Antiviral Agents, RNA

1
Antiviral Agents, RNA

• Chutima Limmatvapirat

2
1. ?????????????????????????????????? RNA virus
??????????????????????????????????????? (FDA)

• 1.1 ????
• ???????????????? 9 ??????????????? FDA
  ????????????????????????????? RNA virus
• ????????????????? amantadine ??? rimantadine
  ?????????????????? influenza ion channel protein
  ?????????????? zanamivir ??? oseltamivir
  ????????????????? influenza neuraminidase
• ???????????????? respiratory syncytial virus
  (RSV) ????????????????????????????????????????????
  ???????????????? ?????????????????? aerosolized
  ribavirin
• ???????????????????? interferon ??? ribavirin
  ?????????????????????????? hepatitis C
  ????????????

3
Amantadine
Rimantadine
Zanamivir
Oseltamivir
Ribavirin
4
1.2 Hepatitis C virus

• ???????????????? (hepatitis C virus, HCV)
  ?????????????? flavivirus ???????
  negative-stranded RNA virus ??????????????????????
  ?????? ???????????????????????????????????????????
  ??????????????????????????????????
  ????????????????????????????????????????????????
  20-30 ?? ?????????????????????????????????????????
  ??????????????????? (hepatitis) ??????????????
  (fibrosis) ????????????? (cirrhosis)
  ??????????????????????????????? (hepatocellular
  carcinoma)

5
1.2.1 Interferon-?

• Interferon ??????? multiple low-molecular-weight
  cellular protein
• Interferon ??????????????????? 4 ???? ???
  recombinant interferon alfa-2b (Intron A),
  recombinant interferon alfa-2a (Roferon), natural
  interferon alpha-n1 (Alferon) ??? recombinant
  consensus interferon (Infergen)
• Interferon ????????????????? ????????????????
  immunomodulator ??????????????????????
  interferon-induced cellular proteins 2-5-oligo
  adenylate synthetase ??? protein kinase R (PKR)
  ?????????????????????????????? RNAse ????????????
  RNA ???????????????????
• Interferon ???????????????????????????????????????
  ???? (HCV RNA translation) ??????????
  PKR-independent pathway

6
1.2.2 ?????? interferon ??????? ribavirin

• Ribavirin ?????????????????????????????????
  interferon ??? ribavirin ??????????????
  inosine monophosphate dehydrogenase (IMPDH)
  ??????????????????????????????
  guanosine triphosphate (GTP)
  ????????????????? IMPDH ????????
  ?GTP ???????
  ??????????????????????????? RNA
• Ribavirin ??????????????????????? HCV RNA
  polymerase ???? ribavirin ????????????????????????
  ????? kinase ???????????????????? ribavirin
  5-triphosphate ???????? analog ??? purine
  nucleotide ??????????? ???????????????????????????
  RNA ???????? ribavirin-triphosphate ?????
  incorporate ???????? RNA product ??????????????
  HCV RNA-dependent RNA polymerase

7
1.2.3 Pegylated interferon

• PEG-Intron ????????? recombinant interferon
  alfa-2b ?????????????? polyethylene glycol (PEG)
  ??????????????????????????????????????????
• PEG-Intron ???? pegylated interferon
  ???????????????????????????? U.S. FDA
• Pegylation ??????????????????????? interferon ???
  PEG ???????????????????????????? interferon
  ???????? interferon ?? MW ?????????
  ????????????????? ????????????????????????????????
  ? interferon ?????????????????????????????????????
  ? ????????????????????????????????????????????????
  ?????
• Half-life ??????? ????????????????????????????????
  ??????????????????????????????????????????????????
  ???????????????????
• ??????????????????? interferon ??? PEG
  ????????????????????????? interferon ????
  ??????????????????????????????????????????????????
  ??????????????????????????????????????????????????
  ?????????
• Pegylated interferon ??? unmodified interferon
  ????????????????????????????? ???
  ??????????????????????? ???????????????????????
  ??????????????? ??????????????????????????
  neutrophil ???????????? (neutropenia) ???????

8
2. ???????????????? inhibitor ??? RNA virus
(?????? HIV)

• 2.1 Influenza A virus ??? influenza B virus
• 2.1.1 Inhibitor ??? influenza
  neuraminidase (Sialidase)
• ?????????????????????????????????? influenza
  neuraminidase (NA) inhibitor ???
• active site amino acid residue ??? influenza A
  ??? B ?????????????????????????????? ????? NA
  inhibitor ????????????????????????????????
  influenza A ??? B ????????
• 2) ??????????????? (mutation) ????????????????????
  ??????? NA ??????????? ???????????????????????????
  ???????????????????????????????????????

