Design, synthesis and biological mechanisms research on 1,2,3-triazole derivatives of Jiyuan Oridonin A

Article abstract of DOI:10.1016/j.bmc.2017.11.005

Two series of derivatives with 1,2,3-triazole as heterocyclic moiety of Jiyuan Oridonin A, a new ent-kaurene diterpenoid which was isolated from genus Isodon rubescens, were synthesized and biologically evaluated. All the derivatives possessed good anti-proliferative activities. Among them, compound 8g was found to significantly induce cell apoptosis and cell cycle arrest in MGC-803 via a series of signals activated by the increased intracellular ROS levels.

Full text of DOI:10.1016/j.bmc.2017.11.005

Accepted Manuscript
Design, synthesis and biological mechanisms research on 1,2,3-triazole deriv-
atives of Jiyuan Oridonin A
Yu Ke, Wang Wang, Long-Fei Zhao, Jian-Jia Liang, Ying Liu, Xiao Zhang, Kai
Feng, Hong-Min Liu
PII:
S0968-0896(17)31573-0
https://doi.org/10.1016/j.bmc.2017.11.005
BMC 14057
DOI:
Reference:
Bioorganic & Medicinal Chemistry
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Received Date:
Revised Date:
Accepted Date:
4 August 2017
25 October 2017
2 November 2017
Please cite this article as: Ke, Y., Wang, W., Zhao, L-F., Liang, J-J., Liu, Y., Zhang, X., Feng, K., Liu, H-M., Design,
synthesis and biological mechanisms research on 1,2,3-triazole derivatives of Jiyuan Oridonin A, Bioorganic &
Medicinal Chemistry (2017), doi: https://doi.org/10.1016/j.bmc.2017.11.005
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Design, synthesis and biological mechanisms research on 1,2,3-
triazole derivatives of Jiyuan Oridonin A
Yu Kea, Wang Wanga, Long-Fei Zhaoa, Jian-Jia Lianga, Ying Liua, Xiao Zhangb,*, Kai
Fengc,**, Hong-Min Liua,***
aCollaborative Innovation Center of New Drug Research and Safety Evaluation, Henan
Province; Key Laboratory of Technology of Drug Preparation (Zhengzhou University),
Ministry of Education of China; Key Laboratory of Henan Province for Drug Quality
and Evaluation; School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou
450001, China
bDepartment of Pharmacy, Xuchang Central Hostipal, Xuchang 461000, China
cDepartment of Pharmacy Administration, Shangqiu Central Hostipal, Shangqiu
476000, China
Corresponding Authors:
Hong-Min Liu, Kai Feng and Xiao Zhang
E-mail: liuhm@zzu.edu.cn (Hong-Min Liu)
fkxxdream@163.com (Kai Feng)
zhangxiao1220@126.com (Xiao Zhang)
ABSTRACT: Two series of derivatives with 1,2,3-triazole as heterocyclic moiety of
Jiyuan Oridonin A, a new ent-kaurene diterpenoid which was isolated from genus
Isodon rubescens, were synthesized and biologically evaluated. All the derivatives
possessed good anti-proliferative activities. Among them, compound 8g was found to
significantly induce cell apoptosis and cell cycle arrest in MGC-803 via a series of
signals activated by the increased intracellular ROS levels.
Keywords: ent-kaurene diterpenoid; 1,2,3-triazole; MGC-803; ROS
1

1. Introduction
Over the past century, natural products have played a major source of therapeutic
agents for cancers. Isodon species are widely distributed plants, and more than 600
diterpenoids have been isolated from this species over the past 30 years1. Some of them
showed potent anti-proliferative activities and low toxicity, especially those with an ent-
kaurane skeleton such as Oridonin, Ponicidin, Longikaurin A, and so on2-4 (Fig. 1). The
unique skeleton as well as potent anticancer activity make them promising candidates as
anticancer agents5.
However, the development of ent-kaurene diterpenoids for cancer therapy was
hampered largely by their moderate activity and structural complexity6. Therefore, it is
highly desirable to develop novel derivatives of these diterpenoids to improve their
potency without reducing the safety profile7. Previously, some researchers reported that
the modified of 14-hydroxy group8-10 and heterocycle-fused A-ring11, 12 could
significantly increase the anti-proliferative efficacy of Oridonin and its analogues (Fig.
1). Among these heterocycles, 1,2,3-triazole is a very well-recognized pharmacophore
appeared in many molecular structures of drugs13-15. It is stable to metabolic
degradation, oxidative/reductive conditions and actively participates in binding to
molecular targets and improves their solubility16. It has various kinds of biological
activities such as anticancer17, anti-HIV18, anti-tuberculosis19, anti-malaria20,
antibacterial21 and so on. In recently years, many evidences22-25 have demonstrated that
leading 1,2,3-triazole ring into lead compounds is a good strategy of anticancer drug
design.
2

Fig. 1.Structures of ent-kaurene diterpenoids from Isodon and some Oridonin incorporated with
heterocycle derivatives.
Reactive oxygen species (ROS) is a family including molecules, ions and free
radicals with the ability of oxidation. ROS can be induced by Cytokine, growth factor,
radiation, and inflammatory stimulation and so on26. When cells generate excessive
ROS, it will cause oxidative stress, which is recognized as an adverse event for
promoting tumorigenesis and progression27. In recent years, it was found that many
anticancer drugs could generate ROS to change mitochondrial permeability, decrease
membrane potential, release cytochrome C, initiate mitochondrial apoptosis pathway
and result in inducing apoptosis of cancer cells in the end28-31. Meanwhile, some
researchers reported that Oridonin could increase ROS level in cancer cells, which
should be an important anticancer mechanism for ent-kaurene diterpenoids1.
3

In our previous work, we have isolated a new kind of ent-kaurene diterpenoid,
Jiyuan Oridonin A32, with the different quantity and position of hydroxyl groups from
Oridonin and Ponicidin (Fig. 1). Also, some derivatives of Jiyuan Oridonin A have been
verified to exhibit good anticancer activity without obvious toxicity by our group33-36
Herein, we describe the design and synthesis of two series of derivatives with 1,2,3-
triazole as heterocyclic moiety of Jiyuan Oridonin A. It aimed at a higher anti-
proliferative efficacy and a lower systemic toxicity. The biological activities and
anticancer mechanism of these derivatives were investigated as well.
2. Results and discussion
.
2.1. Chemistry
The synthetic route of series 1 was shown in Scheme 1. Jiyuan Oridonin A mixed
with 2-bromoethanol catalyzed by toluene-p-sulfonic acid (p-TsOH) in tetrahydrofuran
(THF) at room temperature to obtain compound 2, and then stirred with NaN3 in the
system of ethyl acetate (EtOAc) and H2O (4:1) to afford compound 3. Compound 4a-g
were obtained through click reaction37 from compound 3 and appropriate alkyne.
Compound 4a showed better anti-proliferative activities than other compounds as
the anti-proliferative activities of series 1 were tested. It was supposed that aromatic
groups may improve the anticancer activities of compounds. On this basis, another
series of compounds was designed and synthesized (Scheme 2). Similarly to the first
route, Jiyuan Oridonin A were mixed with propargylbromide in THF to obtain
compound 5. Compound 6a-i were stirred with NaN3 in acetone to obtain compound
7a-i. Compound 8a-i were obtained through click reaction from compound 5 and
compound 7a-i.
4

