistance

Streptococcus pneumoniaeβ-lactams, cephalosporins, macrolides Otitis media, pneumonia,

Tetracyclines sinusitis, meningitis

Staphylococcus aureus

Community-associated Meticillin, cephalosporins, macrolides Skin, soft tissue, sepsis

pneumonia

Healthcare-associated Meticillin, cephalosporins, quinolones, Endocarditis, pneumonia,

aminoglycosides, macrolides sepsis

Enterococcus spp. Ampicillin, vancomycin, aminoglycosides Sepsis, urinary tract

Furuya, E.Y., Lowy, F.D., Nature, 2006, 4, 36

what should be targeted
What should be targeted?

The compounds with,

  • Novel structures
  • New modes of action

Fernandes, P., Nature Biotechnology, 2006, 24, 1497

slide12

NATURE

Where do the antibiotics come from?

slide13

NATURE

Where do the antibiotics come from?

TS

NP

SS

slide14

NATURE

Where do the antibiotics come from?

Helps in designing

the molecules

TS

NP

SS

natural products as antibiotics
Natural products as antibiotics
  • Naturally occurring compounds that are end products of secondary metabolism.
  • Mostly extracted from plants, marine organisms, or microorganisms.

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

natural products as antibiotics16
Natural products as antibiotics
  • Naturally occurring compounds that are end products of secondary metabolism.
  • Mostly extracted from plants, marine organisms, or microorganisms.
  • Eg:

Isolation- Streptomyces erythreus in 1952

Uses - Respiratory tract diseases,

genital infections

MOA - Inhibition of protein synthesis

Erythromycin

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Pal, S., Tetrahedron, 2006, 62, 3171

antibiotics which are semi synthesized
Antibiotics which are semi-synthesized
  • Synthetically modified chemical compounds which are originated

from natural products.

Walsh, C., Antibiotics Actions origins and Resistance, 2003, 4

erythromycin is
Erythromycin is

Acid unstable

Pal, S., Tetrahedron, 2006, 62, 3171

antibiotics which are semi synthesized19
Antibiotics which are semi-synthesized

Clarithromycin

Azithromycin

TE802

HMR3647

Pal, S., Tetrahedron, 2006, 62, 3171

antibiotics which are totally from synthesis
Antibiotics which are totally from synthesis
  • Totally synthesized molecules which are potent as antibiotics.
  • Three main types.

1. Sulfa drugs

2. Quinolones

3. Oxazolidinones

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

antibiotics which are totally from synthesis21
Antibiotics which are totally from synthesis
  • Sulfa drugs (Sulphonamides)

Sulfamethoxazole

Uses - Urinary tract infections, pneumonia etc.

MOA - Inhibition of folate synthesis

Harold, P.L., O’Grady, F.W., Antibiotic and Chemotherapy, 1992, 6, 268-272

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

antibiotics which are totally from synthesis22
Antibiotics which are totally from synthesis
  • Sulfa drugs (Sulphonamides) Naturally occurring

Sulfamethoxazole

p-aminobenzoic acid

Uses - Urinary tract infections, pneumonia etc.

MOA - Inhibition of folic acid biosynthesis

Harold, P.L., O’Grady, F.W., Antibiotic and Chemotherapy, 1992, 6, 268-272

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Walsh, C., Antibiotics Actions origins and Resistance, 2003, 80-82

antibiotics which are totally from synthesis23
Antibiotics which are totally from synthesis
  • Quinolones

Ciprofloxacin

Uses - Urinary tract infections, Lower respiratory infections, Gastrointestinal

infections

MOA - Inhibition of DNA synthesis

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

antibiotics which are totally from synthesis24
Antibiotics which are totally from synthesis
  • Quinolones Naturally occurring

Aurachin D

Ciprofloxacin

Aurachin C

Uses - Urinary tract infections, Lower respiratory infections, Gastrointestinal

infections

MOA - Inhibition of DNA synthesis

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Kunze, B., Hofle, G., Reichenbach, H., J. Antibiotics, 1987, 40, 258

antibiotics which are totally from synthesis25
Antibiotics which are totally from synthesis
  • Oxazolidinones

Linezolid

Uses - Soft tissue infections, skin infections, Tuberculosis etc.

