Identification of Human Toll-like Receptor 2-Agonistic Activity in

Subscriber access provided by University of Winnipeg Library

Letter

Identification of Human Toll-like Receptor 2-Agonistic Activity in Dihydropyridine-Quinolone Carboxamides Ziwei Hu, Janardhan Banothu, Mallesh Beesu, Collin J. Gustafson, Michael J. H. Brush, Kathryn L. Trautman, Alex C.D. Salyer, Balaji Pathakumari, and Sunil A. David ACS Med. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acsmedchemlett.8b00540 • Publication Date (Web): 20 Dec 2018 Downloaded from http://pubs.acs.org on December 23, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Medicinal Chemistry Letters

Identification of Human Toll-like Receptor 2-Agonistic Activity in Dihydropyridine-Quinolone Carboxamides. Ziwei Hu, Janardhan Banothu, Mallesh Beesu, Collin J. Gustafson, Michael J. H. Brush, Kathryn L. Trautman, Alex C.D. Salyer, Balaji Pathakumari, Sunil A. David*. Department of Medicinal Chemistry, University of Minnesota, Sixth Street SE, Minneapolis, Minnesota 55455, United States KEYWORDS: Vaccine adjuvants, Toll-like receptor 2, Chemokines, Cytokines, Dihydropyridine-quinolones. ABSTRACT: Using a multiplexed, reporter gene-based, high-throughput screen, we identified 9-fluoro-7-hydroxy-3-methyl-5-oxoN-(pyridin-3-ylmethyl)-2,3-dihydro-1H,5H-pyrido[3,2,1-ij]quinoline-6-carboxamide as a TLR2 agonist. Preliminary SAR studies on the carboxamide moiety led to the identification of analogues that induce chemokines and cytokines in a TLR2-dependent manner. These results represent new leads for the development of vaccine adjuvants.

The sustained decrease in mortality caused by infectious diseases is largely attributable to immunization, and vaccines continue to play an indispensable role in decreasing the burden of infectious diseases worldwide.1 The major categories of vaccines are those that contain live attenuated microbes, those that contain killed microbes, and those that contain one or more of an antigenic subunit (such as protein or polysaccharide) derived from the microbe.2 Modern vaccines increasingly rely on well-defined, highly purified subunit and recombinant antigens, and often require the incorporation of appropriate immune potentiators (also termed adjuvants), along with the antigen. Adjuvants initiate early innate immune responses and thereby enhance immunogenicity, leading to more robust and long-lasting adaptive immune responses.3 Toll-like receptors (TLRs) are a family of pattern recognition receptors that serve as key sentinels of innate immune system. There are 10 TLRs in the human genome; these trans-membrane proteins recognize pathogen-associated molecular patterns that are shared by pathogens but are sufficiently different so as to be distinguishable from host molecules. 4-6 The engagement of innate immune receptors plays a role in the action of vaccine adjuvants such as monophosphoryl lipid A (TLR4 agonist)7 and Adjuvant 1018 (TLR9 agonist),8-9 highlighting the importance of innate immune stimulatory molecules in the design and development of novel vaccines. Using a recently-described multiplexed, reporter gene-based, high-throughput screen (HTS) capable of detecting agonists of TLR2, TLR3, TLR4, TLR5, TLR7, TLR8, TLR9, NOD1 and NOD2,10 we identified a novel immunostimulatory chemotype, typified by the hit compound 2 (9-fluoro-7-hydroxy-3-methyl5-oxo-N-(pyridin-3-ylmethyl)-2,3-dihydro-1H,5H-pyrido [3,2,1-ij]quinoline-6-carboxamide, Scheme 1). Subsequent deconvolution of activity in individual TLR/NLR screens indicated TLR2 activity with no detectable activity for other TLR/NLR targets in counter-screens. Other than numerous

