Design, synthesis, and biological activity evaluation of a series of pleuromutilin derivatives with novel C14 side chains

Article abstract of DOI:10.1016/j.bmcl.2020.126969

In this work, according to the ‘me-too me-better’ design strategy, a peculiar side chain different from lefamulin at C14 position of pleuromutilin was introduced. A series of novel thioether pleuromutilin derivatives containing cyclohexane in the C14 chain was synthesized by ten-step synthesis reaction. All derivatives were characterized by Nuclear Magnetic Resonance (NMR) and High Resolution Mass Spectrometer (HRMS). Furthermore, majority of derivatives displayed moderate antibacterial activity in vitro. However, the compound 2C and 2J exhibited comparable or superior antibacterial activity to lefamulin. The summarized structure-activity relationship not only made the variety of pleuromutilin derivatives more diverse, but also provided new ideas for its design and development.

Full text of DOI:10.1016/j.bmcl.2020.126969

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Design, Synthesis, and Biological Activity Evaluation of A series of Pleuromu-
tilin Derivatives with Novel C14 Side Chains
Yun-Ge Li, Ju-Xian Wang, Guo-Ning Zhang, Mei Zhu, Xue-Fu You, Yu-Cheng
Wang, Fan Zhang
PII:
S0960-894X(20)30022-6
DOI:
https://doi.org/10.1016/j.bmcl.2020.126969
BMCL 126969
Reference:
Bioorganic & Medicinal Chemistry Letters
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Accepted Date:
25 August 2019
4 January 2020
13 January 2020
Please cite this article as: Li, Y-G., Wang, J-X., Zhang, G-N., Zhu, M., You, X-F., Wang, Y-C., Zhang, F., Design,
Synthesis, and Biological Activity Evaluation of A series of Pleuromutilin Derivatives with Novel C14 Side Chains,
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Graphical Abstract
Design, Synthesis, and Biological Activity Evaluation of A series of Pleuromutilin Derivatives
with New C14 Side Chains
Yunge Li b, Yucheng Wang a*and Fan Zhang b,*
aInstitute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical
College, Beijing 100050, China
bSchool of Pharmacy, Jinzhou Medical University, Jinzhou 121001, P. R. China
O
O
O
O
S
OH
MIC=0.25μg/ml(MSSE)
MIC=0.5μg/ml(MRSE)
MIC=0.5μg/ml(MSSA)
MIC=0.25μg/ml(MRSA)
MIC=0.06μg/ml(VSE)
MIC=0.12μg/ml(VRE)
O
N
H
O
S
O
O
O
H
OH
O
H2N
O
S
Compound 2C
O
H
O
O
O
O
Compound K
MIC=0.25μg/ml(MSSE)
MIC=0.25μg/ml(MRSE)
MIC=1μg/ml(MSSA)
MIC=1μg/ml(MRSA)
MIC=0.25μg/ml(VSE)
MIC=0.25μg/ml(VRE)
O
S
OH
MIC=0.25μg/ml(MSSE)
MIC=0.25μg/ml(MRSE)
MIC=0.25μg/ml(MSSA)
MIC=0.25μg/ml(MRSA)
MIC=≤0.03μg/ml(VSE)
MIC=0.25μg/ml(VRE)
O
N
H
O
S
O
H
O
Compound 2J

Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com
Design, Synthesis, and Biological Activity Evaluation of A series of Pleuromutilin
Derivatives with Novel C14 Side Chains
Yun-Ge Li b, Ju-Xian Wang a, Guo-Ning Zhang a, Mei Zhu a, Xue-Fu You a, Yu-Cheng Wang a*and Fan
Zhang b*
a Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100050, China
b School of Pharmacy, Jinzhou Medical University, Jinzhou 121001, P. R. China
ARTICLE INFO
ABSTRACT
In this work, according to the ‘me-too me-better’ design strategy, a peculiar side chain
different from lefamulin at C14 position of pleuromutilin was introduced. A series of
novel thioether pleuromutilin derivatives containing cyclohexane in the C14 chain was
synthesized by ten-step synthesis reaction. All derivatives were characterized by Nuclear
Magnetic Resonance (NMR) and High Resolution Mass Spectrometer (HRMS).
