A novel series of resveratrol derivatives were synthesized according to Wittig-Horner reaction with 3,5-dihydroxybenzyl alcohol or 3,5-dimethoxybenzyl alcohol or 4-hydroxybenzyl alcohol as raw material and the inhibitory activities on breast carcinoma (MDA-MB-231) and gastric carcinoma cell lines (SGC-7901) in vitro were evaluated by the standard methyl thiazole tetrazolium (MTT) method. The result of biological test shows that some of resveratrol derivatives possess stronger anti-cancer activities than 5-FU. Compound 5c shows the strongest activity against breast carcinoma (MDA-MB-231) and gastric carcinoma cell lines (SGC-7901) with IC50 value of 50.19 ± 1.02 μM, 122.68.27 ± 2.04 μM, compared to that IC50 value of 5-FU is 98.59±3.61 μM,156.74±6.16 μM, respectively.
Cancer is the term used for diseases in which abnormal cells divide without control and are able to invade other tissues. All cancers begin in cells, when the DNA of a cell becomes damaged or changed, it will produce mutations that will affect normal cell growth and division. In recent years, cancer has become one of the main causes of death to the human being [
Resveratrol (3,5,4’-trihydroxy-trans-stilbene,
Although resveratrol possesses a series of pharmacological activities, its therapeutic application is still limited due to its short biological half-life (8 - 14 min) [
1H NMR spectra were recorded with an Agilent Technologies 400/54 Premium shielded spectrometer (400 MHz). 19F NMR spectra were recorded with an Agilent Technologies 400/54 Premium shielded (376 MHz). 13C NMR spectra were recorded with an Agilent Technologies 400/54 Premium shielded (101 MHz) spectrometer.
MS was recorded with a Hewlett-Packard HP-5989A spectrometer. Infrared spectra were measured with a Perkin-Elmer 983 spectrometer. Melting point was detected by DSC-Q2000. Unless otherwise noted, reagents were commercially available analytical grade materials used as supplied, without further purification.
General procedures for the preparation of compounds 5a ~ 5c
The synthetic route of resveratrol derivatives 5a ~ 5c is shown in Scheme 1. To obtain the product via four- step reaction by using commercially available 3,5-dimethoxylbenzyl alcohol as the starting material. First, the raw material (2.5 g, 15 mmol) was dissolved in DCM (15 mL) and stirred at 0˚C, then a solution of phosphorous bromide (1.5 mL, 16 mmol) in the presence of DCM (10 mL) was added drop wise at the condition of ice-salt bath for 2 h. The resulting mixture was poured into ice-water (40 mL), separating the organic layer, washing it with saturated brine to neutral pH. Dried and evaporated solvent under vacuum. The mixture was filtered through silica gel to get a white needle crystal compound 2 (3,5-dimethoxybenzyl bromide), yield 85%. A solution of compound 2 (1.5 g, 6.5 mmol) and triethylphosphite (1.5 mL, 8.7 mmol) was stirred at 130˚C for 5 h. Vacuum distilling to remove excess triethylphosphite to get colorless oil compound 3 (3,5-dime-thoxybenzyl phosphonate). Next, in the same reacting three-necked bottle, after sodium methanolate (1.1 g, 20.5 mmol) in DMF (7 mL) stirring at 0˚C for 30 min, the fluorine-substituted benzaldehyde 4a ~ 4c (6.6 mmol) was added under ice-salt bath condition for 2 h and room temperature over night. The resulting mixture was poured into ice-water (30 mL), white solid precipitation appeared and then it was washed till neutral and recrystallize with ethyl alcohol (95%) to get white crystal compound 5a ~ 5c.
General method for synthesis of compounds 10a - 10c
Compounds 10a ~ 10c were obtained as shown in Scheme 2. A solution of hydroxy-substituted benzyl alcohol (50 mmol) into acetone (50 mL) and potassium carbonate (150 mmol) as base was stirred at room temperature for 30 min and then bromoalkane was added at refluxing temperature for 18 ~ 48 h. The mixture was filtered to remove potassium carbonate. Filtrate was evaporated under vacuum to give the compound 7 (alkoxy- substituted benzyl alcohol). Longer alkyl chains resulted in longer reaction times. The next steps for these compounds 10a ~ 10c were similar to the synthesis of compounds 5a ~ 5c.
