JP2007063156A - Fatty acid synthetase (fas) inhibitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a FAS inhibitor which is expected to be pharmacologically high selectively useful as an antiobestic medicine and an anticancer agent. <P>SOLUTION: Non-natural type (S)-thiolactomycin and (S)-3-demethylthiolactomycin are synthesized, and it has been found that the compounds have excellent fatty acid synthetase (FAS) inhibiting activities. Such the FAS inhibitor is useful as an antiobestic medicine and an anticancer agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to (S) -thiolactomycin (R ¹ represents a methyl group) and (S) -3-demethylthiolactomycin (R ¹ represents a hydrogen atom) represented by the following general formula (1). The present invention relates to an inhibitor of fatty acid synthase (hereinafter abbreviated as FAS).

  (R) -thiolactomycin (2) is a thiotetronic acid antibiotic isolated from Nocardia sp. And its structure determined (Non-patent Document 1).

(R) -thiolactomycin has been reported to exhibit antibacterial activity by inhibiting bacterial FAS (Non-Patent Documents 2, 3, and 4). Racemic thiolactomycin and its derivatives have been reported to have antimalarial activity (Non-patent Document 5). In addition, since it has an action mechanism of FAS inhibition, development of thiolactomycin and its derivatives as anti-obesity agents and anti-cancer agents is expected (Non-patent Document 6). In thiolactomycin, (R) and racemic FAS inhibitory activity has been reported (Non-patent Document 6 and Patent Document 1), and in 3-demethylthiolactomycin, racemic FAS inhibitory activity has been reported. (Non-patent document 6 and Patent document 1). There were no synthesized examples of (S) -thiolactomycin and (S) -3-demethylthiolactomycin which are non-naturally occurring, and their FAS inhibitory activity was not clear.

Oishi, H. et al., J. Antibiot. 1982, 35, 391. Miyakawa, S. et al., J. Antibiot. 1982, 35, 411. Noto, T. et al., J. Antibiot. 1982, 35, 401. Slayden, R.A., et al., Antimicrob. Agents Chemother. 1996, 40, 2813. Waller, R. F., et al., Antimicrob. Agents Chemother. 2003, 47, 297. Townsend, C.A., et al., J. Med. Chem., 2005, 28, 956. WO 2004/005277 Brochure

  The aim is to develop an excellent FAS inhibitor that has high pharmacological selectivity and is expected to be used as an antiobesity agent and anticancer agent.

  As a result of synthesizing both enantiomers of thiolactomycin and 3-demethylthiolactomycin and measuring their FAS inhibitory activity, the present inventors have found that (S) -thiolactomycin and (S) The inventors have found that -3-demethylthiolactomycin has an FAS inhibitory activity superior to its enantiomers and racemates, thereby completing the present invention. Although (S) -thiolactomycin and (S) -3-demethylthiolactomycin of the present invention show excellent FAS inhibitory activity, they do not show antibacterial activity, so they are highly pharmacologically selective FAS inhibitors. is there.

That is, the present invention is 1) General formula (1)

(Wherein R ¹ represents a hydrogen atom or a methyl group) or a fatty acid synthase inhibitor comprising a compound represented by the formula or a pharmacologically acceptable salt thereof as an active ingredient,

2) a fatty acid synthase inhibitor comprising the compound represented by the general formula (1) as an active ingredient (S) -thiolactomycin or a pharmacologically acceptable salt thereof,

3) a fatty acid synthase inhibitor whose compound represented by the general formula (1) is (S) -3-demethylthiolactomycin or a pharmacologically acceptable salt thereof as an active ingredient,
It is about.

Non-natural (S) -thiolactomycin and (S) -3-demethylthiolactomycin exhibit superior FAS inhibitory activity compared to their enantiomers and racemates, so they are highly pharmacologically selective It can be used as an anti-obesity agent or anti-cancer agent.

  When the compound represented by the general formula (1) forms a salt, a metal salt such as sodium salt, potassium salt, calcium salt, magnesium salt, aluminum salt, and zinc salt, ammonium salt, tetramethylammonium salt, etc. Illustrative are organic amine salts with ammonium salts, morpholine, piperazine and the like, and addition salts with amino acids such as glycine, lysine, arginine, phenylalanine and proline. Of these, sodium salt or potassium salt is preferred.

  The compound represented by the general formula (1) or a salt thereof includes any of intramolecular salts and adducts, solvates or hydrates thereof.

The compound represented by the general formula (1) can be produced, for example, according to a known method (the above Non-Patent Document 6) or a method described in Examples.

EXAMPLES Hereinafter, although a reference example and an Example demonstrate this invention in detail, it cannot be overemphasized that this invention is not what is limited to these.