Furthermore, majority of derivatives displayed moderate antibacterial activity in vitro..
However, the compound 2C and 2J exhibited comparable or superior antibacterial
activity to lefamulin. The summarized structure-activity relationship not only made the
variety of pleuromutilin derivatives more diverse, but also provided new ideas for its
design and development.
Keywords:
design
pleuromutilin derivatives
synthesis
antibacterial activity
structure-activity relationship
Antibiotics have experienced rapid development since the
discovery of penicillin.1 However, with the widespread use of
antibacterial drugs, multi-drug resistant bacteria infection have
become an increasingly serious social and medical problem.2
Therefore, effective antibacterial drugs with novel structure and
unique mechanism of actionare urgently needed to be
developed.3, 4
20
18
19
OH
O
12
13
11
R
22
17
H190
7
21
14
O
15
5
16
1
4
8
6
3
2
O
Pleuromutilin, constituted of 5−6−8 tricyclic carbon skeleton,
was a natural product, which was first discovered and isolated in
1951 from Pleurotus mutilus (Fr.) Sacc.and Pleurotus
Passeckerianus Pilat.5-7 Pleuromutilin displayed modest
antibacterial activity in vitro, but pleuromutilin derivatives
incorporating substituents in the C14 side chain usually were
more efficient against mycoplasmas and drug-resistant Gram-po
sitive bacteria, especially Staphylococcus aureus (MRSA),
penicillin-resistant Streptococcus pneumoniae (PRSP), and
H
S
R=
N
OH
N
S
O
Tiamulin
Pleuromutilin
Valnemulin
OH
N
S
S
S
8-11
methicillin-resistant Staphylococcus epidermidis (MRSE).5,
Retapamulin
BC-7013
H2N
To date, only three pleuromutilin derivatives have been marketed
： tiamulin, valnemulin, and retapamulin (Figure 1). Tiamulin
and Vlnemulin were used as veterinary drugs.12, 13 Retapamulin
was the first new topical antibacterial drug for human skin
infections developed by GlaxoSmithKline, which was approved
NH2
S
N
HO
Lefamulin
BC-3205
by FDA in April 200714, 15
.
Figure 1. Structures of pleuromutilin and its derivatives
The research on pleuromutilin and its derivatives has never
stopped. Many authors realized that the presence of thioether in
C-14 position could improve biological activity and enhance
water-solubility.18-20 BC-3205 and BC-7013 (Figure 1) were
pleuromutilin derivatives developed by Nabria Therapeutics,
which were used to treat acute skin and skin structure infections
(ABSSSI) and respiratory infections (RTI) caused by Gram-
positive bacteria. Sexual bacterial pneumonia (CABP) could be
The target of pleuromutilin and its derivatives was the
peptidyl transferase center (PTC) of the bacterial ribosome. The
extension of the ternary nucleus and the C14 side chain interfered
with the binding of the tRNA to the P-site and the A-site, thereby
blocking protein synthesis.16, 17

administered orally or intravenously, and Phase I clinical studies
have completed.21, 22 Lefamulin (Figure 1) was currently the most
promising pleuromutilin derivative. February this year, FDA has
accepted the New Drug Applications (NDAs) and both
applications have been granted priority review. In addition to
priority review, lefamulin has been granted Qualified Infectious
Disease Product (QIDP) and Fast Track designations by the
FDA.23
position of pleuromutilin. The hydroxyl group of lefamulin is
replaced by its electron isostere amino group. By comparing the
antibacterial activity of compounds J and K
，we found that
compound K has better antibacterial activity, so we modified it
further.
