Supporting Materials
for
A Magnetic Biomimetic Nano-Catalyst for Cleaving Phosphoester
and Carboxylic Ester Bonds under Mild Conditions
Yan Zheng, Chuansong Duanmu, and Yong Gao*
Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois
62901-4409
*: To whom correspondence should be addressed. Ph: (618)453-4904.
Email: [email protected]
S1
Materials and Instrumentation.
Most chemicals were purchased from Acros Organics
(Somerville, NJ), and Aldrich (Milwaukee, WI) and used as received without further
purification. Amino acids were bought from Bachem Bioscience (King of Prussia, PA). Water
was obtained from a Milli-Q reagent water system purchased from Millipore Corporation
(Milford, MA). The heavy metal and bacterial contaminant levels in Milli-Q water are below 10
ppb. 1H NMR and 13C data were obtained on a Varain VXR-300 system with an Oxford widebore magnet and the chemical shifts were reported in parts per million (ppm) downfield relative
to tetramethylsilane using the residual proton resonance of solvents as the references (1H NMR):
CDCl3 δ 7.27; CD2Cl2 δ 5.32 and (13C NMR): CDCl3 δ 77.2; CD2Cl2 δ 54.0.
TEM
measurements were accomplished with a Hitachi H7100FA operating at an accelerating voltage
of 75 or 100kV. Iron oxide nanoparticle specimens were deposited onto Formvar- and siliconcoated, 200 mesh copper grids (Structure Probe, Inc., West Chester, PA) and the edge of the grid
touched to a filter paper to wick away most of the solvent. Images were recorded either on
conventional photographic films or captured using a Gatan 789 digital camera. Magnification
was calibrated using a MAG*I*CAL high resolution magnification standard accurated to 1 x
10E6 X. The permanent magnet (LifeSepTM 50sx magnetic separator) was purchased from
Dexter Magnetic Technologies (Elk Grove Village, IL).
Elemental analyses were done in
Galbraith Laboratories, Inc. (Knoxville, TN). HPLC analyses were carried out on a Shimadzu
LC-10Ai system equipped with a UV and an ELSD (evaporative light scattering) detector. An
Alltech C-18, 5 µm column (4.6 x 150 mm) (Deerfield, IL) was employed in our HPLC
experiments. LC-MS experiments were carried out in the Mass Spectrometry Laboratory in the
University of Illinois at Urbana-Champaign. Optical rotation measurements were carried out by
using an automatic polarimeter from Rudolph Research (Flaners, NJ).
OH
O
H2N CHC OH
CH2
O
Ac2O
pH=10
N
NH
O
OH
O
OH
H2N
N CHC OH
H
CH2
HOBt, DIC, DMF
O
N CHC N
H
H
CH2
N
N
NH
NH
1
2
S-Scheme 1. Synthesis of N-Ac-dopamine-His.
S2
OH
Synthesis of N-(3, 4-dihydroxyphenethyl)-2-acetamido-3-(1H-imidazol-4-yl)propanamide
(N-Ac-dopamine-his) (2). The solution of histidine hydrochloride monohydrate (10.5 g, 50
mmol) in water (25 mL) was adjusted to pH=9-10 with 8 M NaOH. Subsequently, acetic
anhydride (9.43 mL, 100 mmol) was added dropwise to the solution at 0oC and the pH was
maintained at 10 by adding 8 M NaOH as necessary. The reaction mixture was stirred for
another 4 h, and then acidified with conc. HCl to pH=2. The solvent and excessive acetic
anhydride were removed in vacuo and the residue was dissolved in 20 mL of MeOH. After
filtration, the solvent was removed in vacuo to lead to 1 a white powder (8.2 g, 83.2%): 1H NMR
(D2O, 400 MHz): δ 8.33 (s, 1 H), 7.08 (s, 1 H), 4.34 (dd, J = 8.8, 5.2 Hz, 1 H), 3.09 (ddd, J =
15.2, 4.4, 0.8 Hz, 1 H), 2.92 (ddd, J =15.2, 7.6, 0.8 Hz, 1 H), 1.84 (s, 3 H); 13C NMR (D2O, 100
MHz): δ 174.14, 173.72, 133.56, 128.88, 117.27, 52.00, 26.39, 21.80; [α]D = +13.8° (c 2.4
MeOH).