Scheme 1. Synthetic route of series 1. Reagents and conditions: (a) 2-bromoethanol, THF, p-TsOH,
rt, 3 h; (b) EtOAc/H2O, NaN3, reflux, 7 h; (c) appropriate alkyne, CuSO4/Cu, THF/H2O, rt, 8.5 h.
Scheme 2. Synthetic route of series 2. Reagents and conditions: (d) propargylbromide, THF, p-TsOH,
rt, 3 h; (e) Acetone, NaN3, reflux, 7 h; (f) CuSO4/Cu, THF /H2O, rt, 6-12 h.
2.2. MTT assay and SAR study
The anti-proliferative activities of all the prepared compounds were determined in
four human cancer cell lines by MTT (3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-
5

phenytetrazoliumromide) assay, with Oridonin was used as control. As shown in Table
1, most of compounds exhibited stronger anti-proliferative activities than Oridonin.
Almost all the compounds showed the strongest anti-proliferative activities in Eca109
cell line (human esophageal cancer cell line) of the four cell lines. The above results
demonstrated that 1,2,3-triazole could significantly improve the anti-proliferative
activities of lead compounds. It would be helpful to the research of structure
modification for ent-kaurene diterpenoids. Furthermore, the SAR showed the length of
carbon chain had little change on IC50 values for those compounds with aliphatic
substituent (compound 4a-g). It could be concluded that the cytotoxicity activity of
compounds with aromatic groups (compound 8a-i) was more potent than compounds
with aliphatic substituent (compound 4a-g). It was speculated that the lipophilicity of
aromatic groups may enhance the ability of compounds across the cell membrane.
Meanwhile, the position and type of substituents had little effect on anticancer activity
of the benzene ring.
Table 1. The anticancer activity of two series of Jiyuan Oridonin A derivatives against four cancer
cell lines. a
IC50 (µM)
Eca109
Compound
EC9706
SMMC7721
53.95 1.08
20.25 2.13
10.01 0.92
6.07 0.51
9.66 1.01
11.02 1.09
5.71 0.45
>50
5.73 0.42
5.62 0.47
15.27 2.01
5.79 0.51
4.81 0.40
3.76 0.34
3.80 0.37
9.03 1.03
5.88 0.49
4.44 0.28
MCF-7
Oridonin 31.78 3.05
1(Jiyuan Oridonin A) 20.68 2.12
38.42 2.64
22.52 2.38
8.71 0.79
5.32 0.42
11.38 1.19
8.29 0.70
7.89 0.72
>50
5.99 0.50
5.85 0.50
7.87 0.75
7.54 0.68
4.67 0.41
4.21 0.38
7.78 0.73
9.50 1.26
4.50 0.42
5.04 0.35
74.18 2.84
22.92 2.52
1.60 0.08
8.95 0.78
10.97 1.03
13.42 1.32
13.58 1.42
>50
3
6.08 0.59
4.26 0.39
4.30 0.42
4.45 0.40
4.81 0.43
4.72 0.41
3.21 0.23
4.70 0.41
10.79 1.08
3.51 0.29
2.57 0.20
2.58 0.18
4.13 0.39
4.51 0.42
3.68 0.26
2.70 0.18
4a
4b
4c
4d
4e
4f
4g
5
8a
8b
8c
8d
8e
8f
8g
8.66 0.75
>50
14.64 1.92
9.45 1,03
7.81 0.71
6.85 0.61
6.45 0.52
8.79 0.85
6.62 0.52
4.76 0.29
6

8h
8i
2.12 0.19
2.73 0.22
6.10 0.49
4.69 0.43
5.68 0.51
4.67 0.42
7.86 0.59
4.92 0.51
a MTT methods, cell lines were treated with target compounds for 48h, The average value of the
three independent experiments was expressed by mean SD.
As shown in Table 2, some compounds with better growth inhibitory effects were
chosen to carry out further studies in PC-3 (human prostate cancer cell line) and MGC-
803 (human gastric cancer cell line). Compound 8g was found to possess the best anti-
proliferative activity, and was chosen to test forward cytotoxic experiment on a number
of cancer cell lines including MGC-803, HGC-27 (human gastric cancer cell line),
Eca109, EC9706 (human esophageal cancer cell line), SMMC-7721 (hepatoma
carcinoma cell line), MCF-7 (human breast cancer cell line) and PC-3. Based on the
results (Table 3), compound 8g was generally observed for stronger anticancer activities
in all tested cell lines compared with Oridonin, suggesting that 1,2,3-triazole as
heterocyclic moiety was beneficial for the cytotoxicity of derivatives. At the same time,
GES-1 (human normal gastric epithelial cells) was used for comparison in Fig. 2A, and
the inhibitory rate of compound 8g on GES-1 cells (IC50 = 28.71 1.24 µM) was
significantly less than that of MGC-803 (IC50 = 2.53 0.10 µM) at the same
concentration. It indicated the selectivity of compound 8g to cancer cells and normal
cells. As the result, compound 8g was selected for further pharmacological study on
MGC-803.
Table 2. IC50 Values of part of compounds for PC-3 and MGC-803 cell line.a
IC50 (µM)
PC-3
Compd
MGC-803
33.10 3.47
14.70 1.91
11.91 1.67
9.62 1.27
4.58 0.23
5.42 0.42
3.77 0.31
4.79 0.43
Oridonin
1
27.55 3.01
14.99 2.09
12.30 1.80
11.22 1.36
3.79 0.34
5.32 0.39
3.92 0.30
4.95 0.46
3
5
4a
4b
4f
8b
7

8g
8h
8i
4.02 0.29
4.90 0.30
4.37 0.31
2.53 0.10
3.89 0.06
4.27 0.41
a MTT methods, cell lines were treated with target compounds for 48h, The average value of the
three independent experiments was expressed by mean SD.
Table 3. Cytotoxicity data of compound 8g a
IC50 (µM)
Cell Lines
8g
Oridonin
MGC-803
HGC-27
ECa109
EC9706
SMMC-7721
MCF-7
2.53 0.10
2.97 0.14
2.70 0.48
5.04 0.83
4.44 0.40
4.76 0.43
4.02 0.29
33.10 3.47
32.03 3.01
31.78 3.03
38.42 3.14
53.95 4.28
74.18 6.41
27.55 3.01
PC-3
a MTT methods, cell lines were treated with target compounds for 48h, The average value of the
three independent experiments was expressed by mean SD.
2.3. Effect of compound 8g on the proliferation of MGC-803 cells
As shown in Fig. 2B, with the increase of drug concentration and the extension of
time, the inhibitory effect was enhanced, which indicated that compound 8g could
inhibit cell proliferation in a time-dependent and dose-dependent manner. With higher
concentration treatments (16, 32 µg/ml), the inhibition rate exceeded 90%, but the effect
of acting time on inhibition rate was not obvious.
8

Fig. 2. (A) Effects of compound 8g on cancer cell line and normal cell line. (B) Inhibitory activity of
compound 8g on MGC-803 cells at different time. (C, D) Level of ROS in MGC-803 cells induced
by compound 8g. *P<0.05, compared with the control group; **P<0.01, compared with the control
group.
2.4. Measurement of ROS levels
As shown in Fig. 2C and Fig. 2D, the level of ROS in MGC-803 cells increased
significantly with the prolongation of the acting time by compound 8g, suggesting that
compound 8g induced the increase of ROS in MGC-803 cells, which tested by flow
cytometry analysis via the DCFH-DA staining.
9