The synthetic route for compound K, J and 2A-2K were
showed in Scheme 1. Intermediate C was synthesized by a three-
steps reaction with pleuromutilin as starting material, which was
esterified by p-toluenesulfonyl chloride under basic conditions to
give compound A, followed by substitution with thioacetic acid
to afford compound B. Compound B was hydrolyzed with
hydrazine monohydrate to obtain Compound C. on the other
hand, the commercially available material (S)-cyclohex-3-ene-1-
carboxylic acid was treated with iodine and potassium iodide to
provide the iodolactone D, which was reated with sodium
hydroxide in alcohol to give compound E. The three-membered
ring of Compound E was opened with ammonia water, and then
the amino group was protected with di-tert-butyl dicarbonate to
afford compound F. Compound G was synthesized by compound
F with p-toluenesulfonyl chloride under basic conditions. The
important intermediate compound H was obtained by reation of
compound C and G under basic conditions. At the end, the final
products J, K and 2A-2K were sythesized from intermediate H
by hydrolysis, deprotection and condensation, respectively. All
O
O
OH
H2N
O
S
NH2
r
O
e
H
ett
me-too-me-b
OH
HO
O
O
S
K
O
H
O
OH
me-too-me-b
ett
e
r
O
Lefamulin
OH
H2N
O
S
O
H
O
J
Figure 2 me-too me-better designed strategy
1
Me-too refers to the original drug pluromutilin, while me-
better refers to further changes in the structure of the original
drug in the hope of obtaining a more active compound. Base on
‘me-too me-better’designed strategy, we focused on the chiral
thioether structure of lefamulin in this study. This study
introduced the core chiral structure of edoxaban at the C14
intermediates and final products were confirmed by HRMS, H
NMR and 13CNMR.
OH
OH
OH
OH
O
O
O
O
HO
TsO
HS
S
(c)
(a)
(b)
O
O
O
O
H
H
H
H
O
O
O
O
O
Pleuromutilin
C
B
A
(h)
O
O
O
O
O
O
O
O
COOH
O
(f)
(g)
(d)
(e)
Boc
Boc
N
H
N
H
(1S) -3- cyclohexene
-1-carboxylate acid
I
D
OTs
G
OH
F
E
O
OH
O
OH
Boc
OH
OH
N
H
O
H2N
O
(j)
S
S
O
O
H
H
O
O
(i)
O
O
I
J
Boc
OH
N
O
H
S
O
H
O
H
O
O
O
O
(k)
R
O
S
O
OH
OH
H2N
O
N
O
H
(l)
S
S
O
O
O
H
H
R
S
Cl
O
O
K
O
2A-2K
O
CH3
O
CH3
CF3
F
R=
H
O CH3
CH3
Cl
Br
NO2
CN
NH

Scheme 1. Synthesis of compound J, K and 2A-2K. Reagents and conditions: (a). TsCl, NaOH, t-butyl methyl ether/H2O, reflux, 1h. (b). Thioacetic acid, cesium
carbonate, DMF, rt. (c). 80% hydrazine monohydrate, DCM, Ar, rt. (d). NaHCO3, I, KI, 0-5℃. (e). NaOH (aq), EtOH. (f). Aqueous ammonia, 45℃. di-tert-butyl
dicarbonate, EtOH. (g). P-Toluenesulfonyl chloride, Et3N, DCM, rt. (h). Sodium ethoxide, THF, Ar, rt. (i). LiOH, MeOH, rt. (j). HCl (gas), DCM, rt. (k). HCl
(gas), DCM, rt. (l). DMAP, N-Ethyldiisopropylamine, DCM, Ar, rt.
Anti-gram-positive bacteria activity in vitro of compound J
、K and 2A-2K was evaluated with Lefamulin as the positive
control and the results were reported in Table 1 and Table 2,
respectively. In Table 1, Compound K was found to be
antibacterial activity of Compounds J and K, with MIC value of
0.25 μg/ml. Therefore, compound K was chosen as the lead
compound for further study. The amino group at C-14 side chain
of compound K was modified by substituted benzenesulfonyl to
generate compound 2A-2K.
significantly superior to Compound J by comparing the in vitro
O
R
OH
H2N
O
S
O
H
O
Table 1 Antibacterial activity of J and K against Gram-positive strains in vitro
MIC (μg/ml)
Compound R=
MSSE
2
MRSE
4
MSSA
MRSA
VSE
16
VRE
8
OH
J
32
1
32
1
O
K
0.25
0.25
0.25
0.25
MSSE, methicillin-sensitive Staphylococcus epidermidis ATCC 12228; MRSE, methicillin-resistant Staphylococcus epidermidis 16-5; MSSA,
methicillin-sensitive Staphylococcus aureus ATCC 29213; MRSA, methicillin-resistant Staphylococcus aureus ATCC 33591; VSE, vancomycin-
sensitive epidermidis 16-5; VRE, vancomycin- resistant epidermidis ATCC 700221.
