The Journal of Organic Chemistry
Article
(1H, s, H-8), 7.12−7.16 (3H, m, H-11′-13′), 6.92−6.95 (2H, m, H-
10′, 14′), 6.67 (1H, s, H-5′), 6.70 (1H, s, H-2′), 5.97 (1H, d, J = 1.3
Hz, H-7′), 6.02 (1H, d, J = 1.3 Hz, H-7′), 5.49 (2H, s, H-8′), 5.54 (1H,
d, J = 11.0 Hz, H-12), 5.46 (1H, d, J = 11.0 Hz, H-12), 3.40 (3H, s, 6-
OCH3), 3.76 (3H, s, 7-OCH3). 5.49 (1H, d, J = 4.3 Hz, H-1″), 4.83
(1H, d, J = 4.3 Hz, H-1″), 3.98 (1H, d, J = 11.7 Hz, H-4″), 4.04 (1H, d,
J = 11.7 Hz, H-4″), 4.87 (2H, s, H-6″), 6.41 (1H, s, H-5″), 7.33−7.39
(3H, m, H-9″-11″), 7.74−7.76 (2H, m, H-8″, H-12″); 13C{1H} NMR
(100 MHz, CDCl3) δ 132.70, 132.65 (s, C-1), 120.24, 120.27 (s, C-2),
130.79, 130.61 (s, C-3), 145.72, 145.84 (s, C-4), 101.60, 101.62 (d, C-
5), 151.78, 151.82 (s, C-6), 151.72, 151.77 (s, C-7), 105.80, 105.84 (d,
C-8), 131.02 (s, C-9), 130.40 (s, C-10), 170.19, 171.34 (s, C-11),
67.38, 67,42 (t, C-12), 56.66, 56.77 (q, OCH3-6), 55.88 (q, OCH3-7),
116.74 (s, C-1′), 97.49, 97.54 (d, C-2′), 141.81, 141.81 (s, C-3′),
148.47 (s, C-4′), 110.72, 110.76 (d, C-5′), 150.37, 150.37 (s, C-6′),
101.62, 101.67 (t, C-7′), 71.82, 71.85 (t, C-8′), 135.25, 135.22 (s, C-
9′), 127.60 (d, C-10′, 14′), 128.30, 128.32 (d, C-11′, 13′), 127.00,
127.02 (d, C-12′), 104.48 (d, C-1″), 82.76 (d, C-2″), 91.51 (s, C-3″),
72.14, 72.13 (t, C-4″), 104.32 (d, C-5″), 63.92 (t, C-6″), 136.40 (s, C-
7″), 127.83, 127.84 (d, C-8″, 12″), 128.62 (d, C-9″, 11″), 127.02 (d,
C-10″).
EtOAc 1:1) to afford compounds 23 (white powder, 8.23 mg, 43.3%)
and 24 (white powder, 8.27 mg, 43.5%).
Compound 23. HRMS (ESI) m/z: [M + H]+ calcd for C26H25O12,
1
529.1346; found, 529.1327; H NMR (CD3OD, 400 MHz) δH 8.001
(1H, s, H-5), 7.074 (1H, s, H-8), 6.560 (1H, s, H-2′), 6.552 (1H, s, H-
5′), 5.938 (1H, d, J = 1.0 Hz, H-7′), 5.970 (1H, d, J = 1.0 Hz, H-7′),
5.585 (1H, d, J = 14.8 Hz, H-12), 5.506 (1H, d, J = 14.8 Hz, H-12),
4.037 (3H, s, 6-OCH3), 3.791 (3H, s, 7-OCH3), 5.482 (1H, d, J = 4.7
Hz, H-1″), 4.235 (1H, d, J = 4.7 Hz, H-2″), 4.203 (1H, d, J = 9.9 Hz,
H-4″), 4.232 (1H, d, J = 9.9 Hz, H-4″), 3.645 (1H, d, J = 11.4 Hz, H-
5″), 3.613 (1H, d, J = 11.4 Hz, H-5″); 13C{1H} NMR (100 MHz,
CDCl3) δ 133.88 (s, C-1), 121.02 (s, C-2), 130.56 (s, C-3), 146.70 (s,
C-4), 102.48 (d, C-5), 153.20 (s, C-6), 151.68 (s, C-7), 107.08 (d, C-
8), 132.04 (s, C-9), 129.12 (s, C-10), 172.33 (s, C-11), 68.82 (t, C-
12), 56.64 (q, OCH3-6), 56.03 (q, OCH3-7), 114.83 (s, C-1′), 98.93
(d, C-2′), 142.18 (s, C-3′), 149.77 (s, C-4′), 111.35 (d, C-5′), 150.86
(s, C-6′), 102.90 (t, C-7′), 106.80 (d, C-1″), 76.68 (d, C-2″), 77.73 (s,
C-3″), 73.80 (t, C-4″), 65.15 (d, C-5″); CD (MeOH) λ (Δε): 200
(−29.98), 212 (11.95), 219 (6.87), 229 (24.50), 247 (−4.84), 263
(4.99), 275 (−6.53), 293 (−0.34), 313 (−1.44) nm.