canonical TLR2 agonists of the thioacylglycerol lipopeptide chemotypes that we had previously explored,11-14 heterocyclic small molecules capable of engaging TLR2 have not been identified as of yet. An examination of the HTS results for the nearest neighbors of 2 suggested that the amide-lined aryl group could be a productive venue for exploration. We report here a preliminary structure-activity relationship study on varying the 6-carboxamide moiety. The tricyclic dihydropyridine-quinolone core was synthesized using an elegant one-pot method developed by Ukrainets et al.15-16 A concerted nucleophilic addition-cyclization reaction of 6-fluoro-2-methyl-1,2,3,4-tetrahydroquinoline with triethyl methanetricarboxylate afforded the ester 1, which was subsequently displaced with a variety of amines to yield analogues 2 (hit compound) through 57 (Scheme 1). We began our SAR exploration by evaluating substituted pyridines (analogues 3-21), an examination of which initially appeared to suggest that substituents at C2 and C6 of the pyridine ring were poorly tolerated, whereas those at C4 and C5 were well tolerated. However, 14, with a 6-aminopyridylmethyl substituent was found to be equipotent to 2 in primary human TLR2-specific reporter gene assays, and compound 11 bearing a 6-chloropyridylmethyl substituent was also found to be weakly active (Figure 1). Surprisingly, 16, with a 2dimethylaminopyridylmethyl group, but not 15 with a 6dimethylaminopyridylmethyl functional group retained TLR2agonistic activity (Figure 1A). Taken together, these results appeared to point to potential Hbonding interactions with the ring nitrogen of the pyridine in a particular rotameric configuration, a surmise that was consistent with the finding that the homologated analogue 26, as well as conformationally constrained derivative 27 also retained activity. Activity was lost in all of the regioisomeric pyridinylmethyl analogues (19-21, 25), as well as pyridazinylmethyl (22, 24) and the pyrimidinylmethyl compound 23 (Figure 1A).

ACS Paragon Plus Environment

ACS Medicinal Chemistry Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 8

Scheme 1a OH O

F

OH O

F

i

OEt

NH

ii

R

N H

O

N

R=

F O

N

1

2-57 F

N 2

N 3

Cl

N 11

N 4

CF3

N

N 5

O

N

12

NH2

N

O

13

OH

N 6

N

14

N 19

N

N

O

N 8

O

N

N

16

17

N 22

21

HN

N

N

N 23

N

N 24

30

31

25

37

N 44

45

N

18

O N 46

40

39

N N O 47

O 48

N

27

N NH 35

34

O

O

38

N

N

NH2

N N

N

N

33

O

O

N

N

32

O

N 36

N

N 26

HN

N NH

NH HN NH 29

N 10

N

N

28

N 9

N

N

20

O

15

O N

N 7

S 49

N N 41

S 50

N 51

N N 42

O 52

N N 43

HN 53

O N 54 H

N 55

NH 56

N 57 H

Reagents and conditions: (i) Triethyl methanetricarboxylate, diphenyl ether, microwave, 180 oC, 1 h; (ii) alkyl/aryl methanamines, DMF, microwave, 100 oC, 30 min (for 2-8, 10-12, 14-26, 28-33, 35, 37-45, 47-52 and 55); alkyl/aryl methanamine (hydrochloride salts), DIPEA, DMF, microwave, 100 oC, 30 min (for 9, 13, 27, 34, 36 and 46); N-Boc protected heterocycloalkyl methanamine, DMF, microwave, 100 oC, 30 min, 4 M HCl in dioxane, 2 h (for 53, 54, 56 and 57). a

Active compounds are depicted in red. Their corresponding EC50 values in human TLR2 screens are listed in Figure 1. Compounds 27, and 51-57 were obtained as the racemates.


Page 3 of 8

Figure 1. (A). Human TLR2-specific agonistic potencies of active analogues in primary screens (reporter gene assay). (B). Human MCP-1 induction (EC50 values) in human TLR2-expressing cells by select analogues. PAM2CSK4 (100 ng/mL) and DMSO (diluent) were used as positive and negative controls, respectively, in both assays. Data shown are means of quadruplicates.

2.5

2.0

2.0

1.5

1.5

1.0

1.0

0.5

0.5

0.0

0.0

trl. K4 CS eg. C M2 N PA

Controls

-8

10

-7

10

-6

10

-5

10

-4

10

500

500

400

400

300

300

200

200

100

100

0

0

trl. K4 CS g. C M2 Ne A P

Congeners with indolylmethyl substituents (28-31), as well as the benzimidazolylmethyl derivative 33 were inactive. The Nmethylpyrazolylmethyl analogue 42 and the morpholinyl derivative 57, a variety of heterocyclic (32, 32-41, 43-50) and saturated heterocyclic compounds (51-56) were also inactive (Scheme 1). In ongoing studies aimed at delineating ‘signatures’ that are diagnostic of innate immune activation regardless of the innate immune sensor involved, we have found using next-generation RNA sequencing of global transcriptomal programs (and subsequently confirmed by analyte-specific immunoassays), prominent upregulation of CC and CXC chemokines by virtually the entire repertoire of innate immune stimuli.17 We therefore examined MCP-1 induction in human TLR2expressing reporter cells to confirm the observations of our primary screens. We were gratified to find that MCP-1 induction was largely concordant with TLR2-agonistic potencies derived from reporter gene assays (Figures 1A and 1B). However, we observed differences in rank-order potencies between the assay platforms for a few compounds, in particular. Compounds 14 and 10 were considerably weaker in eliciting MCP-1 (Figure 1B) than would be expected from their corresponding hTLR2 EC50 values (Figure 1A); conversely, analogue 26 was considerably more potent in eliciting MCP-1.