O
O
R
O
S
OH
O
N
O
H
S
O
H
O
Table 2 In vitro antibacterial activity of 2A-2K against Gram-positive strains
MIC (μg/ml)
Compound R=
MSSE
0.5
MRSE
1
MSSA
MRSA
VSE
2
VRE
2
2A
2B
2C
2D
2E
2F
H
1
1
0.5
1
CH3
0.25
0.25
0.5
0.5
0.5
1
0.5
0.06
1
0.5
0.12
1
O CH3
F
0.5
1
0.25
1
Cl
0.5
0.5
1
1
0.5
1
1
1
Br
1
1
1
1
NO2
CN
2G
2H
0.5
0.5
0.5
1
1
2
2
0.25
1
1
0.25
0.25

CF3
CH3
2I
2J
1
64
64
64
32
32
0.25
0.25
0.25
0.25
≤0.03
0.25
O
O
CH3
2K
0.5
0.5
0.5
0.5
0.5
1
1
NH
≤0.03
Lefamulin
0.25
0.25
0.06
0.12
In Table 2, most of the derivatives exhibited potent
antibacterial activity in vitro against Gram-positive bacteria. In
particular, compound 2C had comparable antibacterial efficacy
to MRSA, VSE and VRE as the control lefamulin. In addition,
the inhibitory potency of compound 2J against MRSE and
MSSA was also comparable to that of lefamulin. The MIC
values of compound 2J for MRSA and VSE were 0.25μg/ml and
≤0.03μg/ml, respectively, which were better than that of
lefamulin.
process. Column chromatography: silica gel (100–200 mesh and
200–300 mesh; Qingdao Ocean Chemical Factory). 1HNMRand
13CNMR spectra were obtained on Bruker 600 MHz
spectrometer (Varian, Palo Alto, CA, USA) in DMSO-d6 or
CDCl3 solvents; Chemical shifts (δ) were expressed in parts per
million (ppm) relative to TMS (tetramethylsilane) as internal
standard, J in Hz. High-resolution mass spectra (HRMS) were
obtained using a MicrOTOF-Q II instrument from Bruker
(Billerica, MA, USA).
4.1.2. 14-O-({[(4-Methylphenyl)sulfonyl]oxy}acetyl)motilin
(A). Pleuromutilin (15.15 g, 40 mmol) and p-toluenesulfonyl
chloride (8.4 g, 44 mmol) were sequentially added to a mixed
solution of water (100 mL) and tert-butyl methyl ether (40 mL),
and then to the mixture Aqueous NaOH (10 N, 10 mL) was
added dropwise. The reaction mixture was stirred at reflux for 1
h and then cooled to rt. The reaction solution was washed with
water (100 mL) was diluted and stirred in an ice bath for 30 min,
filtered off with suction, washed with water (100 mL × 3) and
cold tert-butyl methyl ether (40 mL) and dried to give a white
powder. Yield: 92.6%. 1HNMR (600 MHz, CDCl3) δ 7.81 (d, J =
8.3 Hz, 2H), 7.35 (d, J = 8.1 Hz, 2H), 6.40 (dd, J = 17.4, 11.0
Hz, 1H), 5.76 (d, J = 8.5 Hz, 1H), 5.32 (d, J = 12.2 Hz, 1H),
5.19 (d, J = 18.8 Hz, 1H), 4.48 (s, 2H), 3.35 (d, J = 6.5 Hz, 1H),
2.45 (s, 3H), 2.28 (p, J = 6.9 Hz, 1H), 2.24 (d, J = 9.7 Hz, 1H),
2.18 (m, 1H), 2.10 – 2.02 (m, 2H), 1.75 (dd, J = 14.5, 2.8 Hz,
1H), 1.64 (m, 2H), 1.56 (s, 1H), 1.53 – 1.42 (m, 2H), 1.40 (s,
3H), 1.34 (dd, J = 14.3, 3.0 Hz, 1H), 1.25 (d, J = 16.1 Hz, 1H),
1.15 (s, 3H), 1.11 (m, 1H), 0.88 (d, J = 7.0 Hz, 3H), 0.62 (d, J =
7.1 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ 216.73 , 164.83,
145.28, 132.54, 138.67 , 129.89 , 128.06 , 117.35 , 74.49 , 70.26
, 65.02 , 57.99 , 45.36, 44.46 , 43.94, 41.80, 36.51 , 36.00 , 34.38
, 30.31 , 26.74 , 26.38 , 24.78 , 21.68, 16.51 , 14.74 , 11.47 ,
HRMS: calcd for C29H40O7S [M + Na]+ ： 555.2392 ， found:
555.2371.