To a solution of 1 (985 mg, 5 mmol) and HOBt (1.35 g, 10 mmol) in DMF (20 ml) was
added DIC (1.26 g, 10 mmol) under Ar. The reaction solution was stirred for 2 h. Then, a
solution of 3-hydroxytyramine HCl salt (758.6 mg, 4 mmol) with K2CO3 (662.4 mg, 4.8 mmol)
in DMF (25 mL) was introduced. After 12 h, water (30 mL) was added. The solvents were
removed in vacuo and the residue was purified by flash chromatography to give 2 as a pale
yellow solid (1.23 g, 74.1%): [α]25 = -2.8° (c 2.2 MeOH); IR (MeOH cast): 3248, 2966, 2929,
1673, 1659, 1650, 1643, 1632, 1530, 1449, 1383, 1267, 1198, 1101, 744 cm-1; 1H NMR (DMSOd6, 300 MHz): δ 8.05 (d, J = 8.1 Hz, 1 H), 7.88 (t, J = 5.4 Hz, 1 H), 7.53 (s, 1 H), 6.75 (s, 1 H),
6.63 (d, J = 7.8 Hz, 1 H), 6.56 (d, J = 2.1 Hz, 1 H), 6.39 (dd, J = 7.8, 2.1 Hz, 1 H), 4.43-4.34 (m,
1 H), 3.14 (t, J = 8.1 Hz, 2 H), 2.89 (dd, J = 15.0, 5.1 Hz, 1 H), 2.72 (dd, J = 15.0, 8.4 Hz, 1 H),
2.42-2.49 (m, 2 H), 1.81 (s, 3 H); 13C NMR (DMSO-d6, 75.5 MHz): δ 171.64, 169.78, 145.83,
143.60, 135.21, 130.71, 128.20, 119.80, 119.05, 116.65, 116.39, 53.54, 41.35, 35.25, 30.32,
23.31; ES MS m/z 333.2 [M+H]+.
S3
O
H2N
H2N CHC OH
CH2
(Boc)2O, NaOH
CH2
O
CH2
CH2
O
NH2
O
CHC OH
CH2
(CH3CO)2O, NaOH
CH2
O
CH2
CH2
O
NHBoc
pH=9-10
O
3
O
HO
HO
NH2
HOBt, DIC, DMF
O
H
NH CHC N
CH2
CH2
CH2
CH2
NHBoc
O
OH
OH
CF3COOH
CH2Cl2
5
O
NH CHC OH
CH2
CH2
CH2
CH2
NHBoc
4
O
H
NH CHC N
CH2
CH2
CH2
CH2
NH2
6
OH
OH
S-Scheme 2. Synthesis of N-Ac-dopamine-lys.
Synthesis of N-(3, 4-dihydroxyphenethyl)-2-acetamido-6-aminohexanamide (N-Acdopamine-lys) (6). The solution of lysine monohydrochloride (9.13 g, 50 mmol) in a mixture of
water (20 mL) and 1,4-dioxane (20 mL) was adjusted to pH=11 with 4M NaOH. Subsequently, a
solution of di-tert-butyl dicarbonate (10.91 g, 50 mmol) was added dropwise to the solution at
0oC and the pH was maintained at 11 by adding 4M NaOH as necessary. The reaction mixture
was stirred at ambient temperature for 12 h, then acidified with 2M HCl to pH = 6. The white
solid obtained was filtered, and then purified via flash chromatography to give 3 (7.85 g, 64%):
1
H NMR (DMSO-d6, 300 MHz): δ 6.75 (s, 1H), 3.08 (t, J=6.9Hz, 1H), 2.86 (t, J=6.0Hz, 2H),
1.30-1.70 (m, 15H).
The solution of 3 (2.46 g, 10 mmol) in the mixture of water (10 mL) and 1,4-dioxane (10
mL) was adjusted to pH=11 with 4M NaOH. Acetic anhydride (1.88 mL, 20 mmol) was added
dropwise at 0oC and the pH was maintained at 11 by adding additional 4M NaOH. The reaction
mixture was stirred at ambient temperature for another 4 h, and then acidified with 2 M HCl to
pH=6. The white solid obtained was filtered, and then purified via flash chromatography to lead
to 4 (2.26 g, 78.5%): 1H NMR (DMSO-d6, 400 MHz): δ 7.30 (d, J = 7.2 Hz, 1 H), 6.69 (s, 1 H),
3.83 (dd, J = 12.0, 6.8 Hz, 1 H), 2.81 (d, J = 6.4 Hz, 2 H), 1.69 (s, 3 H), 1.13-1.64 (m, 15 H); 13C
NMR (DMSO-d6, 100 MHz): δ 175.62, 168.80, 156.24, 77.96, 54.79, 49.26, 33.25, 30.36, 28.97,
24.68, 23.65.