2.5. Effects of NAC on MGC-803 cells
Previous experiments confirmed that compound 8g could induce an increase in
intracellular ROS. Then we used ROS scavenger N-acetly cysteine (NAC) to antagonize
the increase of ROS and to further verify the cell death mechanism action of compound
8g. The results showed that (Fig. 3) compared to the only dosing group, the cell
proliferation inhibition rate of the adding NAC (5 mmol) group had evidently decreased.
We also found that NAC could reduce the cytotoxic of compound 8g on MGC-803,
especially at low concentration. Apparently, ROS played an important role in MGC-803
cells death caused by compound 8g.
Fig. 3. The proliferation effect of NAC on compound 8g. (A) the proliferation inhibition effect of
compound 8g on MGC-803 after NAC pretreatment; (B) the proliferation inhibition effect of
compound 8g on MGC-803 at 8 µg/ml and 16 µg/mL after NAC pretreatment. **P<0.01, compared
with the control group; ##P<0.01, compared with single compound 8g treatment group.
We used JC-1 staining to observe the effect of NAC on compound 8g induced the
mitochondrial membrane potential (∆Ψm) reduced. The result was shown in Fig. 4.
When 1.5 and 3 µg/mL of compound 8g affected on MGC-803 cell for 24 h, JC-1 in
monomer form showed green fluorescence. It showed that the ∆Ψm of MGC-803 cells
decreased with adding compound 8g (Fig. 4A, 4B, 4C). 5 mM NAC alone did not affect
10

the ∆Ψm, but it could significantly inhibit the decrease of ∆Ψm induced by compound
8g (Fig. 4a, 4b, 4c). The above results demonstrated that NAC had obvious protective
effect on the decrease of ∆Ψm induced by compound 8g and the increase of ROS could
be a prerequisite for mitochondrial membrane potential collapse.
Fig. 4. Protection of compound 8g induced decrease in membrane potential induced by NAC. (A)
control group; (B) 1.5 µg/ml compound 8g; (C) 3 µg/ml compound 8g; (a) 5 mM NAC; (b) NAC +
1.5 µg/ml compound 8g; (c) NAC + 3 µg/ml compound 8g.
The decrease of mitochondrial membrane potential could lead to the release of
cytochrome C in mitochondria. From Fig. 5 we could see, in the presence of compound
8g, Caspase-9 proenzyme protein was activated followed by increased levels of
11

Cytochrome C in the cytoplasm. The expression of Cleaved-Caspase-9 increased with
the increase of compound 8g concentration, activation of Caspase-9 continued initiating
downstream of Caspase cascade reaction, finally causing cells apoptosis.
Fig. 5. Release of Cytochrome C and Caspase-9 activation by compound 8g; (A) Cytochrome C; (B,
C) Caspase-9. **P<0.01, Compared with the control group.
2.6. Effect of NAC on cell cycle and apoptosis by compound 8g
To obtain further insight into the mechanism of compound 8g, the percentage of
apoptotic MGC-803 cells were determined by flow cytometry and the results showed
NAC could inhibit cell apoptosis induced by compound 8g (Fig. 6). Meanwhile, it is
worthwhile to discuss the morphological changes of apoptotic cells (Fig. 7) and the
blocking of compound 8g induced cell cycle arrest induced by NAC (Fig. 8). In the
control group, the cell wall growth was good (Fig. 7, 1A), however, with the increase of
drug concentration, the number of cell was significantly decreased and cell debris
12

increased, compared with the control group (Fig. 7, 1B-1D). By Hoechst 33258 staining,
apoptotic bodies could be observed more clearly (Fig. 7, 2B-2D).
Fig. 6. Inhibition of compound 8g induced apoptosis by NAC. (A) control group; (B) 1.5 µg/mL
compound 8g; (C) 3 µg/mL compound 8g; (a) 5 mM NAC; (b) NAC + 1.5 µg/mL compound 8g; (c)
NAC + 3 µg/mL compound 8g.
Fig. 7. Hoechst 33258 fluorescent staining method was used to treat the cells with different
13

concentrations of 24 h. Apoptotic cells morphology were observed under inverted microscope and
fluorescence microscope (×200). (A) control group; (B) 1.5 µg/mL compound 8g; (C) 3 µg/mL
compound 8g; (D) 6 µg/mL compound 8g.
As shown in the Fig. 8 and Table 4, compound 8g could increase the proportion of
G2/M phase cells in MGC-803 cells in a dose-dependent manner. On the other hand,
NAC almost completely reversed the cell cycle arrest induced by compound 8g (Fig. 8,
b-c, Table 4).
Table 4. Growth inhibitory effects of different reagents on MGC-803 cells.
Groups
G0/G1(%)
S(%)
G2/M(%)
A
B
C
a
52.5 3.71
46.3 2.65*
30.5 3.26*
51.3 4.34
55.4 3.94#
50.4 4.04#
32.5 2.25
29.2 1.78*
29.6 2.06*
33.1 2.63
29.1 1.56
33.2 2.26
17.2 1.35
26.7 1.97*
40.3 2.16*
14.3 0.52
16.1 1.31#
14.8 1.01#
b
c
(A) control group; (B) 1.5 µg/mL compound 8g; (C) 3 µg/mL compound 8g; (a) 5 mM NAC; (b)
NAC + 1.5 µg/mL compound 8g; (c) NAC + 3 µg/mL compound 8g. *P<0.05, compared with the
#
control group; P<0.05, compared with single compound 8g treatment group.
2.7. Effect on the expression of apoptosis-related proteins
To elucidate the potential mechanisms contributed to apoptosis of MGC-803 cells
induced by compound 8g, several proteins related to apoptosis were determined by
Western blotting. As shown in Fig. 9, it is clearly to find the up-regulation of
proapoptotic protein p53 and p21, the down-regulation of anti-apoptotic protein
surviving and the ratio of Bcl-2/Bax. It can prove that compound 8g induced apoptosis
of MGC-803 cells through the mitochondrial pathway.
14

Fig. 8. The growth inhibitory effect of compound 8g in MGC-803 cells was blocked by NAC after
24h. (A) control group; (B) 1.5 µg/mL compound 8g; (C) 3 µg/mL compound 8g; (a) 5 mM NAC; (b)
NAC + 1.5 µg/mL compound 8g; (c) NAC + 3 µg/mL compound 8g.
Fig. 9. Expression changes of apoptosis related proteins. (A) compound 8g induced expression
changes of apoptosis related proteins in MGC-803 cells; (B, C) Statistical analysis of protein
15

expression levels. The results shown were representative of three independent experiments.
**P<0.01, Compared with the control group.
3. Conclusion
To summarize, we designed two series of new derivatives with 1,2,3-triazole as
heterocyclic moiety of Jiyuan Oridonin A. These compounds displayed moderate to
good anti-proliferative activity against the tested cancer cells and might serve as
bioactive fragments and lead compounds for developing more potent cytotoxic agents.
The preliminary SAR illustrated that 1,2,3-triazole could significantly improve the anti-
proliferative activities of the ent-kaurene diterpenoids.
Compound 8g was found to possess the best anti-proliferative activity among
above compounds. The further mechanism investigation showed that it increased ROS
level in cancer cells, leading to the decrease of mitochondrial membrane potential and
the release of Cytochrome C into the cytoplasm, which was then cut and activated
Caspase-9 to induce apoptosis. Meanwhile, it halted cell cycle progression at the G2/M
phase and altered the expression of cell cycle-related proteins. More mechanism studies
are underway and will be reported in due course.
4. Experimental
4.1. Chemistry
All commercially available starting materials and solvents were reagent grade and
used without further purification. Reactions were monitored by thin-layer
chromatography (TLC) on 0.25 mm silicagel plates (GF254) and visualized under UV
light. Infrared spectra (IR) were recorded on PE-1710 type instrument of PE Company
(KBr pellet). Melting points were determined on an X-5 micromelting apparatus and are
uncorrected. 1H NMR and 13C NMR spectra were recorded on a Bruker 400 MHz and
100 MHz spectrometer, respectively. High resolution mass spectra (HRMS) of all
16