(Reference Example 1)
Synthesis of 2, 4-dimethyl-2, 4-hexadienoic acid

Literature method
(Petroski, RJ et al., Synth. Commun. 2001, 31, 89.). t-BuOLi (94 mL, 94.0 mmoL) was added over 5 minutes and stirred for 25 minutes. Subsequently, tiglylaldehyde (8.4 mL, 82.6 mmoL) was added over 15 minutes under ice cooling, and the mixture was further stirred for 30 minutes. Ice water was added to the reaction mixture, and the mixture was extracted with hexane (100 mL x 3). The combined organic layers were dried over anhydrous sodium sulfate and evaporated. Ethanol (90 mL) was added to the residue, then 10% aqueous sodium hydroxide solution was added, and the mixture was stirred at 50 ° C. for 16 hr. The reaction mixture was washed with hexane (100 mL x 3), adjusted to pH 1 with concentrated hydrochloric acid, extracted with diethyl ether (100 mL x 3), the organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated. The residue was purified by recrystallization (MeOH—H ₂ O) to obtain 5.26 g of the title compound as light yellow crystals (yield 45%). The filtrate was purified again by recrystallization to obtain 1.77 g of the title compound as light yellow crystals (yield 15%). The filtrate was further purified by silica gel chromatography to obtain 3.05 g of the title compound as a pale yellow solid (yield 26%).
MS (EI ⁺ )
(m / z): 140 (M ⁺ ).
Analysis Calcd.
for C ₈ H ₁₂ O ₂ : C, 68.54; H, 8.63; Found: C,
68.60; H, 8.60.
IR (KBr): 1663,
1273 cm ^-1 .

(Example 1)
(4R) -3- (2,
4-dimethylhexa-2,
Synthesis of 4-dienoyl) -4- (phenylmethyl) -2-oxazolidinone

To a solution of Reference Example 1 compound (2.00 g, 14.3 mmoL) in anhydrous tetrahydrofuran (72 mL) was added triethylamine (4.8 mL, 34.4 mmoL) at -15 ° C, and then pivaloyl chloride (1.9 mL, 15.4 mmoL). Was added over 5 minutes and stirred for 15 minutes. Lithium chloride (730 mg, 17.2 mmoL) was added, and then (R) -4-benzyl-2-oxazolidinone (3.20 g, 17.2 mmoL) dissolved in anhydrous tetrahydrofuran (12 mL) was added over 5 minutes. It returned to room temperature and stirred for 16 hours. Saturated aqueous ammonium chloride solution (100 mL) was added to the reaction mixture, and the mixture was extracted with ethyl acetate (50 mL x 2). The organic layer was washed successively with saturated sodium bicarbonate (50 mL) and saturated brine (50 mL), dried over anhydrous sodium sulfate, and the solvent was evaporated. The obtained residue was purified by silica gel column chromatography (hexane: ethyl acetate = 4: 1), 3.93
The title compound was obtained as a colorless solid of g (yield 92%). Recrystallization (Et ₂ O) was performed to obtain 1.92 g of colorless crystals. The filtrate was purified again by recrystallization to obtain 1.50 g of colorless crystals.
MS (EI ⁺ )
(m / z): 299 (M ⁺ ).
Analysis Calcd.
for C ₁₈ H ₂₁ NO ₃ : C, 72.22; H, 7.07; N, 4.68;
Found: C, 72.07; H, 7.00; N, 4.70.
IR (KBr): 1786,
1674 cm ^-1 .

(Example 2)
(4S) -3- (2,
4-dimethylhexa-2,
Synthesis of 4-dienoyl) -4- (phenylmethyl) -2-oxazolidinone

According to the method of Example 1, the compound of Reference Example 1 (2.00
g, 14.3 mmoL), triethylamine (4.8 mL, 34.4 mmoL), pivaloyl chloride (1.9 mL, 15.4 mmoL), lithium chloride (730 mg, 17.2
mmoL) and (S) -4-benzyl-2-oxazolidinone (3.20 g, 17.2 mmoL), and the residue was purified by silica gel column chromatography (hexane: ethyl acetate = 4: 1) to give 3.83
The title compound was obtained as a colorless solid (yield 89%). Recrystallization (Et ₂ O) gave colorless crystals.
MS (EI ⁺ )
(m / z): 299 (M ⁺ ).
Analysis Calcd.
for C ₁₈ H ₂₁ NO ₃ : C, 72.22; H, 7.07; N, 4.68;
Found: C, 72.12; H, 7.07; N, 4.59.
IR (KBr): 1786,
1674 cm ^-1 .

(Example 3)
(4R) -3-[(2R) -2- (3,
Synthesis of 3-dimethoxypropylsulfanyl) -2,4-dimethylhexa-3,5-dienoyl] -4- (phenylmethyl) -2-oxazolidinone

(Process 1)
Synthesis of thioacetic acid S- (3,3-dimethoxypropyl) ester

3-Bromopropionaldehyde Dimethylacetal (11.5 mL, 81.7 mmoL) in anhydrous tetrahydrofuran (500 mL)
In triethylamine (13.7 mL,
After adding 98.3 mmoL), thioacetic acid (6.3 mL, 86.4 mmoL) was added over 5 minutes, and the mixture was stirred for 1 hour and 30 minutes, then returned to room temperature and stirred for 14 hours. Insoluble matter was filtered off and the filtrate was evaporated. The residue was purified by silica gel chromatography (hexane: ethyl acetate = 10: 1) to obtain 14.8 g of the title compound as a colorless oil (yield 100%).
MS (EI ⁺ )
(m / z): 147 (M-OCH ₃ ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₇ H ₁₄ O ₃ S (M-OCH ₃ ⁺ ):
147.0480. Found, 147.0516.
IR (NaCl): 1694,
1125 cm ^-1 .