To a solution of 4 (1.44 g, 5 mmol) and HOBt (1.35 g, 10 mmol) in N,N-dimethyl
formamide (20 ml) was added DIC (1.26 g, 10 mmol) under Argon atmosphere. The reaction
S4
solution was stirred for 2 h, and then treated with a solution of 3-hydroxytyramine HCl salt
(758.6 mg, 4 mmol) with K2CO3 (662.4 mg, 4.8 mmol) in DMF (25 mL). After 12 h, H2O (30
mL) was added and the mixture was extracted with CHCl3 (3 x 50 mL). The combined organic
layers were dried over anhydrous Na2SO4 and filtered. The solvent was removed in vacuo and
the residue was purified via flash chromatography to give 5 (1.88 g, 87.6%): IR(neat): 3265,
2972, 2933, 1700, 1673, 1659, 1650, 1643, 1632, 1569, 1558, 1530, 1519, 1444, 1366, 1282,
1252, 1169, 1116, 957, 774, 669 cm-1; 1H NMR (CDCl3, 400 MHz): δ 6.81 (d, J = 8.0 Hz, 1 H),
6.67 (d, J = 2.0 Hz, 1 H), 6.64 (d, J = 8.0 Hz, 1 H), 6.56 (dd, J = 8.0, 2.0 Hz, 1 H), 6.30 (s, 1 H),
4.79 (s, 1 H), 4.26-4.32 (m, 1 H), 3.30-3.61 (m, 2 H), 2.99-3.05 (m, 2 H), 2.63-2.72 (m, 2 H),
1.98 (s, 3 H), 1.64-1.72 (m, 2 H), 1.12-1.54 (m, 13 H); 13C NMR (DMSO-d6, 100 MHz): δ
171.67, 170.79, 156.87, 144.22, 143.20, 130.63, 120.46, 116.16, 115.57, 80.01, 53.31, 40.57,
40.10, 34.36, 32.07, 29.71, 28.45, 23.09, 22.28; ES MS m/z 424.2 [M+H]+.
Trifluoroacetic acid (3.0 mL, 40 mmol) was added dropwise to the solution of 5 (846 mg,
2 mmol) in CH2Cl2 (5 mL). The mixture was stirred for 2 h. MeOH (10 mL) was added and the
solvents were removed in vacuo to give 6 as a yellow solid (535 mg, 83%): 1H NMR (CDCl3,
300 MHz): δ 7.93 (d, J = 8.0 Hz, 1 H), 7.85 (t, J = 5.6 Hz, 1 H), 6.61 (d, J = 8.0 Hz, 1 H), 6.54 (d,
J = 2.0 Hz, 1 H), 6.38 (dd, J = 8.0, 2.0 Hz, 1 H), 4.10-4.15 (m, 1 H), 3.10-3.21 (m, 2 H), 2.71 (t,
J = 6.4 Hz, 2 H), 2.48 (t, J = 5.6 Hz, 2 H), 1.82 (s, 3 H), 1.19-1.59 (m, 6 H). 13C-NMR (DMSOd6, 75.5 MHz): δ 172.11, 170.00, 145.67, 144.16, 130.76, 119.89, 116.64, 116.08, 53.10, 41.16,
40.71, 35.22, 32.18, 27.34, 23.15, 23.00.
Synthesis of N-(3, 4-dihydroxyphenethyl)-2-acetamido-3-carboxyl-propanamide (N-Acdopamine-asp). Procedures similar to those of 1 and 2 were adopted and DL-Aspartic acid was
employed as the starting material (42%): IR(neat) 3263, 3070, 2951, 2929, 1665, 1658, 1650,
1643, 1632, 1530, 1439, 1372, 1283, 1200, 1115, 754, 670 cm-1; 1H NMR (D2O, 400 MHz): δ
6.54 (d, J=8.0Hz, 1H), 6.47 (dd, J=8.0, 2.0Hz, 1H), 6.31-6.35 (m, 1H), 4.32-4.42 (m, 1H), 3.053.10 (m, 2H), 2.39-2.50 (m, 2H), 2.35 (t, J=6.4Hz, 1H), 1.80 (s, 3H). 13C NMR (D2O, 100 MHz):
δ 176.52, 172.04, 171.48, 143.94, 142.42, 131.67, 121.12, 116.55, 116.13, 50.16, 40.73, 33.79,
31.40, 21.81. ES-HRMS. Calcd for C14H19N2O6 [M+H+]: 311.1243, Found: 311.1231; [α]25 -1.9°
(c 3.2 MeOH).