derivatives were recorded on a Waters Micromass Q-T of Micromass spectrometer by
electrospray ionization (ESI).
4.2. General procedure to synthesize all compounds
4.2.1. synthesis of compound 2 and compound 3
Jiyuan Oridonin A (150 mg) was dissolved in THF (8 mL). 2-bromoethanol (150
µL) and p-TsOH (10 mg) were added to this solution. The mixture was stirred for 3 h at
room temperature. Then the mixture was treated by heric-vacuum distillation and
diluted with water and extracted with ethyl acetate. The extract was washed with brine,
dried over anhydrous Na2SO4, filtered, evaporated and the crude product was purified
by column chromatography to obtain compound 2. After that, compound 2 was put in
the system of EtOAc/H2O (5:1) with NaN3 and stirred for 7 h at 70 ℃ to obtain
compound 3.
4.2.1.1. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-bromoethoxy)-11,14-dihydroxy-
4,4-dimethyl-8-methylenedecahydro-1H-6,11b-(epoxymethano)-6a,9-
methanocyclohepta[a]naphthalen-7(8H)-one (Compound 2)
White solid, 78% yield; Mp: 121-122 ℃; IR (KBr, cm-1): 3608, 3362, 2951, 2869,
1723, 1643, 1431, 1362, 1258, 1103, 1037, 654; 1H NMR (400 MHz, DMSO-d6) δ 5.79,
5.38 (each 1H, s, H-17), 5.11 (1H, s, H-20), 5.10 (1H, d, J = 2.9 Hz, H-14-OH), 4.51
(1H, s, H-11-OH), 4.45 (1H, d, J = 8.0 Hz, H-11α), 4.26 (1H, d, J = 7.0 Hz, H-7β),
3.98-3.81 (2H, m, H-21), 2.80 (1H ,d, J = 8.9 Hz, H-13α), 2.68 (1H, d, J = 12.8 Hz, H-
6β), 2.64 (1H, dd, J = 6.7 Hz, H-12α), 1.99 (1H, d, J = 12.4 Hz, H-1α), 1.86-1.72 (2H,
m, H-22), 1.61 (1H, d, J = 4.7 Hz, H-6α), 1.49-1.32 (3H, m, H-3α, H-2), 1.29-1.26 (2H,
m, H-1β, H-12β), 1.25-1.15 (2H, m, H-5β, H-9β), 1.11-1.05 (1H, m, H-3β), 0.92 (3H, s,
H-19), 0.82 (3H, s, H-18). 13C NMR (101 MHz, DMSO-d6) δ 206.20, 152.73, 119.69,
17

116.61, 99.94, 70.15, 65.85, 63.56, 62.88, 56.84, 48.90, 39.80, 39.59, 39.38, 34.17,
33.14, 30.31, 24.71, 21.19, 18.89, 18.23. ESI-HRMS: m/z cacld. For C22H31BrNaO5,
[M+Na]+: 476.1247, found 476.1242.
4.2.1.2. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-azidoethoxy)-11,14-dihydroxy-
4,4-dimethyl-8-methylenedecahydro-1H-6,11b-(epoxymethano)-6a,9-
methanocyclohepta[a]naphthalen-7(8H)-one (Compound 3)
White solid, 94% yield; Mp: 130-132 ℃; IR (KBr, cm-1): 3648, 3612, 3421, 3136,
2950, 2868, 1723, 1646, 1362, 1252, 1108, 1078, 1023, 766; 1H NMR (400 MHz,
DMSO-d6) δ 5.80, 5.38 (each 1H, s, H-17), 5.11 (1H, d, J = 2.9 Hz, H-14-OH), 5.10
(1H, s, H-20), 4.51 (1H, s, H-11-OH), 4.45 (1H, d, J = 7.8 Hz, H-11α), 4.26 (1H, d, J =
7.2Hz, H-7β), 3.99-3.82 (2H, m, H-21), 2.81 (1H, d, J = 9.1 Hz, H-13α), 2.68 (1H, d, J
= 12.9 Hz, H-6β), 2.60 (1H, s, H-12α), 2.00 (1H, d, J = 11.9 Hz, H-1α), 1.87-1.74 (2H,
m, H-22), 1.63-1.44 (1H, m, H-6α), 1.39 (2H, dd, J = 29.4, 11.2 Hz, H-2), 1.36-1.27
(2H, m, H-1β, H-12β), 1.25-1.14 (2H, m, H-5β, H-9β), 1.09-1.01 (1H, m, H-3β), 0.92
(3H, s, H-19), 0.84 (3H, s, H-18). 13C NMR (101 MHz, DMSO-d6) δ 206.25, 152.77,
116.54, 99.99, 70.13, 66.53, 65.78, 63.59, 57.77, 56.82, 51.24, 48.97, 39.99, 39.78,
39.57, 39.36, 34.17, 33.17, 30.38, 24.75, 21.20, 18.25. ESI-HRMS: m/z cacld. For
C22H31N3NaO5, [M+Na]+: 439.2156, found 439.2152.
4.2.2. General procedure to synthesize Compound 4a-g
Coumpound 3 (150 mg) and appropriate alkynes were dissolved in THF (4 mL) ,
then added 1 mL H2O to this solution. Finally, the mixture was stirred at room
temperature for 8.5 h by using CuSO4 (57 mg) and Cu (107 mg) as catalytic agents and
then was filtered and condensed. The residue was extracted with ethyl acetate. The
organic layer was washed with brine, dried over anhydrous Na2SO4, filtered, evaporated
18

to afford the crude product. The crude product was purified by column chromatography
to give Compound 4a-g.
4.2.2.1. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-11,14-dihydroxy-4,4-dimethyl-8-
methylene-12-(2-(4-phenyl-1H-1,2,3-triazol-1-yl)ethoxy)decahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 4a)
White solid, 92% yield; Mp: 152-153 ℃; IR (KBr, cm-1): 3648, 3612, 3421, 3136, 2950,
2868, 1723, 1646, 1362, 1252, 1108, 1078, 1023, 766, 695; 1H-NMR (400 MHz,
DMSO-d6) δ 8.52 (1H, s, H-23), 7.86 (2H, d, J = 7.3 Hz, H-26, H-30), 7.45 (2H, t, J =
7.6 Hz, H-27, H-29), 7.34 (1H, t, J = 7.4 Hz, H-28), 5.74, 5.30 (each 1H, s, H-17), 5.12
(1H, s, H-20), 5.00 (1H, d, J = 2.9 Hz, H-14-OH), 4.64 (2H, dd, J = 10.4, 6.1 Hz, H-22),
4.25-4.05 (2H, m, H-21), 4.19 (1H, s, H-14α), 4.11 (1H, s, H-11α), 4.03 (1H, d, J = 7.1
Hz, H-11-OH), 3.79 (1H, dd, H-5β), 2.74-2.53 (2H, m, H-6β, H-12α), 2.42 (1H, d, J =
13.7 Hz, H-12α), 1.99 (1H, s, H-1α), 1.87 (1H, s, H-6α), 1.63-1.46 (1H, m, H-3α), 1.42-
1.33 (2H, m, H-2), 1.25-1.18 (2H, m, H-1β, H-12β), 1.15-1.10 (2H, m, H-5β, H-9β),
1.01 (1H, dd, J = 19.2 Hz, H-3β), 0.88 (3H, s, H-19), 0.79 (3H, s, H-18); 13C-NMR (101
MHz, DMSO-d6) δ 206.19, 152.75, 146.74, 131.45, 129.31, 128.21, 125.63, 121.99,
116.38, 100.21, 69.94, 66.48, 65.83, 63.57, 57.75, 50.50, 48.79, 42.90, 42.12, 40.82,
39.84, 34.12, 33.12, 30.38, 24.68, 21.18, 18.06. ESI-HRMS: m/z cacld. For
C30H37N3NaO5, [M+Na]+: 542.2631, found 542.2619.
4.2.2.2. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-(4-cyclopropyl-1H-1,2,3-triazol-
1-yl)ethoxy)-11,14-dihydroxy-4,4-dimethyl-8-methylenedecahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 4b)
White solid, 95% yield; Mp: 140-141 ℃; IR (KBr, cm-1): 3647, 3613, 3445, 2950,
2870, 1716, 1646, 1557, 1394, 1362, 1254, 1107, 1024, 668; 1H-NMR (400 MHz,
19