(Process 2)
Synthesis of 3,3-dimethoxypropyl disulfide

Compound of step 1 of Example 3 (22.3 g,
Sodium methoxide (9.24 g, 162 mmoL) was added to an anhydrous methanol solution (310 mL) of 125 mmoL) under ice cooling, and the mixture was returned to room temperature and stirred for 50 minutes. Next, iodine (15.9 g, 62.6 mmoL) was added and stirred for 30 minutes. The reaction mixture was evaporated, H ₂ O (200 mL) was added, and the mixture was extracted with ethyl acetate (100
mL x 3). The organic layer was washed with saturated brine (50 mL), dried over anhydrous sodium sulfate, and the solvent was distilled off. The obtained residue was purified by silica gel chromatography (hexane: ethyl acetate = 4: 1) to obtain 16.6 g of the title compound as a pale yellow oil (yield 98%).
MS (EI ⁺ )
(m / z): 270 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₀ H ₂₂ O ₄ S ₂
(M ⁺ ): 270.0960. Found, 270.0978.
IR (NaCl): 1122
cm ^-1 .

(Process 3)
Methyl
Synthesis of 3,3-dimethoxypropylthiolsulfonate

According to literature methods (Fujiki, K. et al., Synthesis. 2002, 343.), the compound of Step 2 of Example 3 (305 mg,
1.13 mmoL) in anhydrous methylene chloride solution (7.0 mL) was added sodium methanesulfinate (400 mg, 3.64 mmoL) at room temperature, then iodine (580 mg, 2.29
mmoL) was added and stirred for 2 hours. 1 mol / L sodium thiosulfate was added to the reaction solution until the reaction solution became colorless, and the mixture was extracted with methylene chloride (50 mL × 1). The organic layer was washed with H ₂ O (50 mL), dried over anhydrous sodium sulfate and evaporated. The obtained residue was purified by silica gel chromatography (hexane: ethyl acetate = 2: 1) to obtain 209 mg of the title compound as a colorless oil (yield 86%).
MS (EI ⁺ )
(m / z): 183 (M-OCH ₃ ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. For C ₆ H ₁₄ O ₄ S ₂
(M-OCH ₃ ⁺ ): 183.0150. Found, 183.0163.
IR (NaCl): 1319,
1132 cm ^-1 .

(Process 4)
(4R) -3-[(2R) -2- (3,
Synthesis of 3-dimethoxypropylsulfanyl) -2,4-dimethylhexa-3,5-dienoyl] -4- (phenylmethyl) -2-oxazolidinone

In a tetrahydrofuran solution (10 mL) of the compound of Example 1 (598 mg, 2.00 mmoL) at room temperature, hexamethylphosphoramide (1.4 mL, 8.05
After adding mmoL), sodium hexamethyldisilazide (2.2 mL, 2.20 mmoL) was added over 5 minutes at −78 ° C., followed by stirring for 30 minutes. An anhydrous tetrahydrofuran solution (2.0 mL) of the compound in Step 3 of Example 3 (645 mg, 3.01 mmol) was added over 5 minutes, and then the temperature was gradually raised and the mixture was stirred for 2 hours. When the reaction solution reached 0 ° C., a saturated aqueous ammonium chloride solution (20 mL) was added, and the mixture was extracted with ethyl acetate (15 mL × 3). The organic layer was washed with saturated brine (15 mL), dried over anhydrous sodium sulfate and evaporated. The obtained residue was purified by silica gel chromatography (hexane: ethyl acetate = 4: 1) to give 780 mg of the title compound as a colorless oil as a mixture of stereoisomers (yield 90%). Further purification by HPLC (CHIRALPAK AD-H hexane: 2-propanol: ethanol = 93: 4: 3) gave 641 mg of a single compound (yield 74%).
MS (EI ⁺ )
(m / z): 433 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₂₃ H ₃₁ NO ₅ S (M ⁺ ):
433.1881. Found, 433.1941.
IR (NaCl): 1790,
1680 cm ^-1 .

