Synthesis and evaluation of new sesamol-based phenolic acid derivatives with hypolipidemic, antioxidant, and hepatoprotective effects

Article abstract of DOI:10.1007/s00044-021-02770-1

The objective of this study is to synthesize a series of sesamol-based phenolic acid derivatives, which were designed by combination principle. The hypolipidemic activity of all these compounds was preliminarily screened by acute hyperlipidemic mice model induced by Triton WR 1339, in which compound T6 exhibited more significant reducing plasma TG and TC than fenofibrate. Compound T6 was also found to obviously decrease TG and TC both in the plasma and hepatic tissue of high-fat-diet-induced hyperlipidemic mice. Moreover, T6 showed hepatoprotective effects, which remarkable amelioration in characteristic liver enzymes was examined and the histopathological observation displayed that compound T6 inhibited lipids accumulation in the hepatic. The levels of PPAR-α receptor related to lipids metabolism in hepatic tissue were upregulated after T6 treatment. Other potent effects of T6 such as antioxidant and anti-inflammatory activity were also observed. On the bases of these findings, compound T6 may serve as an effective hypolipidemic and hepatoprotective agent. [Figure not available: see fulltext.]

Full text of DOI:10.1007/s00044-021-02770-1

MEDICINAL
CHEMISTRY
RESEARCH
Medicinal Chemistry Research (2021) 30:1688–1702
https://doi.org/10.1007/s00044-021-02770-1
ORIGINAL RESEARCH
Synthesis and evaluation of new sesamol-based phenolic acid
derivatives with hypolipidemic, antioxidant, and hepatoprotective
effects
Yundong Xie1 Jiping Liu1,2 Yongheng Shi1,2 Bin Wang1,2 Xiaoping Wang1 Wei Wang1 Meng Sun1
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Xinya Xu1 Shipeng He3
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Received: 5 May 2021 / Accepted: 12 July 2021 / Published online: 22 July 2021
© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2021
Abstract
The objective of this study is to synthesize a series of sesamol-based phenolic acid derivatives, which were designed by
combination principle. The hypolipidemic activity of all these compounds was preliminarily screened by acute hyperlipidemic
mice model induced by Triton WR 1339, in which compound T6 exhibited more significant reducing plasma TG and TC than
fenofibrate. Compound T6 was also found to obviously decrease TG and TC both in the plasma and hepatic tissue of high-fat-diet-
induced hyperlipidemic mice. Moreover, T6 showed hepatoprotective effects, which remarkable amelioration in characteristic
liver enzymes was examined and the histopathological observation displayed that compound T6 inhibited lipids accumulation in
the hepatic. The levels of PPAR-α receptor related to lipids metabolism in hepatic tissue were upregulated after T6 treatment.
Other potent effects of T6 such as antioxidant and anti-inflammatory activity were also observed. On the bases of these findings,
compound T6 may serve as an effective hypolipidemic and hepatoprotective agent.
Graphical Abstract
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Keywords Sesamol derivatives Hypolipidemia Antioxidant Anti-inflammation Hepatoprotection
Abbreviations
ALT
AST
alanine aminotransferase
aspartate transaminase
* Shipeng He
heshipeng@shu.edu.cn
13C NMR 13C-nuclear magnetic resonance
1
2
3
College of Pharmacy, Shaanxi University of Chinese Medicine,
Shiji Ave, Xi’an-xianyang New Ecomic Zone, Xianyang, Shaanxi
712046, People’s Republic of China
DMF
DPPH
MS
N,N-dimethylformamide
diphenylpicryphenylhydrazine
mass spectrometry
Key Laboratory of Pharmacodynamics and Material Basis of
Chinese Medicine, Shaanxi Administration of Traditional Chinese
Medicine, Xianyang 712046, P. R. China
FF
fenofibrate
GSH-PX glutathione peroxidase
HDL-C high-density lipoprotein cholesterol
Institute of Translational Medicine, Shanghai University, 99
Shangda Road, Shanghai 200444, People’s Republic of China

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1H-NMR 1H-nuclear magnetic resonance
HUVEC human umbilical vein endothelial cells
biological functions. Sesamol (3,4-methylenedioxyphenol)
was obtained from the food source of sesame oil (Sesamum
indicum L) and which was extensively researched as a bene-
ficial agent [8]. Sesamol has a series of biological activity,
including weak hypolipidemic, antibacterial, weight loss, anti-
melanin, antiaging, anticancer, neuroprotection, and anti-
inflammation [9, 10]. Recent literatures survey revealed that
sesamol-tagged structures were appearing as potential struc-
tures for cardiovascular disease treatment [8, 11, 12], such as
sesamin, sesamolin, sesaminol, pinoresinol, sesamolinol.
Based on this, new compounds with sesamol as a functional
synergistic structure will be considered.
IL-6
interleukin-6
LDL-C
MDA
low density lipoprotein cholesterol
malondialdehyde
PPAR-α peroxisome proliferator-activated receptor-α
SOD
superoxide dismutase
TC
total cholesterol
TG
triglyceride
TNF-α
tumor necrosis factor-α
Introduction
Based on the pathological process of hyperlipidemia and
its complications such as oxidative stress, inflammation, and
liver damage, decreasing the blood lipid level, ameliorating
oxidative stress and inflammation have attracted obvious
interest in therapy of hyperlipidemia and its complications. In
the design of novel hypolipidemic agents, the development
of cohere molecules via the combination of different phar-
macophores may contribute to compounds with multi-
functional biological profiles. Recently, we have reported
some natural polyphenols-based cohere molecules, which
showed significant antioxidant activity [13, 14]. Based on
these, we plan to figure the design and synthesis of novel
sesamol-based phenolic acid derivatives possessing natural
products. Previous studies have found that these small nat-
ural phenolic molecules have significant advantages in drug
structure modification and optimization [13, 14]. The natural
products included cinnamic acid, ferulic acid, caffeic acid, 4-
hydroxycinnamic acid, gallic acid, 3, 4- dihydroxybenzoic
acid, 3, 4-dihdroxyphenylacetic acid, and so on. The
sesamol-based phenolic acid derivatives will be evaluated in
hyperlipidemic mice induced by Triton WR 1339 or/and
high-fat diet (HFD). We hope that the target compouds have
multifunctional properties such as hypolipidemic, hepato-
protective, antioxidant, and anti-inflammatory activity.
These novel target compounds have multi-target char-
acteristics that a single chemical entity can be able to regulate
multiple targets. It is meaningful to apply this type of agents
for the treatment of complicated diseases. Here we report the
results of the study on the properties of hypolipidemia,
hepatoprotection, antioxidant, anti-inflammation of target
compounds. Moreover, the hypolipidemic activity was eval-
uated both in Triton WR 1339 and HFD-induced hyperlipi-
demic mice model. The hepatoprotective activity was
evaluated by the level of transaminase in plasma and liver
tissue and the examination of liver tissue section in hyperli-
pidemic mice, and further evaluated by the level of anti-
oxidation and inflammatory reaction. All of the synthetic
compounds were designed through hybridization of natural
molecules with widely regulated antioxidant activity and
sesamol structure. The sesamol structure-tagged revealed
broadly modulated cardiovascular diseases in vivo.
Hyperlipidemia was an increase of lipid profiles in the
blood and the lipid profiles included total cholesterol (TC),
triglycerides (TG), fatty acids, fats, cholesterol esters,
phospholipids, and lipoproteins [1]. An elevation in plasma
lipids was a common characteristic of atherosclerosis, a
condition involving vascular endothelial injury, which may
lead to cardiovascular and cerebrovascular diseases, such
as ischaemic heart, myocardial infarction, stroke, and cer-
ebrovascular accidents [2]. These conditions were respon-
sible for 31% of deaths in the world, in which more than
75% occurred in low- and middle-income countries.
Hyperlipidemia was regarded as a major cardiovascular and
cerebrovascular risk factor. Lipid-lowering therapy played
an important role in reducing atherosclerosis-related vas-
cular diseases [3]. A series of researches have revealed that
chronic hyperlipidemia activated the inflammatory signal-
ing pathway, activated nuclear factor kappa B (NF-κB) and
induced the expression of inflammatory gene products [4].
Activation of NF-κB generated excess endogenous reactive
oxygen species (ROS), which consumed a lot of endo-
genous antioxidant enzymes. These finally lead to the
occurrence of oxidative stress. Moreover, NF-κB activation
and oxidative stress were responsible for the down-
regulation of PPAR-α, which will further aggravate dysli-
pidemia [5]. Lipolysis of TG also involved in the
pathophysiology of inflammation. Oxidized low density
lipoprotein could greatly upregulate the expression of pro-
inflammatory factors. Long-term hyperlipidemia will lead
to fat accumulation in the liver and induce the production
of fatty liver. In addition, oxidative stress and inflammation
caused by hyperlipidemia will further damage the liver.
The commonly clinically used lipid-lowering drugs inclu-
ded statins and fibrates, which were associated with severe
side effects, particularly the hepatotoxicity [6, 7]. There-
fore, a more effective drug possessing hypolipidemic,
hepatoprotective, antioxidant, and anti-inflammatory
activity is in great demand.
Recently, more and more attention has been attracting on
the natural compounds isolated from the plants with potential