Compound 24. HRMS (ESI) m/z: [M + H]+ calcd for C26H25O12,
529.1346; found, 529.1331; 1H NMR (CD3OD, 400 MHz), δH 7.965
(1H, s, H-5), 7.073 (1H, s, H-8), 6.554 (1H, s, H-2′), 6.548 (1H, s, H-
5′), 5.929 (1H, d, J = 1.0 Hz, H-7′), 5.965 (1H, d, J = 1.0 Hz, H-7′),
5.488 (1H, d, J = 14.8 Hz, H-12), 5.577 (1H, d, J = 14.8 Hz, H-12),
4.028 (3H, s, 6-OCH3), 3.793 (3H, s, 7-OCH3), 5.451 (1H, d, J = 4.6
Hz, H-1″), 4.218 (1H, d, J = 4.6 Hz, H-2″), 4.221 (1H, d, J = 9.9 Hz,
H-4″), 4.195 (1H, d, J = 9.9 Hz, H-4″), 3.610(1H, d, J = 11.2 Hz, H-
5″), 3.642 (1H, d, J = 11.2 Hz, H-5″); 13C{1H} NMR (100 MHz,
CDCl3) δ 133.83 (s, C-1), 121.00 (s, C-2), 130.52 (s, C-3), 146.62 (s,
C-4), 102.47 (d, C-5), 153.14 (s, C-6), 151.62 (s, C-7), 107.08 (d, C-
8), 131.98 (s, C-9), 129.03 (s, C-10), 172.31 (s, C-11), 68.81 (t, C-
12), 56.63 (q, OCH3-6), 56.02 (q, OCH3-7), 114.80 (s, C-1′), 98.92
(d, C-2′), 142.15 (s, C-3′), 149.75 (s, C-4′), 111.41 (d, C-5′), 150.80
(s, C-6′), 102.84 (t, C-7′), 106.26 (d, C-1″), 76.68 (d, C-2″), 77.72 (s,
C-3″), 73.80 (t, C-4″), 65.20 (d, C-5″); CD (MeOH) λ (Δε): 200
(24.69), 212 (−0.50), 218 (0.808), 229 (−11.93), 246 (1.61), 262
(−3.42), 275 (4.40), 291 (1.36), 314 (2.82) nm.
Cells and Plasmids. The HIV vector pNL4-3.Luc.R-.E- was
obtained from the AIDS Research and Reference Program, Division of
AIDS, NIAID, NIH (Rockville, MD). The plasmid pHEF-VSV-G was
kindly provided by Dr Lijun Rong (University of Illinois at Chicago,
Chicago, IL).
Human lung epithelial cell line A549 and human embryonic kidney
cell line 239T were cultured in DMEM supplemented with 10% (v/v)
fetal bovine serum, 100 μg/mL of streptomycin and 100 units/mL of
penicillin (all Gibco, Carlsbad, CA) at 37 °C and 5% CO2.
Anti-HIV Activity Assay. HIV/VSV pseudovirions were prepared
by using the same protocol described previously.6 The antiviral
evaluation assay was adopting the same protocol described in our
previous study.6 Briefly, target A549 cells were seeded in 96-well plates
at a density of 4000 cells/well 24 h before infection. The tested
compounds were added in the 96-well plates together with the viruses
at various concentrations in 0.5% DMSO (v/v). The wells treated with
viruses alone with 0.5% DMSO were used as negative controls, and the
wells treated azidothymidine (AZT) were used as positive controls.
Each compound was tested in triplicate in three independent
experiments. Inhibitory concentrations 50% (IC50) and cytotoxic
concentrations 50% (CC50) were calculated using GraphPad Prism
Software (version 6, La Jolla, CA).
Scan the Rotation Barrier of the 6′-Hydroxy-Substituted in
6′-Hydroxyusticidin B and the Aglycone of Justatropmers.
Molecular Merck force field (MMFF) and DFT/TDDFT calculations
were performed with the Spartan 14 software package (Wavefunction
Inc., Irvine, CA) and Gaussian16 program package,36 respectively,
using default grids and convergence criteria. MMFF conformational
search generated low-energy conformers within a 10 kcal/mol energy
window were subjected to geometry optimization using the B3LYP/6-
31G(d) method. Based on the input structures of 6′-hydroxyjusticidin
B, the aglycones of justatropmer rotational energy barriers were
To a solution of 22a (25.13 mg, 0.04 mmol) in the mixed solvents of
THF/MeOH (1:3, 4 mL) was added Pd(OH)2 on carbon (4 mg,
20%). The reaction was degassed 3 times with H2 and stirred for 6 h
under H2 balloon. TLC showed the 22a disappeared, and two new
spots with higher polarity were formed. The mixture was purified by a
silica gel column (PE/EtOAc 1:1) to provide justatropmers A (1)
(white powder, 7.80 mg, 42.2%) and B (2) (white powder, 8.10 mg,
43.8%).