2 (1.35 M) 26 (1.86 M) 10 (4.52 M) 16 (3.09 M) 14 (7.56 M)

-7

B

-6

10

Controls

Compound Concentration (M)

-5

10

10

-4

10


Figure 2. Dose-response profiles of cytokine and chemokine induction in THP-1 cells. Data shown are means of triplicates. 80

20

TNF-

18

IL-1

16

60

14 26 2

40

14 12 10 8

20

6 4

0

Analyte Concentration (pg/mL)

2.5

A

2 (0.3 M) 14 (0.32 M) 10 (1 M) 26 (1.35 M) 5 (1.45 M) 27 (3 M) 16 (3.2 M) 11 (5 M)

3.0

hMCP-1 Concentration (pg/mL)

3.0

Relative hTLR2-specific NF-B Induction (A620 nm)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


2

1000

IP-10

300

MCP-1

800 250

600

200

150 400 100 200 50

0

700

0

MIP-1

80

MIP-1

600 60 500

400 40 300

200

20

100

0

0

10

-8

10

-7

10

-8



10

-7


OH O

Scheme 2

F F N

ii

F

iii

F

OEt

N H

O TsN 58a

N

OH O N

O

59a

N H

N

61 (R-enantiomer of 2) iv OH O

O F

60a

N

O

N H

NH2

N

62 (R-enantiomer of 14)

F i N H

OH O F N

F N O TsN 58b

ii

O

F

iii

F N

F

O

N

59b

N

OH O

OEt iv

N H

N H

63 (S-enantiomer of 2)

OH O

O

N H

60b

N

NH2

64 (S-enantiomer of 14) OH O F N

O

F

N H

N 65 (S-enantiomer of 10)

Reagents and conditions: (i) (a) N-tosyl-L-proline, oxalyl chloride, DMF, toluene, RT, overnight; (b) DIPEA, DCM, reflux, 30 min; (ii) NaOEt, EtOH, reflux, overnight; (iii) Triethyl methanetricarboxylate, diphenyl ether, microwave, 180 oC, 1h; (iv) 3-picolylamine (for 61 and 63), or 5(aminomethyl)pyridine-2-amine (for 62and 64), or (5-fluoropyridin-3-yl)methanamine (for 65), DMF, microwave, 100 oC, 30 min.

In order to identify the eutomer, distomer (and eudysmic ratios) of the racemic TLR-active compounds, we initially undertook the syntheses of R- and S- enantiomers of 2 and 14 (Scheme 2). N-acylation of 6-fluoro-2-methyl-1,2,3,4-tetrahydroquinoline with tosyl-S-prolinoyl chloride resulted in easily separable diastereoisomers 58a and 58b (Scheme 2), whose characterization exactly matched the findings of Sonawane and co-workers.18 Solvolysis with NaOEt furnished enantiomeric intermediates 59a and 59b, which furnished the enantiopure targets 61-65 (Scheme 2). Examination of these compounds in TLR2-specific reporter gene assays revealed that the Senantiomers were eutomeric, which was confirmed again in 65, the S-enantiomer of 10 (Fig. 3). Given that cells of myeloid lineage are the primary responder cells for TLR2 stimuli,19-21 we sought to re-examine select active enantiopure compounds in THP-1 cells of monocytic lineage using multiplexed cytokine/chemokine assays. Consistent with results depicted in Figure 1B, the Senantiomeric compounds 63-65 were found to be prominent inducers of chemokines MCP-1, MIP-1 and MIP-1 (Figure S1) .

Figure 3. TLR2-agonistic activity of enantiopure compounds. Data shown are means of triplicates. 3

Relative hTLR2-specific NF-B Induction (A620 nm)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 8

R-enantiomers: 61 62

2

S-enantiomers: 63 64 65 Controls: PAM2CSK4 DMSO

1

0

10

-11

10

-10

10

-9

10

-8

10

-7

10

-6

10

-5

Compound Concentration (g/mL)


4

Page 5 of 8

Figure 4. (A). NF-B induction by PAM2CSK4 (canonical TLR2 agonist) and the enantiopure compounds 63-65 in THP-1 Blue reporter cells showing relative potencies of the two compounds. (B) Additive effect of PAM2CSK4 and 63. Dose-response profiles to 63 in THP-1 Blue reporter cells are enhanced in the presence of increasing concentrations (0.015 pM to 9.83 pM) of PAM2CSK4. Data shown are means of quadruplicates. Similar enhancements were also observed for 64 and 65.