S5
Synthesis of N-(3, 4-dihydroxyphenethyl)-2-acetamido-4-carboxyl-butanamide (N-Acdopamine-glu). Procedures similar to those of 1 and 2 were adopted and DL-Glutamic acid
monohydrate was employed as the starting material (64.8%): IR 3256, 3077, 2943, 1734, 1656,
1648, 1642, 1630, 1545, 1529, 1442, 1375, 1283, 1237, 1198, 1022, 743, 667 cm-1; 1H NMR
(D2O, 400 MHz): δ6.57 (d, J = 8.0 Hz, 1 H), 6.52 (s, 1 H), 6.42 (t, J = 8.0 Hz, 1 H), 4.14-4.19
(m, 1 H), 3.10-3.23 (m, 2 H), 2.44 (t, J = 6.4 Hz, 2 H), 2.26 (t, J = 6.8 Hz, 2 H), 1.94-2.06 (m, 2
H), 1.81, (s, 3H); 13 C NMR (D2O, 75.5 MHz): δ 175.59, 175.12, 174.36, 143.94, 142.47,
131.69, 121.12, 116.58, 116.18, 52.09, 37.02, 31.50, 30.08, 25.85, 21.68; ES-MS. Calcd for
C15H21N2O6 [M+H+]: 325.1400, Found: 325.1000.
O
(CH3CO)2O
H2N CHC OH
CH2
pH=10
OH
O
O
NH CHC OH
CH2
OH
Trt-Cl, Et3N
CH2Cl2
7
O
O
H
N CHC OH
CH2
O
O
HO
HO
NH2
O
H
H
N CHC N
CH2
O
HOBt, DIC, DMF
8
CF3COOH
CH2Cl2
O
O
H
H
N CHC N
CH2
OH
10
OH
OH
9
OH
OH
S-Scheme 3. Synthesis of N-Ac-dopamine-ser.
Synthesis of N-(3, 4-hydroxyphenethyl)-2-acetamido-3-hydroxypropanamide (N-Acdopamine-ser) (10). The solution of serine (5.25 g, 50 mmol) in water (25 mL) was adjusted to
pH=9~10 with 8M NaOH. Subsequently, acetic anhydride (9.43 mL, 100 mmol) was added
dropwise at 0oC and the pH was maintained at 10 by adding 8M NaOH. The reaction mixture
was stirred for another 4 h, then acidified with conc. HCl to pH=2. The solvent and excessive
acetic anhydride were removed in vacuo and the residue was dissolved in 20 mL of MeOH.
After filtration, the filtrate was concentrated in vacuo to give 7 as a white solid (5.96 g, 81.1%):
1
H NMR (D2O, 300 MHz): δ 4.38-4.45 (m, 1 H), 3.72-3.87 (m, 2 H), 1.95 (s, 3 H).
S6
To a mixture of 7 (1.47 g, 10 mmol) and Et3N (3.04 g, 30 mmol) in CH2Cl2 (30 mL) was
added dropwise a solution of TrtCl (4.18 g, 15 mmol) in CH2Cl2 (20 mL). The solution was
stirred at ambient temperature for 12 h and 50 mL of MeOH was added. Removal of the solvent
in vacuo to give 8 as a white solid (2.54 g, 65.3%): 1H NMR (DMSO-d6, 300 MHz): δ 8.28 (d, J
= 8.1 Hz, 1 H), 7.25-7.38 (m, 15 H), 4.44-4.50 (m, 1 H), 3.18 (d, J = 8.7 Hz, 2 H), 1.89 (s, 3 H).