DMSO-d6) δ 7.76 (1H, s, H-23), 5.77, 5.36 (each 1H, s, H-17), 5.07 (1H, s, H-20), 4.95
(1H, d, J = 3.0 Hz, H-14-OH), 4.59-4.39 (2H, m, H-22), 4.27-4.18 (2H, m, H-28), 4.15
(1H, s, H-14α), 4.06 (1H, d, J = 7.2 Hz, H-11-OH), 3.96 (1H, d, J = 2.9 Hz, H-11α),
3.71 (1H, d, J = 4.5 Hz, H-5β), 2.71 (1H, d, J = 9.1 Hz, H-6β), 2.64 (1H, s, H-12α),
2.00-1.90 (1H, m, H-1α), 1.84 (1H, s, H-6α), 1.61-1.49 (1H, m, H-3α), 1.42-1.35 (2H, m,
H-2), 1.26-1.20 (2H, m, H-1β, H-12β), 1.18-1.10 (2H, m, H-5β, H-9β), 1.08-0.99 (1H,
m, H-3β), 0.91-0.87 (5H, m, H-19, H-26, H-27), 0.80 (3H, s, H-18), 0.76-0.68 (2H, m,
H-26, H-27). 13C-NMR (101 MHz, DMSO-d6) δ206.18, 152.80, 149.33, 121.17, 116.40,
100.17, 69.93, 66.60, 65.81, 63.53, 57.77, 56.71, 50.19, 48.83, 42.99, 42.18, 40.87,
39.74, 34.12, 33.13, 30.34, 24.70, 21.19, 18.14, 18.06, 17.86, 17.03. ESI-HRMS: m/z
cacld. For C27H37N3NaO5, [M+Na]+: 506.2631, found 506.2622.
4.2.2.3. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-(4-butyl-1H-1,2,3-triazol-1-
yl)ethoxy)-11,14-dihydroxy-4,4-dimethyl-8-methylenedecahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 4c)
White solid, 92% yield; Mp: 148-150 ℃; IR (KBr, cm-1): 3419, 3131, 2954, 2930,
2866, 1723, 1646, 1557, 1457, 1146, 1108, 1021, 931, 726, 667; 1H-NMR (400 MHz,
DMSO-d6) δ 7.80 (1H, s, H-23), 5.77, 5.36 (each 1H, s, H-17), 5.07 (1H, s, H-20), 4.98
(1H, d, J = 3.0 Hz, H-14-OH), 4.54-4.43 (2H, m, H-22), 4.25-4.07 (3H, m, H-21, H-14α,
H-11α), 3.96 (1H, d, J = 3.1 Hz, H-7β), 2.69 (1H, t, J = 8.0 Hz, H-13α), 2.64 (2H, d, J =
7.4 Hz, H-25), 2.61 (1H, s, H-6β), 2.53 (1H, s, H-12α), 1.84 (1H, d, J = 8.1 Hz, H-1α),
1.65-1.57 (2H, m, H-26), 1.40 (1H, d, J = 4.9 Hz, H-6α), 1.36 (2H, d, J = 7.5 Hz, H-27),
1.34 (1H, s, H-3α), 1.31 (1H, d, J = 7.2 Hz, H-1β), 1.25 (3H, d, J = 5.9 Hz, H-2, H-12β),
1.21 (1H, d, J = 6.2 Hz, H-5β), 1.03 (1H, d, J = 8.8 Hz, H-3β), 0.96-0.91 (3H, m, H-28),
0.89 (3H, s, H-19), 0.80 (3H, s, H-18). 13C-NMR (101 MHz, DMSO-d6) δ 206.20,
20

152.77, 147.29, 122.24, 116.45, 100.13, 69.95, 66.68, 65.79, 63.53, 57.76, 56.68, 50.14,
48.82, 42.98, 42.20, 40.85, 39.69, 34.12, 33.13, 31.60, 30.33, 25.22, 24.69, 22.18, 21.17,
18.13, 14.20. ESI-HRMS: m/z cacld. For C28H41N3NaO5, [M+Na]+: 529.2944, found
529.2940.
4.2.2.4. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-11,14-dihydroxy-4,4-dimethyl-8-
methylene-12-(2-(4-pentyl-1H-1,2,3-triazol-1-yl)ethoxy)decahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 4d)
White solid, 91% yield; Mp: 159-160 ℃; IR (KBr, cm-1): 3419, 2952, 2936, 2868,
1723, 1698, 1646, 1455, 1363, 1264, 1108, 1023, 934, 791; 1H-NMR (400 MHz,
DMSO-d6) δ 7.80 (1H, s, H-23), 5.77, 5.36 (each 1H, s, H-17), 5.07 (1H, s, H-20), 4.97
(1H, d, J = 3.0 Hz, H-14-OH), 4.51 (2H, ddd, J = 16.9, 10.3, 7.2 Hz, H-22), 4.31-4.19
(1H, m, H-21), 4.17 (1H, d, J = 1.4 Hz, H-11-OH), 4.14-4.09 (1H, m, H-14α), 4.07 (1H,
d, J = 7.2 Hz, H-11α), 3.96 (1H, d, J = 2.9 Hz, H-7β), 3.72 (1H, ddd, J = 10.7, 6.5, 4.1
Hz, H-21), 2.69 (1H, t, J = 8.0 Hz, H-13α), 2.64 (1H, s, H-6β), 2.61 (2H, d, J = 7.4 Hz,
H-25), 1.84 (1H, d, J = 8.1 Hz, H-1α), 1.66-1.58 (2H, m, H-26), 1.39 (1H, d, J = 4.9 Hz,
H-6α), 1.35-1.29 (4H, m, H-27, H-3α, H-1β), 1.26 (3H, d, J =7.2 Hz,H-2, H-12β), 1.21
(1H, d, J = 6.2 Hz, H-5β), 1.14 (2H, t, J = 6.4 Hz, H-28), 1.04 (1H, d, J =8.8 Hz, H-3β),
0.91-0.85 (6H, m, H-29, H-19), 0.80 (3H, s, H-18). 13C-NMR (101 MHz, DMSO-d6) δ
206.19, 152.78, 147.34, 122.22, 116.43, 100.14, 69.95, 66.68, 65.80, 63.53, 57.77,
56.69, 50.14, 48.81, 42.99, 42.20, 40.86, 39.68, 34.12, 33.13, 31.34, 30.33, 29.14, 25.54,
24.69, 22.37, 21.17, 18.14, 14.32. ESI-HRMS: m/z cacld. For C29H43N3NaO5 , [M+Na]+:
536.3100, found 536.3094.
21