MOA - Inhibition of protein synthesis

Ford, C.W., Zurenko, G.E., Barbachyn, M.R., Current Drug Targets-Infectious Disorders, 2001, 1,181

antibiotics which are totally from synthesis26
Antibiotics which are totally from synthesis
  • Oxazolidinones Naturally occurring

(-)-Cytoxazone

Linezolid

(+)-Sreptazolin

Uses - Soft tissue infections, skin infections, Tuberculosis etc.

MOA - Inhibition of protein synthesis

Ford, C.W., Zurenko, G.E., Barbachyn, M.R., Current Drug Targets-Infectious Disorders, 2001, 1,181

Zappia, G., et al., Mini-Reviews in Medicinal Chemistry, 2007, 7, 389

sources of antibacterial drugs from 1981 to 2002
Sources of antibacterial drugsfrom1981 to 2002

Newman, D.J., Cragg, G.M., Snader, K.M., J. Nat. Prod., 2003, 66, 1022

slide28

NATURE

Approach B

Generating

the Nature Mimics

Approach A

By exploring the novel

Natural Products

Ways of probing nature for antibiotics

slide29

NATURE

Approach B

Generating

the Nature Mimics

Approach A

By exploring the novel

Natural Products

Ways of probing nature for antibiotics

New antibiotics

New architectural scaffolds

approach a
Approach A

Conventional way of NP discovery

Extraction to the

solvents

Natural materials

Isolation and

Structure Elucidation

Bioassay guided fractionation

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

www.spc.int, www.oceanexplorer.noaa.gov, www.nature.com, www.textbookofbacteriology.net

approach a31
Approach A

Conventional way of NP discovery

Why isn’t it successful?

  • Problems associated with the growth or the availability of the source
  • Replication of the hits
  • Do not distinguish novel from old
  • Mostly miss the novel compounds due to the lack of sensitivity
  • No hints about MOA
  • Cannot reveal potency at screening stage

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Clardy, J., Fischbach, M.A., Walsh, C., Nat. Rev. Biotechnol.,2006, 24, 1541

approach a32
Approach A

What are the new strategies to explore nature for NPs

Novel culturing techniques

Heterologous expression of biosynthetic genes &

Metagenomics

Molecular Biology

based Techniques

Genomics and Combinatorial biosynthesis

Precursor directed biosynthesis & Mutasynthesis

Differential sensitivity screening approach

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Clardy, J., Fischbach, M.A., Walsh, C., Nat. Rev. Biotechnol.,2006, 24, 1541

Donadio, S., Chemistry & Biology, 2006, 13, 560

approach a33
Approach A

What are the new strategies to explore nature for NPs

Novel culturing techniques

Heterologous expression of biosynthetic genes &

Metagenomics

Molecular Biology

based Techniques

Genomics and Combinatorial biosynthesis

Precursor directed biosynthesis & Mutasynthesis

Differential sensitivity screening approach

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Clardy, J., Fischbach, M.A., Walsh, C., Nat. Rev. Biotechnol.,2006, 24, 1541

Donadio, S., Chemistry & Biology, 2006, 13, 560

approach a34
Precursor Directed Biosynthesis & MutasynthesisApproach A

Extraction

to the

Solvents

Producing organisms

found in nature

Pathogen

Wild type

Mutant type

approach a35
Approach A

Precursor Directed Biosynthesis & Mutasynthesis

Wild type

Natural Biosynthetic pathway

Kennedy, J., Nat. Prod. Rep.,2008, 25, 25

Weist, S., Sϋssmuth, R. D., Appl. Microbiol. Biotechnol.,2005, 68, 141

approach a36
Approach A

Precursor Directed Biosynthesis and Mutasynthesis

Wild type

Precursor-Directed Biosynthesis

Kennedy, J., Nat. Prod. Rep.,2008, 25, 25

Weist, S., Sϋssmuth, R. D., Appl. Microbiol. Biotechnol.,2005, 68, 141

approach a37
Approach A

Mutant

Precursor Directed Biosynthesis and Mutasynthesis

Mutasynthon

Mutasynthesis

Kennedy, J., Nat. Prod. Rep.,2008, 25, 25

Weist, S., Sϋssmuth, R. D., Appl. Microbiol. Biotechnol.,2005, 68, 141

approach a38
Approach A

Mutasynthesis

Ring A Ring B Ring C

Novobiocin (Albamycin)

