Synthesis and biological evaluation of novel thienopyrimidine derivatives as diacylglycerol acyltransferase 1 (DGAT-1) inhibitors

Figures & data

Figure 1. (a) Structures of reported DGAT1 inhibitors; (b) diagram showing structural features of DGAT-1 inhibitors.

Figure 2. A schematic strategy for the design of target molecules.

Scheme 1. Synthesis of thienopyrimidine derivatives. Reagents and conditions: (a) Pd(PPh₃)₄, 2 N Na₂CO₃, 1,4-Dioxane; (b) H₂, 20% PdOH, EtOH/1,4-Dioxane; (c) TFA, DCM, rt; (d) aryl chloride, pyridine, DCM 0 °C to rt or aryl isocyanate, THF, 12 h, rt; (e) NaOH or LiOH, THF/MeOH/H₂O (1:1:1), rt.

Scheme 2. Reagents and conditions: (a) THF, rt; (b) separation by using ethyl acetate at 60–70 °C; filtrate for 15a and solid for 15b; (c) NaOH, THF/MeOH/H₂O; (d) 1 M NaOH, MeOH, rt.

Table 1. DGAT-1 inhibitors and their in vitro data.

^a Data present mean values.

Table 2. Enzyme and cellular inhibitory potencies for selected compounds.

IC50 (nM)
Compound	DGAT1(SF9)	hDGAT1	hDGAT2	hACAT1	hACAT2
2	157	57	>10,000	>10,000	>10,000
17a	74	61	>10,000	>10,000	>10,000
17b	89	–	–	–	–

Table 3. Pharmacokinetic profiles of compounds 17a, 17b in ICR mice.^a

Compounds	17a	17b
AUC 0∼24 (ng·h/mL)	861.2	233.7
Cmax (ng/mL)	479.3	74.8
T1/2 (h)	1.2	5.2
Bioavailability (%)	19	0.7

^a All parameters were determined after oral administration (10 mg/kg, n = 3) and intravenous (iv) injection (3 mg/kg, n = 2) in ICR mice; both compounds were dissolved in a vehicle solution of DMSO/Tween80/saline (1:6:23) for iv., and 0.5% methylcellulose/0.5% Tween80 in distilled water for oral administration. Data represent mean values.

Table 4. Oral pharmacokinetic profile of 17a in rat and dog.

Parameters	AUC 0 ∼ 24 (ng·h/mL)	T 1/2 (h)	Cl (L/hr/kg))	Bioavailability (%)
Rat^a	18,594.5 ± 6764.2	3.0 ± 0.4	0.5 ± 0.2	30
Dog^b	8243.0 ± 2296.3	3.6 ± 0.7	0.4 ± 0.1	53

^a Dose; 3 mg/kg for iv, 10 mg/kg for po.; Vehicle: DMSO/Tween80/saline (1:6:23) for iv.; 0.5% methylcellulose/0.5% Twee80 in distilled water for po.

^b Dose: 1 mg/kg for iv, 3 mg/kg for po.; Vehicle: DMSO/Tween80/saline (1:3:26) for iv; 0.5% methylcellulose/0.5% Tween80 in distilled water for po.

Table 5. In vitro microsomal stability and cytochrome P450 (CYP) inhibition assay of compound 17a.

	Microsomal stability, (%)^a				CYPs enzyme inhibition, IC50 (μM)^b
No	Human	Dog	Rat	Mouse	CYP3A4	CYP1A2	CYP2C9	CYP2C19	CYP2D6
17a	94	82	87	82	16.2	10.6	2.9	>20	8.7

^a Remaining percent of metabolism by incubation of the parent molecule (5 μM) with liver microsomes of mouse, rat, dog, and human for 60 min (duplicate).

^b Data were analysed by a fluorescence detection method.

Figure 3. Effect of 17a in the oral lipid tolerance test (n = 5, ***p < .001). Serum TG (or TAG) concentration was measured before and 1, 2, and 4 h after oral administration of corn oil in ICR mice treated with 17a (3 mg/kg) or 2 (1 mg/kg). Vehicle for 2: 0.5% methylcellulose/0.5% Tween80 in distilled water, vehicle for 17a: 0.5% Tween80 in distilled water.

Figure 4. Effect of 17a in a canine oral lipid tolerance test (n = 2, *p < .05; ***p < .001). The dog was treated with 17a (po. 1 mg/kg) or 2 (po. 1 mg/kg) before oral administration of corn oil. Vehicle for 2: 0.5% methylcellulose/0.5% Tween80 in distilled water, vehicle for 17a: 0.5% Tween80 in distilled water.

Figure 5. Tissue distribution of 17a in mice. 17a and 2 were orally administered to ICR mice at 30 mg/kg (n = 3). (a) AUC values of 17a and 2 in indicated tissues. Each bar shows AUC obtained from concentrations measured at 0.5 h, 1 h, 2 h, 4 h, and 24 h after dosing. Data represent mean value. (b) Tissue-to-plasma (T/P) ratio of 17a and 2. S.I.: small intestine, L.I.: large intestine.