4.2.2.5. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-(4-hexyl-1H-1,2,3-triazol-1-
yl)ethoxy)-11,14-dihydroxy-4,4-dimethyl-8-methylenedecahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 4e)
White solid, 90% yield; Mp: 163-164℃; IR (KBr, cm-1): 3420, 2952, 2928, 2868,
1723, 1646, 1456, 1363, 1265, 1219, 1108, 1079, 1026, 933, 721, 667; 1H-NMR (400
MHz, DMSO-d6) δ 7.80 (1H, s, H-23), 5.77, 5.35 (each 1H, s, H-17), 5.07 (1H, s, H-20),
4.99 (1H, d, J = 2.8 Hz, H-14-OH), 4.64-4.42 (2H, m, H-22), 4.30-4.23 (1H, m, H-21),
4.15 (1H, d, J = 1.4 Hz, H-11-OH), 4.11 (1H, t, J = 6.6 Hz, H-14α), 4.09-4.00 (1H, m,
H-11α), 3.95 (1H, d, J = 2.9 Hz, H-7β), 2.70 (1H, t, J = 8.0 Hz, H-13α), 2.65-2.57 (3H,
m, H-6β, H-25), 2.52 (1H, s, H-12α), 1.84 (1H, d, J = 8.1 Hz, H-1α), 1.65-1.50 (3H, m,
H-26, H-6α), 1.43-1.18 (9H, m, H-27, H-28, H-2, H-1β, H-12β, H-9β), 1.16-1.08 (2H,
m, H-29), 1.07-0.99 (1H, m, H-3β), 0.92-0.84 (6H, m, H-30, H-19), 0.80 (3H, s, H-18).
13C-NMR (101 MHz, DMSO-d6) δ 206.21, 152.78, 147.35, 122.21, 116.43, 100.13,
69.94, 66.67, 65.79, 63.51, 57.75, 56.66, 50.14, 48.81, 42.97, 42.18, 40.84, 39.66, 33.13,
31.55, 30.33, 29.45, 28.82, 25.59, 24.69, 22.48, 21.16, 18.13, 14.43. ESI-HRMS: m/z
cacld. For C30H45N3NaO5, [M+Na]+: 550.3257, found 550.3253.
4.2.2.6. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-(4-heptyl-1H-1,2,3-triazol-1-
yl)ethoxy)-11,14-dihydroxy-4,4-dimethyl-8-methylenedecahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 4f)
White solid, 92% yield; Mp: 164-165℃; IR (KBr, cm-1): 3420, 2927, 2867, 1723,
1646, 1455, 1363, 1267, 1211, 1108, 1048, 1026, 932, 666; 1H-NMR (400 MHz,
DMSO-d6) δ 7.80 (1H, s, H-23), 5.77, 5.35 (each 1H, s, H-17), 5.07 (1H, s, H-20), 4.98
(1H, d, J = 2.8 Hz, H-14-OH), 4.60-4.42 (2H, m, H-22), 4.32-4.25 (1H, m, H-21), 4.15
(1H, d, J = 1.4 Hz, H-11-OH), 4.10-4.02 (2H, m, H-14α, H-11α), 3.98 (1H, d, J = 2.9
22

Hz, H-7β), 3.80-3.58 (1H, m, H-21), 2.68 (1H, t, J = 8.0 Hz, H-13α), 2.65-2.58 (3H, m,
H-6β, H-25), 1.84 (1H, d, J = 8.1 Hz, H-1α), 1.65-1.50 (3H, m, H-26, H-6α), 1.44-1.19
(11H, m, H-27, H-28, H-29, H-2, H-1β, H-12β, H-9β), 1.18-1.10 (2H, m, H-30), 1.03
(1H, d, J = 8.8 Hz, H-3β), 0.93-0.83 (6H, m, H-30, H-19), 0.80 (3H, s, H-18). 13C-NMR
(101 MHz, DMSO-d6) δ 206.21, 152.78, 147.35, 122.21, 116.42, 100.13, 69.94, 66.68,
65.78, 63.51, 57.76, 56.66, 50.14, 48.81, 42.98, 42.19, 40.84, 39.67, 34.12, 33.13, 31.65,
30.33, 29.48, 29.10, 28.97, 25.59, 24.69, 22.58, 21.16, 18.14, 14.43. ESI-HRMS: m/z
cacld. For C31H47N3NaO5, [M+Na]+: 564.3413, found 564.3408.
4.2.2.7. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-11,14-dihydroxy-4,4-dimethyl-8-
methylene-12-(2-(4-octyl-1H-1,2,3-triazol-1-yl)ethoxy)decahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 4g)
White solid, 92% yield; Mp: 171-172℃; IR (KBr, cm-1): 3419, 2926, 2856, 1723,
1645, 1550, 1457, 1364, 1265, 1219, 1108, 1079, 1026, 933, 724, 655; 1H-NMR (400
MHz, DMSO-d6) δ 7.80 (1H, s, H-23), 5.77, 5.35 (each 1H, s, H-17), 5.07 (1H, s, H-20),
4.98 (1H, d, J = 2.9 Hz, H-14-OH), 4.62-4.41 (2H, m, H-22), 4.31-4.19 (1H, m, H-21),
4.16 (1H, s, H-11-OH), 4.14-4.07 (2H, m, H-14α, H-11α), 3.96 (1H, d, J = 3.1 Hz, H-
7β), 3.82-3.62 (1H, m, H-21), 2.68 (1H, t, J = 7.5 Hz, H-13α), 2.65-2.57 (3H, m, H-6β,
H-25), 1.84 (1H, d, J = 9.0 Hz, H-1α), 1.56-1.40 (3H, m, H-26, H-6α), 1.38-1.24 (13H,
m, H-27, H-28, H-29, H-30, H-2, H-1β, H-12β, H-9β), 1.17-1.09 (2H, m, H-31), 1.03
(1H, d, J = 15.0 Hz, H-3β), 0.90-0.84 (6H, m, H-30, H-19), 0.80 (3H, s, H-18). 13C-
NMR (101 MHz, DMSO-d6) δ 206.20, 152.79, 147.35, 122.21, 116.41, 100.13, 69.94,
66.68, 65.79, 63.51, 57.76, 56.66, 50.14, 48.81, 42.98, 42.19, 40.84, 39.68, 34.11, 33.13,
31.77, 30.33, 29.47, 29.28, 29.15, 29.08, 25.59, 24.69, 22.57, 21.16, 18.14, 14.42. ESI-
HRMS: m/z cacld. For C32H49N3NaO5, [M+Na]+: 578.3570, found 578.3572.
23

4.2.3. synthesis of compound 5
Jiyuan Oridonin A (150 mg) was dissolved in THF (8 mL). Propargylbromide (150
µL) and p-TsOH (10 mg) were added to this solution. The mixture was stirred for 3 h at
room temperature. Then the mixture was treated by heric-vacuum distillation and
diluted with water and extracted with ethyl acetate. The extract was washed with brine,
dried over anhydrous Na2SO4, filtered, evaporated and the crude product was purified
by column chromatography to give compound 5.
4.2.3.1. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-11,14-dihydroxy-4,4-dimethyl-8-
methylene-12-(prop-2-yn-1-yloxy)decahydro-1H-6,11b-(epoxymethano)-6a,9-
methanocyclohepta[a]naphthalen-7(8H)-one (Compound 5)
White solid, 80% yield; Mp: 125-126℃; IR (KBr, cm-1): 3608, 3365, 3291, 2594,
2875, 1688, 1337, 1255, 1110, 1037, 990, 939, 952, 668; 1H-NMR (400 MHz, DMSO-
d6) δ 5.79, 5.36 (each 1H, s, H-17), 5.17 (1H, s, H-20), 5.03 (1H, d, J = 2.5 Hz, H-14-
OH), 4.62 (1H, s, H-14α), 4.50 (1H, d, J = 16.3 Hz, H-11α), 4.14 (1H, d, J = 7.1 Hz, H-
11-OH), 3.98 (1H, d, J = 2.9 Hz, H-7β), 3.81-3.73 (2H, m, H-21), 2.84 (1H, d, H-24),
2.79 (1H, d, J = 8.9 Hz, H-13α), 2.68 (1H, dd, J = 16.1, 6.7 Hz, H-6β), 2.62 (1H, dd, J =
16.1, 6.7 Hz, H-12α), 2.44 (2H, dd, J = 6.1, 4.1 Hz, H-22), 2.02 (1H, d, J = 12.9 Hz, H-
1α), 1.56 (1H, dd, J = 13.8, 4.6 Hz, H-6α), 1.50-1.42 (2H, m, H-2), 1.37-1.29 (3H, m,
H-3α, H-1β, H-12β), 1.27-1.15 (2H, m, H-5β, H-9β), 1.06 (1H, dd, J = 19.2 Hz, H-3β),
0.93 (3H, s, H-19), 0.82 (3H, s, H-18). 13C-NMR (101 MHz, DMSO-d6) δ 206.39,
152.92, 116.36, 99.64, 82.49, 72.24, 70.15, 65.88, 65.71, 63.56, 57.80, 56.86, 48.94,
43.07, 42.39, 40.92, 39.89, 34.18, 33.15, 30.40, 24.74, 21.18, 20.02, 18.29. ESI-HRMS:
m/z cacld. For C24H32NaO5, [M+Na]+: 423.2147, found 423.2143.
4.2.4. General procedure for the synthesis of Compound 7a-i
24

