1,3-Benzodioxole-based fibrate derivatives as potential hypolipidemic and hepatoprotective agents

Article abstract of DOI:10.1016/j.bmcl.2021.127898

A series of target compounds 1,3-benzodioxole-based fibrate derivatives were designed and synthesized. All the target compounds were preliminarily evaluated by hyperlipidemia mice induced by Triton WR-1339, in which compound 12 displayed a greater anti-hyperlipidemia activity than other compounds as well as positive drug fenofibrate (FF). 12 showed a significant reduction of plasma lipids, such as triglycerides (TG), total cholesterol (TC) and low-density lipoprotein cholesterin (LDL-C), in high fat diet (HFD) induced hyperlipidemic mice. In addition, hepatic transaminases (AST and ALT) were ameliorated after administration of 12, in particular the AST, and the histopathological examination showed that 12 improved the hepatic lipid accumulation. The expression of PPAR-α involved in lipids metabolism was up-regulated in the liver tissues of 12-treated group. Other significant activity such as antioxidant, and anti-inflammation was confirmed and reinforced the effects of 12 as a potential hypolipidemia and hepatoprotective agent.

Full text of DOI:10.1016/j.bmcl.2021.127898

Bioorg. Med. Chem. Lett. 43 (2021) 127898
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
1,3-Benzodioxole-based fibrate derivatives as potential hypolipidemic and
hepatoprotective agents
,
c
,
,
*
c
,
,c,
Yun-Dong Xiea, Yan-Hong Xue, Ji-Ping Liua d, Bin Wanga d, Yong-Heng Shia d, Wei Wanga,
Xiao-Ping Wanga, Meng Suna, Xin-Ya Xua, Xiao-Li Bianb
,
a College of Pharmacy, Shaanxi University of Chinese Medicine, Xi’an-xianyang New Ecomic Zone 712046, China
b Department of Pharmacy, Xi’an Jiaotong University, Xi’an 710061, China
c Key Laboratory of Pharmacodynamics and Material Basis of Chinese Medicine, Shaanxi Administration of Traditional Chinese Medicine, Xianyang 712046, China
d Subject Innovation Team of Shaanxi University of Chinese Medicine, China
e The People’s Hospital of Yongcheng, 888 Ouya Road, Yongcheng City, Shangqiu City, Henan Province 476600, China
A R T I C L E I N F O
A B S T R A C T
Keywords:
A series of target compounds 1,3-benzodioxole-based fibrate derivatives were designed and synthesized. All the
target compounds were preliminarily evaluated by hyperlipidemia mice induced by Triton WR-1339, in which
compound 12 displayed a greater anti-hyperlipidemia activity than other compounds as well as positive drug
fenofibrate (FF). 12 showed a significant reduction of plasma lipids, such as triglycerides (TG), total cholesterol
(TC) and low-density lipoprotein cholesterin (LDL-C), in high fat diet (HFD) induced hyperlipidemic mice. In
addition, hepatic transaminases (AST and ALT) were ameliorated after administration of 12, in particular the
AST, and the histopathological examination showed that 12 improved the hepatic lipid accumulation. The
1,3-benzodioxole-based fibrate derivatives
Hypolipidemia
Hepatoprotection
PPAR-
α
expression of PPAR-α involved in lipids metabolism was up-regulated in the liver tissues of 12-treated group.
Other significant activity such as antioxidant, and anti-inflammation was confirmed and reinforced the effects of
12 as a potential hypolipidemia and hepatoprotective agent.
Hyperlipidemia, caused by lipids metabolism disorder, is a serious
health-threatening disease physically and mentally which can increase
the lipids in the blood and is also a major risk factor for cardio-
cerebrovascular diseases and metabolic syndrome.1,2 Studies have
showed that the elevated triglyceride (TG) plays a major role in the
occurrence and development of cardio-cerebrovascular diseases, dia-
betes and fatty liver by triggering oxidative stress, inflammation,
atherosclerosis and other pathological processes.3 Prevention and
treatment of hypertriglyceridemia are very important to cardio-
cerebrovascular related diseases. Therefore, the effective control the
level of TG has enormous significance for the prevention and treatment
of cardio-cerebrovascular diseases and/or metabolic syndrome.
available in pharmacies or hospitals, which were widely used in the
treatment of hyperlipidemia. These fibrates increase lipolysis and
eliminate TG by activating the nuclear transcription factor (PPAR-α),
which increases lipoprotein lipase activity.4 However, fibrates need a
higher dose to reduce blood lipids and were accompanied by an increase
in liver transaminase, especially in combination with the statins.