To a solution of 8 (1.95 g, 5 mmol) and HOBt (1.35 g, 10 mmol) in N,N-dimethyl
formamide (20 ml) was added DIC (1.26 g, 10 mmol) under Argon atmosphere. The reaction
solution was stirred for 2 h and then was treated with a mixture of 3-hydroxytyramine HCl with
K2CO3 (662.4 mg, 4.8 mmol) in DMF (25 mL). The resultant reaction mixture was stirred at
room temperature for 12 h. Water (30 mL) was added and the mixture was extracted with
EtOAc (3 x 50 mL). The combined organic layers were dried over anhydrous Na2SO4. After
filtration, the solvent was removed in vacuo. The residue was purified via flash chromatography
to give 9 as a pale yellow solid (1.93 g, 73.7%): IR(neat) 3277, 3085, 2934, 1734, 1696, 1657,
1650, 1644, 1633, 1530, 1495, 1449, 1372, 1281, 1153, 1094, 762, 747, 707, 632 cm-1; 1H NMR
(CDCl3, 400 MHz): δ 7.19-7.36 (m, 15 H), 6.75 (d, J = 7.6 Hz, 1 H), 6.63 (d, J = 1.6 Hz, 1 H),
6.51 (t, J = 6.4 Hz, 1 H), 6.48 (dd, J = 7.6, 1.6 Hz, 1 H), 6.32 (d, J = 7.2 Hz, 1 H), 4.47 (dd, J =
12.0, 5.2 Hz, 1 H), 3.62 (dd, J = 9.6, 4.4 Hz, 1 H), 3.40-3.46 (m, 2 H), 3.20 (dd, J = 9.6, 5.6 Hz,
1 H), 2.63 (t, J = 6.4 Hz, 2 H), 1.86 (s, 3 H); 13C NMR (CDCl3, 100 MHz): δ 171.43, 170.26,
144.19, 143.49, 130.75, 128.69, 128.27, 127.58, 120.79, 116.36, 115.51, 87.48, 68.22, 63.51,
53.69, 41.28, 34.77, 23.24; ES-HRMS. Calcd for C32H32N2O5Na [M+23+]: 547.2209, Found:
547.22227; [α]25 +3.9° (c 3.8 MeOH).
Trifluoroacetic acid (3.0 mL, 40 mmol) was added dropwise to the solution of 9 (1.05 g,
2 mmol) in CH2Cl2 (5 mL) at room temperature. The mixture was stirred for about 2 h. The
solvent and excess trifluoroacetic acid were removed in vacuo and the residue was subjected to
column chromatography purification to give 10 as a yellow solid (356 mg, 63.2%): IR(neat)
3279, 2929, 1700, 1665, 1659, 1650, 1643, 1632, 1546, 1530, 1442, 1372, 1285, 1201, 1141,
1026, 797, 718, 669 cm-1; 1H NMR (CDCl3, 400 MHz): δ 7.22 (d, J = 7.6 Hz, 1 H), 7.04 (s, 1 H),
6.77 (d, J = 8.0 Hz, 1H), 6.70 (d, J = 2.0 Hz, 1 H), 6.54 (dd, J = 8.0, 2.0 Hz, 1 H), 4.40-4.44 (m,
1 H), 3.92-3.95 (m, 1 H), 3.61-3.65 (m, 1 H), 3.40-3.44 (m, 2 H), 2.66 (t, J = 6.8 Hz, 2 H), 2.01
(s, 3 H); 13C NMR (CDCl3, 100 MHz): δ 171.12, 170.79, 144.64, 143.47, 130.81, 120.40, 116.22,
115.59, 62.66, 54.66, 41.02, 34.86, 23.16; ES MS m/z 283.1 [M+H]+.
S7
O
H2N CHC OH
CH2
SH
Ph3CCl
DMF
H3C
O
H2N CHC OH (CH3CO)2O, NaOH
O
CH2
SCPh3
HOBt, DIC, DMF
O
O
pH=9-10
O
NH2
O
SO3- +H3N CHC OH
CH2
SH
11
H3C
12
HO
HO
SO3H
O
H
H
N CHC N
CH2
SCPh3
14
O
H
N CHC OH
CH2
SCPh3
13
O
TFA
OH
OH
O
H
N CHC
CH2
SH
H
N
OH
15
OH
S-Scheme 4. Synthesis of N-Ac-dopamine-cys.