2.5

A

Pam2CSK4 Relative NF-B Induction (A620 nm)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


2.0

2.5

2.0

63 64 65

1.5

9.83 pM 4.92 pM 2.46 pM 1.23 pM 0.614 pM 0.307 pM 0.015 pM

1.5

1.0

1.0

0.5

0.5

0.0

10

B

PAM2CSK4 Conc.

0.0

-11

10

-10

10

-9

10

-8

10

-7


Given that the dihydropyridine-quinolone carboxamides represent a novel class of TLR2 agonists, it was of particular interest to explore if these compounds bind to TLR2 at a site distinct from that of the canonical lipopeptides. While definitive conclusions must await crystallographic studies, co-stimulation experiments (Figure 4) clearly indicate additive effects of 63 in the presence of PAM2CSK4. Similar additive results with PAM2CSK4 were also observed for 64 and 65 (Figure S2). These results suggest that the binding site of the dihydropyridine-quinolone carboxamides are likely to be distinct. These results represent exciting new leads of non-canonical small-molecule agonists of TLR2, and charts a course forward for a detailed exploration of SAR of both the dihydropyridine and quinolone rings of the tricyclic core.

10

-8

10

-7

10

-6

Compound 63 Concentration (M)

Author Contributions The manuscript was written through contributions of all authors.

Funding Sources This work was supported by NIH/NIAID contract HHSN272201400056C.

ABBREVIATIONS HTS, high-throughput screen; IL-1 alpha, Interleukin-1 alpha; MCP-1, Monocyte chemoattractant protein 1 (CCL2); MIP-1 alpha/beta, macrophage inflammatory protein 1-alpha/beta; NOD1/2, Nucleotide-binding oligomerization domain-containing protein 1/2; NLR, NOD-like receptor; TLR, Toll-like receptor; TNF-alpha, tumor necrosis factor alpha.

REFERENCES

Supporting Information The Supporting Information is available free of charge on the ACS Publications website. Syntheses and experimental procedures, and characterization of compounds (PDF).

AUTHOR INFORMATION Corresponding Author * Sunil A. David, Department of Medicinal Chemistry, University of Minnesota, 2-132 CCRB, 2231 6th Street SE, Minneapolis, MN 55455. Phone: (612) 625-3848. Email: [email protected]

1. Plotkin, S. A. Vaccines: the fourth century. Clin. Vaccin. Immunol. 2009, 16, 1709-1719. 2. Plotkin, S. A. Vaccines: past, present and future. Nat. Med. 2005, 11, S5-S11. 3. Ahmed, S. S.; Plotkin, S. A.; Black, S.; Coffman, R. L. Assessing the safety of adjuvanted vaccines. Sci. Transl. Med. 2011, 3, 93rv2. 4. Takeda, K.; Akira, S. Toll-like receptors. Curr. Protoc. Immunol. 2015, 109, 14.12.1-14.12.10. 5. Pandey, S.; Kawai, T.; Akira, S. Microbial sensing by Toll-like receptors and intracellular nucleic acid sensors. Cold Spring Harb. Perspect. Biol. 2014, 7, a016246. 6. Hoffmann, J.; Akira, S. Innate immunity. Curr. Opin. Immunol. 2013, 25, 1-3. 7. Tagliabue, A.; Rappuoli, R. Vaccine adjuvants: the dream becomes real. Hum.Vaccin. 2008, 4, 347-349.