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Results and discussion
reacting with 1-ethyl-3-(3-dimethylaminopropyl) carbo-
diimide hydrochloride (EDCI) and 4-N, N-dimethy
laminopyridine (DMAP) in N,N-dimethylformamide
(DMF). Compounds 4a–4h in dry ethanol solution were
mixed with palladium over charcoal, which was hydro-
genated under the atmosphere of hydrogen to obtain the
target compounds T1–T8. Compounds 5a–5c, respec-
tively, reacted with sesamol in the presence of EDCI and
DMAP in DMF solution to give T9–T11.
Chemistry
The synthesis of T1–T8 were described in Scheme 1
[15, 16]. The hydroxy groups of 1a–1h were benzyl-
protected by benzyl bromide in acetone solution with
potassium carbonate to obtain the corresponding deriva-
tives 2a–2h. Compounds 3a–3h were obtained by ester
hydrolysis with 6 M sodium hydroxide in THF solution
under 60 °C, then the acid solution with HCl. The final
protected products 4a–4h were obtained by sesamol
The synthetic approach to the T12–T15 was showed in
Scheme 2 [13]. The preparation of compounds 9a–9c was
the same as the procedures of compounds 4a–4h. Target
Scheme 1 Synthesis route of target compounds T1–T11. Reagents and conditions: (a) BnBr, K2CO3, acetone; (b) 6 M NaOH, THF, 60 °C; (c)
0.2 M HCl; (d) sesamol, EDCI, DMAP, DMF, r. t.; (e) H2, Pd/C, ethanol; (f) sesamol, EDCI, DMAP, DMF, r. t.

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Scheme 2 Synthesis route of target compounds T12–T14. Reagents and conditions: (a) BnBr, K2CO3, acetone; (b) 6 M NaOH, THF, 60 °C; (c)
0.2 M HCl; (d) sesamol, EDCI, DMAP, DMF, r. t.; (e) TiCl4, CH2Cl2; (f) Ph2CCl2, PhMe, 110 °C; (g) sesamol, EDCI, DMAP, DMF, r. t.; (h)
AcOH:H2O = 4:1, 90 °C
compounds T12–T14 were obtained by using titanium
tetrachloride (TiCl4) in dichloromethane (CH2Cl2) solu-
tion. Caffeic acid (10a) reacted with dichlor-
odiphenylmethane in methylbenzene under 110 °C to
give 11a, which then reacted with sesamol in the presence
of EDCI and DMAP in DMF solution to give 12a [17].
Compound T15 was obtained by 12a in acetic acid aqu-
eous solution (AcOH:H2O = 4:1) under 90 °C.
T15 (0.2997 0.0168) containing catechol have the
excellent scavenging radical capacity of hydroxyl radical,
which were better than that of compounds containing one
phenolic hydroxyl, such as T1, T2, T4, T5, T7, T12, and
T13, or containing none phenolic hydroxyl, such as
T9–T10. The scavenging activity of DPPH radical showed
that the target compound T6 had the strongest scavenging
activity, followed by compounds T3, T8, T15. Compounds
T1, T2, T4, T5, T7, T12–T14 showed poor scavenging
activity. Compounds T9–T11 did not show DPPH
scavenging activity. The study on the structure–activity
relationship of antioxidant activity in vitro showed that the
antioxidant activity was closely related to the phenolic
hydroxyls in the structure of the compound. The more the
number of phenolic hydroxyls, the stronger the antioxidant
activity. On the contrary, the less the number of phenolic
hydroxyls, the worse the antioxidant activity. Without
phenolic hydroxyl, there was no antioxidant activity.
Comparing compounds containing one phenolic hydroxyl,
we found that the structure of ortho-methoxy in compound
T14 can enhance the antioxidant activity.
Biological evaluation
Antioxidant activity in vitro
The antioxidant effects of target compounds were eval-
uated by scavenging radicals (·OH and DPPH·) as the
method reported in the previous literatures [14]. The results
were displayed in Table 1, which showed that T6
(0.0730 0.0053) exhibited the strongest hydroxyl radical
scavenging activity, which has three phenolic hydroxyl
groups. T3 (0.2703 0.0147), T8 (0.2910 0.0100), and