Synthesis of N-(3, 4-dihydroxyphenethyl)-2-acetamido-3-mercaptopropanamide (N-Acdopamine-cys) (15). The solution of cysteine hydrochloride hydrate (7.88 g, 50 mmol) and 2
mL of conc. HCl in 15 mL of H2O was slowly added to a solution of p-toluenesulfonic acid
hydrate (11.41 g, 60 mmol) in 5 mL of H2O. After 24 h, 11 was recovered as precipitate, and
washed with a solution of 10 % p-toluenesulfonic acid in water and dried under vacuum (10.3 g,
70.4%): 1H NMR (D2O, 300 MHz): δ 7.57 (d, J = 6.6 Hz, 2 H), 7.25 (d, J = 7.8 Hz, 2 H), 4.16
(dd, J = 5.4, 4.2 Hz, 1 H), 2.94-3.09 (m, 2 H), 2.27 (s, 3 H).
To the solution of 11 (2.92 g, 10 mmol) in 10 mL of DMF was added trityl chloride (4.18
g, 15 mmol) and the mixture was stirred for 48 h at room temperature. About 50 mL of 10%
sodium acetate solution was added, and compound 12 precipitated out. The precipitate was
collected, washed with water (3 x 10 mL), and then purified via recrystallization (2.26 g 62.2%):
1
H NMR (DMSO-d6, 300 MHz) δ 7.18-7.36 (m, 15 H), 2.92-2.96 (m, 1 H), 2.37-2.60 (m, 2 H).
The solution of 12 (1.82 g, 5 mmol) in the mixture of water (10 mL) and 1,4-dioxane (10
mL) was adjusted to pH=9-10 with 4M NaOH. Acetic anhydride (0.94 mL, 10 mmol) was added
dropwise at 0oC and the pH was maintained at 9-10 by adding 4M NaOH as necessary. The
reaction mixture was stirred at ambient temperature for 12 h, and then acidified with 2M HCl to
pH = 6. The solvent was removed in vacuo and the residue was subjected to flash
chromatography purification to give 13 (1.22 g, 60.2%): 1H NMR (DMSO-d6): δ 12.72, (s, 1 H),
S8
8.22 (d, J = 8.1 Hz, 1 H), 7.23-7.36 (m, 15 H), 4.11-4.19 (m, 1 H), 2.33-2.51 (m, 2 H), 1.82 (s, 3
H); 13C NMR (DMSO-d6, 75.5 MHz): δ 173.62, 168.50, 144.90, 129.76, 128.79, 127.53, 63.96,
56.79, 22.68, 21.15.
To a solution of 13 (1.01 g, 2.5 mmol) and HOBt (0.68 g, 5 mmol) in N,N-dimethyl
formamide (10 ml) was added DIC (0.63 g, 5 mmol) under Argon atmosphere. The reaction
solution was stirred for 2 h and then was treated with a solution of 3-hydroxytyramine HCl salt
(0.38 g, 2 mmol) with K2CO3 (0.33 g, 2.4 mmol) in DMF (20 mL). The reaction mixture was
stirred at room temperature for 12 h. Water (20 mL) was added and the mixture was extracted
with EtOAc (3 x 30mL). The combined organic layers were dried over anhydrous Na2SO4 and
filtered. The solvent was removed in vacuo, and the residue was subjected to flash
chromatography purification to give 14 as a pale yellow solid (72.5%): IR (neat) 3277, 3055,
2921, 1703, 1658, 1650, 1644, 1632, 1558, 1530, 1519, 1490, 1369, 1282, 1194, 1115, 1033, 743,
700, 675, 617 cm-1; 1H NMR (CDCl3, 400 MHz): δ 7.15-7.39 (m, 15 H), 6.73 (d, J = 8.0 Hz, 1
H), 6.59 (d, J = 2.0 Hz, 1 H), 6.47 (dd, J = 8.0, 2.0 Hz, 1 H), 6.36 (d, J = 7.6 Hz, 1 H), 6.13 (s, 1
H), 3.94-3.99 (m, 1 H), 3.20-3.39 (m, 2 H), 2.48-2.72 (m, 4 H), 1.84 (s, 3 H); 13C NMR (DMSOd6, 100 MHz): δ 171.35, 170.30, 144.46, 143.56, 130.57, 129.76, 128.30, 127.18, 120.91, 117.00,
115.37, 53.07, 41.03, 34.29, 33.71, 23.30; ES-HRMS: Calcd for C32H33N2O4S [M+H+]:
541.2161, Found: 541.2177.