Although the hypolipidemic effect of fibrates was significant, the most
common adverse effects were liver injury. Therefore, a more effective
agent having both hypolipidemia and hepatoprotective properties was
in great demand.
In designing novel drugs (Fig. 1), hybrid molecules method was
largely applied. The strategy through the combination of different
pharmacophores may obtain compounds with multifunctional biolog-
ical effects. Natural products provide a variety of leading compounds for
drug discovery and research. Sesamol (1,3-benzodioxole) is the core
component of sesame oil, which has the effects of antioxidation, anti-
Fibric acid derivatives have been frequently used in the synthesis of
hypolipidemic agents and played an important role in the therapy of
hyperlipidemia for many years. The fibrates (Fig. 1), such as clofibrate,
ciprofibrate, gemfibrozil, beclobrate, fenofibrate and so on, were
Abbreviations: ALT, alanineaminotransferase; AST, aspartate transaminase; FF, fenofibrate; GSH-PX, glutathione peroxidase; HDL-C, high-density lipoprotein
cholesterin; HFD, high-fat diet; IL-6, interleukin; LDL-C, low-density lipoprotein cholesterin; MDA, malondialdehyde; PPAR- , peroxisome proliferator-activated re-
α
ceptor α; SOD, superoxide dismutase; TC, total cholesterol; TG, triglyceride; TNF-α, tumor necrosis factor α.
* Corresponding author.
E-mail address: bianxl@mail.xjtu.edu.cn (X.-L. Bian).
https://doi.org/10.1016/j.bmcl.2021.127898
Received 3 December 2020; Received in revised form 12 February 2021; Accepted 16 February 2021
Available online 6 March 2021
0960-894X/© 2021 Published by Elsevier Ltd.

Y.-D. Xie et al.
Bioorganic & Medicinal Chemistry Letters 43 (2021) 127898
Fig. 1. Designing of sesamol-fibrate hybrids on the basis of sesamol and fibrate scaffolds displaying hypolipidemic and liver protective effects.
Scheme 1. Synthesis route of target compounds 1 ~ 12.
inflammation and regulating blood lipids.5,6 1,3-benzodioxole de-
rivatives, such as sesamin, sesamolin, sesaminol, sesamolinol, have
significant effects on anti-oxidation, anti-inflammation and regulation
of blood lipids, which have significant preventive and protective effects
on cardiovascular diseases and liver injury.7–11 The effects were closely
connected with the structure of 1,3-benzodioxole. Based on these, ac-
cording to the structure activity relationship of fibrates, sesamol was
introduced into the structure of brominated alkanoates by ether bond to
synthesize the analogs of fibrates. The target compounds were expected
to have both hypolipidemia and hepatoprotective properties.
containing sesamol pharmacophore. As displaying in Scheme 1, com-
pounds 1–4 were produced by the action of sesamol with different ethyl
bromocarboxylates in the presence of potassium carbonate. Then, the
ester bond was hydrolyzed under the condition of strong base, and then
acidified to achieve the target compounds 5–8. Target compounds 9–12
were issued by compounds 5–8 and sesamol under the action of EDCI
and DMAP, respectively. Target compounds 1–12 were identified by 1H
NMR, 13C NMR and EI-MS12
.
Firstly, we evaluated the hypolipidemic activity of these novel syn-
thesized compounds by acute hyperlipidemia mice model induced by
Triton WR 1339 (400 mg/kg). The relevant experimental methods have
In this study, we reported the synthesis of target compounds
2

Y.-D. Xie et al.