Ring A Ring B Ring C

Clorobiocin

Pojer, F., Li, S.M., Heide, L., Microbiology, 2002, 148, 3901

Galm, U., et al, Chemistry & Biology, 2004, 11, 173

Weist, S., Sϋssmuth, R. D., Appl. Microbiol. Biotechnol.,2005, 68, 141

approach a39
Approach A

Mutasynthesis

CloQ- mutants

Pojer, F., Li, S.M., Heide, L., Microbiology, 2002, 148, 3901

Galm, U., et al, Chemistry & Biology, 2004, 11, 173

Eustảquio, A.S., et al, Arch. Microbiol., 2003, 180, 25

approach a40
Approach A

Mutasynthesis

Clorobiocin

CloQ-mutant

Galm, U., et al, Chemistry & Biology, 2004, 11, 173

Pojer, F., Li, S.M., Heide, L., Microbiology, 2002, 148, 3901

approach a41
Approach A

Mutasynthesis

Clorobiocin

CloQ-mutant

Galm, U., et al, Chemistry & Biology, 2004, 11, 173

Pojer, F., Li, S.M., Heide, L., Microbiology, 2002, 148, 3901

approach a42
Approach A

Mutasynthesis

CloQ-mutant

Analogs of Clorobiocin

Galm, U., et al, Chemistry & Biology, 2004, 11, 173

Galm, U., et al, Antimicrob. Agents Chemother., 2004, 48, 1307

Pojer, F., Li, S.M., Heide, L., Microbiology, 2002, 148, 3901

approach a43
Approach A

What are the new strategies to explore nature for NPs

Novel culturing techniques

Heterologous expression of biosynthetic genes &

Metagenomics

Molecular Biology

based Techniques

Genomics and Combinatorial biosynthesis

Precursor directed biosynthesis & Mutasynthesis

Differential sensitivity screening approach

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Clardy, J., Fischbach, M.A., Walsh, C., Nat. Rev. Biotechnol.,2006, 24, 1541

Donadio, S., Chemistry & Biology, 2006, 13, 560

approach a44
Approach A

Differential sensitivity screening approach

Producing

organism from nature

Pathogen

Expression of

certain protein/s

Wild type

Normal

Extraction

to the

solvents

Low

Disabled type

Increased

sensitivity

Target the

pathway

Couzin, J., Nature, 2006, 314, 34, Forsyth

R.A., Molecular Biology, 2002, 43, 1387

Wang, J., et al, Antimicrob. Agents Chemother., 2006, 50, 519

approach a45
Approach A

Fatty Acid Biosynthesis… A good target

Differential sensitivity screening approach

FAB Type I

- In mammals

FAB Type II

- In bacteria

Campbell, J.W., Cronan, J.E.Jr., Annu. Rev. Microbiol., 2001, 55, 305

slide46

Biosynthesis of Saturated Fatty Acids

Campbell, J.W., Cronan, J.E.Jr., Annu. Rev. Microbiol., 2001, 55, 305

slide47

Biosynthesis of Saturated Fatty Acids

Campbell, J.W., Cronan, J.E.Jr., Annu. Rev. Microbiol., 2001, 55, 305

slide48

Biosynthesis of Saturated Fatty Acids

Campbell, J.W., Cronan, J.E.Jr., Annu. Rev. Microbiol., 2001, 55, 305

approach a49
Differential sensitivity screening approach

Antisense RNA

Sense DNA

Antisense DNA

5` ………ATGGCCTGGACTTCA…………3`

3` ………TACCGGACCTGAAGT…………5`

Transcription

mRNA

5` ………AUGGCCUGGACUUCA…………3`

Translation

Peptide

Met - Ala - Trp - Thr - Ser -

Approach A

RNA-mediated gene silencing technique

Singh, S.B., et al, J. Am. Chem. Soc., 2006, 128, 11916

Forsyth, R.A., Molecular Biology, 2002, 43, 1387

Wang, J., et al, Antimicrob. Agents Chemother., 2006, 50, 519

approach a50
Approach A

Differential sensitivity screening approach

RNA-mediated gene silencing technique

In Prokaryotes-

ds RNA

5`……… AUGGCCUGGACUUCA………3`

3`……… UACCGGACCTGTTGU ………5`

Degradation of fabF mRNA or inhibition of translation

Reduced or No FabF expression

Higher sensitivity towards FabF inhibitors

Singh, S.B., et al, J. Am. Chem. Soc., 2006, 128, 11916

Forsyth, R.A., Molecular Biology, 2002, 43, 1387

Wang, J., et al, Antimicrob. Agents Chemother., 2006, 50, 519

approach a51
Approach A

Results - RNA-mediated gene silencing technique

Differential sensitivity screening approach

Wild type

fabF Anti-sense

Inhibitor (μg)