9
Catalytic mechanism ??? neuraminidase-mediated
cleavage ??? sialic acid

• ?????? sialic acid ?????????? NA ??????????
  oxonium cation transition state ?????
  conformation ???? half-chair ???????? transition
  state ????????????????????????????????????????????
  ?? NA ?????????????? 2-deoxy-2,3-dehydro-N-acetyln
  euraminic acid (Neu5Ac2en) ???? DANA ???? analog
  ??????????????? pyranosidic ring ???? planar
  structure ????? putative sialosyl cation
  transition state intermediate ?????????????????
  NA ?????

10
Inhibitor ??? neuraminidase (NA)
R OH 2-Deoxy-2,3-dehydro-N-acetylneuraminic
acid (DANA)
R Zanamivir
11
2.1.1.1 Zanamivir (GG-167)

• ?????????????????????????????? C4 , C5 ??? C6 ???
  sialic acid ??????????????????????? NA active
  site ???????????????????? ???? 4-guanidino group
  ???? zanamivir ????????????????????? influenza
  virus
• DANA ??????????????????????? C5 ??? C6 ?????????
  sialic acid ????? OH ???????????? 4 ???????? DANA
  ???????????? non-selective inhibitor

12
2.1.1.1 Zanamivir (???)

• Dihydropyran ring ??? zanamivir
  ?????????????????? half-chair (near-flat)
  conformation ?????????????????????? C4 , C5 ???
  C6 ?????????????????????? equatorial
  ??????????????? ??????????????????????????????????
  ?????????????????????????????????????????????
  arginine residue 3 ???? (Arg-292, -371 ??? -118)
• Triarginyl cluster ???????????????????????????????
  ?????????? ? ?????????????????????????????????????
  ????? NA (inhibitor) ??????????????????????????
  (carboxylate ???? phosphate) ?????????????????????
  ????? (????????????????????) ??? triarginyl
  pocket ???????????????????????????????????? NA
  active site ??????????????????????????????????????
  ??? N-acetyl methyl group ??? hydrophobic region
  ?????????? residue Ile-222 ??? Trp-178
  ????????????????? amide carbonyl oxygen ???
  Arg-152 ??????????????????????????????????????????
  ?????? zanamivir ??? inhibitor ???????? ?

13
2.1.1.1 Zanamivir (???)

• ??????????????????????????????????????????????????
  ??????????? NA ??????????? C7 hydroxyl group
  ????? ?????????? C7 hydroxyl group
  ?????????????????????????????????????????????? NA
• ????????? C4 hydroxyl group ?? DANA
  ??????????????????????????? ??????????????
  binding affinity ?????????????????? salt bridge
  ??? Glu-119 ?????????????? affinity ???????
  inhibitor ??? NA active site ??????????????????
  inhibitor ?? guanidino group ?????????????????????
  ????????? ????? N ??? guanidino group ????????
  Glu-119 ??? Glu-227
• Zanamivir ?????? NA ????????????????????? N ???
  guanidino group ???????????????????? Glu-227
  ???????? Glu-119 ????????????? secondary
  guanidinyl nitrogen ????????? electrostatic
  interaction ?????????????????????????? Asp-151
  ???????????????????? guanidino group ???????

14
2.1.1.2 Zanamivir analog

• ??????????? guanidine nitrogen ??????????
  inhibitor ???????????????????????
• ?????????? C6 glycerol moiety ??????? ether,
  ketone, carboxamide ???? heterocycle (????
  triazole) ????????????????????????????????????????
  ????? influenza A virus ?????????????? influenza
  B virus ????????

15
Zanamivir analog

• Ether R
• Ketone R
• Carboxamide R
• Triazole R

16
2.1.1.3 Oseltamivir (GS-4104)

• Oseltamivir ???????? transition state form ????
  flat oxonium cation ???????? isostere ???????????
  ??????? oseltamivir ????? cyclohexene scaffold
  ?????? oxonium ring ????? cyclohexene ring
  ??????????????????????????????????????????????????
  ?? dihydropyran ring
• Oseltamivir ???? prodrug ??? GS-4071

Oseltamivir
GS-4071
17
SAR ??? Modification ??? Zanamivir

• ??????????????????????????????????????
  lipophilicity ??? hydrophilicity
  ???????????????????????????????????????
  ??????????????????????????????????????????
  guanidino group ??????????????? zanamivir
  ??????????????????????????????????????????????????
  ?????????????
• Zanamivir ???? cyclohexene-based inhibitor ?????
  carboxylate ??? acetamido moiety ??????????????
  C1 ??? C4 ??? cyclohexene ring ????????
  ???????????????????????? Arg triad (Arg-292, -371
  ??? -118) ???????????? ?????????????????????
  amide recognition region (Trp-178, Ile-222 ???
  Arg-152) ???????????????????????????????????
  ?????????????????????????????? inhibitor
  ??????????????? NA binding site
• ????????? glycerol chain ??? zanamivir
  ???????????????????????? ??? C8
  ??? glycerol chain
  ?????? hydrophobic interaction ???
  hydrocarbon chain ??? Arg-224
  ?????????????????????
  ?????????? inhibitor
  ?????????????????????????????
  ???????????????????????????????