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Table 1 The effects of target
compounds T1–T15 on
Compounds
·OH (mM)a
DPPH· (mM)a
HUVEC (IC50, μM)a
hydroxyl radical and DPPH
radical scavenging in vitro and
on HUVEC cells in vitro
T1
NDb
NDb
0.9357 0.0239
0.8817 0.0197
0.0177 0.0019
0.6347 0.0180
1.0420 0.0235
0.0147 0.0009
0.7117 0.0128
0.0177 0.0015
NDb
30.1 2.7
20.3 3.8
26.3 4.7
25.5 1.9
24.6 6.2
>50
T2
T3
0.2703 0.0085
NDb
NDb
T4
T5
T6
0.0730 0.0031
NDb
T7
13.7 2.6
31.2 5.6
27.1 3.1
29.5 5.5
31.5 5.1
>50
T8
0.2910 0.0058
NDb
NDb
NDb
NDb
T9
T10
NDb
NDb
T11
T12
1.0693 0.0264
0.9473 0.0224
0.2630 0.0243
0.0370 0.0015
0.0103 0.0003
T13
NDb
>50
T14
0.7750 0.0429
0.2997 0.0097
1.2350 0.0296
26.4 1.6
20.9 0.7
–
T15
Ascorbic acid
aThe results summarized were the mean S.E.M of n = 3 for IC50 value
bThe IC50 values could not be detected at the maximum concentration
Evaluation of toxicity in vitro
In addition, to verify the biocompatibility for further evalua-
tion in vivo, the cytotoxicity of all compounds was tested by
Cell Counting Kit-8 (CCK8) assays against human umbilical
vein endothelial cells (HUVEC). The results showed in Table
1 and exhibited that most of compounds showed poor inhi-
bitory activity against the growth of HUVEC cells with IC50
that surpassed 20 μM, indicating that these target compounds
had certain biological safety and provided a guarantee for the
subsequent study of biological activity in vivo.
Study on acute lipid-lowering activity
The hypolipidemic effects of compounds T1–T15 were firstly
assessed in Triton WR 1339-induced hyperlipidemic mice as
the method reported previously [18]. Target compounds
T1–T15 (0.362 mmol/kg), well-suspended/dissolved in CMC-
Na solution (of a final concentration of ~0.5%) were respec-
tively given by intragastric administration for 7 days. The
normal and model group mice were treated with CMC-Na
solution only. Fenofibrate (FF, 0.036 mmol/kg) was selected
as positive control. On the 6th day, the model group and
compounds T1–T15 groups mice were injected Triton WR
1339 to induce hyperlipemia by the tail vein. After 24 h,
blood was taken from the orbit of all group mice, and the
levels of plasma TG and TC were determined.
Fig. 1 The plasma levels of TG and TC in hyperlipidemic mice
induced by Triton WR 1339 after administration with target com-
pounds T1–T15 for a week. The results were expressed as mean
S.E.M. (n = 10). ##P < 0.01 vs. normal group; *P < 0.05, **P < 0.01
vs. model group. a The effects of the target compounds on TG. b The
effects of the target compounds on TC
The effects of compounds T1–T15 on blood lipid
indexes TG and TC in Triton-induced acute hyperlipidemia
model mice are shown in Figs. 1 and 2. Compounds T1, T3,
T6, T8, T9, T10, T14, and T15 significantly decreased TG

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Fig. 2 Effects of compound T6 on plasma levels of TG, TC, HDL-C, and LDL-C in HFD-induced hyperlipidemic mice. The results described as
mean S.E.M. (n = 12). *P < 0.05, **P < 0.01 vs. normal group; #P < 0.05, ##P < 0.01 vs. model group; △△P < 0.01 vs. FF group. a The effects of
the target compounds on TG. b The effects of the target compounds on TC. c The effects of the target compounds on HDL-C. d The effects of the
target compounds on LDL-C
activity in plasma. Compared with the model group, plasma
TG decreased by 19.68%, 23.47%, 79.01%, 15.80%,
29.92%, 25.43%, 16.64%, and 16.88%, respectively (P <
0.05). Compounds T3, T6, T9, T10, T12, T13, T14, and
T15 significantly reduced plasma TC. Plasma TC decreased
by 19.40%, 69.02%, 30.38%, 17.53%, 32.00%, 24.85%,
37.45%, and 33.87%, respectively (P < 0.05). Compound
T6 has the strongest effect on reducing TG and TC.
Among these target compounds, we found that com-
pound T6 showed the best hypolipidemic activity than other
target compounds and the standard agent FF in Triton WR
1339-induced hyperlipidemic mice model. Summarizing the
structure–hypolipidemic activity relationship of these target
compounds, it had reached some conclusions. When the
parent nucleus of polyphenolic acid was benzoic acid with
different substituents, the para-hydroxyl group of benzene
was beneficial structure to lowering blood lipids, and the
more the hydroxyl groups in the ortho-position, the stronger
the lipid-lowering effect. The sequence of lipid-lowering
activity of this type compounds was T6 > T3 > T1. When
the ortho-position of the para-hydroxyl group was meth-
oxyl, it did not show lipid-lowering activity. Moreover, the
presence of a single hydroxyl group outside the para-
position of the benzene ring also did not show lipid-
lowering activity. When the parent nucleus of polyphenolic
acid was phenylacetic acid, the 3,4-ortho-catechol structure
of benzene displayed hypolipidemic activity. When there
were no substituents on the benzene ring, the carboxylic
acid structure of the saturated chain hydrocarbon is con-
ducive to the lipid-lowering activity. When the parent
nucleus of polyphenolic acid was a carboxylic acid structure
of unsaturated chain hydrocarbon, disubstituted benzene
showed lipid-lowering activity, while mono-substituted
benzene showed no lipid-lowering activity.
Study on chronic lipid-lowering activity of
compound T6
With the potential hypolipidemic activity in hand, chronic
lipid-lowering effect on compound T6 was performed in
HFD-induced hyperlipidemic mice to further evaluate the
lipid-lowering activity as the method reported previously
[18]. KM male mice (20 2 g) were used and FF was
served as standard control. Normal group mice were fed
with normal diet for 60 days and vehicle (10 ml/kg) for
30 days. HFD was administrated to the other groups

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(Model, T6, and FF) for 60 days and vehicle (10 ml/kg), T6
(0.362 mmol/kg), and FF (0.036 mmol/kg) were treated,
respectively, for 30 days. After finishing the experiment, the
blood and livers of all mice were withdrawn. Then, the lipid
profiles (TC, TG, HDL-C, and LDL-C), antioxidant indices
(SOD, GSH-PX, and MDA), and anti-inflammatory factors
(IL-6 and TNF-α) were measured. Moreover, hepatic bio-
chemical indices (AST and ALT), hepatic histopathology,
and the expression of PPAR-α in hepatic were also
examined.
Aminotransferases level in plasma
Furthermore, the levels of AST and ALT were also mea-
sured. Interestingly, clear protective effects were observed
in hepatic biochemical indices in T6 group mice. As
described in Fig. 5, the levels of plasma AST significantly
reduced (P < 0.01) compared to model group. Although,
compound T6 showed no significant difference, the level of
ALT was lessened.
Pathological examination of liver tissue
Effects of compound T6 on lipids profile in plasma
The positive effect was also confirmed by hepatic histo-
logical findings. Figure 6 exhibited that lipid accumula-
tion was suppressed in both T6 and FF administrated
mice. The sudan III and hematoxylin staining revealed
that the suppression was more obvious in T6 group than in
FF group. These results suggested that T6 treatment
suppresses the development of HFD-induced hepatic lipid
accumulation.
As showed in Fig. 2, compound T6 exhibited significant
hypolipidemic activity. T6 was found to be able to
obviously reduce plasma TG, TC, and LDL-C. While FF
markedly decreased plasma TG and LDL-C, but had no
effect on TC. Compound T6 displayed the significant
activity of reducing TC (P < 0.01) compared to FF (P >
0.05). Hence, T6 exhibited more extensive activity on
antihyperlipidemia than FF.
The expression level of PPAR-α in hepatic
Antioxidant and anti-inflammative level in plasma
Based on the above significant lipid-lowering activity, we
studied the lipid-lowering activity mechanism of compound
T6. It has been reported that sesamol can exert its lipid-
lowering activity by activating PPAR-α receptor [19].
Therefore, we detected the expression levels of PPAR-α
protein in the liver of mice in each group. As showed in Fig.
7, after long-term administration of HFD, the expression of
PPAR-α receptor protein decreased significantly by 75.8%
(P < 0.01) in the liver of mice in the model group.
T6 significantly increased the expression of PPAR-α in
hepatic compared to model group (P < 0.05). The findings
suggested that the hypolipidemic mechanism of T6 may be
through the activation of PPAR-α receptor.
As expected, compound T6 also showed significant anti-
oxidant, anti-inflammatory activity in vivo and ameliora-
tion of hepatic function. The antioxidant results showed
that plasma SOD levels were apparently increased (P <
0.01) and MDA levels were obviously decreased (P <
0.01) in compound T6 group mice (Fig. 3). While positive
control FF significantly increased SOD level only. Com-
pound T6 also showed anti-inflammatory property, the IL-
6 levels were significant lower compared with model
group (Fig. 4). As was well-known, hyperlipidemia could
contribute to both inflammation and oxidative stress, thus,
it can improve the conditions of hyperlipidemia by
strengthening the antioxidant properties and reducing
inflammatory cytokines of the body.
Hyperlipidemia associated with oxidative stress and
inflammation will aggravate the occurrence and
Fig. 3 Effects of compound T6 on plasma levels of SOD, GSH-Px, and MDA in HFD-induced hyperlipidemic mice. The results described as
mean S.E.M. (n = 12). **P < 0.01 vs. Normal group; ##P < 0.01 vs. model group. a The effects of the target compounds on SOD. b The effects of
the target compounds on GSH-PX. c The effects of the target compounds on MDA

