Synthesis and biological evaluation of nitric oxide-releasing matrine derivatives as anticancer agents

Article abstract of DOI:10.1016/j.cclet.2009.11.033

A series of furoxan-based nitric oxide-releasing matrine derivatives (10a-f) were synthesized. The biological evaluation showed that compounds 10a, 10b, 10e and 10f had stronger cytotoxic activities than 5-fluorouracil against human hepatoma cells (HepG2) in vitro.

Full text of DOI:10.1016/j.cclet.2009.11.033

Available online at www.sciencedirect.com
Chinese Chemical Letters 21 (2010) 381–384
www.elsevier.com/locate/cclet
Synthesis and biological evaluation of nitric oxide-releasing matrine
derivatives as anticancer agents
b
Li Qin He a,b, Jing Liu b, Deng Ke Yin b, Yi Hua Zhang a, , Xiao Shan Wang
*
a Center of Drug Discovery, China Pharmaceutical University, Nanjing 210009, China
b Anhui University of Traditional Chinese Medicine, Anhui Key Laboratory of Modernized Chinese Material Medical, Anhui, Hefei 230031, China
Received 31 August 2009
Abstract
A series of furoxan-based nitric oxide-releasing matrine derivatives (10a–f) were synthesized. The biological evaluation showed
that compounds 10a, 10b, 10e and 10f had stronger cytotoxic activities than 5-fluorouracil against human hepatoma cells (HepG2)
in vitro.
# 2009 Yi Hua Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Keywords: Matrine; Furoxan; Anti-tumor activity; HepG2
Matrine 1 is one of the major active alkaloids isolated from the Sophora alopecuroides L, a useful Chinese herbal
drug. [1]. Matrine 1 possesses antipyretic, anti-inflammatory, analgesic, and notable antiviral activities [2–4], and has
been used for the treatment of lipopolysaccharide-induced liver injury [5]. Matrine also could regulate immunity, treat
cardiac arrhythmia, increase the number of white blood cells and relax cancer pain. Recently, it was reported that
matrine 1 could inhibit the growth of tumor cells and effect on cervical, hepatic and gastric carcinomas [6–9].
Therefore, it is interesting to develop more matrine derivatives with potent anticancer effects.
Nitric oxide (NO), a highly reactive molecule, implicated in numerous physiologic and pathologic processes,
playing an important role in nonspecific anti-tumor immune response [10,11]. NO is naturally released from L-arginine
in the presence of NO synthase (NOS) in vivo, it could also be generated from NO donor compounds, such as furoxan,
nitrate, diazeniumdiolate in vitro and in vivo [12]. Recently, it was showed that high concentration of NO was cytotoxic
and could induce the apoptosis of tumor cells, prevent tumors from metastasizing and assist macrophage to kill tumor
cells [13,14]. Therefore the conjugation strategy for NO donor with active compounds could be a promising way for
the selective anticancer drugs development. With the consideration of the above a group of NO-releasing derivatives of
matrine that act as a new class of improved matrine-related agents were described. Benzenesulfonyl-substituted
furoxans, a kind of NO donors which can donate two molecules of NO in vivo under the action of thiol cofactors [15],
had been incorporated to the –COOH of matrine derivatives compound 4 through various spacers to synthesize
compounds 10a–f (Scheme 1). By releasing NO in vivo, we hope to enhance the anticancer activity of these
derivatives.
* Corresponding author.
E-mail address: zyh@sohu.com (Y.H. Zhang).
1001-8417/$ – see front matter # 2009 Yi Hua Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
doi:10.1016/j.cclet.2009.11.033