Wang, J., et al, Nature, 2006, 441, 358

approach a52
Approach A

Results - RNA-mediated gene silencing technique

Differential sensitivity screening approach

Wild type

fabF Anti-sense

200 times more potent

than Cerulenin

Wild type

fabF Anti-sense

Inhibitor (μg)

Wang, J., et al, Nature, 2006, 441, 358

Price, A.C., et al, The Journal of Biological Chemistry, 2001, 276, 6551

Heath, R.J., White, S.W., Rock, C.O., Progress in Lipid Research, 2001, 40, 467

approach a53
Approach A

Discovery of Platensimycin

Differential sensitivity screening approach

Platensimycin

from a strain of Streptomyces platensis

Singh, S.B., et al, J. Am. Chem. Soc., 2006, 128, 11916

approach a54
Approach A

Potency of Platensimycin

Differential sensitivity screening approach

Organism and genotypePlatensimycinLinezolid

Antibacterial activity(MIC, µg/ml)

S. aureus (MSSA) 0.5 4

S. aureus (MRSA) 0.5 2

S. aureus (MRSA, macrolideR) 0.5 2

S. aureus (MRSA, linezolidR) 1 32

Enterococcus faecium (VRE) 0.1 2

Toxicity(µg/ml)

HeLa MTT (IC50) >1,000 >100

MIC – Concentration of inhibitor used to result no visible growth of the pathogens

IC50 – Concentration of the inhibitor used to kill 50%population of the living cells

Wang, J., et al, Nature, 2006, 441, 358

approach a55
Approach A

Differential sensitivity screening approach

High FabF selectivity

  • Cell - free gel - elongation assay

Malonyl-ACP

C4:1(Δ2)-ACP

C4:0-ACP

>6C-ACP

Wang, J., et al, Nature, 2006, 441, 358

Heath, R.J., Nat.Prod.Rep., 2002, 19, 581

slide56

NATURE

Approach B

Generating

the Nature Mimics

Approach A

By exploring the novel

Natural Products

Ways of probing nature for antibiotics

New antibiotics

New architectural scaffolds

approach b
Approach B

Generating Nature Mimics

Biosynthetic pathway

Enzyme purification &

3D structural determination

Designing theoretical chemical space that fits the active site or

docking the database structures

Translate to a real structure by synthesis

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Clardy, J., Fischbach, M.A., Walsh, C., Nat. Rev. Biotechnol.,2006, 24, 1541

approach b58
Approach B

Generating Nature Mimics

Biosynthesis of lysine… A good target

  • Essential for the bacterial growth
  • Does not exist in mammals

Hutton, C.A., Perugini, M.A., Gerrard, J.A., Mol. Biosyst.,2007, 3, 458

Hutton, C.A., Southwood, T.J., Turner, J.J., Mini-Reviews in Medicinal Chemistry, 2003, 3,115

slide59

Biosynthesis of lysine

methionine

threonine

isoleucine

Hutton, C.A., Perugini, M.A., Gerrard, J.A., Mol. Biosyst.,2007, 3, 458

Hutton, C.A., Southwood, T.J., Turner, J.J., Mini-Reviews in Medicinal Chemistry, 2003, 3,115

slide60

methionine

threonine

isoleucine

Biosynthesis of lysine

Hutton, C.A., Perugini, M.A., Gerrard, J.A., Mol. Biosyst.,2007, 3, 458

Hutton, C.A., Southwood, T.J., Turner, J.J., Mini-Reviews in Medicinal Chemistry, 2003, 3,115

approach b61
Approach B

Generating Nature Mimics

Proposed mechanism

Hutton, C.A., Perugini, M.A., Gerrard, J.A., Mol. Biosyst.,2007, 3, 458

Hutton, C.A., Southwood, T.J., Turner, J.J., Mini-Reviews in Medicinal Chemistry, 2003, 3,115

approach b62

Acyl-enzyme intermediate

(Streptococcus pneumoniae)