All the new compounds were characterized by detailed spectroscopic analysis.
5a (trans-3,5-dimethoxy-2’-fluoro-4’-methoxy stilbenes)
White solid, yield 31%, m.p. 59.7˚C ~ 60.3˚C. IR υmax (cm−1), 832, 962, 1032, 1066, 1290, 1457, 1506, 1597, 1620, 2837, 2938. 19F NMR (376 MHz, CDCl3) δ −115.51 (dd, J = 12.5, 8.8 Hz). 1H NMR (400 MHz, CDCl3) δ 7.50 (t, J = 8.8 Hz, 1H), 7.17 (d, J = 16.5 Hz, 1H), 6.97 (d, J = 16.5 Hz, 1H), 6.71 (dd, J = 8.7, 2.5 Hz, 1H), 6.66 (d, J = 2.2 Hz, 2H), 6.63 (dd, J = 12.6, 2.5 Hz, 1H), 6.39 (t, J = 2.2 Hz, 1H), 3.83 (s, 6H), 3.82 (s, 3H). 13C NMR (101 MHz, CDCl3) δ 162.32 (s), 160.94 (s), 160.30 (d, J = 11.2 Hz), 159.84 (s), 139.58 (s), 128.53 (d, J = 4.8 Hz), 127.65 (d, J = 5.6 Hz), 121.25 (d, J = 3.1 Hz), 117.56 (d, J = 12.5 Hz), 110.48 (d, J = 2.9 Hz), 104.40 (s), 101.58 (d, J = 26.0 Hz), 99.91 (s), 55.47 (d, J = 22.7 Hz). HRMS(EI), Calcd. for, C17H17O3F, 288.1162, Found, 288.1158.
Scheme 1. Synthetic steps of compounds 5a ~ 5c. Reagents and conditions, a) DCM, ice salt bath, 2 h to room temperature, 2 h, b) 130˚C, 5 h, c) DMF, MeONa, 0˚C to room temperature, overnight.
Scheme 2. Synthetic steps of compounds 10a ~ 10c. Reagents and conditions, d) Acetone, reflux, 18 ~ 48 h, e) PBr3, DCM, ice salt bath, 2 h to room temperature, 2h, f) 130˚C, 5 h, g) DMF, MeONa, 0˚C to room temperature, overnight.
5b (trans-3,5-diethoxy-3’-fluoro-4’-methoxy stilbenes)
White solid, yield 35%, m.p. 59.9˚C ~ 62.3˚C. IR υmax (cm−1), 683, 827, 958, 1065, 1155, 1204, 1459, 1518, 1591, 2838, 2937. 19F NMR (376 MHz, CDCl3) δ −135.24 (dd, J = 12.4, 8.5 Hz). 1H NMR (400 MHz, CDCl3) δ 7.29 (dd, 12.4, 8.5 Hz, 1H), 7.18 (d, J = 8.5 Hz, 1H), 6.98 (d, J = 16.2 Hz, 1H), 6.92 (d, J = 8.5 Hz, 1H), 6.88 (d, J = 16.2 Hz, 1H), 6.64 (d, J = 2.2 Hz, 2H), 6.39 (t, J = 2.2 Hz, 1H), 3.91 (s, 3H), 3.83 (s, 6H). 13C NMR (101 MHz, CDCl3) δ 160.96 (s), 153.74 (s), 151.29 (s), 147.29 (d, J = 11.1 Hz), 139.15 (s), 130.68 (d, J = 6.6 Hz), 127.86 (s), 127.72 (d, J = 2.5 Hz), 123.02 (d, J = 3.2 Hz), 113.48 (s), 113.28 (d, J = 2.6 Hz), 104.43 (s), 99.90 (s), 56.25 (s), 55.34 (s). HRMS(EI), Calcd. for, C17H17O3F, 288.1162, Found, 288.1158.
