Laccase-Catalyzed Dimerization of Hydroxystilbenes
FULL PAPERS
(d, J=8.46 Hz, 2H), 6.70 (d, J=2.02 Hz, 2H), 6.90 (d, J=
8.70 Hz, 2H), 6.96 and 7.14 (AB system, J=16.31 Hz, 2H),
7.02 (d, J=8.46 Hz, 2H), 7.42 (d, J=8.70 Hz, 2H), 9.20 (s,
1H); 13C NMR (DMSO-d6): d=55.4 (2C), 55.6, 76.5, 84.4,
99.4, 100.0, 104.6 (2C), 106.1 (2C), 114.7 (2C), 116.5, 126.7,
128.1, 128.9 (2C), 129.0, 130.0, 132.3, 139.9, 141.4, 158.3,
160.2 (2C), 161.1 (2C).
Laccase-Catalyzed Dimerization of the
Hydroxystilbenes; General Procedure
One of the hydroxystilbenicsubstrates (100 mg) was dis-
solved in 7 mL AcOEt, while the laccase (10 U) was dis-
solved in 7 mL of 20 mm acetate buffer, pH 4.5. The biphasic
system was shaken at room temperature and monitored by
TLC. When the TLC spots indicated that the products were
prevalent with respect to the initial substrate, the reaction
was quenched by phase separation followed by AcOEt ex-
traction of the water solution, and the organic solvent was
evaporated. The crude residue was purified by flash chroma-
tography.
12a: Substrate: 65 mg; reaction time: 96 h; TLC
(PetEt:AcOEt, 6:4): Rf =0.12; TLCrp (CH3CN:H2O, 7:3):
Rf =0.45; flash chromatography: PetEt:AcOEt, 6:4; yield:
1
9 mg (14%). H NMR (DMSO-d6): d=3.74 (s, 3H), 3.75 (s,
3H), 5.07 (d, J=8.70 Hz, 1H), 5.35 (d, J=8.70 Hz, 1H),
6.58 (bs, 1H), 6.63 (dd, J=2.05, 8.02 Hz, 1H), 6.71 (d, J=
8.02 Hz, 1H), 6.78 (d, J=2.05 Hz, 1H), 6.83 and 6.93 (AB
system, J=16.21 Hz, 2H), 6.89 (d, J=8.70 Hz, 2H), 6.91 (bs,
1H), 6.92 (d, J=8.70 Hz, 2H), 7.14 (d, J=8.70 Hz, 2H),
7.45 (d, J=8.70 Hz, 2H), 8.37 (s, 1H), 8.97 (s, 1H), 9.40 (s,
1H); 13C NMR (DMSO-d6): d=55.5, 55.6, 56.3, 93.3, 113.8,
114.2, 114.4, 114.5 (2C), 114.7 (2C), 115.8, 118.2, 125.6,
126.9, 127.8 (2C), 129.6 (2C), 130.5, 131.3, 131.8, 133.0,
133.9, 141.8, 145.7, 146.0, 146.8, 158.8, 159.0.
6a: Substrate: 200 mg; reaction time: 70 h; TLC
(PetEt:AcOEt, 4:6): Rf =0.16; TLCrp (CH3CN:H2O, 1:1):
Rf =0.21; flash chromatography: PetEt:AcOEt, 6:4/5.5:4.5/
1
5:5/3:7/2:8; yield: 37 mg (19%). H NMR (DMSO-d6): d=
3.74 (s, 3H), 3.87 (s, 3H), 4.62 (d, J=9.28 Hz, 1H), 5.41 (d,
J=9.28 Hz, 1H), 6.68 (bs, 1H), 6.73 (d, J=8.64 Hz, 2H),
6.74 (d, J=8.50 Hz, 2H), 6.75 (bs, 2H), 6.93 (s, 2H), 6.95
(bs, 1H), 7.02 (d, J=8.50 Hz, 2H), 7.12 (bs, 1H), 7.35 (d,
J=8.64 Hz, 2H), 9.10 (s, 1H), 9.39 (s, 1H), 9.50 (s, 1H);
13C NMR (DMSO-d6): d=55.7, 56.1, 56.2, 93.7, 110.4, 111.3,
115.3, 115.7, 116.0 (4C), 117.9, 125.9, 126.5, 127.9 (2C),
128.9, 129.7 (2C), 130.7, 131.6, 132.2, 133.1, 144.5, 147.3
(2C), 148.1, 156.9, 157.3.
6a’: Substrate: 200 mg; reaction time: 70 h; TLC
(PetEt:AcOEt, 4:6): Rf =0.21; TLCrp (CH3CN:H2O, 1:1):
Rf =0.15; flash chromatography: PetEt:AcOEt, 6:4/5.5:4.5/
5:5/3:7/2:8; yield: 16 mg (8%). 1H NMR (DMSO-d6): d=
3.74 (s, 3H), 3.79 (s, 3H), 4.62 (d, J=9.19 Hz, 1H), 5.43 (d,
J=9.19 Hz, 1H), 6.72 (d, J=8.12 Hz, 1H), 6.75 (s, 1H), 6.75
(bs, 1H), 6.75 (d, J=8.61 Hz, 2H), 6.88 and 7.00 (AB
system, J=16.70 Hz, 2H), 6.89 (d, J=8.70 Hz, 1H), 6.92
(dd, J=1.89, 8.12 Hz, 1H), 6.96 (bs, 1H), 7.03 (d, J=
8.61 Hz, 2H), 7.10 (bs, 1H), 7.14 (d, J=1.89 Hz, 1H), 7.38
(dd, J=1.45, 8.70 Hz, 2H), 9.01 (s, 1H), 9.07 (s, 1H), 9.37 (s,
1H); 13C NMR (DMSO-d6): d=55.4, 56.0, 56.1, 93.5, 109.8,
110.1, 111.1 (2C), 115.7, 115.9, 116.1, 119.8, 120.1, 122.6,
125.8, 126.5, 127.3, 129.5, 129.7 (2C), 132.5, 146.7, 147.2,
148.1, 148.2, 157.0, 158.9.