18
SAR ??? Modification ??? Zanamivir

• C7 OH ????????????????????????????????????????????
  ??????????????????????? ??????????????????????????
  ?????? inhibitor ???????????? C7 OH
  ??????????????????????????? ??????????????????????
  ????????? inhibitor ??????? GS-4071 ??? analog
  ?????? ???????????????????? glycerol chain ????
  alkoxy group (??? C3 ??? cyclohexene ring)
  ????????????????? C3 linker atom
  ?????????????????????????????????????????????????
  ????????? C3 ??????? N , S ???? O
• ?????????????? GS-4071 ??????????????? linkage
  ????????????????????????????????????????????
  cyclohexene ring ???????????????
  sialosyl oxonium transition state
  intermediate ?????????????
• ??????????? SAR ?????????????????????????? ????
  ??? branching ???
  alkyl chain
  ????????????????????????????????????????????? NA

19
SAR ??? Modification ??? Zanamivir

• ???????????? GS-4071 ??? related carbocyclic
  inhibitor ?????????? NA ????? Glu-276
  ?????????????????????????????????? conformation
  ???????????????????????????????????????
  (????????????????????) ??? guanidino group ???
  Arg-224 ???????????????? ?????????????????????????
  ??????????? aliphatic side chain ??? inhibitor
  ?????????????????????????????????? binding site
  ????????????????????????????????????????????????
  ?????????????????????????????? pentyloxy group
  ??????????????? GS-4071 ???
• ????????????????????? pentyloxy group
  ????????????????????????????????????????????????
  hydrocarbon chain ??? Ile-222, Arg-224 ???
  Ala-246 ???? pocket ??????????????????????????????
  ???????????????? ???? cyclohexyl ring

GS-4071
20
2.1.1.4 Oseltamivir analog

• ???????????????????? cyclohexene ring
  ???????????????????????? ????????? molecular
  modeling analysis ???????????????? GS-4071 ??????
  A ???????????????????????? ???????????????????????
  ???????????????????? NA ?????????????
• GS-4071 ?????????????????????????????????????
  oxonium ion double bond ?? transition state
  ???????????????????? influenza B virus
  ???????????? A ????????????????????? B
  ???????????????????????????? C

A
B
C
GS-4071
21
2.1.1.4 Oseltamivir analog (???)

• GS-4071 analog ?? tetrahydropyridazine ring
  ?????? cyclohexene ring ??? GS-4071 ???? analog
  ??????????? NA A/PR (H1N1) ??? B/Lee/40
• GS-4071 analog ?? amino gr ??? acetamido gr
  ????????????? pseudo-axial position ???????
  pseudo-equatorial position ???????????????????????
  ???????????? GS-4071 ???????? 3-pentyloxy group
  ???????? pocket ???????????????????? (pocket
  ??????????????????????????????? Glu-276)
• GS-4071 ?? 2 ethyl moiety ??? 3-pentyl side-chain
  ?????? pocket ????????????? 2 ????
• GS-4071 analog ?????????????????????? (planar) ??
  tetrahydropyridazine ring ????????????????????????
  ???????? NA ????????????????

GS-4071
GS-4071 analog
22
2.1.1.4 Oseltamivir analog (???)

• ?????????????????? C2 ??? GS-4071
  ????????????????????????? ???? chloro, methyl
  ???? methylthio ???????????????????????????????
  2,000 ???? ???????????????????????? C2 ???
  GS-4071 ???????????? ????? C2-fluoro analog
  ?????????????????????????? type A NA
  ????????????? GS-4071 ????????????????????????
  type B NA ???????????? 30 ????

GS-4071
C2-fluoro analog ??? GS-4071
23
2.1.1.5 BANA compound

• ???????????????????????????????????????????? BANA
  compound ????????
• ????????????????????????????????????? arginine
  triad (Arg-292, -371 ??? -118) ?? NA active site
  
• ?? planar conformation ???????????????????????????
  ? ???????????????? transition-state-like
  structure
• ??????????????????????????????????????????
  acetamido group ????????????????????????????
• ??????????????????? influenza NA inhibitor ?????
  benzoic acid template (scaffold)
  ??????????????????