5c (trans-3,5-diethoxy-4’-((trifluoromethyl)thio) stilbenes)
White solid, yield 37%, m.p. 96.1˚C ~ 96.7˚C. 19F NMR (376 MHz, CDCl3) δ −42.84 (s, 3F). 1H NMR (400 MHz, CDCl3) δ 7.63 (d, J = 8.3 Hz, 2H), 7.54 (d, J = 8.3 Hz, 2H), 7.12 (d, J = 16.3 Hz, 1H), 7.06 (d, J = 16.3 Hz, 1H), 6.68 (d, J = 2.2 Hz, 2H), 6.43 (t, J = 2.2 Hz, 1H), 3.84 (s, 6H). 13C NMR (101 MHz, CDCl3) δ 161.01 (s), 139.77 (s), 138.62 (s), 136.63 (s), 131.07 (s), 128.01 (s), 127.59 (s), 127.36 (s), 122.93 (d, J = 2.1 Hz), 104.82 (s), 100.47 (s), 55.38 (s). HRMS(EI), Calcd. for, C17H15F3O2S, 340.0745, Found, 340.0747.
10a (trans-3,5-diethoxy-2’-fluoro-4’-methoxy stilbenes)
White solid, yield 28%, m.p. 57.3˚C ~ 58.2˚C. IR υmax (cm−1), 835, 962, 1106, 1170, 1290, 1444, 1506, 1532, 1619.2933, 2979. 19F NMR (376 MHz, CDCl3) δ −115.55 (dd, J = 12.8, 8.7 Hz). 1H NMR (400 MHz, CDCl3) δ 7.49 (t, J = 8.7 Hz, 1H), 7.15 (d, J = 16.4 Hz, 1H), 6.95 (d, J = 16.4 Hz, 1H), 6.70 (dd, J = 8.7, 2.4 Hz, 1H), 6.63 (dd, J = 12.8, 2.3 Hz, 3H), 6.37 (t, J = 2.3 Hz, 1H), 4.05 (q, J = 7.0 Hz, 4H), 3.81 (s, 3H), 1.42 (t, J = 7.0 Hz, 6H). 13C NMR (101 MHz, CDCl3) δ 162.30 (s), 160.25 (t, J = 5.2 Hz), 159.82 (s), 139.46 (s), 128.63 (d, J = 4.7 Hz), 127.61 (d, J = 5.6 Hz), 121.03 (d, J = 3.1 Hz), 117.63 (d, J = 12.6 Hz), 110.46 (d, J = 2.9 Hz), 104.98 (s), 101.57 (d, J = 26.0 Hz), 100.79 (s), 63.49 (s), 55.56 (s), 14.85 (s). HRMS(EI), Calcd. for C19H21O3F, 316.1475, Found, 316.1469.
10b (trans-3,5-n-dipropoxy-2’-fluoro-4’-methoxy stilbenes)
White solid, yield 21%, m.p. 58.3˚C ~ 60.2˚C. IR υmax (cm−1), 831, 962, 1066, 1197, 1290, 1445, 1506, 1596, 1619, 2876, 2964. 19F NMR (376 MHz, CDCl3) δ −115.55 (dd, J = 12.4, 8.7 Hz). 1H NMR (400 MHz, CDCl3) δ 7.49 (t, J = 8.7 Hz, 1H), 7.16 (d, J = 16.5 Hz, 1H), 6.96 (d, J = 16.5 Hz, 1H), 6.70 (dd, J = 8.7, 2.4 Hz, 1H), 6.63 (dd, J = 12.4, 2.2 Hz, 3H), 6.38 (t, J = 2.2 Hz, 1H), 3.94 (t, J = 6.6 Hz, 4H), 3.81 (s, 3H), 1.88 - 1.75 (m, 4H), 1.04 (t, J = 7.4 Hz, 6H). 13C NMR (101 MHz, CDCl3) δ 162.30 (s), 160.45 (s), 160.23 (d, J = 11.2 Hz), 159.82 (s), 139.42 (s), 128.68 (d, J = 4.7 Hz), 127.61 (d, J = 5.6 Hz), 121.00 (d, J = 3.1 Hz), 117.66 (d, J = 12.6 Hz), 110.46 (d, J = 2.9 Hz), 104.97 (s), 101.57 (d, J = 26.0 Hz), 100.82 (s), 69.57 (s), 55.57 (s), 22.62 (s), 10.56 (s). HRMS(EI), Calcd. for, C21H25O3F, 344.1788, Found, 344.1782.