Compound 6a-i was put in the system of acetone with NaN3. The reaction mixture
was stirred for 7 h at 65 ℃ to obtain compound 7a-i. The structure confirmation of
compound 7a-i. were described in the Supplementary data.
4.2.5. General procedure for the synthesis of Compound 8a-i
Coumpound 5 (150 mg) and compound 7a-i were dissolved in THF (6 mL), then
put 3 mL H2O in the system. Finally, the mixture was stirred at room temperature for 6-
12 h by using CuSO4 (53 mg) and Cu (103 mg) as catalytic agents and then was filtered
and condensed. The residue was extracted with ethyl acetate. The organic layer was
washed with brine, dried over anhydrous Na2SO4, filtered, evaporated to afford the
crude product. The crude product was purified by column chromatography to give
Compound 8a-i.
4.2.5.1. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-(4-benzyl-1H-1,2,3-triazol-1-
yl)ethoxy)-11,14-dihydroxy-4,4-dimethyl-8-methylenedecahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (compound 8a)
White solid, 90% yield; Mp: 165-167 ℃; IR (KBr, cm-1): 3521, 3397, 3159, 2953,
2922, 2868, 1716, 1643, 1497, 1358, 1265, 1225, 1101, 1024, 799, 736; 1H-NMR (400
MHz, DMSO-d6) δ 7.91 (1H, s, H-24), 7.42-7.27 (5H, m, H-Ph), 5.78, 5.36 (each 1H, s,
H-17), 5.64-5.46 (2H, s, H-25), 5.12 (1H, s, H-20), 4.99 (1H, d, J = 2.6 Hz, H-14-OH),
4.49-4.24 (2H, m, H-14α, H-11α), 4.10 (1H, d, J = 7.0 Hz, H-11-OH), 3.98 (2H, q, J =
6.4 Hz, H-21), 3.59 (1H, dd, J = 16.2, 6.8 Hz, H-7β), 2.91 (2H, t, J = 6.5 Hz, H-22),
2.73 (1H, d, J = 9.0 Hz, H-13α), 2.65 (1H, t, J = 12.7 Hz, H-6β), 1.90 (1H, d, J = 6.9 Hz,
H-1α), 1.64-1.49 (1H, m, H-6α), 1.39 (1H, d, J = 12.6 Hz, H-3α), 1.26 (3H, t, J = 13.6
Hz, H-2, H-1β), 1.22-1.18 (1H, m, H-12β), 1.16 (2H, d, J = 9.3 Hz, H-5β, H-9β), 1.05
(1H, d, J = 11.4 Hz, H-3β), 0.90 (3H, s, H-19), 0.81 (3H, s, H-18). 13C-NMR (101 MHz,
25

DMSO-d6) δ 206.26, 152.87, 144.99, 136.64, 129.18, 128.48, 128.29, 122.92, 116.35,
99.77, 70.06, 67.19, 65.62, 63.58, 57.83, 56.78, 53.20, 48.90, 43.01, 42.32, 40.91, 39.76,
34.14, 33.16, 30.47, 26.79, 24.76, 21.19, 18.15. ESI-HRMS: m/z cacld. For
C31H39N3NaO5, [M+Na]+: 556.2787, found 556.2783.
4.2.5.2. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-11,14-dihydroxy-12-(2-(4-(4-
methoxybenzyl)-1H-1,2,3-triazol-1-yl)ethoxy)-4,4-dimethyl-8-methylenedecahydro-1H-
6,11b-(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound
8b)
White solid, 92% yield; Mp: 203-204 ℃; IR (KBr, cm-1): 3421, 2932, 1748, 1715,
1646, 1515, 1362, 1250, 1102, 1030, 667; 1H-NMR (400 MHz, DMSO-d6) δ 7.85 (1H, s,
H-24), 7.28 (2H, d, J = 8.4 Hz, H-27, H-31), 6.93 (2H, d, J = 8.4 Hz, H-28, H-30), 5.78,
5.35 (each 1H, s, H-17), 5.47 (2H, s, H-25), 5.11 (1H, s, H-20), 5.00 (1H, d, J = 2.4 Hz,
H-14-OH), 4.40-4.31 (2H, m, H-14α, H-11α), 4.12 (1H, d, J = 7.0 Hz, H-11-OH), 4.00-
3.92 (2H, m, H-21), 3.74 (3H, s, H-32), 3.56 (1H, dd, J = 15.7, 6.6 Hz, H-7β), 2.89 (2H,
t, J = 6.5 Hz, H-22), 2.75-2.68 (1H, m, H-13α), 2.64 (1H, t, J = 12.6 Hz, H-6β), 1.89
(1H, d, J = 7.5 Hz, H-1α), 1.58-1.45 (1H, m, H-6α), 1.39 (1H, d, J = 12.4 Hz, H-3α),
1.34-1.22 (4H, m, H-2, H-1β, H-12β), 1.19-1.12 (2H, m, H-5β, H-9β), 1.05 (1H, d, J =
7.6 Hz, H-3β), 0.89 (3H, s, H-19), 0.81 (3H, s, H-18). 13C-NMR (101 MHz, DMSO-d6)
δ 206.29, 159.56, 152.87, 144.94, 129.97, 128.53, 122.56, 116.36, 114.56, 99.76, 70.04,
67.20, 65.64, 63.56, 57.82, 56.75, 55.60, 52.76, 48.88, 42.99, 42.30, 40.88, 39.51, 34.14,
33.15, 30.49, 26.79, 24.75, 21.17, 18.13. ESI-HRMS: m/z cacld. For C32H41N3NaO6,
[M+Na]+: 586.2893, found 586.2883.
4.2.5.3. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-(4-(3,4-dichlorobenzyl)-1H-
1,2,3-triazol-1-yl)ethoxy)-11,14-dihydroxy-4,4-dimethyl-8-methylenedecahydro-1H-
26

6,11b-(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound
8c)
White solid, 93% yield; Mp: 170-171 ℃; IR (KBr, cm-1): 3355, 3147, 2948, 2865,
2101, 1720, 1643, 1473, 1361, 1264, 1223, 1104, 1033, 938, 778;1H-NMR (400 MHz,
DMSO-d6) δ 7.95 (1H, s, H-24), 7.64-7.42 (2H, m, H-27, H-31), 7.29 (1H, dd, J = 8.3
Hz, H-28), 5.78, 5.35 (each 1H, s, H-17), 5.59 (2H, s, H-25), 5.10 (1H, s, H-20), 4.99
(1H, d, J = 2.9 Hz, H-14-OH), 4.40-4.25 (2H, m, H-14α, H-11α), 4.10 (1H, d, J = 7.1
Hz, H-11-OH), 4.02-3.91 (2H, m, H-21), 3.58 (1H, dt, J = 9.5, 6.7 Hz, H-7β), 2.90-2.84
(2H, m, H-22), 2.76-2.66 (2H, m, H-6β, H-12α), 1.85 (1H, d, J = 7.5 Hz, H-1α), 1.60-
1.52 (1H, m, H-6α), 1.37 (1H, d, J = 12.7 Hz, H-3α), 1.24 (2H, dd, J = 16.6 Hz, H-2),
1.23-1.19 (3H, m, H-1β, H-12β, H-5β), 1.16-1.11 (1H, m, H-9β), 1.10-0.97 (1H, m, H-
3β), 0.88 (3H, s, H-19), 0.80 (3H, s, H-18). 13C-NMR (101 MHz, DMSO-d6) δ 206.29,
161.72, 159.27, 152.87, 144.99, 131.09, 131.06, 123.37, 123.02, 116.38, 116.14, 115.94,
99.75, 70.05, 67.15, 65.64, 63.56, 57.82, 56.75, 48.89, 40.02, 39.81, 39.60, 39.39, 34.14,
33.16, 30.47, 26.75, 24.75, 21.17, 18.12. ESI-HRMS: m/z cacld. For C31H37Cl2N3NaO5,
[M+Na]+: 624.2008, found 624.2001.
4.2.5.4. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-11,14-dihydroxy-4,4-dimethyl-8-
methylene-12-(2-(4-(4-nitrobenzyl)-1H-1,2,3-triazol-1-yl)ethoxy)decahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 8d)
White solid, 91% yield; Mp: 205-206 ℃; IR (KBr, cm-1): 3421, 2949, 2867, 1722,
1646, 1608, 1523, 1347, 1223, 1105, 734, 667; 1H-NMR (400 MHz, DMSO-d6) δ 8.23
(2H, d, J = 8.7 Hz, H-Ph), 7.98 (1H, s, H-24), 7.51 (2H, d, J = 8.7 Hz, H-Ph), 5.77, 5.34
(each 1H, s, H-17), 5.75 (2H, s, H-25), 5.10 (1H, s, H-20), 5.00 (1H, d, J = 2.8 Hz, H-
14-OH), 4.45-4.24 (2H, m, H-14α, H-11α), 4.11 (1H, d, J = 7.0 Hz, H-11-OH), 4.04-
27