Bioorganic & Medicinal Chemistry Letters 43 (2021) 127898
Fig. 2. Plasma Lipids (TG and TC) and MDA levels with the administration of compounds (1–12) in Triton WR-1339 induced hyperlipidemic mice. All results were
expressed as the mean ± SEM, n = 8, ##P < 0.01 vs Normal group; *P < 0.05, **P < 0.01 vs Model group. The dosage of the test compounds was 0.362 mmol/kg,
Sesamol was 0.362 mmol/kg and Fenofibrate (FF) was 0.036 mmol/kg.
been reported in the previous literature.13,14 In this research, the levels
of serum TG, TC and MDA were determined. The results displayed that
compounds 2, 4, 5 and 7–12 obviously reduced serum TG at the dose of
0.362 mmol/kg. Compounds 1–4 and 7–12 declined significantly the
levels of TC. The antioxidant activity showed that only compounds 11
and 12 significantly decreased the MDA of lipid peroxidation product in
hyperlipidemic mice. The hypolipidemia structure–activity relationship
showed that the longer the alkyl chain length between benzodioxalene
structure and carboxyl or ester bond, the better the lipid-lowering effect
in the homologue. On the whole, the lipid-lowering activity of the
compounds containing two benzodioxalene structures was better than
that of the compounds containing one benzodioxalene structure (Fig. 2).
Molecular docking studies were performed on the protein PPARα for
the affinity activity, employing the docking procedure using MOE pro-
gram installed on Win 10 software. The PDB code was 1K7L. Fenofibrate
(FF) was selected as the reference. The results were showed that all the
target have been found to dock well in the active site of PPAR
α
(Table 1).
affinity
From these molecular docking studies, we found that the PPAR
α
3

Y.-D. Xie et al.
Table 1
Bioorganic & Medicinal Chemistry Letters 43 (2021) 127898
blood lipid was greater. The findings suggested compound 12 exhibited
concentration-dependent effects towards hypolipidemia activity
(Fig. 3).
The target compounds with their PPAR
α
receptor affinity ac-
tivity by MOE docking scores.a
Compounds
With the promising activity in hand, chronic hypolipidemia activity
on 12 was performed on HFD-induced hyperlipidemia mice. Fenofibrate
(FF) was selected as positive drug. The experimental process and
methods have been reported in previous literature.15 After intragastric
administration, the serum biochemical indexes were detected as follows:
total lipid profiles (TC, TG, HDL-C and HDL-C), antioxidant indexes
Scores (kJ/mol⋅K)
1
ꢀ 5.0996
ꢀ 5.0275
ꢀ 5.3548
ꢀ 5.7275
ꢀ 4.4528
ꢀ 4.7678
ꢀ 4.7846
ꢀ 5.4045
ꢀ 5.7004
ꢀ 5.8941
ꢀ 5.9192
ꢀ 6.3502
ꢀ 3.6841
ꢀ 7.3294
ꢀ 5.7012
2
3
4
5
6
(SOD, GSH-PX and MDA), inflammation factors (IL-6 and TNF-
liver transaminase levels (AST and ALT). In addition, hepatic histopa-
thology and the expression of PPAR- in liver were also determined.
α), and
7
8
9
α
10
Results of lipids-lowering (Fig. 4) showed that 12 significantly
reduced serum TG (P < 0.01), and obviously decreased LDL-C (P < 0.05)
compared with the model group, which was similar to FF, the positive
drug. Compound 12 was also able to ameliorate the levels of TC (P <
0.01), while the standard agent FF did not show the activity of lowering
TC (P > 0.05). From the lipid-lowering activity, it can be found that 12
revealed the better lipid-lowering activity than FF.
11
12
Sesamol
GW409544b
Fenofibrate (FF)c
a
b
PDB code: 1K7L.