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L.Q. He et al. / Chinese Chemical Letters 21 (2010) 381–384
Scheme 1. Reaction conditions and reagents: (a) 1, NaOH (aq.), 100 8C, 2 h; 2, 20% H2SO4; 95%. (b) PhCH2Br, DMF, K2CO3, 70 8C, 4 h; 80%. (c)
NaOH, EtOH, 2 h; 86%. (d) DCC, DMAP, CH2Cl2, rt, 24 h; 67–87%.
Matrine 1 was reacted with sodium hydroxide giving the hydrolytic ring-opening derivative 2. In the presence of
potassium carbonate 2 reacted with benzyl chloride to afford 3, then through the hydrolysis with sodium hydroxide 3
can produce 4. The substituted furoxans were prepared as the following. The starting material benzenethiol 5 was
converted to 2-(phenylthio)acetic acid 6 by treatment with chloroacetic acid. The next oxidation with 30% H2O2 and
then nitration can offer 8. It was then converted to various mono-phenylsulfonylfuroxans 9a–f by treatment with
corresponding diol, or amino substituted alcohol (spacers 1–6). Finally, 9a–f conjugated with 4 to give target
compounds 10a–f. The structures of the target compounds were shown in Table 1 and the data of m.p., MS, IR, 1H
NMR spectra and elemental analysis (EA) for the 6 compounds were shown in Ref. [16].
We initially tried to synthesize compounds 11a–f by the treatment of 2 with 9a–f under different conditions, but
failed (Scheme 2). Matrine, rather than the desired products, was gained. It is probably that the compound 2 could be
easily converted to relatively stable lactam in the presences of SOCl2, DCC or Boc2O.
All target compounds were evaluated for cytotoxicity against HepG2 cells in vitro by MTT method [17], using
5-fluorouracil (5-FU) as control. The results indicated that 10a–f had potent cytotoxic activities which were
comparable to or stronger than that of 5-FU, especially 10a, 10b and 10f with IC50 values of 11.36, 11.45 and
Table 1
The structures and cytotoxic activity (IC50 at mmol/L) against HepG2 cells (human hepatoma cells) of the target compounds.
Compound
R
IC50
11.36
10a
10b
O(CH2)2
O(CH2)3
11.45
16.73
25.14
14.21
8.02
10c
10d
O(CH2)4
OCH(CH3)CH2CH2
O(CH2)2O(CH2)2
NHCH2CH2
10e
10f
Matrine
5-Fluorouracil
8069
15.92

L.Q. He et al. / Chinese Chemical Letters 21 (2010) 381–384
383
Scheme 2. Reaction conditions and reagents: (a) 1, NaOH (aq.), 100 8C, 2 h; 2, 20% H2SO4; 95%. (b) 1, SOCl2, ClCH2CH2Cl, 0–70 8C; 2, DCC or
CDI, DMAP; 3, NaOH (aq.), Boc2O, t-BuOH.
8.02 mmol/L, respectively (Table 1). The different results of the tested compounds may be due to the different spacers.
Derivatives with spacers of 4–5 atoms and linear chain are more active than the compounds with longer and branched
chain spacers.
In summary, a series of furoxan-based NO-donating matrine derivatives were synthesized and in vitro cytotoxicity
against HepG2 cells were evaluated. Preliminary bioassay indicated that all of the target compounds exhibited
cytotoxic activity to certain extent. Among them, compounds 10a, 10b, 10e and 10f had stronger cytotoxic activity
than 5-FU against HepG2 cells. Further biological evaluations are in progress.
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[16] Data. 10a: m.p. 122.4–124.3 8C. IR (KBr): 3018, 2930, 2862, 1734, 1626, 1264, 1167 cmÀ1; MS (ESI, m/z): [M+H]+ 625; 1H NMR (300 MHz,
CDCl3): d 1.28–1.95 (m, 17H, CH2, CH); 2.06 (s, 1H, CH); 2.36 (t, 2H, N-CH2); 2.78 (t, 1H, CH); 2.84 (d, 1H, CH); 2.91 (m, 2H, CH); 3.15 (d,
1H, CH); 4.10 (d, 1H, CH); 4.47 (t, 2H, OCH2); 4.59 (t, 2H, OCH2); 7.23 (t, 1H, ArH); 7.32 (d, 2H, ArH); 7.35 (t, 2H, ArH); 7.61 (t, 2H, ArH);
7.75 (t, 1H, ArH); 8.07 (d, 2H, ArH); Anal. Calcd. for C32H40N4O7S: C 61.54, H 6.41, N 8.97; found: C 61.15, H 6.32, N 8.20. 10b: m.p. 85.1–
86.7 8C. IR (KBr): 3062, 2927, 2856, 1728, 1617,1552,1258, 1163 cmÀ1; MS (ESI, m/z): [M+H]+ 639; 1H NMR (300 MHz, CDCl3): d 1.25–
2.24 (m, 20H, CH2, CH); 2.39 (t, 2H, N-CH2); 2.78–2.86 (m, 4H, CH2, CH); 3.18–3.21 (m, 1H, CH); 4.08 (d, 1H, CH); 4.12–4.15 (t, 2H,
OCH2); 4.40–4.43 (t, 2H, OCH2); 7.28 (t, 1H, ArH); 7.35 (d, 2H, ArH); 7.40 (t, 2H, ArH); 7.68 (t, 2H, ArH); 7.74 (t, 1H, ArH); 8.05 (d, 2H,
ArH); Anal. Calcd. for C33H42N4O7S: C 62.07, H 6.58, N 8.78; found: C 61.84, H 6.23, N 8.52. 10c: m.p. 74–75 8C. IR (KBr): 3029, 2926,
2851, 1730, 1627, 1576, 1243, 1163 cmÀ1; MS (ESI, m/z): [M+H]+ 653; 1H NMR (300 MHz, CDCl3): d 1.10–1.96 (m, 21H, CH2, CH); 2.32–
2.33 (t, 3H, CH); 2.78–2.86 (m, 4H, CH2, CH); 3.16–3.20 (m, 1H, CH); 4.12–4.15 (t, 3H, OCH2, CH); 4.40–4.43 (t, 2H, OCH2); 7.19–7.36 (m,
5H, ArH); 7.54–7.61 (m, 2H, ArH); 7.68–7.73 (m, 1H, ArH); 7.99–8.01 (m, 2H, ArH); Anal. Calcd. for C34H44N4O7S: C 62.58, H 6.75, N 8.59;
found: C 62.16, H 6.54, N 8.72. 10d: m.p. 102.4–103.2 8C. IR (KBr): 3032, 2928, 2852, 1729, 1626, 1557, 1246, 1165 cmÀ1; MS (ESI, m/z):
[M+H]+ 653; 1H NMR (300 MHz, CDCl3): d 1.20–2.05 (m, 23H, CH2, CH); 2.13 (m, 1H, CH); 2.36 (t, 2H, N-CH2); 2.42 (m, 2H, CH2); 3.16–
3.20 (m, 1H, CH); 4.05 (d, 1H, CH); 4.10–4.12 (m, 2H, OCH2); 4.40–4.43 (t, 2H, OCH2); 7.28 (t, 1H, ArH); 7.33 (d, 2H, ArH); 7.36 (t, 2H,
ArH); 7.64 (t, 2H, ArH); 7.75 (t, 1H, ArH); 8.06 (d, 2H, ArH); Anal. Calcd. for C34H44N4O7S: C 62.58, H 6.75, N 8.59; found: C 62.79, H 6.96,
1
N 8.08. 10e: m.p. 62.2–63.5 8C. IR (KBr): 3032, 2928, 2852, 1731, 1626, 1557, 1246, 1165 cmÀ1; MS (ESI, m/z): [M+H]+ 669; H NMR
(300 MHz, CDCl3): d 1.15–2.12 (m, 19H, CH2, CH); 2.32–2.33 (t, 2H, CH2); 2.78–2.86 (m, 3H, CH2, CH); 3.16–3.20 (m, 1H, CH); 3.80 (t, 2H,