12c: Substrate: 65 mg; reaction time: 96 h; TLC (PetEt:
AcOEt, 6:4): Rf =0.22; TLCrp (CH3CN:H2O, 7:3): Rf =0.26;
flash chromatography: PetEt:AcOEt, 6:4; yield: 9 mg
1
(14%). H NMR (DMSO-d6): d=3.72 (s, 3H), 3.78 (s, 3H),
5.02 (d, J=7.98 Hz, 1H), 5.07 (d, J=7.98 Hz, 1H), 6.49 (d,
J=7.99 Hz, 1H), 6.59 (d, J=7.99 Hz, 1H), 6.65 (bs, 1H),
6.83 (d, J=8.62 Hz, 2H), 6.93 (d, J=8.37 Hz, 2H), 6.95 (d,
J=8.42 Hz, 1H), 7.00 and 7.07 (AB system, J=17.15 Hz,
2H), 7.10 (d, J=8.42 Hz, 1H), 7.18 (d, J=8.62 Hz, 2H),
7.20 (bs, 1H), 7.50 (d, J=8.37 Hz, 2H), 8.83 (s, 1H), 8.94 (s,
1H); 13C NMR (DMSO-d6): d=55.5, 55.6, 78.5, 79.7, 113.9
(2C), 114.6 (3C), 115.7, 115.9, 117.4, 119.8, 120.0, 126.2,
126.9, 127.8, 128.0 (2C), 129.2, 129.8 (2C), 130.4, 131.5,
143.9, 144.4, 145.3, 145.9, 159.2, 159.6.
Supporting Information
More detailed characterization data for products 4–13 are
available in the Supporting Information.
9a: Substrate: 150 mg; reaction time: 120 d; TLC (PetEt:
AcOEt, 7:3): Rf =0.35; TLCrp (CH3CN:H2O, 7:3): Rf =0.20;
flash chromatography: PetEt:AcOEt, 7:3/6:4; yield 88 mg
Acknowledgements
1
(59%). H NMR (DMSO-d6): d=3.71 (s, 6H), 3.75 (s, 6H),
We gratefully thank Prof. Dietmar Haltrich (BOKU Univer-
sity, Wien, Austria)for a generous gift of Trametes pubescens
laccase.
4.62 (d, J=8.49 Hz, 1H), 5.60 (d, J=8.49 Hz, 1H), 6.38 (t,
J=1.64 Hz, 1H), 6.41 (d, J=2.03 Hz, 2H), 6.45 (t, J=
2.03 Hz, 1H), 6.74 (d, J=1.64 Hz, 2H), 6.80 (d, J=8.49 Hz,
2H), 6.93 (d, J=8.54 Hz, 1H), 6.96 and 7.23 (AB system,
J=16.95 Hz, 2H), 7.22 (d, J=8.49 Hz, 2H), 7.23 (bs, 1H),
7.46 (d, J=8.54 Hz, 1H), 9.56 (s, 1H); 13C NMR (DMSO-
d6): d=55.6 (2C), 56.3, 92.6, 99.0, 100.0, 104.6 (2C), 106.8
(2C), 109.9, 115.8 (2C), 123.4, 126.2, 128.1, 128.3 (2C), 129.3,
130.5, 130.8, 131.9, 140.0, 144.1, 158.1, 159.4, 161.1 (2C),
161.2 (2C).
9b: Substrate: 150 mg; reaction time: 120 h; TLC
(PetEt:AcOEt, 7:3): Rf =0.21; TLCrp (CH3CN:H2O, 7:3):
Rf =0.39; flash chromatography: PetEt:AcOEt, 7:3/6:4;
yield: 9 mg (6%). 1H NMR (DMSO-d6): d=3.60 (s, 6H),
3.76 (s, 6H), 4.74 (dd, J=4.51, 6.26 Hz, 1H), 5.21 (d, J=
6.26 Hz, 1H), 5.48 (d, J=4.51 Hz, 1H), 6.27 (t, J=2.03 Hz,
1H), 6.30 (d, J=2.03 Hz, 2H), 6.37 (t, J=2.02 Hz, 1H), 6.60
References
[1] J. Burns, T. Yokota, H. Ashihara, M. E. J. Lean, A.
Crozier, J. Agric. Food Chem. 2002, 50, 3337–3340.
[2] E. N. Frankel, A. L. Waterhouse, J. E. Kinsella, Lancet
1993, 341, 1103–1104.
[3] R. H. Cichewicz, S. A. Kouzi, in: Studies in natural
products chemistry, Vol. 26: Bioactive natural products
(Part G), (Ed.: Atta-ur-Rahman), Elsevier, Dordrecht,
2002, pp 507–579.
[4] a) N. Latruffe, D. Delmas, B. Jannin, M. Cherkaoui
Malki, P. Passilly-Degrace, J. P. Berlot, Int. J. Mol. Med.
Adv. Synth. Catal. 2007, 349, 1497 – 1506
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1505