24
2.1.1.5 BANA compound (???)

• ???????????????????????????????????????????? BANA
  compound ????????
• ????????????????????????????????????? arginine
  triad (Arg-292, -371 ??? -118) ?? NA active site
  
• ?? planar conformation ???????????????????????????
  ? ???????????????? transition-state-like
  structure
• ??????????????????????????????????????????
  acetamido group ????????????????????????????
• ??????????????????? influenza NA inhibitor ?????
  benzoic acid template (scaffold)
  ??????????????????

25
2.1.1.5 BANA compound (???)

• Benzoic acid analog ??? zanamivir ??????????????
  NA ??? BANA-113 ??????????? type A NA ??? type B
  NA ??????? guanidino group ????????????
  C4-guanidino group ??? zanamivir
  ????????????????????? active site residue
  (Glu-119 ??? Glu-227)
• guanidino group ??? BANA-113 ?????????????????????
  ????????????? residue Glu-276 ????????
  glycerol-binding site ??? zanamivir
• BANA-113 ???????????????????? guanidino group
  ???????? binding pocket ???????????????????
  interaction ???
• Active site pocket ??? glycerol substituent ???
  zanamivir ????????????????????? ?????? binding
  pocket ?????? guanidino group ???? ????????
  benzoic acid analog ??? zanamivir ??????????
  ????? benzene scaffold ?? orientation
  ????????????????????????????????????????????? NA
  active site ?????

26
2.1.1.5 BANA compound (???)
Benzoic acid analog ??? zanamivir R1
R2
BANA-113 R1 H R2
Guanidino group ??? BANA-113 ?????????????
3-pentyloxy R1
H R2
Benzoic acid analog ??? GS-4071 R1
R2 NH2
27
2.1.1.5 BANA compound (???)

• ????? guanidino group ??? BANA-113 ?????????????
  3-pentyloxy ????????????????????????? type A NA
  ??????????? ?????????????????????????? type B NA
  
• ????????? benzoic acid analog ??? GS-4071
  ?????????????????????????? type A NA ????????????
  BANA-113 ????????????????? type B NA
• ?????????? binding energy ????????????????????????
  ??????????????????????????? NA

Guanidino group ??? BANA-113 ?????????????
3-pentyloxy R1
H R2
Benzoic acid analog ??? GS-4071 R1
R2 NH2
28
2.1.1.5 BANA compound (???)

• Benzoic acid-based inhibitor ?????????????????????
  ?????? cyclic ????? side-chain ???? pyrrolidinone
  ??????????????????????????? N-acetyl group ???
  benzoic acid analog ??? zanamivir ???? N-acetyl
  group ???????????????????????????????? rigid
• ????? N-acetylamino group ??? BANA-113
  ????????????? bis(hydroxymethyl)pyrrolidine-2-one
  ring ???????? BANA-205 ????? IC50 ???????
  BANA-113
• ????????? N-acetylamino group ??? guanidino group
  ??? BANA-113 ????????????? bis(hydroxymethyl)pyrro
  lidine-2-one group ??? 3-pentylamino group
  ???????? ???????? BANA-206 ?????????????????????
  type A NA ???????? ???????????????????????? type
  B NA ??????

29
2.1.1.5 BANA compound (???)

• ????????????????? BANA-205 ??? BANA-113 ??
  guanidino group ??? interact ??? active site
  residue Glu-276 ??????????????? native
  conformation ??? ?????????????????????????????????
  ?????????????????? type A NA ??? type B NA
  ???????????? ????????????????? BANA-206
  ???????????????????? conformation
  ?????????????????? Glu-276 ?? active site
  ?????????????????????? pentylamino functional
  group ???????????? ????????????? inhibition
  constant ???????
• 2-pyrrolidinone ??? benzene ring
  ?????????????????????????? ?????????? BANA-206
  ???? simple achiral benzoic acid derivative
  ???????????????????????? type A NA ??????? nM

30
2.1.1.5 BANA compound (???)
BANA-205 R BANA-206 R
31
2.1.1.6 RWJ-270201 (BCX-1812, Peramivir)

• ??????????????????????????? ?/?-6-acetyl-amino-3,6
  -dideoxy-D-glycero-altro-2-nonulofuranosonic acid
  ???????? micromolar inhibitor ??? DANA
  ?????????????? carboxylic acid, glycerol,
  acetamido group ??? C4-hydroxy group
  ????????????????????????? active site ?????
  interaction ?????????? NA ?????????
• ??????? cyclopantane ring ??????? scaffold
  ???????????????? NA inhibitor ???????????????
  carboxylate, guanidino, acetamido ??? 3-pentyl
  group ?????????????? NA ??????????????? ????
  RWJ-270201 ?????????????? cyclopantane ring
  ????????????????????? 4 ??????????????????????????
  ??????????? interaction ??? NA binding site
  ???????????