Approach B

Generating Nature Mimics

Supportive data

Faehnle, C.R., Coq, J.L., Liu, X., Viola, R.E., Journal of Biological Chemistry, 2006, 281, 31031

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Hutton, C.A., Southwood, T.J., Turner, J.J., Mini-Reviews in Medicinal Chemistry, 2003, 3,115

approach b63
Approach B

Generating Nature Mimics

Inhibitors of lysine biosynthesis

Cox, R.J., Gibson, J.S., Martín, M.B.M., Chem. Commun., 2001, 1710

Cox, R.J., Gibson, J.S., Hadfield, A.T., ChemBioChem, 2005, 6, 2255

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

approach b64
Approach B

Generating Nature Mimics

Inhibitors of lysine biosynthesis

Cox, R.J., Gibson, J.S., Martín, M.B.M., Chem. Commun., 2001, 1710

Cox, R.J., Gibson, J.S., Hadfield, A.T., ChemBioChem, 2005, 6, 2255

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

approach b65
Approach B

Generating Nature Mimics

In vitro assays

Reverse Biosynthesis

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Cox, R.J., Gibson, J.S., Hadfield, A.T., ChemBioChem, 2005, 6, 2255

approach b66
Approach B

Generating Nature Mimics

Competitive assays

Direct assay

KI (ASA) KI (Phosphate)

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Blanco, J., Moore, R.A., Viola, R.E., PNAS, 2003, 100, 12613

Han, S., Moore, R.A., Viola, R.E., Synlett, 2003, 6, 845

approach b67
Approach B

Generating Nature Mimics

Competitive assays

Direct assay

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Blanco, J., Moore, R.A., Viola, R.E., PNAS, 2003, 100, 12613

Han, S., Moore, R.A., Viola, R.E., Synlett, 2003, 6, 845

approach b68
Approach B

Generating Nature Mimics

Competitive assays

Direct assay

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Blanco, J., Moore, R.A., Viola, R.E., PNAS, 2003, 100, 12613

Han, S., Moore, R.A., Viola, R.E., Synlett, 2003, 6, 845

approach b69
Approach B

Generating Nature Mimics

Competitive assays

Direct assay

KI (ASA) KI (Phosphate) 2nd pKa

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Blanco, J., Moore, R.A., Viola, R.E., PNAS, 2003, 100, 12613

Han, S., Moore, R.A., Viola, R.E., Synlett, 2003, 6, 845

approach b70
Approach B

Generating Nature Mimics

Time-dependent inhibition assays

Pre-incubation assay

KI (ASA)

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Blanco, J., Moore, R.A., Viola, R.E., PNAS, 2003, 100, 12613

Han, S., Moore, R.A., Viola, R.E., Synlett, 2003, 6, 845

approach b71
Approach B

Generating Nature Mimics

Time-dependent inhibition assays

Pre-incubation assay

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Blanco, J., Moore, R.A., Viola, R.E., PNAS, 2003, 100, 12613

Han, S., Moore, R.A., Viola, R.E., Synlett, 2003, 6, 845

slide72

NATURE

Approach B

Generating

the Nature Mimics

Approach A

By exploring the novel

Natural Products

Ways of probing nature for antibiotics

New antibiotics

New architectural scaffolds

please don t flush
Please, Don’t flush!
  • Average american receives more than 11 prescriptions a year.
  • About 3.3 billion a total.
  • Nonprescription drugs !

Halford, B., C & EN News, 2008, 86, 13

Halford, B., C & EN News, 2008, 86, 16

slide74

AcknowledgementDr. WalkerDr. HausingerDr. ArnostiDr. StoltzfusDr. Stephen Soisson, Dr. Jun Wang (Merck)Labmates - Behnaz, Danielle, Joshua, Mark, Washington, Yemane Friends - Samantha, Sue, Tharanga, Xiaofei

approach a77
Approach A

In vivo studies of Platensimycin

Differential sensitivity screening approach

In a mouse model of disseminated S. aureus infection

Wang, J., et al, Nature, 2006, 441, 358

timeline of discovery of novel classes of antibiotics and introduction in clinic
Timeline of discovery of novel classes of antibiotics and introduction in clinic

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

approach b79
Approach B

Generating the Nature Mimics

Faehnle, C.R., Coq, J.L., Liu, X., Viola, R.E., Journal of Biological Chemistry, 2006, 281, 31031

Hutton, C.A., Perugini, M.A., Gerrard, J.A., Mol. Biosyst.,2007, 3, 458

Hutton, C.A., Southwood, T.J., Turner, J.J., Mini-Reviews in Medicinal Chemistry, 2003, 3,115

antibiotics which are totally from synthesis80
Antibiotics which are totally from synthesis
  • Sulfa drugs (Sulphonamides) Naturally occurring

Sulfamethoxazole

p-aminobenzoic acid

Uses - Urinary tract infections, pneumonia etc.