The X-ray crystal structure of PPAR
α
protein reported as
As showed in Fig. 5, the levels of SOD in 12 group was significantly
increased (P < 0.01), compared with the model group. The levels of
GSH-PX were increased, but did not demonstrate statistical significance
(P > 0.05) both in 12 group and FF group. The levels of MDA, one of the
indicators of lipid peroxidation products, was apparently reduced in 12
group (P < 0.01), compared with model group, while the levels of MDA
in the positive drug FF group decreased, but did not show statistical
significance (P > 0.05). As showed in Fig 6, 12 revealed the potent anti-
complex with GW409544 deposited in Brookhaven Protein.
c
Fenofibrate (FF) was selected as reference.
activity of aroxyalkyl carboxylic acids (compounds 5, 6, 7, 8) was worse
than that of carboxylic esters. Among esters, sesamol esters (compounds
9, 10, 11, 12) have stronger PPARα affinity activity than ethanol esters
(compounds 1, 2, 3, 4). Although the PPAR
α
affinity activity of sesamol
affinity activity
was weak, it has synergistic function, and the PPAR
α
inflammatory activity, the levels of TNF-α (P < 0.05) and IL-6 (P < 0.01)
was significantly enhanced after esterification with carboxylic acid.
Moreover, we also found that the affinity activity between these com-
were significantly decreased in 12 group compared with the model
group. The findings indicated that compound 12 could inhibit the in-
flammatory response to exhibit anti-inflammatory activity in
hyperlipidemia.
pounds and PPARα was positively correlated with the alkyl chain length
between aroxy and carbonyl groups. The longer the alkyl chain length is,
the stronger the affinity activity is. Among these compounds, compound
12 displayed the excellent affinity activity with the score was ꢀ 6.3502
kJ/mol⋅K, which was better than that of the positive drug FF (ꢀ 5.7012
kJ/mol⋅K) and seems to have good affinity for the active residues of
PPAR. The results of molecular docking were quite co-relatable to the
results of lipid-lowering activity in Triton WR 1339 induced hyper-
lipidemic mice mode.
To evaluate the liver function of hyperlipidemia mice, the levels of
serum AST and ALT were determined, which were typically used as a
detection index. As showed in Fig. 7, the levels of AST and ALT were
obviously increased in the model group, as expected, compound 12 has
the effects of protecting the liver. The levels of AST (P < 0.01) were
significantly decreased in 12 group compared to model group, the levels
of ALT were reduced by 6%, while there was no statistical difference.
However, FF group did not show the significance compared with the
model group.
Among these novel compounds, the hypolipidemia and antioxidant
activity of 12 was most effective compared to other synthesized com-
pounds. The dose-dependent study on compound 12 (concentration at
0.121 mmol/kg, 0.362 mmol/kg and 1.086 mmol/kg body weight) was
conducted on a different set of experimental animals. The results showed
that compound 12 reduced TG by 10.4% (P > 0.05), 68.8% (P < 0.01)
and 74.1% (P < 0.01), and decreased TC by 14.3% (P > 0.05), 67.3% (P
< 0.01) and 70.1% (P < 0.01) at three doses, respectively, compared
with model group. With the increase of dose, the activity of lowering
In addition, the hepatoprotective effects were also evaluated by
histopathological examine.15,16 As showed in Fig. 8, oil red O staining in
liver tissue sections showed that in the normal group, the liver cells were
arranged neatly, the cell morphology was normal, and there were no
obvious lipid droplets in the cytoplasm of liver cells. In contrast, a large
number of irregular lipid droplets were found in the liver tissue of mice
Fig. 3. Dose-response effects of compound 12 in Triton WR 1339 induced hyperlipidemic mice on plasma TG and TC. All results were expressed as the mean ± SEM,
n = 8, ##P < 0.01 vs Normal group; **P < 0.01 vs Model group. The dosage of compound 12 was 0.121 mmol/kg, 0.362 mmol/kg and 1.086 mmol/kg respectively
and FF was 0.036 mmol/kg.
4

Y.-D. Xie et al.
Bioorganic & Medicinal Chemistry Letters 43 (2021) 127898
Fig. 4. Effects of 12 on plasma lipids in HFD-induced hyperlipidemic mice. Each parameter represents pooled data from 12 mice/group, and values were expressed
as mean ± SEM, #P < 0.05, ##P < 0.01 vs Normal group; *P < 0.05, **P < 0.01 vs Model group. The dosage of 12 was 67 mg/kg and FF was 13 mg/kg.