3.93 (2H, m, H-21), 3.59 (1H, dt, J = 9.4, 6.6 Hz, H-7β), 2.98-2.86 (2H, m, H-22), 2.70
(1H, d, J = 9.0 Hz, H-6β), 2.64 (1H, t, J = 12.7 Hz, H-12α), 1.86 (1H, d, J = 7.5 Hz, H-
1α), 1.62-1.48 (1H, m, H-6α), 1.37 (1H, d, J = 12.4 Hz, H-3α), 1.25 (3H, dd, J = 16.6,
6.2 Hz, H-2, H-1β), 1.16-1.12 (3H, m, H-12β, H-5β, H-9β), 1.01 (1H, d, J = 8.7 Hz, H-
3β), 0.89 (3H, s, H-19), 0.80 (3H, s, H-18). 13C-NMR (101 MHz, DMSO-d6) δ 206.25,
152.85, 147.66, 145.26, 144.14, 129.39, 124.34, 123.38, 116.37, 99.78, 70.03, 67.16,
65.65, 63.60, 57.82, 56.73, 52.30, 48.86, 43.00, 42.28, 40.87, 39.71, 34.13, 33.14, 30.49,
26.77, 24.75, 21.17, 18.14. ESI-HRMS: m/z cacld. For C31H38N4NaO7, [M+Na]+:
601.2632, found 601.2631.
4.2.5.5. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-11,14-dihydroxy-4,4-dimethyl-8-
methylene-12-(2-(4-(3,4,5-trimethoxybenzyl)-1H-1,2,3-triazol-1-yl)ethoxy)decahydro-
1H-6,11b-(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one
(Compound 8e)
White solid, 90% yield; Mp: 228-229 ℃; IR (KBr, cm-1): 3446, 2939, 1722, 1646,
1593, 1507, 1463, 1423, 1362, 1242, 1126, 1020, 717; 1H-NMR (400 MHz, DMSO-d6)
δ 7.90 (1H, s, H-24), 6.70 (2H, s, H-Ph), 5.78, 5.35 (each 1H, s, H-17), 5.45 (H, s, H-
25), 5.11 (1H, s, H-20), 4.99 (1H, d, J = 2.8 Hz, H-14-OH), 4.47-4.25 (2H, m, H-14α,
H-11α), 4.11 (1H, d, J = 7.1Hz, H-11-OH), 4.07-3.90 (2H, m, H-21), 3.76 (6H, s, H-32,
H-34), 3.64 (3H, s, H-33), 2.99-2.80 (2H, m, H-22), 2.69 (1H, d, J = 9.1Hz, H-6β), 2.62
(1H, t, J = 12.6 Hz, H-12α), 1.87 (1H, d, J = 9.1 Hz, H-1α), 1.60-1.47 (1H, m, H-6α),
1.37 (1H, d, J = 12.4 Hz, H-3α), 1.31-1.10 (6H, m, H-2, H-1β, H-12β, H-5β, H-9β),
1.02 (1H, d, J = 8.8 Hz, H-3β), 0.89 (3H, s, H-19), 0.80 (3H, s, H-18). 13C-NMR (101
MHz, DMSO-d6) δ 206.30, 153.48, 152.87, 144.98, 137.82, 131.85, 122.66, 116.34,
106.31, 99.73, 70.03, 67.13, 65.64, 63.56, 60.42, 57.80, 56.72, 56.38, 53.53, 48.87,
28

42.98, 42.26, 40.88, 39.91, 34.13, 33.15, 30.50, 26.80, 24.73, 21.16, 18.06. ESI-HRMS:
m/z cacld. For C34H45N3O8, [M+Na]+: 646.3099, found 646.3098.
4.2.5.6. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-(4-(4-fluorobenzyl)-1H-1,2,3-
triazol-1-yl)ethoxy)-11,14-dihydroxy-4,4-dimethyl-8-methylenedecahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 8f)
White solid, 89% yield; Mp: 178-180 ℃; IR (KBr, cm-1): 3420, 2950, 2868, 1722,
1645, 1607, 1512, 1393, 1362, 1224, 1103, 1019, 934, 775; 1H-NMR (400 MHz,
DMSO-d6) δ 7.91 (1H, s, H-24), 7.37 (2H, dd, J = 8.2, 5.7 Hz, H-Ph), 7.20 (2H, t, J =
8.8 Hz, H-Ph), 5.78, 5.36 (each 1H, s, H-17), 5.55 (2H, s, H-25), 5.11 (1H, s, H-20),
5.01 (1H, d, J = 2.8 Hz, H-14-OH), 4.45-4.26 (2H, m, H-14α, H-11α), 4.12 (1H, d, J =
7.1Hz, H-11-OH), 4.01-3.90 (2H, m, H-21), 3.58 (1H, dd, J = 16.0, 6.6 Hz, H-7β), 2.90
(2H, t, J = 6.3 Hz, H-22), 2.71 (1H, d, J = 9.1Hz, H-6β), 2.64 (1H, t, J = 12.6 Hz, H-
12α), 1.87 (1H, d, J = 9.1 Hz, H-1α), 1.55 (1H, dd, J = 8.6, 5.7 Hz, H-6α), 1.39 (1H, d, J
= 12.4 Hz, H-3α), 1.22-1.17 (6H, m, H-2, H-1β, H-12β, H-5β, H-9β), 1.05 (1H, d, J =
9.2 Hz, H-3β), 0.89 (3H, s, H-19), 0.81 (3H, s, H-18). 13C-NMR (101 MHz, DMSO-d6)
δ 206.28, 152.86, 145.05, 122.85, 116.38, 99.76, 70.04, 67.16, 65.64, 63.57, 57.81,
56.74, 52.39 48.87, 42.99, 42.29, 40.88, 39.68, 34.14, 33.15, 30.48, 26.77, 24.74, 21.17,
18.13. ESI-HRMS: m/z cacld. For C31H38FN3NaO5, [M+Na]+: 574.2687, found
574.2683.
4.2.5.7. (4aR,6R,6aS,9S,11S,11aS,11bS,12S,14R)-12-(2-(4-(4-chlorobenzyl)-1H-1,2,3-
triazol-1-yl)ethoxy)-11,14-dihydroxy-4,4-dimethyl-8-methylenedecahydro-1H-6,11b-
(epoxymethano)-6a,9-methanocyclohepta[a]naphthalen-7(8H)-one (Compound 8g)
White solid, 94% yield; Mp: 180-181 ℃; IR (KBr, cm-1): 3419, 2949, 2867, 1722,
1644, 1493, 1362, 1266, 1222, 1103, 1078, 1016, 934, 769; 1H-NMR (400 MHz,
29