Medicinal Chemistry Research (2021) 30:1688–1702
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Fig. 4 Effects of compound T6 on plasma levels of IL-6 and TNF-α in HFD-induced hyperlipidemic mice. The results described as mean S.E.M.
#
(n = 12). **P < 0.01 vs. normal group; P < 0.05 vs. model group. a The effects of the target compounds on IL-6. b The effects of the target
compounds on TNF-α
Fig. 5 Effects of compound T6 on plasma levels of AST and ALT in HFD-induced hyperlipidemic mice. The results described as mean S.E.M.
(n = 12). *P < 0.05, **P < 0.01 vs. normal group; ##P < 0.01 vs. model group. a The effects of the target compounds on AST. b The effects of the
target compounds on ALT
Fig. 6 Histopathological studies of compound T6 on hepatic lipid accumulation in normal and HFD-induced hyperlipidemic mice (Sudan III and
hematoxylin 100×). a Normal group mouse liver; b Model group mouse liver; c T6 group mouse liver; d FF group mouse liver
development of cardiovascular diseases. Hyperlipidemia is
regarded to a pivotal cardiovascular risk factor in treatment
guidelines. Lipids lowering treatment has play an important
role in improving hyperlipidemia-related complications,
such as atherosclerosis, vascular injury. At present, statins
and fibrates were the best choice for the intervention of
hyperlipidemia. However, both of them have the major side
effects that are hepatic damage. It has been suggested that
statins or fibrate-induced hepatotoxicity may be associated
with the oxidative stress and inflammation [20, 21]. Sesa-
mol has the effects of regulating blood lipids and anti-
inflammation [22, 23]. The natural antioxidants have good
free radical scavenging activity and strong antioxidant
activity. These characteristics will be beneficial to the
treatment of hyperlipidemia and its complications. The
design of sesamol-based phenolic acid derivatives (T1–T15)

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was carried out by using HFD-induced hyperlipidemic mice.
The HFD-induced hyperlipidemic mice model was fit for
research, because the consume food and water was similar to
the patterns of human eating [27]. In this study, it was found
that HFD feeding for 5 weeks lead to lipids in blood
increasing, then treatment of T6 for the next 4 weeks. HFD
increased significantly the lipids, such as TG, TC, and LDL-
C, in plasma as well as in hepatic tissue. The followed
treatment of T6 for 4 weeks resulted in amelioration of dys-
lipidemia, oxidative stress, inflammation as well as hepatic
injury. T6 significantly decreased TG, TC, and LDL-C both
in plasma (Fig. 2), which can be interpreted as activation of
PPAR-α receptor. The study on the mechanism of lowering
lipids showed that the expression of PPAR-α protein in liver
was significantly upregulated 4 weeks after compound 6 was
treated. Activation of PPAR-α regulates the expression of
some genes involved in lipoprotein metabolism [28]. More-
over, related studies have revealed that PPAR-α can modulate
the hepatic inflammation response [29, 30]. Activation of
PPAR-α inhibited C reaction proteins promoter activity and
decrease expression levels of p50-NF-κB and C/EBP-β in
hepatic tissue, which may participate in the regulation of the
IL-6-induced acute inflammatory response [31, 32]. Because
PPAR-α leads to a regulation of the inflammation response,
the levels of inflammatory cytokines induced by dyslipidemia
were measured. Interestingly, T6 showed significantly anti-
inflammatory activity (Fig. 4).
Fig. 7 The expression levels of PPAR-α in hepatic tissue of HFD-
induced hyperlipidemic mice. The results described as mean S.E.M.,
#
n = 3, **P < 0.01 vs. normal group; P < 0.05 vs. model group
was based on the incorporation of a structure moiety of the
hypolipidemic and anti-inflammation agent sesamol into the
structure of the antioxidant natural products. Preliminary
screening of sesamol-based phenolic acid derivatives
(T1–T15) on Triton WR 1339-induced hyperlipidemic mice
resulted in a more promising compound T6, in comparison
to fenofibrate by improving the TG and TC (Fig. 1).
ROS were involved in the damage of various kind of cells,
including endothelial and hepatic cells (in hyperlipidemia),
acting by lipid peroxidation. In a state of hyperlipidemia,
elevated LDL-C is easily oxidized by ROS, which will lead to
abnormalities in endothelium function [24]. Moreover, oxi-
dative stress is responsible for the progressive injury of
hepatic cells. The antioxidant activity of the compounds was
first determined in vitro and evaluated by hydroxyl radical
and DPPH radical, respectively. The antioxidant activity was
related to the number of phenolic hydroxyl groups in the
structure of the compound. The more the number of phenolic
hydroxyl groups, the better the antioxidant activity (Table 1).
Among these compounds, compound T6 showed the best
antioxidant activity in vitro. The potential antioxidant activity
of compound T6 was also exhibited in vivo, as it significantly
increased SOD and GSH-PX levels and decreased MDA
levels in hyperlipidemic mice (Fig. 3). This promising activity
of T6 was furthermore accompanied by obvious anti-
inflammatory activity in vivo, reducing IL-6 and TNF-α
levels in hyperlipidemic mice (Fig. 4). It has been reported
that its anti-inflammatory and antioxidant activity may ame-
liorate tissue damage and inflammation from oxidative stress
or/and free radical accumulation that were implicated in
hepatic injury as well as in hyperlipidemia [25, 26].
The significant hypolipidemic, antioxidant, and anti-
inflammatory activity of T6 may improve liver injury
induced by hyperlipidemia. Therefore, the indices of liver
function were detected in plasma. The results showed that
T6 could reduce the levels of AST and ALT by 41.17% and
5.31% in plasma, respectively. The staining results of liver
oil red O sections also showed that T6 could significantly
reduce the accumulation of fat in the liver (Fig. 6), which
were beneficial to the protection of the liver. T6 showed
remarkable liver-protecting activity with ameliorating of
liver aminotransferase and histopathology. The possible
interpretation may be considered to be via the antioxidant
and anti-inflammatory properties. It has been reported that
compounds with antioxidant or/and anti-inflammatory
activity can significantly attenuate ROS or/and inflamma-
tory factor-induced hepatotoxicity [33–36]. Moreover, T6
treatment can modulate the expression of PPAR-α, which
were related to ameliorate liver function and the significant
hypolipidemia in plasma and hepatic was also helpful to
improve the liver injury induced by hyperlipidemia.
Conclusions
With the potential hypolipidemic and antioxidant of
compound T6, further researched on this potential compound
In conclusions, the combination principle method led us to
synthesize a series of sesamol-based phenolic acid