5


Page 6 of 8

8. Jackson, S.; Lentino, J.; Kopp, J.; Murray, L.; Ellison, W.; Rhee, M.; Shockey, G.; Akella, L.; Erby, K.; Heyward, W. L.; Janssen, R. S. Immunogenicity of a two-dose investigational hepatitis B vaccine, HBsAg-1018, using a toll-like receptor 9 agonist adjuvant compared with a licensed hepatitis B vaccine in adults. Vaccine 2018, 36, 668674. 9. Campbell, J. D. Development of the CpG Adjuvant 1018: A Case Study. Methods Molec. Biol. 2017, 1494, 15-27. 10. Salyer, A. C.; Caruso, G.; Khetani, K. K.; Fox, L. M.; Malladi, S. S.; David, S. A. Identification of Adjuvantic Activity of Amphotericin B in a Novel, Multiplexed, Poly-TLR/NLR High-Throughput Screen. PloS ONE 2016, 11, e0149848. 11. Wu, W.; Li, R.; Malladi, S. S.; Warshakoon, H. J.; Kimbrell, M. R.; Amolins, M. W.; Ukani, R.; Datta, A.; David, S. A. Structure-activity relationships in Toll-like receptor-2 agonistic diacylthioglycerol lipopeptides. J. Med. Chem. 2010, 53, 3198-3213. 12. Agnihotri, G.; Crall, B. M.; Lewis, T. C.; Day, T. P.; Balakrishna, R.; Warshakoon, H. J.; Malladi, S. S.; David, S. A. Structure-activity relationships in Toll-like receptor 2-agonists leading to simplified monoacyl lipopeptides. J. Med. Chem. 2011, 54, 8148-8160. 13. Salunke, D. B.; Connelly, S. W.; Shukla, N. M.; Hermanson, A. R.; Fox, L. M.; David, S. A. Design and development of stable, watersoluble, human Toll-like receptor 2 specific monoacyl lipopeptides as candidate vaccine adjuvants. J. Med. Chem. 2013, 56, 5885-5900. 14. Salunke, D. B.; Shukla, N. M.; Yoo, E.; Crall, B. M.; Balakrishna, R.; Malladi, S. S.; David, S. A. Structure-activity relationships in human Toll-like receptor 2-specific monoacyl lipopeptides. J. Med. Chem. 2012, 55, 3353-3363. 15. Ukrainets, I. V.; Sidorenko, L. V.; Gorokhova, O. V.; Shishkin, O. V.; Turov, A. V. 4-Hydroxy-2-quinolones. 108. N-R-amides of 9fluoro-1-hydroxy-5-methyl-3-oxo-6,7-dihydro-3H,5H-pyrido[3,2,1ij]quinoline-2-carboxylic acid and their antitubercular activity. Chem. Heterocycl. Compd. 2006, 42, 1208-1222. 16. Ukrainets, I. V.; Sidorenko, L. V.; Gorokhova, O. V.; Mospanova, E. V.; Shishkin, O. V. 4-hydroxy-2-quinolones. 94. Improved synthesis and structure of 1-hydroxy-3-oxo-5,6-dihydro-3h-pyrrolo[3,2,1-i,j]quinoline-2-carboxylic acid ethyl ester. Chem. Heterocycl. Compd. 2006, 42, 631-635. 17. Salyer, A. C. D.; David, S. A. Transcriptomal signatures of vaccine adjuvants and accessory immunostimulation of sentinel cells by Tolllike receptor 2/6 agonists. Hum. Vaccin. Immunother. 2018, 14, 16861696. 18. Sonawane, Y. A.; Zhu, Y.; Garrison, J. C.; Ezell, E. L.; Zahid, M.; Cheng, X.; Natarajan, A. Structure-Activity Relationship Studies with Tetrahydroquinoline Analogs as EPAC Inhibitors. ACS Med. Chem. Lett. 2017, 8, 1183-1187. 19. Kimbrell, M. R.; Warshakoon, H.; Cromer, J. R.; Malladi, S.; Hood, J. D.; Balakrishna, R.; Scholdberg, T. A.; David, S. A. Comparison of the immunostimulatory and proinflammatory activities of candidate Gram-positive endotoxins, lipoteichoic acid, peptidoglycan, and lipopeptides, in murine and human cells. Immunol. Lett. 2008, 118, 132-141. 20. Hood, J. D.; Warshakoon, H. J.; Kimbrell, M. R.; Shukla, N. M.; Malladi, S.; Wang, X.; David, S. A. Immunoprofiling toll-like receptor ligands: Comparison of immunostimulatory and proinflammatory profiles in ex vivo human blood models. Hum. Vaccin. 2010, 6, 1-14. 21. Warshakoon, H. J.; Hood, J. D.; Kimbrell, M. R.; Malladi, S.; Wu, W. Y.; Shukla, N. M.; Agnihotri, G.; Sil, D.; David, S. A., Potential adjuvantic properties of innate immune stimuli. Hum. Vaccin. 2009, 5, 381-394.


6

Page 7 of 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


TOC GRAPHIC OH

R=

O

F

OH N H

N

O

HIT Compound in HTS

R

SAR

O

F

N H N

R

O

N N

TLR2-active Compounds

NH2 F

N


7


Page 8 of 8

TOC GRAPHIC


7

Identification of Human Toll-like Receptor 2-Agonistic Activity in

Recommend Documents