Scaffold hopping and optimisation of 3’,4’-dihydroxyphenyl- containing thienopyrimidinones: synthesis of quinazolinone derivatives as novel allosteric inhibitors of HIV-1 reverse transcriptase-associated ribonuclease H

Figures & data

Figure 1. Bioisosteric core replacement.

Table 1. Inhibition of wild type and p66/p51C280A mutant HIV-1 RNase H activity by compounds 2–17.

Compound	CORE	IC50 (µM)
		WT	C280A
2^12		0.41 ± 0.01	0.37 ± 0.01
3		0.50 ± 0.02	0.23 ± 0.02
4		0.57 ± 0.02	0.41 ± 0.01
5		0.73 ± 0.02	0.33 ± 0.003
6		0.37 ± 0.01	0.29 ± 0.006
7		1.1 ± 0.04	0.51 ± 0.05
8		0.15 ± 0.01	0.12 ± 0.001
9		0.45 ± 0.008	0.40 ± 0.01
10		0.31 ± 0.01	0.20 ± 0.01
11		0.43 ± 0.01	0.66 ± 0.05
12		0.52 ± 0.06	0.84 ± 0.03
13		0.31 ± 0.01	0.17 ± 0.004
14		0.56 ± 0.25	0.40 ± 0.03
15		0.64 ± 0.03	0.39 ± 0.01
16		2.4 ± 1.6	2.0 ± 0.1
17^27		3.46 ± 0.47	–

Scheme 1. Synthetic protocol for compounds 2–13 and 15–21. Reagents and conditions: i) I₂/CH₃CN, rt, 6 h. ii) SnCl₂/HCl 37%,−5 °C (1 h), rt (30 h).

Scheme 2. Synthetic protocol for compounds 14, 22, and 23. Reagents and conditions: i) CH₂Cl₂/CH₃CN, reflux, 40 h. ii) Pd(OAc)₂/K₂CO₃, EtOH/H₂O 3/1, rt (18 h). iii) BBr₃ 1 M in CH₂Cl₂, CH₂Cl₂, 0 °C (1 h), rt (3 h).

Table 2. Inhibition of HIV-1 RNase H activity by compounds 18–21.

Compound	Ar	IC50 (µM)
		WT
18		13.6 ± 0.3
19		>50
20		>50
21		>50

Table 3. Inhibition of wild type and p66/p51C280A mutant HIV-1 RNase H activity by compounds 22 and 23.

Compound		IC50 (µM)
		WT	C280A
22		2.9 ± 0.89	0.61 ± 0.22
23		0.71 ± 0.03	1.2 ± 0.04

Table 4. Effect of compounds 2–17 on HIV-1 RDDP and IN functions.

Compound	IC50 (µM)
	RDDP	IN
2	>100	4.3 ± 1.5
3	60 ± 9	2.35 ± 0.44
4	57 ± 3	8.5 ± 0.3
5	>100	6.5 ± 2.5
6	63 ± 11	89 ± 10
7	23.4 ± 0.5	31.5 ± 6.5
8	26.7 ± 2.2	3.4 ± 0.83
9	46 ± 3	7 ± 2
10	30.5 ± 0.4	3.4 ± 0.6
11	>100	7.2 ± 0.7
12	>100	6.61 ± 0.93
13	99 ± 1	23.18 ± 0.8
14	>100	>100
15	25.3 ± 6.3	5.35 ± 0.35
16	38 ± 4	0.69 ± 0.19
17	70 ± 1	1.44 ± 0.40
EFV	0.010 ± 0.005	ND
RAL	ND	0.055 ± 0.002

Figure 2. Effect of compounds 2–17, 22, and 23 on the thermal stability of p66/p51 HIV-1 RT. Tm values are the average of triplicate analysis.

Figure 3. Yonetani–Theorell analysis. Combination of compound 11 and 24 on HIV-1 RNase H activity. HIV-RT was incubated in the presence of 24 alone (●) or combined with increasing concentrations of compound 11: 2,5 µM (O); 5 µM(Δ) and 10 µM (■).