32
2.1.1.6 RWJ-270201 (???)
DANA
?/?-6-Acetyl-amino-3,6-dideoxy- D-glycero-altro-2-
nonulofuranosonic acid
RWJ-270201
33
2.1.1.7 Pyrrolidine-based inhibitor

• ??????????????????????????zanamivir ??????????
• A-87380 ?????????????????? type A NA ???????
  tri-substituted pyrrolidine analog ???
  tetra-substituted pyrrolidine analog
• A-192558 ???? inhibitor ???????????????????
  ???????????? type A NA ??? type B NA
• ?????? A-192558 ?????? NA ????????????????????????
  ??? arginine triad (?????????? Arg-118, Arg-292
  ??? Arg-371) ??????????????????????? NA

A-87380 R1 R2 H
A-192558 R1
R2
34
2.1.1.7 Pyrrolidine-based inhibitor (???)

• Tertiary amine N-oxide ???? ether group
  ????????????? hydrophobic sub-site ?????????????
  Arg-224, Ile-222 ??? Ala-246 ?????????????????????
  ????????? NA ?????
• ??????????????????????????? intra-molecular
  H-bond ?????????????????? pyrrolidine nitrogen
  ????????????????????? aliphatic side-chain
  ???????????????? hydrophobic surface ?? active
  site ??????????

A-87380 R1 R2 H
A-192558 R1
R2
35
2.1.2 Inhibitor ??? Influenza Hemagglutinin
2.1.2.1 Monomeric Inhibitor ??? Influenza
Hemagglutinin
2.1.2.1.1 BMY-27709 ?????????????????

• BMY-27709 (28) ???????? lead ?????????????????
  influenza fusion inhibitor ????
  ??????????????????????????????? H1 ??? H2 subtype
  ??? influenza A virus
• ??????????????? ??? ?????????? HA-mediated
  membrane fusion ????????????????????????
  conformation ?????????? native HA ???????????????
  pH ??? ? (??????? membrane fusion
  ????????????????????????????????????????????)

BMY-27709
36
2.1.2.1.1 BMY-27709 ????????????????? (???)

• phenolic hydroxy group ???????????????????????
  ??????? BMY-27709 ????????????? acid surrogate
  ketophenol moiety ???? interaction ??? Arg-106
• ?????????????????????? 5 ?????????????????????????
  ???? 5-halo ???? 5-methyl derivative
  ???????????????????????? ???? 5-methyl phenol
  derivative ?????????????? BMY-27709
• ????????? quinolizidine ring ???? simpler
  heterocycles-piperidines ???? decahydroquinolines
  ??????????????????????????????????????????????????
  ???????? ???? 2-methyl-cis-decahydroquinoline

37
2.1.2.1.1 BMY-27709 ????????????????? (???)
BMY-27709
5-Methyl phenol derivative ??? BMY-27709
2-Methyl-cis-decahydroquinoline
38
2.1.2.1.3 Podocarpic Acid Derivative

• 180299 ????????????????????????????? podocarpic
  acid
• ?????????????? influenza A virus
  ??????????????????????????????????????????

180299
39
2.1.2.1.4 Diiodofluorescein

• diiodofluorescein ???? lead ??????????????????????
  ??????
• ?????????????????????? viral fusion

Diiodofluorescein
40
2.1.2.1.5 Stachyflin ?????????????????

• stachyflin ??????????????? sesquiterpene
  derivative
• ????????????????
• ?????????????? H1 ??? H2 subtype-specific
  anti-influenza A virus
• ????????????????? HA-mediated virus-cell membrane
  fusion process
• Stachyflin ??????????????????????????????????????
  ?????????????????????
• ????????????? phosphate ester prodrug
  ??????????????? stachyflin ?? polyethylene glycol
  (PEG), PEG 400 ???? PEG 4000

Stachyflin
41
2.1.2.1.5 Stachyflin ????????????????? (???)

• Keto derivative ??? phosphate prodrug III-Phos
  ??? stachyflin III ???????????????????????????????
  ?????????????????????????????
• ?????? III-Phos ??????????? ??????????????????????
  ???????????????????????????????????????
• ?????????????????? III-Phos ??????????????????????
  ??????? ??? III-Phos ??????????????????????????