Fig. 5. Effects of 12 on serum SOD, MDA, and GSH-PX levels of the HFD-induced hyperlipidemic mice. The results were expressed as mean ± SEM, n = 12, ##P <
0.01 vs Normal group; **P < 0.01 vs Model group. The dosage of 12 was 67 mg/kg and FF was 13 mg/kg.
Fig. 6. Effects of 12 on serum TNF-
α
and IL-6 levels of the HFD-induced hyperlipidemic mice. The results were expressed as mean ± SEM, n = 12, ##P < 0.01 vs
Normal group; *P < 0.05, **P < 0.01 vs Model group. The dosage of 12 was 67 mg/kg and FF was 13 mg/kg.
5

Y.-D. Xie et al.
Bioorganic & Medicinal Chemistry Letters 43 (2021) 127898
Fig. 7. Effects of 12 on serum AST and ALT levels of the HFD-induced hyperlipidemic mice. The results were expressed as mean ± SEM, n = 12, #P < 0.05, ##P <
0.01 vs Normal group; **P < 0.01 vs Model group. The dosage of 12 was 67 mg/kg and FF was 13 mg/kg.
Fig. 8. Effects of 12 on hepatic lipid accumulation in HFD-induced hyperlipidemic mice (Sudan III and hematoxylin 100 × ). (a) Normal group mouse liver. (b)
Model group mouse liver. (c) 12 group mouse liver. (d) FF group mouse liver. (e) Relative lipid accumulation in the hepatic. Data indicate the mean of six inde-
pendent experiments ± SEM. ##P＜0.01 vs Normal group; *P＜0.05, **P＜0.01 vs Model group.
in the model group. Interestingly, in 12 and FF groups mice liver, the
amount of lipid droplets in the liver tissue of mice was much lower than
that in the model group. The content of lipid droplets in the liver of mice
in each group was quantitatively expressed as showed in Fig. 8(e). The
content of lipid droplets in 12 group and FF group was significantly
lower than that in the model group. These results showed that 12
improved lipid accumulation condition in the hepatic of hyperlipidemia
mice.
Based on previous study and the lipids-lowering activity, we specu-
lated that the hypolipidemia mechanism of compound 12 may be
through the activation of the nuclear transcription factor peroxisome
proliferator α (PPAR-α). Hence, the expression of PPAR-α protein in liver
tissue was examined. The procedure has been reported in previous
papers.16–18 As outlined in Fig. 9, the expression of PPAR-
α in model
group was significantly reduced compared with normal group. As ex-
pected, 12 showed significantly activation of PPAR-
model group (P < 0.01), and the expression of PPAR-
also obviously increased (P < 0.01). Interestingly, 12 significantly
α
compared with the
α
in FF group was
upregulate the expression of PPAR-α more than FF. The results suggested
that the molecular mechanism of hypolipidemic effect of compound 12
may be the same as that of fibrates.
In this research, a series of novel compounds were synthesized.
Among these compounds, compound 12 provides a multifunctional ac-
tivity, such as antioxidant, anti-inflammation, hypolipidemia and hep-
atoprotective effects, which were beneficial for ameliorating
hyperlipidemia. Fibrates, such as fenofibrate and clofibrate, can activate
Fig. 9. The expression of PPAR-
α in hepatic tissue of HFD-induced hyper-
lipidemic mice. The results were displayed as mean ± SEM, n = 6, ##P < 0.01
vs Normal group; **P < 0.01 vs model group. The dosage of 12 was 67 mg/kg
and FF was 13 mg/kg.
PPAR-
α
to exert the hypolipidemic activity.19 Compound 12 also can
6

Y.-D. Xie et al.