(Example 4)
(4S) -3-[(2S) -2- (3,
Synthesis of 3-dimethoxypropylsulfanyl) -2,4-dimethylhexa-3,5-dienoyl] -4- (phenylmethyl) -2-oxazolidinone

According to the method of Example 3, the compound of Example 2 (600
mg, 2.00 mmoL), hexamethylphosphoramide (1.4 mL, 8.05 mmoL), sodium hexamethyldisilazide (2.2 mL, 2.20 mmoL) and the compound of step 3 of Example 3 (645 mg, 3.01 mmoL). Reaction was performed, and the residue was purified by silica gel column chromatography (hexane: ethyl acetate = 4: 1).
mg of the colorless oily title compound was obtained as a mixture of stereoisomers (yield 85%). Further purification by HPLC (CHIRALPAK AD-H hexane: 2-propanol: ethanol = 93: 1: 6) gave 581 mg of a single compound (yield 67%).
MS (EI ⁺ )
(m / z): 433 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₂₃ H ₃₁ NO ₅ S (M ⁺ ):
433.1881. Found, 433.1881.
IR (NaCl): 1790,
1680 cm ^-1 .

(Example 5)
(2R) -2- (3,
Synthesis of 3-dimethoxypropylsulfanyl) -2,4-dimethylhexa-3,5-dienoic acid benzyl ester

Literature method
(Evans, DA et al., J. Am. Chem. Soc. 1990. 112. 4011.) in room temperature in anhydrous benzyl alcohol (4.3 mL, 41.6 mmoL) at room temperature with titanium isopropoxide (0.61
mL, 2.07 mmoL) was added, followed by stirring for 2.5 hours under reduced pressure (0.5 mmHg to 1.0 mmHg). The solution was added to the compound of Example 5 (432 mg, 1.00 mmol) and stirred at 70 ° C. for 14 hours. After adding methylene chloride (100 mL), 1 mol / L hydrochloric acid (5 mL) was added. The precipitated insoluble material was removed with celite, H ₂ O (50 mL) was added, and the mixture was extracted with methylene chloride (50 mL).
x 3). The organic layer was washed with saturated brine (100 mL), dried over anhydrous sodium sulfate, and the solvent was distilled off. The obtained residue was purified by silica gel chromatography (hexane: ethyl acetate = 10: 1) to obtain 250 mg of the title compound as a colorless oil (yield 69%).
MS (EI ⁺ )
(m / z): 364 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₂₀ H ₂₈ O ₄ S (M ⁺ ):
Found, 364.1710.
IR (NaCl): 1726
cm ^-1 .

(Example 6)
(2S) -2- (3,
Synthesis of 3-dimethoxypropylsulfanyl) -2,4-dimethylhexa-3,5-dienoic acid benzyl ester

According to the method of Example 5, anhydrous benzyl alcohol (4.8 mL, 46.4 mmoL), titanium isopropoxide (0.69 mL,
2.34 mmoL) and the compound of Example 4 (487 mg,
The residue was purified by silica gel chromatography (hexane: ethyl acetate = 10: 1) to obtain 291 mg of the title compound as a colorless oil (yield 71%).
MS (EI ⁺ )
(m / z): 364 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₂₀ H ₂₈ O ₄ S (M ⁺ ):
364.1708.Found, 364.1737.
IR (NaCl): 1726
cm ^-1 .

(Example 7)
Synthesis of rac-2- (3,3-dimethoxypropylsulfanyl) -2,4-dimethylhexa-3,5-dienoic acid benzyl ester

According to the method of step 4 of Example 3, the literature (Goodman, M. et al., J. Org. Chem., 1996, 61,
2582.) (345 mg, 1.50 mmoL), hexamethylphosphoramide (1.1 mL, 6.32 mmoL), sodium hexamethyldisilazide (1.8 mL,
1.80 mmoL) and the compound of Step 3 of Example 3 (486 mg, 2.27 mmoL), and the residue was purified by silica gel column chromatography (hexane: ethyl acetate = 8: 1).
mg of the title compound was obtained as a colorless oil (yield 82%).
MS (EI ⁺ )
(m / z): 364 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₂₃ H ₃₁ NO ₅ S (M ⁺ ):
364.1708.Found, 433.1698.
IR (NaCl): 1726
cm ^-1 .

(Example 8)
(2R)-
Synthesis of 2, 4-dimethyl-2- (2-formylethylsulfanyl) hexa-3,5-dienoic acid benzyl ester

In a tetrahydrofuran solution (9.0 mL) of the compound of Example 5 (805 mg, 2.21 mmoL), 6% hydrochloric acid (7.0
mL) and stirred for 6 hours. A saturated aqueous sodium hydrogen carbonate solution (20 mL) was added under ice-cooling, and the mixture was extracted with ethyl acetate (15 mL x 3). The organic layer was washed with saturated brine (15 mL), dried over anhydrous sodium sulfate and evaporated. The obtained residue was purified by silica gel chromatography (hexane: ethyl acetate = 6: 1) to obtain 667 mg of the title compound as a colorless oil (yield 95%).
MS (EI ⁺ )
(m / z): 318 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₈ H ₂₂ O ₃ S (M ⁺ ):
318.1290. Found, 318.1308.
IR (NaCl): 1726
cm ^-1 .