Trifluoroacetic acid (3.0 mL, 40 mmol) was added dropwise to the solution of 14 (1.08 g,
2 mmol) in CH2Cl2 (5 mL) at room temperature. The mixture was stirred for about 2 h. The
solvent and excess trifluoroacetic acid were removed in vacuo and the residue was subjected to
column chromatography purification to give 15 as a yellow solid (338 mg, 56.7%). 1H-NMR
(DMSO, 400 MHz): δ 6.52-6.61 (m, 2H), 6.37 (dd, J=8.0, 2.0Hz, 1H), 4.26 (dd, J=8.0, 2.0Hz,
1H), 3.09-3.20 (m, 2H), 2.22-2.53 (m, 4H), 1.85 (s, 3H); 13C-NMR (DMSO-d6, 100 MHz): δ
170.28, 169.76, 144.99, 144.23, 130.64, 119.87, 119.40, 116.13, 55.84, 52.30, 41.33, 35.22,
23.15.
General procedures for the synthesis of maghemite nanoparticle-amino acid complexes. To
a solution of maghemite nanoparticles with an average core dimension of 12 nm1 (50 mg) in 1
mL of CHCl3 was treated with either a monad (60 mM) or a mixture of an amino acid dyad (30
mM for each amino acid) of dopamine analogues in 1 mL of MeOH. The mixture was reacted
S9
under sonication for 6 h. Then, the magnetic nanoparticle-amino acid complex was magnetically
concentrated via externally applying a permanent magnet (LifeSepTM 50sx magnetic separator
from Dexter Magnetic Technologies). The recovered magnetic nano-composites were washed
with MeOH (5 x 20 mL) and H2O (5 x 20 mL) sequentially. The magnetic nano-complexes were
usually stored in 2 mL of Milli-Q water at ambient temperature. Elemental analyses were
employed for determining the composition and amount of amino acid coatings on the surface of
each nano-complex.
General procedures for the hydrolysis of paraoxon and 4-nitrophenyl acetate. To a solution
of paraoxon (0.5 mM) in 2 mL of Milli-Q water was treated with a magnetic nano-complex. The
amino acid concentration in the mixture was kept at about 0.06 mM. The heavy metal and
bacterial contaminant levels in Milli-Q water are below 10 ppb. After 48 h at 37 oC, magnetic
nanoparticles were magnetically concentrated and removed. The solution was then subjected to
HPLC analyses using an internal standard for the conversion yield of paraoxon. The structures
of the hydrolytic products were confirmed by LC-MS experiments. The hydrolysis of 4nitrophenyl acetate was carried out similarly.
General procedures for measuring kinetic parameters of Fe2O3-Asp-His. To a stirred
solution of paraoxon in 2 mL of phosphate buffer (pH 7.4, 0.08 mM) was added 92. mg of
Fe2O3-Asp-His. The reaction mixture was maintained at 40 oC. At a fixed time interval, 200 µL
of the reaction mixture was taken out. Magnetic nanoparticles were removed and the remaining
solution was subjected to HPLC analyses using an internal standard. The paraoxon
concentration was varied from 0.423 mM to 0.923 mM and a series of similar experiments were
carried out. The Linewear-Burk plot of the hydrolysis of paraoxon by Fe2O3-Asp-His was shown in S-5 -1
Figure 2. Analysis of the plot led to KM=1.1 mM and kcat=4.3x10 s .
S10
S-Figure 1. TEM micrograph of maghemite nanoparticles protected by oleate.
6 10
5
5 10
5
4 10
5
3 10
5
2 10
5
1 10
5
1/V (h/M)
y = 1.0834e+05 + 118.46x R= 0.93932
1000
1200
1400
1600
1800
2000
2200
2400
-1
1/[S] (M )
S-Figure 2. The Linewear-Burk plot of the hydrolysis of paraoxon by Fe2O3-Asp-His.
References Cited:
1.
(a) Park, J.; An, K.; Hwang, Y.; Park, J.-G.; Noh, H.-J.; Kim, J.-Y.; Park, J.-H.;
Hwang, N.-M.; Hyeon, T. Nature Mater. 2004, 3, 891. (b) Lu, J.; Fan, J.; Xu, R.;
Roy, S.; Ali, N.; Gao, Y. J. Colloid Interface Sci. 2003, 258, 427.