Keto derivative ??? stachyflin III R OH
Phosphate prodrug III-Phos ??? stachyflin
R
42
2.1.2.2 Polymeric Carbohydrate-Based Inhibitors
??? Influenza Hemagglutinin

• Multivalency (polyvalency) ??????????
  (simultaneous binding) ??? multiple ligand
  ???????????????? ??? multiple receptor
  ??????????????????
• Influenza virion ???? HA trimeric unit
  ????????????????? ????????? unit ??????????
  binding site ?????? sialic acid (SA ???? Neu5Ac)
• ????????? binding pocket ?????????????????
  ????????????????????????????? single HA binding
  site ??? single SA ????????????????
• ??????????????????????????????????????????????????
  ? multivalent (polyvalent) inhibitor ?????
  multiple copy ??? SA ????????
• ???????????????? multivalent sialoside ?????
  multiple sialyl moiety ???????????? synthetic
  backbone ??????? polymer, liposome ???? dendrimer

43
2.1.2.2.1 Sialic Acid-Containing Polymers

• Multivalent SA-containing polymer ??? couple ???
  polyacrylamide ??????? 4-N-linkage ??? 2-linked
  conjugate ??????????? influenza H3 subtype (X-31)
  ??? H1 subtype ????? ?????????????????????????
  influenza virus ??? erythrocyte (surrogate target
  cell) ???????

2-Linked conjugate
Multivalent SA-containing polymer
44
2.1.2.2.1 Sialic Acid-Containing Polymers (???)

• Polyacrylamide pA(NeuAc, ?) ???????????? SA ????
  linker ?????????????????? ????????????????????????
  ???????????????? (hemagglutination)
• ???????????????? potent monomeric NA inhibitor
  ????? SA group ??????????????????????? HA-binding
  pocket ??? NA active site ????????????????????????
  ??????????????????? NA ???? ??????????????????????
  ????????? ????????????????????????????????????????
  ?????? SA group ????????????? NA active site

??????????? polyacrylamide pA(NeuAc, ?)
45
2.1.2.2.1 Sialic Acid-Containing Polymers (???)

• Polymer ??? L-glutamic acid ??????????????????
  lysoganglioside GM3 ??????????? influenza virus
  ?????????? parent lysoganglioside ??? 103 ????
• ??????????????????????????????????????????????????
  ???????? polymer/HA ??????? chain lock
  ????????????????????????????? active site
  ??????????? HA ???? ?????????????????????? (????
  sphingosine moiety) ??? lysoganglioside GM3
  ??????????????? hydrophobic site ?? stem area
  ??????????????????????? HA

46
2.1.2.2.1 Sialic Acid-Containing Polymers (???)
Polymer ??? L-glutamic acid ??????????????????
lysoganglioside GM3
47
2.1.2.2.2 Liposomes

• ????????? influenza virus ???????????????
  multivalent ??? sialoside ?? liposome
• ???????????????? 3-OH ???? 3-F-substituted SA
  derivative ?????????????? distearoylphosphatidylet
  hanolamine (DSPE) ????????????????? liposome
  ?????????????? A/PR/8/34 (H1N1) ?????????
  monomeric SA ?????? 103 ????

3-F-Substituted SA derivative with
distearoylphosphatidylethanolamine (DSPE)
48
2.1.5 Other Inhibitor ??? Influenza Virus
2.1.5.1 Bisindolylmaleimide

• Bisindolylmaleimide I ?????????????????????
  protein kinase C (PKC) ????? ?????????????????????
  ??????????? influenza A ??? B virus ???
• ???????????????????????????????? influenza virus
  ????? 60 ?????????????????????????????

Bisindolylmaleimide I
49
2.1.5.2 Pyrimidine derivative

• 2-amino-4-(?-hydroxy-alkylamino)pyrimidine
  derivative ????????????? cyclobutyl group ???
  cyclobutyl group (???????????????????????? 3
  ???? phenylalkyl group) ??? ?-position ???
  aminoalkyl side-chain
• ?????????????? type A ??? B influenza virus
• ???????????????? stationary cell ???
  proliferating MDCK cell
• ????????????????????????????????????? influenza
  virus ?????

2-Amino-4-(?-hydroxy-alkylamino)pyrimidine
derivative
50
2.1.5.3 Natural Product

• Biflavonoid ??????????????? Rhus succedanea ???
  Garcinia multiflora
• ?????????????? influenza A ??? B virus ?????

Robustaflavone
Agathisflavone
Amentoflavone
51
2.2 Respiratory Syncytial Virus,
Parainfluenza Virus ??? Measles Virus 2.2.1
Inhibitor ??? RSV ??? Paramyxovirus
Fusion Protein 2.2.1.1 RFI-641
(WAY-154641)

• CL-309623 ??????????? RSV ????????????????????????
  ?????