Example 9
(2S) -2,
Synthesis of 4-dimethyl-2- (2-formylethylsulfanyl) hexa-3,5-dienoic acid benzyl ester

According to the method of Example 8, the reaction was carried out using the compound of Example 6 (498 mg, 1.26 mmoL) and 6% hydrochloric acid (5.0 mL), and the residue was subjected to silica gel chromatography (hexane: ethyl acetate = 6: 1). To obtain 380 mg of the title compound as a colorless oil (yield 95%).
MS (EI ⁺ )
(m / z): 318 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₈ H ₂₂ O ₃ S (M ⁺ ):
318.1290. Found, 318.1277.
IR (NaCl): 1726
cm ^-1 .

(Example 10)
Synthesis of rac-2, 4-dimethyl-2- (2-formylethylsulfanyl) hexa-3, 5-dienoic acid benzyl ester

According to the method of Example 8, the reaction was carried out using the compound of Example 7 (73 mg, 0.20 mmoL) and 6% hydrochloric acid (0.6 mL), and the residue was subjected to silica gel chromatography (hexane: ethyl acetate = 6: 1). To obtain 58 mg of the title compound as a colorless oil (yield 91%).
¹ H-NMR (400 MHz, CDCl ₃ ): δ (ppm.) 1.66 (3H, s), 1.72 (3H,
s), 2.56 (2H, t, J = 7.3 Hz), 2.75-2.85 (2H, m), 5.05 (1H, d, J = 10
Hz), 5.20 (1H, d, J = 17 Hz), 5.20 (2H, q, J = 12 Hz), 5.74 (1H, s),
6.34 (1H, dd, J = 17, 10 Hz), 7.30-7.39 (5H, m), 9.61 (1H, s).
Thin-layer chromatography (Merck silica gel 60F ₂₅₄ ): Rf value 0.4 (hexane: ethyl acetate = 6: 1)

(Example 11)
(2R)
Of 2,4-dimethyl-2- (propionylsulfanyl) hexa-3,5-dienoic acid benzyl ester

(Process 1)
(2R)
Synthesis of -2, 4-dimethyl-2-sulfanylhexa- 3,5 -dienoic acid benzyl ester After suspending cesium carbonate (6.81 g, 20.9 mmoL) in absolute ethanol (105 mL), ice Under cooling, an absolute ethanol solution (7.0 mL) of the compound of Example 8 (666 mg, 2.09 mmol) was added over 20 minutes and stirred for 20 minutes. The reaction solution was poured into a saturated aqueous solution of ammonium chloride / 1 mol / L hydrochloric acid = 3/1 (120 mL), and extracted with diethyl ether (20 mL × 3). The organic layer was dried over anhydrous sodium sulfate and the solvent was distilled off. Ethyl acetate (100
mL) was added, dried over anhydrous sodium sulfate again, and the solvent was distilled off.

(Process 2)
(2R)
Synthesis of -2, 4-dimethyl-2- (propionylsulfanyl) hexa- 3,5 -dienoic acid benzyl ester To the residue obtained in step 1 was added anhydrous methylene chloride (21 mL), and the mixture was cooled with ice. Triethylamine (0.45 mL, 3.23 mmoL), propionyl chloride (0.24 mL,
2.69 mmoL) was added, and the mixture was stirred on an ice bath for 30 minutes. Saturated aqueous ammonium chloride solution (50 mL) was added, and the mixture was extracted with methylene chloride (30 mL x 3). The organic layer was washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, and the solvent was distilled off. The obtained residue was purified by silica gel chromatography (hexane: ethyl acetate = 20: 1) to obtain 501 mg of the title compound as a colorless oil (yield 75%).
MS (EI ⁺ )
(m / z): 318 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₈ H ₂₂ O ₃ S (M ⁺ ):
318.1290. Found, 318.1301.
IR (NaCl): 1738,
1694 cm ^-1 .

(Example 12)
(2S)
Of 2,4-dimethyl-2- (propionylsulfanyl) hexa-3,5-dienoic acid benzyl ester

(Process 1)
(2S)
-2, 4-dimethyl-2-sulfanylhexa-3,
Synthesis of 5-dienoic acid benzyl ester The reaction was performed according to Step 1 of Example 11 using cesium carbonate (3.88 g, 11.9 mmoL) and the compound of Example 9 (380 mg, 1.19 mmoL).

(Process 2)
(2S)
-2, 4-dimethyl-2- (propionylsulfanyl) hexa-3,
Synthesis of 5-dienoic acid benzyl ester Reaction was carried out using triethylamine (0.25 mL, 1.57 mmoL) and propionyl chloride (0.14 mL, 1.57 mmoL) according to Step 2 of Example 11 and the residue was chromatographed on silica gel. Purification with (hexane: ethyl acetate = 20: 1) gave 290 mg of the title compound as a colorless oil (yield 77%).
MS (EI ⁺ )
(m / z): 318 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₈ H ₂₂ O ₃ S (M ⁺ ):
318.1290. Found, 318.1273.
IR (NaCl): 1738,
1695 cm ^-1 .