MOA - Inhibition of folate synthesis

Harold, P.L., O’Grady, F.W., Antibiotic and Chemotherapy, 1992, 6, 268-272

Singh, S.B., Barrett, J.F., Biochemical Pharmacology, 2006, 71, 1006

Walsh, C., Antibiotics Actions origins and Resistance, 2003, 80-82

approach a81
Approach A

Precursor Directed Biosynthesis

Penicillium

Chrysogenum

(Penicillium notatum)

6-APA

Nayer, J.H.C., Trends. Biochem. Sci., 1991, 16, 195

Nayer, J.H.C., Trends. Biochem.Sci., 1991, 16, 234

Kennedy, J., Nat. Prod. Rep.,2008, 25, 25

approach a82
Approach A

Precursor Directed Biosynthesis

Penicillin G

Penicillium

Chrysogenum

(Penicillium notatum)

Penicillin V

Nayer, J.H.C., Trends. Biochem. Sci., 1991, 16, 195

Nayer, J.H.C., Trends. Biochem.Sci., 1991, 16, 234

Kennedy, J., Nat. Prod. Rep.,2008, 25, 25

approach a83
Approach A

Mutasynthesis

Nov L

Clo L

Ring A Ring B Ring C

Novobiocin (Albamycin)

Ring A Ring B Ring C

Clorobiocin

Pojer, F., Li, S.M., Heide, L., Microbiology, 2002, 148, 3901

Galm, U., et al, Chemistry & Biology, 2004, 11, 173

Eustảquio, A.S., et al, Arch. Microbiol., 2003, 180, 25

slide84

NATURE

Kekule stucture of benzene

Where do the antibiotics come from?

TS

NP

SS

www.boomeria.org

approach a85
Approach A

Precursor Directed Biosynthesis

Drawbacks

  • Involves complex purification procedures
  • Require high concentrations of synthetic precursor
  • Only few intermediates will incorporate into the product

Kennedy, J., Nat. Prod. Rep.,2008, 25, 25

Weist, S., Sϋssmuth, R. D., Appl. Microbiol. Biotechnol.,2005, 68, 141

slide86

Inhibitors of Fatty Acids Biosynthesis

Triclosan,

Isoniazid,

Ethionamide

Continues...

Cerulenin,

Thiolactomycin

Campbell, J.W., Cronan, J.E.Jr., Annu.Rev.Microbiol., 2001, 55, 305

Price, A.C., et al, The Journal of Biological Chemistry, 2001, 276, 6551

Heath, R.J., White, S.W., Rock, C.O., Progress in Lipid Research, 2001, 40, 467

approach b88
Approach B

Generating the Nature Mimics

Cox, R.J., Gibson, J.S., Martín, M.B.M., Chem. Commun., 2001, 1710

Cox, R.J., Gibson, J.S., Hadfield, A.T., ChemBioChem, 2005, 6, 2255

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

approach b89
Approach B

Generating the Nature Mimics

Direct assay

Cox, R.J., Gibson, J.S., Martín, M.B.M., ChemBioChem, 2002, 3, 874

Blanco, J., Moore, R.A., Viola, R.E., PNAS, 2003, 100, 12613

Han, S., Moore, R.A., Viola, R.E., Synlett, 2003, 6, 845

biosynthesis of saturated fatty acids
Biosynthesis of Saturated Fatty Acids

FabI / K / L

ACP

FabD

FabZ

FabH

FabG

Campbell, J.W., Cronan, J.E.Jr., Annu. Rev. Microbiol., 2001, 55, 305

biosynthesis of saturated fatty acids91
Biosynthesis of Saturated Fatty Acids

FabI / K / L

Continues...

FabD

FabZ

FabF

FabG

Campbell, J.W., Cronan, J.E.Jr., Annu. Rev. Microbiol., 2001, 55, 305

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