52
2.2 Respiratory Syncytial Virus,
Parainfluenza Virus ??? Measles Virus 2.2.1
Inhibitor ??? RSV ??? Paramyxovirus
Fusion Protein 2.2.1.1 RFI-641
(WAY-154641)

• ????????????????????????????????? ???
• core ????????? rigid ????????????????????????????
  2 ???? ????????????? 2,2-position
• sulfonic group ?????? carboxylic group
• ??????????????????????????? aminobenzenesulfonamid
  o fragment ????????? 3 ???? ??????????????????????
  ??????? ????????????????????????? fragment ????
  meta ??????????????????????????????????????
• side-chain ??????????????????? hydrogen bonding
  group ???????? 2 side chain ??????????????????
  side chain ?????
• ?????????????? multiple functional group
  ??????????????????????????????????????????????????
  ?????????????????????????????????????????
  ??????????????????? F protein ???????????????
  multivalency

53
2.2.3 Inhibitor ??????????? RSV 2.2.3.1
????????????????????

• Phenylpropanoid glycosides ?????? Markhamia lutea
  Verbascoside ???????????????? RSV
• ??????????????????????????????????????????? 3
  ???????????????????????????????????

R1 H R2 R3
R4 H
54
2.3 Picornavirus 2.3.1 Inhibitor ???
Picornaviral attachment ??? uncoating
2.3.1.1 Long-chain compound

• Picornavirus ?? icosahedral capsid ????????????
  long-chain hydrophobic capsid-binding antiviral
  compound ??? ???? pleconaril ????????????
  hydrophobic pocket ???????????????????????????????
  ??????????? stabilizing viral particle
  ???/????????????????????????????????????
  ?????????????????????????????????????????
  conformation ??? drug-binding pocket ???
  stabilize ??? entire viral capsid ???????????????
  enzymatic degradation

Pleconaril
55
2.3.1.2 Isothiazole, Dibenzofuran
???Dibenzosuberane

• IS-2 ??????? 3,4,5-trisubstituted isothiazole
  ??????????? poliovirus-1 ????????

IS-2 R H
56
2.3.2 Inhibitor ??? Picornaviral
Protease 2.3.2.1 Peptidic Inhibitor

• Rhinovirus ?? 3C protease ????????????????????????
  ????????????????????????????????
  ????????????????????????????????????????????????
  Gln-Gly bond
• ?Hexapeptide H2N-Thr-Leu-Phe-Gln-Gly-Pro-CO2H
  ????????????????? HRV 3C protease
• ????????? amide carbonyl group ???? electrophilic
  functionality ???? aldehyde, ketone ???? Michael
  acceptor ??????????? nucleophilic attack ???
  thiol group ??? active site cysteine
  ??????????????
  inhibitor
  ??? HRV 3C protease

Hexapeptide H2N-Thr-Leu-Phe-Gln-Gly-Pro-CO2H
57
2.3.2.1.1 AG7088 ??? Peptidyl Michael Acceptor

• ?????????????????????????????? inhibitor
  ?????????????????????????????? ??????
• 1) inhibitor ???????????????????????? 3 ????
  ??????????????????????????
• 2) trans-?-?-unsaturated ester ???????????????????
  ???????????? Michael acceptor
• 3) ????? P1 glutamine ????????????????????????????
  ???????? inhibitor ????????? primary amide
  ??????????????????????????????? cis-amide
  geometry ???????????? ?-carboxamide side-chain
  ???????? stereochemistry ??? (S)-?-lactam moiety
  ??????????
• 4) P2 side-chain ?????????????????????????
  ????????? P2 phenyl ring ???? 4-fluorophenyl
  ????????????????????????? ????????????????????????
  ????????????????????????????????????????
• 5) ???????????? P2-P3 peptide bond ????
  ketomethylene isostere ???????????????????????????
  ???
• 6) ??????????? P3 ?????????????????????? ?
  ?????????????????????????????? ????????? P3
  leucine ???? valine ??????????????????????????????
  ?????????????????????
• 7) P4 ????????????????????????? ????????????
  N-terminal P4 amide ???? thiocarbamate ????
  5-methyl-isoxasole-3-carboxamide
  ??????????????????????????????????????????????????
  ??

