Biotage Microwave Symposium

Transcription

1 Biotage Microwave Symposium 3-Aryl-4-hydroxyquinolin-2(1)-one Derivatives as Type I Fatty Acid Synthase Inhibitors: Development of a Solvent-Free Microwave Synthesis for Rapid SAR Studies Alexey Rivkin, Ph.D. May 10, 2007

2 uman Fatty Acid Synthase (Type 1 FAS) Acetyl CoA +7 Malonyl CoA +14 ADP FAS Palmitate +7 C 2 +8 CoA +14 ADP Mammalian FAS is a multifunctional enzyme consisting of two identical 272-kD polypeptide chains, each containing 7 domains. KS MAT D core ER KR ACP TE Smith et al. Prog. Lipid Res. 2003, 42, C

3 uman Fatty Acid Synthase (Type 1 FAS) Two models have been proposed: ead to Tail (A) ead to ead (B) Sememkovich, C. F. Prog. Lipid Res. 1997, 36,

4 uman FAS as a Potential Therapeutic Target uman FAS is a target for drug development against: 1. besity 2. Diabetes and cardiovascular disorders (obesity related diseases) 3. Cancer

5 Fatty Acid Synthase and uman Cancer -Inhibition of FAS has been shown to induce apoptosis in cancer cells. Targeting FAS provides a large therapeutic window: - uman cancer cells express high levels of fatty acid synthase and undergo significant endogenous fatty acid synthesis. - FAS is down regulated in most normal human tissues because of the fat in our diet. This differential tissue distribution makes FAS an attractive therapeutic target for the treatment of cancer.

6 Biosynthesis of Palmitate by FAS S-CoA Acetyl CoA - S-CoA Malonyl CoA MAT KS - S-Cys-KS KS S-ACP S-ACP KR Acetoacetyl-CoA S-ACP D S-ACP ER S-ACP Palmitoyl-ACP 6X Palmitoyl-ACP -ACP TE Palmitate D = B-hydroxyacyl-ACP dehydrase KR = B-ketoacyl-ACP reductase ER = enol-acp reductase KS = B-ketoacyl-ACP synthase MAT= Malonyl/acetyl-CoA-ACP transacylase TE = palmitoyl thioesterase

7 Reported Inhibitors of FAS Inhibitors of Ketoacyl Synthase (KS) Inhibitors of Thioesterase (TE) C 2 Cerulenin n-c n-c 6 13 C n-c 7 15 C75 n-c 7 15 S C247 - rlistat (Tetrahydrolipstatin) inhibits thioesterase domain Marketed as Xenical by Roche for treatment of obesity - inhibits pancreatic lipase in the gastrointestinal tract, thereby preventing uptake of dietary fat. KS MAT D core ER KR ACP TE C

8 Lead Compound from igh Throughput Screen 2 IC 50 =1403 nm (uman FAS) igh Throughput Screen Initial Strategy: Develop a rapid synthesis of 3-aryl-4-hydroxyquinolin- 2(1)-one derivatives to perform SAR studies.

9 Reported Synthetic Methods 2 + Et Ph Et μw, 290 o C 15 min 81% Lange et al. Tetrahedron Lett. 2001, 42, X 2 Me Ph Me X C 3 equiv. 2 C 2, amds, reflux, 3-12 h TF, 0C 50-90% Ph 50-90% X DeVita et al. Bioorg. Med. Chem. Lett. 1999, 9,

10 Limitations of Lange s Microwave Reaction Me 2 μw, 290 o C 15 min Et Ph Et Me 40% + B.P. = 78 C F 3 C μw, 290 o C 15 min F 3 C 2 Et Ph Et 0% Limitations: 1. Reaction has to be conducted in an open microwave vessel. 2. Reaction does not work with electron deficient anilines.

11 vercoming Limitations by Using Arylmalonates 2 μw, 290 o C 15 min 2 2 Et Et Ph 0% Proposal: 2 2 μw 2 Ph μw 2 + Ph - More reactive - Can perform reaction in closed vessel B.P. = 246 o C

12 Microwave Synthesis of TS Lead Compound 2 2 μw, 250 o C 15 min 2 67% Internal pressure never surpassed 1 bar μw, 250 C 15 min Filter and dry under vacuum Purity: 95% o solvent Add diethyl ether and product precipitates

13 Scope of the Microwave Reaction F 3 C Et or Ph B Et F 3 C 2 A A: 78%; B: 0% μw, 250 o C, 15 min S F 3 C S A: 74%; B: 0% A: 71%; B: 0% 2 Et A: 67%; B: 0% A: 93%; B: 15% 2 Me A: 81%; B: 0% A: 89%; B: 6% 2 A: 91%; B: 51% A: 93%; B: 54%

14 Scope of the Microwave Reaction 2 Et or Ph Et B A: 95% B: 58% A μw, 250 o C, 15 min A: 83% B: 20% A: 95% B: 58% A: 87% B: 58% A: 80% B: 36% Br A: 89% B: 64% A: 71% B: 0% A: 92% B: 63% A: 86% B: 61%

15 SAR ighlights C 2 C IC 50 =136nM uman FAS IC 50 =1403nM IC 50 =1294nM C IC 50 =360nM Inactive: 2 S C 2

16 SAR ighlights C C C Me uman FAS IC 50 =136nM IC 50 =52nM IC 50 =19nM C R R= S IC 50 =4100nM IC 50 =194nM IC 50 =54nM F IC 50 =734nM

17 Summary Developed an efficient and general microwave synthesis of 4- hydroxy-3-pyridin-2(1)-one derivatives. C μw, 250 o C 15 min C 2 Ph 83% Rivkin et al. Tetrahedron Lett. 2006, 47, This microwave synthesis allowed for rapid SAR studies to be performed. 2 SAR Studies C 70X Fold Improvement IC 50 =1403 nm IC 50 =19 nm Rivkin et al. Bioorg. Med. Chem. Lett. 2006, 16,