Medicinal Chemistry Research (2021) 30:1688–1702
1697
derivatives. The hypolipidemic activity was evaluated in
two hyperlipidemic mouse models. Compound T6 showed
more extensive hypolipidemic activity toward reducing
TG, TC, and LDL-C levels. T6 exerted its hypolipidemic
effect by activating PPAR-α receptor. Furthermore, T6
ameliorated liver damage induced by HFD by reducing
AST and fat accumulation in liver. Other potent activity
such as antioxidant and anti-inflammation confirmed and
reinforced the effects of T6. These findings suggested that
T6 could ameliorate the levels of lipids profile and liver
injury in hyperlipidemic mice, which may be through the
activation of PPAR-α receptor, antioxidation, and anti-
inflammation. Therefore, compound T6 may seem to be a
potent candidate for the development of a novel multi-
functional hypolipidemic agent.
(1.85 g) was obtained by column chromatography (pet-
roleum ether–ethyl acetate, 15:1). The yield was 80.23%.
Compound 2a (1.85 g mmol, 5.81 mmol) was dissolved in
tetrahydrofuran (10 mL), and 6 mol/L NaOH solution
(30 mL) was added. The mixture was stirred at 50 °C.
After the reaction was complete, the solvent was removed
under reduced pressure, and the residue was adjusted to acid
to precipitate white solid 3a (1.05 g). The yield was 78.95%.
3,4-methylenedioxyphenol 5 (0.50 g, 3.62 mmol), com-
pound 3a (0.91 g, 3.98 mmol), EDCI (0.76 g, 3.98 mmol),
and DMAP (0.04 g, 0.36 mmol) were dissolved in DMF
(30 mL). The reaction was reacted overnight at room
temperature under the condition of nitrogen, and the
reaction process was monitored by TLC. At the end of
the reaction, 60 mL ethyl acetate was added to the reaction
system, and then washed with 1 mol/L hydrochloric acid
solution (20 mL × 3), saturated sodium carbonate solution
(20 mL × 3) and saturated sodium chloride solution
(20 mL × 3), dried with anhydrous sodium sulfate, filtered,
and the solvent ethyl acetate was removed by decompres-
sion. The white solid 4a (1.01 g) was obtained by column
chromatography (petroleum ether–ethyl acetate, 10:1). The
yield was 80.16%.
Experimental protocols
Materials
Unless otherwise specified, all materials, reagents, and
solvents were obtained from commercial suppliers and used
directly. Every step of the reactions was monitored by TLC
(GF254, Qingdao Haiyang Chemical Co. Ltd). Isolations
and purifications of compounds were performed by flash
column chromatography (silica gel (100–200 mesh),
Qingdao Haiyang Chemical Co. Ltd). Melting points were
recorded by X-4A melting point apparatus (Shanghai
Thermal instrument Scientific instrument Co., Ltd). 1H-
NMR and 13C NMR spectra were recorded on the Bruker
AV400 and AV500 spectrometer (Bruker Company, Ger-
many), using CDCl3 or DMSO-d6 as solvents. Chemical
shifts were recorded in ppm (δ) and coupling constants (J)
were given in Hertz. The mass spectra (MS) were obtained
by LC-MS (Skyray instrument LC-MS 1000).
Compound 4a (1.01 g, 2.90 mmol) was dissolved in
anhydrous ethanol (30 mL) and reacted overnight at room
temperature with palladium–carbon catalyst (0.10 g)
under hydrogen atmosphere. After the reaction was
complete, the solvent was removed by filtration and
decompression, and the residue was isolated and purified
by column chromatography (petroleum ether–ethyl acet-
ate, 8:1) to get the target compound T1 (0.68 g). Yield:
90.67%, mp 198.4–200.3 °C. MS (m/z) C14H10O5 [M +
1
Na]+ 281.2333. H-NMR (400 MHz, DMSO-d6) δ: 10.50
(s, 1H, –Ph–OH), 7.97–7.93 (m, 2H, –Ar–H), 6.95–6.89
(m, 4H, –Ar–H), 6.69–6.65 (m, 1H, –Ar–H), 6.07 (s, 2H,
–OCH2O–). 13C NMR (126 MHz, DMSO) δ 165.05,
163.10, 148.09, 145.56, 145.33, 132.63, 119.86, 116.02,
114.72, 108.34, 104.60, 102.14.
Synthesis of target compounds
4-hydroxybenzoic acid-(3,4-methylene dioxy) phenyl ester
(T1) Compound 1a (1.00 g, 7.24 mmol) was dissolved in
dry acetone (30 mL), benzyl bromide (1.73 g mL,
14.55 mmol), and potassium carbonate (3.00 g mL,
21.74 mol) were added, stirred, and refluxed overnight at
75 °C under the nitrogen atmosphere, and the reaction
process was monitored by TLC. The stirring was stopped
after the end of reaction, and the solution was cooled to
room temperature. The filtrate was filtered by a Brinell
funnel and decompressed to remove organic solvents on a
rotary evaporator. The residue was dissolved in ethyl
acetate, washed with saturated sodium carbonate solution
(30 mL × 2) and saturated sodium chloride solution
(30 mL × 2), dried with anhydrous sodium sulfate, filtered
and concentrated under vacuum. The white solid 2a
2-hydroxybenzoic acid-(3,4-methylene dioxy) phenyl ester
(T2) The synthesis process was the same as compound T1.
Yield: 75.00%, mp 88.6–91.0 °C. MS (m/z) C14H10O5 [M-
H]− 257.4482. 1H-NMR (400 MHz, DMSO-d6) δ: 10.30 (s,
1H, –Ph–OH), 7.96 (dd, 1H, –Ar–H), 7.61–7.55 (m, 1H,
–Ar–H), 7.08–6.94 (m, 4H, –Ar–H), 6.75 (dd, 1H, –Ar–H),
6.09 (s, 2H, –OCH2O–). 13C NMR (126 MHz, DMSO) δ
165.05, 163.10, 148.09, 145.56, 145.33, 132.63, 119.86,
116.02, 114.72, 108.34, 104.60, 102.14.
3,4-dihydroxybenzoic acid-(3,4-methylene dioxy) phenyl
ester (T3) The synthesis process was the same as com-
pound T1. Yield: 74.77%, mp 196.9–199.0 °C. MS (m/z)
C14H10O6 [M + H]+ 275.2311. 1H-NMR (400 MHz,

