1.
Structure-Activity Relationships of Sulfonimide and Ester-Based Inhibitors of
Plasminogen Activator Inhibitor-1
Karen L. Sanders,1 Nadine C. El-Ayache,1 Gregory A. Abernathy,1 Jacinda M. Lisi,1 Melinda S. Myers,1 Paul R. North,1 Shih-Hon
Li,2 Mark Warnock,2 Daniel A. Lawrence,2 Cory D. Emal1*; (1) Chemistry Department, Eastern Michigan University, Ypsilanti,
48197; (2) Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, 48109
Effect of modifying the gallate to a protocatechuate on PAI-1 inhibition:
Design and Synthesis
Introduction/Background
Scheme 1: Synthesis of sulfonimide-based PAI-1 inhibitors (5)
The inhibition of plasminogen activator-inhibitor-1 (PAI-1) is
anticipated to increase our understanding of various human O O O OO O O OO O
MeO S ArSO2Cl MeO S S OMe BBr3 HO S S OH
ailments including diabetes, stroke, and atherosclerosis, with NHR N N
R R
which high levels of PAI-1 have been associated.(1) PAI-1 MeO NaH MeO OMe HO OH
prevents certain serine proteases from cleaving peptide bonds IC50: IC50: IC50:
and thus is able to regulate various cellular processes such as Scheme 2: Synthesis of ester-based PAI-1 inhibitors (4) X = OH: 0.104 µM X = OH: 0.062 µM X = OH: 0.105 µM
controlling the levels of other intracellular proteins, such as tissue- X = H: (ND) X = H: 0.048 µM X = H: 0.029 µM
type plasminogen activator (tPA) and urokinase-type plasminogen O O
BocHN OH O
1) BnCl, KI, K2CO3 OH
activator (uPA).(2) O (CH3)2CO, reflux OH EDCįHCl, DMAP O
O
OBn
Effect on PAI-1 inhibition of manipulating the carbamate side chain:
CH2Cl2 O
HO 2) NaOH,C2H5OH BnO HN
BnO
reflux, 18 hr
O O
O
O
O
OBn
O TFA
BnO H3N
CH2Cl2
CF3CO2
O
triphosgene
RO Cl IC50 = 4.75 µM IC50 = 4.69 µM IC50 = 0.159 µM
NaHCO3 (aq.)
CH2Cl2 OH OH
pyridine OH
OH OH
O O
OH
O HO O HO O
O O O
O R-OH HO O
O O O
O triethylamine O HO HN HO HN
O O
O OBn HO HN
OBn CH2Cl2 O O
O O O O
BnO HN O O
Fibrinolysis: BnO N Cl
C O OR 7
Green arrows = stimulatory effect O
Red arrows = inhibitory effect
O IC50 = 0.02 µM IC50 = 0.027 µM IC50 = 0.022 µM
O
10% Pd¼
/C O OH
O
H2
CH2Cl2
HO HN Conclusions
O OR
The goal of this research is to develop small-molecule inhibitors of
• Sulfonamide inhibitors have an optimum methylene unit length of 6.5
PAI-1, a major natural inhibitor of fibrinolysis, the process which leads which correlates to a chain length of approximately 780-1000 pm.
to the breakdown of blood clots. The structural complexity of the PAI-1 Inhibition Assay Results • The protocatechuate modification tends to moderately improve PAI-1
protein allows for multiple potential binding sites. Several classes of inhibition compared to gallate moieties.
PAI-1 inhibitors have been reported, recently including a furan-2-one
Effect of side-chain length on PAI-1 inhibition: • Potency of ester-based inhibitors is enhanced by the side-chain:
and pyrrolin-2-one series. (3) • Inhibition improves as size of carbamate handle increases.
• Ring ending carbamate handles or linker handles composed of
• Drawbacks of these inhibitors: approximately 7 methylene units give most potent inhibitors in series.
• low binding affinity for PAI-1
• inability to inhibit PAI-1 in the presence of vitronectin
Future Directions
• Route of developing our PAI-1 inhibitor scaffolds
• Test the inhibitory effect of electronically larger species attachments.
• high-throughput screen of MicroSource SPECTRUM library.(4) R IC50 Values (µM) • Synthesize inhibitors with nonsymmetrical gallate attachments.
• hypothesized effective inhibitors based on tannic acid as a lead • Incorporate different functionality into linking unit.
compound (IC50 = 6.6 nM) H N.D.
• gallate/digallate-containing species (CH2)2CH3 2.670 Acknowledgements
• synthesized a number of novel small-molecule inhibitors (4,5) (CH2)4CH3 0.240 Funding from:
- National Institutes of Health (HL089407); Camille and Henry Dreyfus Foundation; Eastern
(CH2)5CH3 0.284 Michigan University
(CH2)7CH3 0.086
(CH2)9CH3 0.250 References
1) Ren, Y.; Himmeldirk, K.; Chen, X. J. Med. Chem. 2006, 49, 2829-2837.
(CH2)11CH3 2.600 2) Wang, Z.; Mottonen, J.; Goldsmith, E. J. Biochemistry. 1996, 35 (51), 16443-16448.
3) Miyazaki, H.; Ogiku, T.; Hiroshi, S.; Moritani, Y.; Ohtanl, A. Chem. Pharm. Bull. 2009, 57 (9), 979-985.
4) Cale, J. M.; Li, S.; Warnock, M.; Su, E. J.; North, P. R.; Sanders, K. L.; Puscau, M. M.; Emal, C. D.; Lawrence, D. A. J. Biol. Chem. 2010, in press.
5) El-Ayache, N. C.; Li, S. H.; Warnock, M.; Lawrence, D. A.; Emal, C. D. Bioorg. Med. Chem. Lett. 2010, 966-970.