10c (trans-4-ethoxy-3’-fluoro-4’-methoxy stilbenes)
White solid, yield 27%, m.p. 160.0˚C ~ 160.6˚C. IR υmax (cm−1), 526, 649, 734, 909, 1025, 1161, 1285, 1442, 1517, 1604, 2842, 2983. 19F NMR (376 MHz, CDCl3) δ −135.43 (dd, J = 12.6, 8.8 Hz). 1H NMR (400 MHz, CDCl3) δ 7.41 (d, J = 8.8 Hz, 1H), 7.24 (d, J = 1.9 Hz, 1H), 7.15 (d, J = 8.4 Hz, 1H), 6.94 (d, J = 8.4 Hz, 1H), 6.90 (d, J = 2.0 Hz, 1H), 6.87 (d, J = 2.0 Hz, 1H), 4.06 (q, J = 7.0 Hz, 2H), 3.91 (s, 3H), 1.43 (t, J = 7.0 Hz, 3H).13C NMR (101 MHz, cdcl3) δ 158.63 (s), 153.78 (s), 151.34 (s), 146.82 (d, J = 11.1 Hz), 131.34 (d, J = 6.6 Hz), 129.77 (s), 127.55 (d, J = 2.4 Hz), 125.00 (d, J = 2.4 Hz), 122.53 (d, J = 3.3 Hz), 114.67 (s), 113.35 (d, J = 2.3 Hz), 113.08 (d, J = 18.7 Hz), 63.47 (s), 56.29 (s), 14.81 (s). HRMS(EI), Calcd. for C17H17O2F, 272.1213, Found, 272.1215.
The in vitro anti-cancer activities of flourine-substituted resveratrol derivatives were studied on human cells breast carcinoma (MDA-MB-231) and gastric carcinoma cell lines (SGC-7901) by applying the MTT assay as described by Mosmann [
MTT assay is dependent on NAD(P)H-dependent oxidoreductase enzymes largely in the cytosolic compartment of the cell [
As summarized in
Compound | Molecular weight | IC50 (μM) | |
---|---|---|---|
MDA-231 | SGC-7901 | ||
5a | 288.11 | 66.23 ± 0.96 | 184.54 ± 1.24 |
5b | 288.11 | 51.27 ± 0.84 | --- |
5c | 340.17 | 50.19 ± 1.02 | 122.68 ± 2.04 |
10a | 316.14 | 440.22 ± 0.78 | 284.5 ± 2.36 |
10b | 344.17 | 57.08 ± 0.32 | --- |
10c | 272.12 | 64.06 ± 0.27 | --- |
5-FU | 262.19 | 98.59 ± 0.74 | 156.74 ± 2.64 |
Resveatrol | 228.24 | 153.32 ± 0.64 | 184.3 ± 1.38 |
IC50 = compound concentration required to inhibit tumor cell proliferation by 50%. Data are expressed as the mean ± SE from the dose-response curves of at least three independent experiments. ---, promotes the growth of cancer cells.
μM, compared to IC50 value of 5-FU is (98.59 ± 3.61 μM, 156.74 ± 6.16 μM, respectively). Moreover, 5c is little better than resvertarol where the difference is about 3-fold. All the compounds except 10a have shown good anti-breast cancer activity than 5-FU and resveratrol which prove that these series of resveratrol derivatives possess visible anti-cancer activity.
In summary, 6 new resveratrol derivatives were successfully synthesized. Most of the synthetic compounds indicated higher activities than resveratrol and 5-FU. From the results, compound 5c was identified as the most effective candidate item against breast cancer and gastric carcinoma cells lines. It is expected that the pharmacological studies described in this article will promote the design of new therapeutic drugs for the clinical treatment of breast cancer and gastric carcinoma. It shows the potentiality as a therapeutic for humans.
This research was supported by the National Natural Science Foundation of China (No. 81273537), the key disciplines of Hunan Province, College Students’ Innovative Projects of Hunan Province, and the Zhengxiang Scholar Program of the University of South China.
Xing Zheng,Liuying Yu,Xu Yao,Bo Lv,Zehua Yang,Qutong Zheng,Haiying Duan,Chen Song,Hailong Xie, (2016) Synthesis and Anti-Cancer Activities of Resveratrol Derivatives. Open Journal of Medicinal Chemistry,06,51-57. doi: 10.4236/ojmc.2016.63005