1698
Medicinal Chemistry Research (2021) 30:1688–1702
1
DMSO-d6) δ: 9.98 (s, 1H, –Ph–OH), 9.50 (s, 1H, –Ph–OH),
7.50–7.42 (m, 2H, –Ar–H), 6.93 (d, 1H, –Ar–H), 6.89 (d,
1H, –Ar–H), 6.87 (d, 1H, –Ar–H), 6.65 (dd, 1H, –Ar–H),
6.07 (s, 2H, –OCH2O–). 13C NMR (126 MHz, DMSO) δ
165.05, 163.10, 148.09, 145.56, 145.33, 132.63, 119.86,
116.02, 114.72, 108.34, 104.60, 102.14.
C15H12O6 [M-H]− 287.2052. H-NMR (400 MHz, DMSO-
d6) δ: 8.92 (s, 1H, –Ph–OH), 8.82 (s, 1H, –Ph–OH), 6.90 (d,
1H, –Ar–H), 6.75 (d, 1H, –Ar–H), 6.73 (d, 1H, –Ar–H),
6.69 (d, 1H, –Ar–H), 6.58 (dd, 1H, –Ar–H), 6.52 (dd, 1H,
–Ar–H), 6.04 (s, 2H, –OCH2O–), 3.68 (s, 2H, –CH2–). 13C
NMR (126 MHz, DMSO) δ 165.05, 163.10, 148.09,
145.56, 145.33, 132.63, 119.86, 116.02, 114.72, 108.34,
104.60, 102.14.
4-hydroxy-3-methoxybenzoic acid-(3,4-methylene dioxy)
phenyl ester (T4) The synthesis process was the same as
compound T1. Yield: 66.25%, mp 152.6–154.1 °C. MS (m/z)
C15H12O6 [M-H]− 287.2565. 1H-NMR (400 MHz, DMSO-d6)
δ: 10.15 (s, 1H, –Ph–OH), 7.62 (dd, 1H, –Ar–H), 7.55 (d, 1H,
–Ar–H), 6.97~6.89 (m, 3H, –Ar–H), 6.68 (dd, 1H, –Ar–H),
6.07 (s, 2H, –OCH2O–), 3.84 (s, 3H, –OCH3). 13C NMR
(126 MHz, DMSO) δ 165.05, 163.10, 148.09, 145.56, 145.33,
132.63, 119.86, 116.02, 114.72, 108.34, 104.60, 102.14.
3-phenylpropionic acid-(3,4-methylene dioxy) phenyl ester
(T9) 3,4-mmethylenedioxyphenol 5 (1.00 g, 7.24 mmol),
phenylpropionic acid 6 (1.30 g, 8.69 mol), EDCI (1.67 g,
8.69 mol), and DMAP (0.18 g, 1.45 mmol) were dissolved
in DMF (30 mL). The subsequence process was the same as
that of compound 4a. The crude product was isolated and
purified by column chromatography (petroleum ether–ethyl
acetate, 15:1) to produce T9 (1.60 g). Yield: 81.63%, mp
46.5–48.0 °C. MS (m/z) C16H14O4 [M + H]+ 271.3398. 1H-
NMR (400 MHz, DMSO-d6) δ: 7.44~7.16 (m, 5H, –Ar–H),
6.89 (d, 1H, –Ar–H), 6.67 (d, 1H, –Ar–H), 6.47 (dd, 1H,
–Ar–H), 6.04 (s, 2H, –OCH2O–), 2.95 (t, 2H, –CH2Ph),
2.86 (t, 2H, –O2CCH2–). 13C NMR (126 MHz, DMSO) δ
165.05, 163.10, 148.09, 145.56, 145.33, 132.63, 119.86,
116.02, 114.72, 108.34, 104.60, 102.14.
4-hydroxy-3,5-dimethoxybenzoic acid-(3,4-methylene dioxy)
phenyl ester (T5) The synthesis process was the same as
compound T1. Yield: 60.57%, mp 139.0–141.4 °C. MS (m/z)
C16H14O7 [M + H]+ 319.4319. 1H-NMR (400 MHz, DMSO-
d6) δ: 9.54 (s, 1H, –Ph–OH), 7.34 (s, 2H, –Ar–H), 6.95 (d,
1H, –Ar–H), 6.92 (d, 1H, –Ar–H), 6.69 (dd, 1H, –Ar–H),
6.08 (s, 2H, –OCH2O–), 3.84 (s, 6H, –OCH3). 13C NMR
(126 MHz, DMSO) δ 165.05, 163.10, 148.09, 145.56,
145.33, 132.63, 119.86, 116.02, 114.72, 108.34, 104.60,
102.14.
4-phenylbutyric acid-(3,4-methylene dioxy) phenyl ester
(T10) The synthesis process was the same as compound T9.
Yield: 94.17%, mp 61.0–63.0 °C. MS (m/z) C17H16O4 [M-H]-
1
Benzo[d][1,3]dioxol-5-yl 3,4,5-trihydroxybenzoate (T6)
The synthesis process was the same as compound T1.
Yield: 70.11%, mp 214.3–216.1 °C. MS (m/z) C14H10O7
283.4220. H-NMR (400 MHz, CD3OD) δ: 7.30–7.25 (m,
2H, –Ar–H), 7.23–7.15 (m, 3H, –Ar–H), 6.77 (d, 1H,
–Ar–H), 6.59 (d, 1H, –Ar–H), 6.49 (dd, 1H, –Ar–H), 5.95 (s,
2H, –OCH2O–), 2.70 (t, 2H, PhCH2–), 2.53 (t, 2H,
–O2CCH2–), 2.04–1.96 (m, 2H, –CH2CH2CH2–). 13C NMR
(126 MHz, DMSO) δ 165.05, 163.10, 148.09, 145.56,
145.33, 132.63, 119.86, 116.02, 114.72, 108.34, 104.60,
102.14.
1
[M + Na]+ 313.3147. H-NMR (400 MHz, DMSO-d6) δ:
9.41 (s, 2H, –Ph–OH), 9.14 (s, 1H, –Ph–OH), 7.08 (s, 2H,
–Ar–H), 6.93 (d, 1H, –Ar–H), 6.89 (d, 1H, –Ar–H), 6.64
(dd, 1H, –Ar–H), 6.06 (s, 2H, –OCH2O–). 13C NMR
(101 MHz, DMSO) δ 165.32, 148.08, 146.21, 145.62,
145.29, 139.66, 118.78, 114.72, 109.60, 108.37, 104.63,
102.13.
(E)-3-phenylacrylic acid-(3,4-methylene dioxy) phenyl ester
(T11) The synthesis process was the same as compound
T9. Yield: 61.86%, mp 120.5–122.5 °C. MS (m/z)
C16H12O4 [M + Na]+ 291.3287. 1H-NMR (400 MHz,
DMSO-d6) δ: 7.88–7.77 (m, 3H, –Ar–H), 7.50–7.42 (m, 3H,
–Ar–H, –CH=CH–Ph), 6.94 (d, 1H, –Ar–H), 6.89 (d, 1H,
–Ar–H), 6.86 (d, 1H, –CH=CH–), 6.65 (dd, 1H, –Ar–H),
6.07 (s, 2H, –OCH2O–). 13C NMR (126 MHz, DMSO) δ
165.05, 163.10, 148.09, 145.56, 145.33, 132.63, 119.86,
116.02, 114.72, 108.34, 104.60, 102.14.
4-hydroxyphenylacetic acid-(3,4-methylene dioxy) phenyl
ester (T7) The synthesis process was the same as com-
pound T1. Yield: 72.00%, mp 92.7–94.5 °C. MS (m/z)
C15H12O5 [M + Na]+ 295.3392. 1H-NMR (400 MHz,
DMSO-d6), δ: 9.37 (s, 1H, –Ph–OH), 7.14 (d, 2H, –Ar–H),
6.89 (d, 1H, –Ar–H), 6.76 (d, 1H, –Ar–H), 6.74 (t, 2H,
−Ar–H), 6.53 (dd, 1H, –Ar–H0, 6.04 (s, 2H, –OCH2O–),
3.77 (s, 2H, –CH2–). 13C NMR (126 MHz, DMSO) δ
165.05, 163.10, 148.09, 145.56, 145.33, 132.63, 119.86,
116.02, 114.72, 108.34, 104.60, 102.14.
(E)-3-(3-hydroxyphenyl) acrylic acid-(3,4-methylene dioxy)
phenyl ester (T12) Compound 9a (2.00 g, 12.18 mmol)
was dissolved in dry acetone (50 mL), and benzyl bromide
(2.97 mL, 24.98 mmol) and potassium carbonate (10.08 g,
73.10 mmol) were added. The synthesis process was the
3-dihydroxyphenylacetic acid-(3,4-methylene dioxy) phenyl
ester (T8) The synthesis process was the same as com-
pound T1. Yield: 64.79%, mp 204.4–206.6 °C. MS (m/z)