(Example 13)
Synthesis of rac-2,4-dimethyl-2- (propionylsulfanyl) hexa-3,5-dienoic acid benzyl ester

(Process 1)
rac -2, 4-dimethyl-2-sulfanylhexa-3,
Synthesis of 5-dienoic acid benzyl ester The reaction was performed according to Step 1 of Example 11 using cesium carbonate (2.46 g, 7.55 mmoL) and the compound of Example 10 (240 mg, 0.754 mmoL).

(Process 2)
Synthesis of rac-2,4-dimethyl-2- (propionylsulfanyl) hexa- 3,5 -dienoic acid benzyl ester According to step 2 of Example 11, triethylamine (0.13 mL, 0.973 mmoL) and propionyl chloride ( 0.070 mL, 0.785 mmoL), and the residue was purified by silica gel chromatography (hexane: ethyl acetate = 20: 1) to give 192 mg of the title compound as a colorless oil (yield 80%) .
¹ H-NMR (400 MHz, CDCl ₃ ): δ (ppm) 1.10 (3H, t, J = 7.3
Hz), 1.77 (3H, d, J = 1.2 Hz), 1.90 (3H, s), 2.49 (2H, d, J = 7.3 Hz),
5.04 (1H, d, J = 10 Hz), 5.18 (1H, d, J = 17 Hz), 5.18 (2H, s),
5.75 (1H, s), 6.30 (1H, dd, J = 17, 10 Hz), 7.30-7.35 (5H, m).
Thin layer chromatography (Merck silica gel 60F ₂₅₄ ): Rf value 0.2 (hexane: ethyl acetate = 20: 1)

(Example 14)
(2R)
Of 2,4-dimethyl-2- (acetylsulfanyl) hexa-3,5-dienoic acid benzyl ester

(Process 1)
(2R)
Synthesis of -2, 4-dimethyl-2-sulfanylhexa- 3,5 -dienoic acid benzyl ester According to step 1 of Example 11, cesium carbonate (2.61
g, 8.01 mmoL) and the compound of Example 8 (510 mg, 1.60 mmoL).

(Process 2)
(2R)
Synthesis of -2, 4-dimethyl-2- (acetylsulfanyl) hexa- 3,5 -dienoic acid benzyl ester According to step 2 of Example 11, triethylamine (0.45 mL, 3.23 mmoL) and acetyl chloride (0.12 (mL, 1.57 mmoL), and the residue was purified by silica gel chromatography (hexane: ethyl acetate = 20: 1) to obtain 332 mg of the title compound as a colorless oil (yield 68%).
MS (EI ⁺ )
(m / z): 304 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₈ H ₂₂ O ₃ S (M ⁺ ):
304.1133. Found, 304.1159.
IR (NaCl): 1738,
1694 cm ^-1 .

(Example 15)
(2S)
Of 2,4-dimethyl-2- (acetylsulfanyl) hexa-3,5-dienoic acid benzyl ester

(Process 1)
(2S)
-2, 4-dimethyl-2-sulfanylhexa-3,
Synthesis of 5-dienoic acid benzyl ester The reaction was carried out according to Step 1 of Example 11 using cesium carbonate (5.12 g, 15.7 mmoL) and the compound of Example 9 (500 mg, 1.57 mmoL).

(Process 2)
(2S)
-2, 4-dimethyl-2- (acetylsulfanyl) hexa-3,
Synthesis of 5-dienoic acid benzyl ester Reaction was carried out using triethylamine (0.45 mL, 3.23 mmoL) and acetyl chloride (0.12 mL, 1.66 mmoL) according to Step 2 of Example 11, and the residue was subjected to silica gel chromatography. Purification with (hexane: ethyl acetate = 20: 1) gave 391 mg of the title compound as a colorless oil (yield 82%).
MS (EI ⁺ )
(m / z): 304 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₈ H ₂₂ O ₃ S (M ⁺ ):
304.1133. Found, 304.1114.
IR (NaCl): 1738,
1694 cm ^-1 .

(Example 16)
rac-2,
Synthesis of 4-dimethyl-2- (acetylsulfanyl) hexa-3,5-dienoic acid benzyl ester

(Process 1)
rac -2, 4-dimethyl-2-sulfanylhexa-3,
Synthesis of 5-dienoic acid benzyl ester The reaction was performed according to Step 1 of Example 11 using cesium carbonate (5.16 g, 15.8 mmoL) and the compound of Example 10 (1.01 g, 3.17 mmoL).

(Process 2)
Synthesis of rac-2,4-dimethyl-2- (acetylsulfanyl) hexa- 3,5 -dienoic acid benzyl ester According to step 2 of Example 11, triethylamine (0.90 mL, 6.46 mmoL) and acetyl chloride ( 0.25 mL, 3.45 mmoL), and the residue was purified by silica gel chromatography (hexane: ethyl acetate = 20: 1) to give 688 mg of the title compound as a colorless oil (yield 71%) .
MS (EI ⁺ )
(m / z): 304 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₈ H ₂₂ O ₃ S (M ⁺ ):
304.1133. Found, 304.1135.
IR (NaCl): 1738,
1694 cm ^-1 .