Bioorganic & Medicinal Chemistry Letters 43 (2021) 127898
decrease blood lipids by activating PPAR-
α
protein. The accumulation of
Medicine (2019-YL13 to BW). Key Laboratory of Pharmacodynamics
and Material Basis of Chinese Medicine, Shaanxi Administration of
Traditional Chinese Medicine is gratefully acknowledged. Thanks for
providing the experimental platform so that the experiment can be
completed smoothly. The authors sincerely thank the Chengdu Lilai
Biotechnology Co. LTD (Sichuan, China) for the detection of experi-
mental results of Western Blotting.
fat in the liver will lead to lipid peroxidation, increase the number of
reactive oxygen species and produce oxidative stress,20 which in turn
causes inflammation, and the whole chain reaction will aggravate liver
injury. The hepatoprotective effect of 12 can be explained as the accu-
mulation of fat in the liver decreases as well as the antioxidant and anti-
inflammation.
In conclusion, a series of 1,3-benzodioxole-based fibrate derivatives
were designed, synthesized and evaluated for lipids-lowering and hep-
atoprotection by experimentally acute and chronic hyperlipidemic mice
models. The results displayed that 12 was regarded as a worthy studying
compound for both hypolipidemia and hepatoprotection. 12 not only
significantly regulated lipid profiles but also improved hepatic injury in
the hyperlipidemia mice which may upregulate the expression of PPAR-
Appendix A. Supplementary data
Supplementary data to this article can be found online at https://doi.
org/10.1016/j.bmcl.2021.127898.
References
α
protein and reduce fat accumulation in the liver. Furthermore, addi-
tional activity such as antioxidation and anti-inflammation confirmed
and reinforced that 12 was a novel potential agent with multifunctional
effects. Therefore, 12 seem to be a candidate and is expected to be
further developed into a new hypolipidemic drug.
1
2
3
4
5
6
7
8
9
Johnathan R. Curr Clin Pharmacol. 2017;12:152.
McQueen MJ, Hawken S, Wang X, et al. Lancet. 2008;372:224.
Rezapour M, Payani E, Taran M, et al. Med J Islamic Repub Iran. 2017;31:80.
´
´
Fernandez AJ, Mijares AH. Clínica E Investigacion En Arteriosclerosis. 2012;24:19.
Haghighian MK, Alipoor B, Sadat BE, et al. Health Promot Perspect. 2014;4:90.
Kuhad A, Chopra K. Exp Brain Res. 2008;185:411.
Katayama S, Sugiyama H, Kushimoto S, et al. J Agric Food Chem. 2016;64:4908.
Umeda-Sawada R, Fujiwara Y, Abe H, et al. J Nutr Sci Vitaminol. 2003;49:442.
Khansai M, Boonmaleerat K, Pothacharoen P, et al. BMC Complem Altern M. 2016;16:
205.
Declaration of Competing Interest
The authors declare that they have no known competing financial
interests or personal relationships that could have appeared to influence
the work reported in this paper.
10 Robert VC, Laurie JC, Okinaka L, et al. Nutr Cancer. 2001;39:66.
11 Lv D, Zhu CQ, Liu L. Int J Clin Exp Patho. 2015;8:5733.
12 Xie YD, Wang W, Li N, Liu JP, Shi YH, Sun M, Xu XY, Chen J, CN110407801A, 2019,
11.
13 Xie YD, Xu YH, Chen ZZ, et al. Biomed Pharmacother. 2017;95:1749.
14 Xie YD, Chen ZZ, Li N, et al. Biomed Pharmacother. 2018;99:715.
15 Chen ZZ, Xie YD, Shao LH, et al. Bioorg Med Chem Lett. 2018;28:3787.
16 Shao LH, Bai Y, Wang QT, et al. Bioorg Med Chem Lett. 2019;29, 126723.
17 Wang XP, Wang PF, Bai JQ, et al. Biomed Pharmacother. 2019;118, 109268.
18 Yao F, Yang GD, Xian YS, et al. Food Funct. 2019;10:5789.
19 Guay DR. Ann Pharmacother. 1999;33:1083.
Acknowledgements
This work was supported by the National Natural Science Foundation
of China (Grant No. 21172177). Thanks for the start-up fund for doctoral
scientific research given by Shaanxi University of Chinese Medicine (No.
124020057). Subject Innovation Team of Shaanxi University of Chinese
20 Grunfeld C, Kotler DP, Shigenaga JK, et al. Am J Med. 1991;90:154.
7