Medicinal Chemistry Research (2021) 30:1688–1702
1699
same as compound 2a. The crude product was isolated and
purified by column chromatography (petroleum ether–ethyl
acetate, 10:1) to get compound 10a, and the yield was
75.71%.
Compound 10a (3.18 g, 9.23 mmol) was dissolved in
tetrahydrofuran (20 mL), and 6 mol/L NaOH solution
(50 mL) was added. The synthesis operation was the same
as compound 3a to give compound 11a (1.50 g), and the
yield was 63.83%.
3,4-methylenedioxyphenol 5 (0.60 g, 4.34 mmol), com-
pound 11a (1.33 g, 5.21 mmol), EDCI (1.00 g, 5.21 mmol),
and DMAP (0.05 g, 0.43 mmol) were dissolved in DMF
(30 mL). The synthesis process of compound 4a was carried
out to produce compound 12a. The crude product was
isolated and purified by column chromatography (petroleum
ether–ethyl acetate, 15:1) to get compound 12a (1.37 g), and
the yield was 84.05%.
The compound 12a (1.37 g, 3.66 mmol) was dissolved in
anhydrous dichloromethane (30 mL), and TiCl4 was added
under the condition of stirring. The reaction was at room
temperature for 30 min and was monitored by TLC. At the
end of the reaction, 30 mL methanol was added to quench
the TiCl4, and remove the solvent, the residue was extracted
by water (30 mL), ethyl acetate (30 mL × 3), the saturated
sodium bicarbonate solution was adjusted to neutral, and the
organic layer was dried by anhydrous sodium sulfate,
filtered, and concentrated under vacuum. The crude product
was isolated and purified by column chromatography
(dichloromethane–methanol, 500:1) to obtain target com-
pound T12 (0.85 g). Yield: 81.73%, mp 132.1–134.3 °C.
MS (m/z) C16H12O5 [M + H]+ 285.3679. 1H-NMR
(400 MHz, DMSO-d6) δ: 9.70 (s, 1H, –Ph–OH), 7.75 (d,
1H, –CH=CH–Ph), 7.31–7.08 (m, 4H, –Ar–H), 6.94 (d,
1H, –Ar–H), 6.89 (d, 1H, –Ar–H), 6.73 (d, 1H,
–CH=CH–Ph), 6.65 (dd, 1H, –Ar–H), 6.08 (s, 2H,
–OCH2O–). 13C NMR (126 MHz, DMSO) δ 165.05,
163.10, 148.09, 145.56, 145.33, 132.63, 119.86, 116.02,
114.72, 108.34, 104.60, 102.14.
the same as compound T12. Yield: 57.58%, mp
134.8–136.7 °C. MS (m/z) C17H14O6 [M + Na]+ 337.3479.
1H-NMR (400 MHz, DMSO-d6) δ: 9.72 (s, 1H, –Ph–OH),
7.72 (d, 1H, –CH=CH–Ph), 7.41 (d, 1H, –Ar–H), 7.20 (dd,
1H, –Ar–H), 6.93 (d, 1H, –Ar–H), 6.85 (d, 1H, –Ar–H),
6.82 (d, 1H, –Ar–H), 6.68 (d, 1H, –CH=CH–Ph), 6.62 (dd,
1H, –Ar–H), 6.06 (s, 2H, –OCH2O–), 3.83 (s, 3H, –OCH3).
13C NMR (126 MHz, DMSO) δ 165.05, 163.10, 148.09,
145.56, 145.33, 132.63, 119.86, 116.02, 114.72, 108.34,
104.60, 102.14.
(E)-3-(3-dihydroxyphenyl) acrylic acid-(3,4-methylene dioxy)
phenyl ester (T15) Caffeic acid 13 (2.00 g, 11.10 mmol) was
dissolved in diphenyl ether (30 mL). Under magnetic stirring,
dichlorodiphenylmethane (2.5 mL, 13.32 mmol) was added
and stirred overnight at 170 °C under the conditions of nitro-
gen atmosphere. The reaction process was monitored by TLC.
After the reaction was over, stop stirring, cool the reaction to
room temperature, added 2 mol/L sodium hydroxide aqueous
solution to the system, adjust the reaction liquid to alkaline,
make acid into salt into aqueous phase, then remove part of
diphenyl ether with petroleum ether (30 mL × 3), adjust pH to
acidity with hydrochloric acid in aqueous phase, then added
ethyl acetate (50 mL × 3) extraction, anhydrous sodium sulfate
drying, filtration, vacuum concentration. The residue was
isolated and purified by column chromatography
(dichloromethane–methanol, 20:1) to get compound 14
(1.50 g) and the yield was 39.27%.
3,4-methylenedioxyphenol 5 (0.60 g, 4.34 mmol), com-
pound 14 (1.80 g, 5.21 mmol), EDCI (1.00 g, 5.21 mmol),
and DMAP (0.10 g, 0.86 mmol) were dissolved in DMF
(30 mL). The synthesis process of compound 4a was carried
out to produce compound 15. The crude product was
isolated and purified by column chromatography
(dichloromethane–methanol, 500:1) to get compound 15
(1.80 g) and the yield was 89.11%.
Compound 15 (1.80 g, 3.88 mmol) was dissolved in the
mixed solution of glacial acetic acid/water (24 mL/3 mL)
and stirred at 100 °C for 6 h under the conditions of nitrogen
and the reaction process was monitored by TLC. After the
reaction, stop stirring, cool to room temperature, extract
with ethyl acetate (30 mL × 3), wash with saturated sodium
bicarbonate solution, dry anhydrous sodium sulfate in
organic layer, filter, and concentrate under reduced pressure.
The crude product was isolated and purified by column
chromatography (dichloromethane–methanol, 50:1) to
obtain target compound T15 (0.56 g). Yield: 48.28%, mp
200.8–203.5 °C. MS (m/z) C16H12O6 [M + Na]+ 323.2870
1H-NMR (400 MHz, DMSO-d6) δ: 9.72 (s, 1H, –Ph–OH),
9.21 (s, 1H, –Ph–OH), 7.65 (d, 1H, –CH=CH–Ph), 7.13 (s,
1H, –Ar–H), 7.09 (dd, 1H, –Ar–H), 6.92 (d, 1H, –Ar–H),
6.85 (d, 1H, –Ar–H), 6.79 (d, 1H, –Ar–H), 6.62 (dd, 1H,
–Ar–H), 6.46 (d, 1H, –CH=CH–Ph), 6.06 (s, 2H,
(E)-3-(4-hydroxyphenyl) acrylic acid-(3,4-methylene dioxy)
phenyl ester (T13) The synthesis process was the same as
compound T12. Yield: 34.91%, mp 189.3–191.6 °C. MS
1
(m/z) C16H12O5 [M + H]+ 285.4257. H-NMR (400 MHz,
DMSO-d6) δ: 10.12 (s, 1H, –Ph–OH), 7.73 (d, 1H,
–CH=CH–Ph), 7.63 (d, 2H, –Ar–H), 6.92 (d, 1H, –Ar–H),
6.85 (d, 1H, –Ar–H), 6.82 (d, 2H, –Ar–H), 6.65~6.55 (m,
2H, –Ar–H, –CH=CH–Ph), 6.06 (s, 2H, –OCH2O–). 13C
NMR (126 MHz, DMSO) δ 165.05, 163.10, 148.09,
145.56, 145.33, 132.63, 119.86, 116.02, 114.72, 108.34,
104.60, 102.14.
(E)-3-(4-hydroxy-3-methoxyphenyl) acrylic acid-(3,4-methy-
lene dioxy) phenyl ester (T14). The synthesis process was