(Example 17)
Synthesis of (5R) -4-hydroxy-3,5-dimethyl-5- (2-methylbuta-1,3-dienyl) -5H-thiophen-2-one (thiolactomycin)

According to the literature method (Patent Document 1), lithium hexamethyldisilazide (4.0 mL, 4.0 mL, 1.5 mL) was added at −78 ° C. in an anhydrous tetrahydrofuran solution (78 mL) of the compound of Step 2 of Example 11 (498 mg, 1.56 mmoL). 4.00 mmoL) was added, and the mixture was stirred for 3 hours 30 minutes while raising the temperature to 0 ° C. The reaction solution was poured into 1 mol / L hydrochloric acid (40 mL), extracted with ethyl acetate (35 mL × 3), dried over anhydrous sodium sulfate, and the solvent was distilled off. Saturated aqueous sodium hydrogen carbonate solution (20 mL) was added to the residue and washed with diethyl ether (20 mL x 2). 1 mol / L hydrochloric acid was added to the aqueous layer to adjust the pH to 2, followed by extraction with diethyl ether (25 mL x 2) and further extraction with ethyl acetate (25 mL x 2). The organic layer was dried over anhydrous sodium sulfate and evaporated to give the title compound as a brown solid (91% yield). Further, trituration with diethyl ether: hexane = 1: 1 gave the title compound as a colorless solid (yield 63%). A sample for instrumental analysis was obtained by recrystallization from diisopropyl ether.
MS (EI ⁺ )
(m / z): 210 (M ⁺ ).
Analysis Calcd.
for C ₁₁ H ₁₄ O ₂ S: C, 62.83; H, 6.71; Found: C,
62.68; H, 6.54.
IR (KBr): 1605
cm ^-1 .
[α] _D ²⁹ = + 197 ^o (c 1.0, MeOH).

(Example 18)
Synthesis of (5S) -4-hydroxy-3,5-dimethyl-5- (2-methylbuta-1,3-dienyl) -5H-thiophen-2-one (thiolactomycin)

According to the method of Example 17, the reaction was performed using the compound of Step 2 of Example 12 (320 mg, 1.00 mmoL) and lithium hexamethyldisilazide (2.5 mL, 2.5 mmoL) to obtain the title compound as a brown solid (Yield 93%). Further, trituration with diethyl ether / hexane = 1: 1 gave the title compound as a colorless solid (yield 42%). A sample for instrumental analysis was obtained by recrystallization from diisopropyl ether.
MS (EI ⁺ )
(m / z): 210 (M ⁺ ).
Analysis Calcd.
for C ₁₁ H ₁₄ O ₂ S: C, 62.83; H, 6.71; Found: C,
62.51; H, 6.68.
IR (KBr): 1605
cm ^-1 .
[α] _D ²⁹ = −192 ^o (c 1.0, MeOH).

Example 19
Synthesis of rac-4-hydroxy-3,5-dimethyl-5- (2-methylbuta-1,3-dienyl) -5H-thiophen-2-one (racemic thiolactomycin)

According to the method of Example 17, the reaction was carried out using the compound of Step 2 of Example 13 (186 mg, 0.584 mmoL) and lithium hexamethyldisilazide (1.5 mL, 1.5 mmoL). mg was obtained (76% yield). Further, recrystallization from diethyl ether / hexane gave 45 mg of the title compound as a colorless solid (yield 37%).
MS (EI ⁺ )
(m / z): 210 (M ⁺ ).
Analysis Calcd.
for C ₁₁ H ₁₄ O ₂ S: C, 62.83; H, 6.71; Found: C,
62.62; H, 6.63.

(Example 20)
Synthesis of (5R) -4-hydroxy-5-methyl-5- (2-methylbuta-1,3-dienyl) -5H-thiophen-2-one

According to the method of Example 17, the reaction was performed using the compound of Step 2 of Example 14 (318 mg, 1.04 mmoL) and lithium hexamethyldisilazide (2.6 mL, 2.6 mmoL), and the resulting residue was subjected to silica gel chromatography. Purification by chromatography (benzene: acetone = 4: 1) gave 121 mg of the title compound as a brown solid (yield 59%). A sample for instrumental analysis was obtained by recrystallization from diisopropyl ether.
MS (EI ⁺ )
(m / z): 196 (M ⁺ ).
Analysis Calcd.
for C ₁₀ H ₁₂ O ₂ S: C, 61.20; H, 6.16; Found: C,
60.90; H, 6.07.
IR (KBr): 1607
cm ^-1 .
[α] _D ²⁹ = + 186 ^o (c 1.0, MeOH).