58
2.3.2.1.1 AG7088 ??? Peptidyl Michael Acceptor
(???)
AG7088
Peptidyl Michael Acceptor ??????????? anti-3C
protease peptidyl Michael acceptor
59
2.3.2.2 Nonpeptidic Inhibitor

• Isatin ??? homophthalimide ???? lead compound
  ?????????? LY353349 ??????????????????????????????
  ?
• LY353349 ?????? 3C enzyme ??????? C3
  (non-benzylic) carbonyl ?????? nucleophilic
  attack ??? active site cysteine

Isatin
Homophthalimide R1 CH3 R2
LY353349 R1 R2
60
2.3.3 Inhibitor ??? Picornaviral Replication
(Enviroxime ??? analog)

• Enviroxime ???????????? benzimidazole derivative
  ?????????????? picornavirus ????? oral
  bioavailabilty ????? ???????????? SE ???? ???????
  
• Vinyl oxime moiety ??? enviroxime
  ??????????????????????? ??????????????
  bioavailability ????????????? CH3 ???? acetylene
  ????????????????? F ????????????? aromatic ring
  ????????????????????????? ????????????????????????
  ????????????????? picornavirus ????????????

Enviroxime
61
2.3.5 Other Anti-Picornaviral Inhibitor
2.3.5.1 ??????????????????????? synthetic analog

• Ethanolic extract ?????? Pterocaulon sphaclatum
  ????? Pterocaulon ????? flavonoid chrysosplenol C
  ?????????????? poliovirus

Chrysosplenol C
62
2.4 Hepatitis C Virus 2.4.1.2 Inhibitor ???
HCV Internal Ribosome Entry Site

• RNA genomic structure ???????????? translation
  ??? HCV ??????? HCV internal ribosome entry site
  (IRES) ???????????????????????????????????????????
  ????
• HCV IRES inhibitor ???????????? phenazine ???
  phenazine-like molecule ???????????????????
• ??????????????????????????????????????????????????
  ???? ?????????????????????????????????????????????
  ? ??????????????????????????????? 2 ??? 8
  ????????????????????????????????

63
2.4.2 HCV NS3 Protein

• NS3 ???? multifunctional protein
  ???????????????????? NS3/4A, NS4A/4B, NS4B/5A ???
  NS5A/5B junction ????????????????? 4 mature viral
  non-structural protein
• ?????????????? NS3 serine protease
  ?????????????????????????????? anti-HCV agent
• ???????????????????????????????????? 3 ????????
  ??? 1) enzyme active site 2) structural
  zinc-binding site ??? 3) NS4A binding site

64
2.4.2.1 Inhibitor ??? HCV NS3 Protease
2.4.2.1.1 Peptide-Based Inhibitor

• Ac-D-Gla-Leu-Ile-Cha-Cys-OH ???? Cha-Cys-OH
  ??????????????? peptide ??????????? HCV NS3
  protease ?????

Ac-D-Gla-Leu-Ile-Cha-Cys-OH
65
2.4.2.1.1 Peptide-Based Inhibitor

• Nanomolar peptide-based inhibitor ??????????? HCV
  serine protease-specific inhibitor
• ?????????????????????????? aromatic group
  ?????????????????????????????????????
  ????????????????????????????????? P2
• ??????????????????????????????????????????????????
  
• tetrapeptide ????? N-terminal truncation
• ????????????????????? ????????????????????????

66
2.4.2.1.2 Low Molecular Weight Inhibitor

• RD3-4082 ???????????? benzamide derivative
  ?????????????? NS3-4A protease ?????
• ????? N-alkyl chain ??????????????????????????????
  ?????????????

RD3-4082
67
2.4.2.2 Inhibitor ??? HCV NS3 Helicase

• Helicase activity ????????????????? HCV NS3
  protein ??????????????????????????????????????
  long-chain compound
• ????????????? NH group ?? benzimidazole ring ??
  benzene group ??? C2 position ??? benzimidazole
  ????? linker

68
2.4.3 Inhibitor ??? NS5B RNA-Dependent RNA
Polymerase

• HCV NS5B protein ??? encode RNA-dependent RNA
  polymerase (RdRp) activity ???????????????????????
  ???????????? gliotoxin
• Gliotoxin ???? poliovirus 3D RdRp inhibitor
  ?????????? HCV NS5B RdRp

gliotoxin (160)
69
2.9 Broad-Spectrum Antiviral Compounds2.9.1
S-Adenosyl-L-Homocysteine Hydrolase Inhibitors

• S-adenosyl-L-homocysteine (SAH) hydrolase
  ?????????????????????????????? transmethylation
  ???????????????????????????????????? SAH
  hydrolase ????????? CH3??? 5-terminal residue
  ??? viral mRNA ?????????????? 5-methylated cap
  structure ????????????????? viral protein
  translation ??? replication
• ?????????????? SAH hydrolase ?????????????????????
  ????? antiviral chemotherapy
• ??????????? ???? D-5-noraristeromycin

D-5-noraristeromycin R
70
??