1700
Medicinal Chemistry Research (2021) 30:1688–1702
–OCH2O–). 13C NMR (126 MHz, DMSO) δ 165.05,
163.10, 148.09, 145.56, 145.33, 132.63, 119.86, 116.02,
114.72, 108.34, 104.60, 102.14.
Evaluation of toxicity by CCK8 assay
The suspension of HUVEC cells was planted on 96-well
transparent plates with 6 × 103 cells/well, and cultured
atmosphere with 37 °C and 5% CO2 saturated humidity.
After 24 h, different concentrations of test compounds
were added into the three Wells. The medium containing
0.1% DMSO was used as control. Then, added 10 μL
CCK8 solution to each well after 72 h and incubated for
another 0.5–1 h. The absorbance (OD) was read at 450 nm
on the BioTek Synergy H2 (laboratory system). The 50%
inhibitory cell growth concentration (IC50) determined
used graphpad software. All experiments were repeated
three times.
Study on antioxidant activity in vitro
Hydroxyl radical scavenging activity [14]
Accurately measure 2.10 mmol/L orthophenanthroline
solution (1 mL), pH 7.4 phosphate buffer solution 2 mL
and double distilled water 1 mL in a tube, and shake well,
then 2.10 mmol/L ferrous sulfate (1 mL) was added,
finally 0.03% hydrogen peroxide solution (1 mL) was
added. The mixture was incubated at 37 °C for 60 min.
After incubation, the absorbances were determined at
536 nm against an appropriate blank group (an equal
amount of distilled water). Hydroxyl radical scavenging
percentage was calculated as follows:
Study on acute lipid-lowering activity
KM mice (male, 20 2 g) were randomly divided into
normal group (N), model group (M), positive drug group
(FF), and target compound (T1–T15) groups after adaptive
feeding for 1 week. There were ten mice in each group
[18, 37].
⋅OH scavenging activity (%) = [1 − (As0 − As1)/(Ab0
−
Ab1)] × 100.
Where As0 was the absorbance of the sample reaction,
which did not contain the H2O2 solution. As1 was the
absorbance of the sample reaction, which included the H2O2
solution. Ab0 was the absorbance of the control reaction,
which did not include the H2O2 solution. Ab1 was the
absorbance of the control reaction, which contained the
H2O2 solution. All tests were performed three times in
parallel. The IC50 values calculated by SPSS 24.0 software
were used to evaluate the DPPH% radical scavenging
activity of target compounds.
N group: 0.5% CMC-Na solution.
M group: 0.5% CMC-Na solution.
T1–T15 group: dose 0.36 mmol/kg.
FF group: dose 0.036 mmol/kg.
During the experiment, the administration volume of
each group was 10 mL/kg body weight, the normal group
and the model group were given 0.5% CMC-Na solution
of the same volume, and the mice in each group were
given common feed and free to eat and drink. Eighteen
hours before the last intragastric administration, the
model group and each treatment group were injected with
Triton WR 1339 (400 mg/kg), respectively, into the tail
vein to establish the acute hyperlipidemia model, and the
normal group was injected with the same volume of
normal saline. Six hours after the last intragastric
administration, the eyeballs were removed and the blood
was collected. The plasma was prepared by 4500 r/min
low temperature centrifugation for 10 min, and stored at
−20 °C. The levels of TG and TC in plasma of mice in
each group were determined according to the instructions
of the kit. The animal experiment was performed in
accordance with the Animal Ethics Committee of Shaanxi
University of Chinese Medicine.
DPPH scavenging activity
Different concentrations of samples (2 mL) and DPPH
free radical standard ethanol solution (2 mL) were accu-
rately extracted and added into a 10 mL test tube and
avoid light at room temperature for 30 min. Using anhy-
drous ethanol as reference zero, the absorbance (A0) of
DPPH free radical standard solution (2 mL) and 2 mL
anhydrous ethanol mixture at 517 nm was determined, and
the absorbance (Aj) at 517 nm wavelength was determined
after samples (2 mL) of different concentrations and
DPPH (2 mL) was shaken in a 10 mL test tube and kept
away from light for 30 min at room temperature. Finally,
the absorbance was monitored at 517 nm and the DPPH
radical scavenging results were displayed as:
À
Á
Study on chronic lipid-lowering activity of compound T6
DPPH Á scavenging activity ð%Þ ¼ A0 À Aj =A0 Â 100:
Where A0 absorbance of the mixture of DPPH and sol-
vent; Aj absorbance of DPPH and sample reaction solution.
The IC50 value (50% scavenging concentration) was used to
evaluate the DPPH· scavenging activity of target com-
pounds and calculated by SPSS 24.0 software.
After adaptive feeding for 1 week, 12 KM mice (male, 20
2 g) were randomly selected as normal group (N) and fed
with normal diet, and the rest were fed with HFD. There
were twelve mice in each group. After 5 weeks of con-
tinuous feeding, the mice were fasted with water for 12 h.

Medicinal Chemistry Research (2021) 30:1688–1702
1701
All the mice in the normal group were taken blood from the
retroocular venous plexus. In the HFD group, 12 mice were
randomly selected to collect blood from the retroocular
venous plexus, and the plasma was prepared by 4500 r/min
low temperature centrifugation for 10 min. The levels of
plasma TG and TC were measured to determine whether the
model was successful or not. After the successful estab-
lishment of the model, the HFD feed group was randomly
divided into three groups: model group (M), positive drug
group (FF), compound T6 group (T6), with 12 mice in each
group. The drugs were given by intragastric administration
continuously for 4 weeks according to the following
regimen:
Laboratory of Pharmacodynamics and Material Basis of Chinese
Medicine, Shaanxi Administration of Traditional Chinese Medicine
is gratefully acknowledged. The authors sincerely thank the
Chengdu Lilai Biotechnology Co. LTD (Sichuan, China) for the
detection of experimental results of Western Blotting and histo-
pathological examination.
Compliance with ethical standards
Conflict of interest The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional affiliations.
N group: 0.5% CMC-Na solution.
M group: 0.5% CMC-Na solution.
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T6 group: dose 0.36 mmol/kg.
FF group: dose 0.036 mmol/kg.
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