Enclosed: spectra
S11
Compound 1 (1H NMR)
O
O
H
NH C C OH
CH2
N
NH
S12
Compound 1 (13C NMR)
O
O
H
NH C C OH
CH2
N
NH
S13
Compound 2 N-Ac-dopamine-his (IR)
O
O
H
H
NH C C N
CH2
OH
N
OH
NH
S14
Compound 2 N-Ac-dopamine-his (1H NMR)
O
O
H
H
NH C C N
CH2
OH
N
NH
OH
S15
Compound 2 N-Ac-dopamine-his (13C NMR)
O
O
H
H
NH C C N
CH2
OH
N
NH
OH
S16
Compound 2 N-Ac-dopamine-his (HR-MS)
S17
Compound 3 (1H NMR)
O
H2N CHC OH
CH2
CH2
CH2
CH2
NHBoc
S18
Compound 4 (1H NMR)
O
O
NH CHC OH
CH2
CH2
CH2
CH2
NHBoc
S19
Compound 4 (13C NMR)
O
O
NH CHC OH
CH2
CH2
CH2
CH2
NHBoc
S20
Compound 5 (IR)
O
O
H
NH CHC N
CH2
CH2
CH2
CH2
NHBoc
S21
OH
OH
Compound 5 (1H NMR)
O
O
H
NH CHC N
CH2
CH2
CH2
CH2
NHBoc
OH
OH
S22
Compound 5 (13C NMR)
O
O
H
NH CHC N
CH2
CH2
CH2
CH2
NHBoc
OH
OH
S23
Compound 5 (MS)
S24
Compound 6 (1H NMR)
O
O
H
NH CHC N
CH2
CH2
CH2
CH2
NH2
OH
OH
S25
Compound 6 (13C NMR)
O
O
H
NH CHC N
CH2
CH2
CH2
CH2
NH2
OH
OH
S26
Compound 7 (1H NMR)
O
O
NH CHC OH
CH2
OH
S27
Compound 8 (1H NMR)
O
O
H
N CHC OH
CH2
O
S28
Compound 9 (IR)
O
O
H
H
CHC
N
N
CH2
O
OH
OH
S29
Compound 9 (1H NMR)
O
O
H
H
N CHC N
CH2
O
OH
OH
S30
Compound 9 (13C NMR)
O
O
H
H
N CHC N
CH2
O
OH
OH
S31
Compound 9 (HR-MS)
S32
Compound 10 N-Ac-dopamine-ser (IR)
O
O
H
N CHC
CH2
OH
H
N
OH
OH
S33
Compound 10 (1H NMR)
O
O
H
N CHC
CH2
OH
H
N
OH
OH
S34
Compound 10 (13C NMR)
O
O
H
N CHC
CH2
OH
H
N
OH
OH
S35
Compound 10 N-Ac-dopamine-ser (HR-MS)
S36
Compound 11 (1H NMR)
H3C
SO3
- +
O
H3N CHC OH
CH2
SH
S37
Compound 12 (1H NMR)
O
H2N CHC OH
CH2
SCPh3
S38
Compound 13 (1H NMR)
O
O
H
N CHC OH
CH2
SCPh3
S39
Compound 14 (IR)
O
O
H
H
N CHC N
CH2
SCPh3
OH
OH
S40
Compound 14 (1H NMR)
O
O
H
H
N CHC N
CH2
SCPh3
OH
OH
S41
Compound 14 (13C NMR)
O
O
H
H
N CHC N
CH2
SCPh3
OH
OH
S42
Compound 14 (HR-MS)
S43
Compound 15 (1H NMR)
O
O
H
N CHC
CH2
SH
H
N
OH
OH
S44
Compound 15 (13C NMR)
O
O
H
N CHC
CH2
SH
H
N
OH
OH
S45
Compound 16 N-Ac-dopamine-asp (IR)
O
O
H H
N C C OH
CH2
C O
HN
OH
OH
S46
Compound 16 N-Ac-dopamine-asp (1H NMR)
O
O
H H
N C C OH
CH2
C O
HN
OH
OH
S47
Compound 16 N-Ac-dopamine-asp (13C NMR)
O
O
H H
N C C OH
CH2
C O
HN
OH
OH
S48
Compound 16 N-Ac-dopamine-asp (HR-MS)
S49
Compound 17 N-Ac-dopamine-glu (IR)
O
O
H
N CH C OH
CH2
CH2
C O
HN
OH
OH
S50
Compound 17 N-Ac-dopamine-glu (1H NMR)
O
O
H
N CH C OH
CH2
CH2
C O
HN
OH
OH
S51
Compound 17 N-Ac-dopamine-glu (13C NMR)
O
O
H
N CH C OH
CH2
CH2
C O
HN
OH
OH
S52
Compound 17 N-Ac-dopamine-glu (HR-MS)
S53