(Example 21)
Synthesis of (5S) -4-hydroxy-5-dimethyl-5- (2-methylbuta-1,3-dienyl) -5H-thiophen-2-one

According to the method of Example 17, the reaction was carried out using the compound of Step 2 of Example 15 (590 mg, 1.94 mmoL) and lithium hexamethyldisilazide (4.8 mL, 4.8 mmoL), and the resulting residue was subjected to silica gel chromatography. Purification by chromatography (benzene: acetone = 4: 1) gave 210 mg of the title compound as a brown solid (yield 55%). A sample for instrumental analysis was obtained by recrystallization from diisopropyl ether.
MS (EI ⁺ )
(m / z): 196 (M ⁺ ).
Analysis Calcd.
for C ₁₀ H ₁₂ O ₂ S: C, 61.20; H, 6.16; Found: C,
60.98; H, 6.08.
IR (KBr): 1607
cm ^-1 .
[α] _D ²⁹ = −184 ^o (c 1.0, MeOH).

(Example 22)
Synthesis of rac-4-hydroxy-5-dimethyl-5- (2-methylbuta-1,3-dienyl) -5H-thiophen-2-one

According to the method of Example 17, the reaction was performed using the compound of Step 2 of Example 16 (674 mg, 2.21 mmoL) and lithium hexamethyldisilazide (5.5 mL, 5.5 mmoL), and the title compound as a brown solid was converted to 430.
mg was obtained (yield 99%). Further, recrystallization from diethyl ether yielded 102 mg of the title compound as a colorless solid (yield 24%). The filtrate was purified by silica gel chromatography (benzene: acetone = 3: 1) to obtain 153 mg of the title compound as a pale yellow solid (yield 35%).
MS (EI ⁺ )
(m / z): 196 (M ⁺ ).
HRMS (EI ⁺ )
(m / z): Calcd. for C ₁₀ H ₁₂ O ₂ S (M ⁺ ):
196.0558. Found, 196.0521.

(Example 23) FAS inhibitory activity (fatty acid synthesis inhibitory action in HepG2 cells)
It is known that the effects on fatty acid synthase in human liver can be experimentally confirmed by measuring fatty acid synthesis from [(14) C] acetic acid using HepG2 cells derived from human liver cancer (J Biol Chem. 1996 Jun 14; 271 (24): 14376-82, Lipids.
2001 Apr; 36 (4): 395-400). In accordance with this experimental method, the inhibitory effect of test compounds on fatty acid synthesis in HepG2 cells was examined.
Method: HepG2 cells were suspended in Dulbecco's modified medium (DMEM) containing 10% calf serum and seeded in a 12-well plate. All cultures were performed at 37 ° C. and 5% carbon dioxide. After culturing for 72 hours, the medium was replaced with serum-free DMEM. After 24 hours, test compound and positive control C75 (Proc Natl Acad Sci US A. 2000 Mar
28; 97 (7): 3450-4), and the medium was changed to Krebs Ringer phosphate hepes buffer (pH 7.4). The compounds of Examples 17 to 22 and C75 were dissolved in dimethyl sulfoxide (DMSO) and added at 2.5, 5, 10, 20, 40, and 80 μg / ml. DMSO was added as a solvent control. All measurements were performed in 3 cases. After 4 hours of culture, further 0.2 μCi
[(14) C] Acetic acid was added and cultured for 2 hours to carry out a fatty acid synthesis reaction. The reaction was stopped with an ethanol solution containing 15% potassium hydroxide, and saponified by heating at 85 ° C. for 2 hours. After removing the fat-soluble fraction with petroleum ether, the saponified product was dissolved by adjusting the pH to 1 with hydrochloric acid, and extracted with petroleum ether. After drying at room temperature, the product was dissolved in chloroform, mixed with purified water to completely remove the water-soluble fraction, and the chloroform layer was recovered. After drying at room temperature, it was dissolved in methanol, mixed with a scintillator, and the radioactivity was measured. IC ₅₀ value was calculated by Prism Version 4.0 (Graph Pad Software).

Results: Table 1 shows the IC ₅₀ values of the test compound and C75 (Non-patent Document 6). (S) -thiolactomycin (the compound of Example 18) and (S) -3-demethylthiolactomycin (the compound of Example 21) showed superior FAS inhibitory activity compared to the enantiomers and racemates. .

It was found that (S) -thiolactomycin and (S) -3-demethylthiolactomycin, which are non-naturally-occurring, have FAS inhibitory activity superior to their enantiomers and racemates. On the other hand, since these compounds do not exhibit antibacterial activity, they are FAS inhibitors with high pharmacological selectivity. Such FAS inhibitors are useful as antiobesity agents or anticancer agents.

Claims (3)

General formula (1)

A fatty acid synthase inhibitor comprising as an active ingredient a compound represented by the formula (wherein R ¹ represents a hydrogen atom or a methyl group) or a pharmacologically acceptable salt thereof. A fatty acid synthase inhibitor wherein the compound represented by the general formula (1) is (S) -thiolactomycin or a pharmacologically acceptable salt thereof as an active ingredient. A fatty acid synthase inhibitor wherein the compound represented by the general formula (1) is (S) -3-demethylthiolactomycin or a pharmacologically acceptable salt thereof as an active ingredient.