Justatropmer A (1) (Synthetic). HRMS (ESI) m/z: [M + H]+ calcd
1
for C26H25O12, 529.1346; found, 529.1339; H NMR (CD3OD, 400
MHz) δH 7.701 (1H, s, H-5), 7.075 (1H, s, H-8), 6.567 (1H, s, H-2′),
6.543 (1H, s, H-5′), 5.946 (1H, d, J = 1.0 Hz, H-7′), 5.968 (1H, d, J =
1.0 Hz, H-7′), 5.498 (1H, d, J = 14.8 Hz, H-12), 5.572 (1H, d, J = 14.8
Hz, H-12), 4.019 (3H, s, 6-OCH3), 3.761 (3H, s, 7-OCH3), 5.531
(1H, d, J = 3.6 Hz, H-1″), 4.516 (1H, d, J = 3.6 Hz, H-2″), 4.345 (1H,
d, J = 9.7 Hz, H-4″), 3.932 (1H, d, J = 9.7 Hz, H-4″), 3.668 (1H, d, J =
11.4 Hz, H-5″), 3.710 (1H, d, J = 11.4 Hz, H-5″); 13C{1H} NMR (100
MHz, CDCl3) δ 133.94 (s, C-1), 121.02 (s, C-2), 130.26 (s, C-3),
146.31 (s, C-4), 101.98 (d, C-5), 153.22 (s, C-6), 151.64 (s, C-7),
107.30 (d, C-8), 132.02 (s, C-9), 128.38 (s, C-10), 172.25 (s, C-11),
68.79 (t, C-12), 56.50 (q, OCH3-6), 56.05 (q, OCH3-7), 114.77 (s, C-
1′), 98.94 (d, C-2′), 142.19 (s, C-3′), 149.80 (s, C-4′), 111.40 (d, C-
5′), 150.79 (s, C-6′), 102.49 (t, C-7′), 112.82 (d, C-1″), 78.66 (d, C-
2″), 80.31 (s, C-3″), 75.91 (t, C-4″), 64.23 (d, C-5″); CD (MeOH) λ
(Δε) 200 (−17.73), 212 (0.95), 217 (−0.34), 229 (9.36), 246
(−1.52), 262 (1.89), 276 (−2.36), 293 (−0.41), 315 (−2.03) nm.
Justatropmer B (2) (Synthetic). HRMS (ESI) m/z: [M + H]+ calcd
1
for C26H25O12, 529.1346; found, 529.1331; H NMR (CD3OD, 400
MHz) δH 7.698 (1H, s, H-5), 7.076 (1H, s, H-8), 6.561 (1H, s, H-2′),
6.545 (1H, s, H-5′), 5.947 (1H, d, J = 1.0 Hz, H-7′), 5.969 (1H, d, J =
1.0 Hz, H-7′), 5.495 (1H, d, J = 14.8 Hz, H-12), 5.569 (1H, d, J = 14.8
Hz, H-12), 4.021 (3H, s, 6-OCH3), 3.762 (3H, s, 7-OCH3), 5.538
(1H, d, J = 3.6 Hz, H-1″), 4.518 (1H, d, J = 3.6 Hz, H-2″), 4.350 (1H,
d, J = 9.7 Hz, H-4″), 3.934 (1H, d, J = 9.7 Hz, H-4″), 3.672 (1H, d, J =
11.4 Hz, H-5″), 3.713 (1H, d, J = 11.4 Hz, H-5″); 13C{1H} NMR (100
MHz, CDCl3) δ 133.94 (s, C-1), 121.07 (s, C-2), 130.26 (s, C-3),
146.34 (s, C-4), 102.02 (d, C-5), 153.28 (s, C-6), 151.69 (s, C-7),
107.33 (d, C-8), 132.06 (s, C-9), 128.44 (s, C-10), 172.27 (s, C-11),
68.79 (t, C-12), 56.50 (q, OCH3-6), 56.06 (q, OCH3-7), 114.81 (s, C-
1′), 98.98 (d, C-2′), 142.22 (s, C-3′), 149.83 (s, C-4′), 111.38 (d, C-
5′), 150.88 (s, C-6′), 102.51 (t, C-7′), 112.84 (d, C-1″), 78.70 (d, C-
2″), 80.31 (s, C-3″), 75.93 (t, C-4″), 64.28 (d, C-5″); CD (MeOH) λ
(Δε) 200 (23.17), 211 (−6.35), 218 (−3.32), 229 (−16.06), 246
(2.85), 260 (−4.02), 274 (4.66), 297 (−0.19), 313 (0.76) nm.
To a solution of 22b (25.20 mg, 0.04 mmol) in THF/MeOH (1:3, 4
mL) was added Pd(OH)2 on carbon (4 mg, 20%). The reaction was
degassed 3 times with H2 and stirred for 6 h under H2 balloon. TLC
showed the 22b disappeared, and two new spots with higher polarity
were formed. The mixture was purified by a silica gel column (PE/
5581
J. Org. Chem. 2021, 86, 5568−5583