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OCH2); 3.92 (t, 2H, OCH2); 4.02 (d, 1H, CH); 4.30 (t, 2H, OCH2, CH); 4.57 (t, 2H, OCH2); 7.20 (t, 1H, ArH); 7.32 (d, 2H, ArH); 7.40 (t, 2H,
ArH); 7.71 (t, 2H, ArH); 7.76 (t, 1H, ArH); 8.08 (d, 2H, ArH); Anal. Calcd. for C34H44N4O8S: C 61.08, H 6.59, N 8.38; found: C 61.43, H 6.92,
1
N 8.12. 10f: m.p. 93.6–94.8 8C. IR (KBr): 3306, 3064, 2932, 2860, 1650, 1616, 1258, 1164 cmÀ1; MS (ESI, m/z): [M+H]+ 624; H NMR
(300 MHz, CDCl3): d 1.25–1.98 (m, 17H, CH2, CH); 2.02 (m, 1H, CH); 2.30 (m, 2H, CH); 2.78–2.86 (m, 4H, CH2, CH); 3.16–3.20 (m, 1H,
CH); 3.98 (d, 1H, CH); 4.12–4.15 (t, 2H, OCH2); 4.45–4.46 (t, 1H,); 4.51–4.62 (t, 2H, OCH2); 7.28–7.36 (m, 5H, ArH); 7.58–7.62 (m, 2H,
ArH); 7.73–7.76 (m, 1H, ArH); 8.03–8.06 (m, 2H, ArH); Anal. Calcd. for C32H41N5O6S: C 61.64, H 6.58, N 11.24; found: C 61.12, H 6.74, N
10.89.
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