The substituents on the para position on the benzene ring
were divided into electron-donating group and electron-
withdrawing group. The results in Table 2 displayed that when
the substituent was methoxy, amide or methyl, the antibacterial
activity of the corresponding derivative was sequentially
decreased. Therefore, it may be considered that the electron
donating ability of the substituent on the benzene ring was
weakened, and the antibacterial activity was lowered. When the
substituent was electron withdrawing group of trifluoromethyl ,
nitro, cyano or acyl, the antibacterial activity of the
corresponding compound was sequentially increased. The
compound in which the substituent was a strong electron
withdrawing group trifluoromethyl group has the worst
antibacterial activity. However, it may be similar to 2C in
structure, and 2J has the best activity. When the substituent on
the benzene ring is a halogen atom. Although the halogen atom
is a weak electron withdrawing group, it forms a P-π conjugate
with the benzene ring, so its activity is not much different.
In conclusions, a series of novel pleuromutilin derivatives
was designed, synthesized and tested for their anti-gram-positive
bacterial activity in vitro. Most of these derivatives displayed
moderate antibacterial activity. Among them, compound 2C and
2J showed comparable or superior antibacterial activity to
lefamulin. The structure-activity relationship obtained from the
results of antimicrobial activity: The stronger the electron
donating ability of the substituent on the para position of the
benzene ring, the better the antibacterial activity of the
derivative; the weaker the electron withdrawing ability of the
substituent on the para position of the benzene ring, the better the
antibacterial activity of the derivative. Which contains oxygen
and methyl 2C and 2J have similar structures and the best
activity. The summarized structure-activity relationship provided
some interesting clues for the exploration and development of
such pleuromutilin derivatives.
4.1.3. 14-O-[(acetylthio)acetyl] mutilin (B). Thioacetic acid
(0.89ml, 12.5 mmol) was added dropwise cesium carbonate
(2.12g, 6.5 mmol) in DMF (25ml) solution, stirred at room
temperature for 30 min.
A
solution of 14-O-({[(4-
methylphenyl)sulfonyl)oxy}acetyl) mutilin in DMF (25 ml) was
added dropwise to the above reaction and allowed to react at
room temperature. After completion of the reaction (confirmed
by TLC), 100 ml of water was added to the reaction, which was
extracted with EtOH (100 ml). The organic layer was washed
with saturated sodium bicarbonate (100ml), dried over
anhydrous sodium sulfate overnight. The crude mixture was
purified by column chromatography on silica to give a viscous
1
liquid product B 3.5g. Yield: 80.01%. H NMR (600 MHz,
General Information
CDCl3) δ 6.40 (dd, J = 17.2, 10.8 Hz, 1H), 5.67 (d, J = 8.5 Hz,
1H), 5.29 (d, J = 13.9 Hz, 3H), 5.15 (d, J = 17.4 Hz, 1H), 3.58 (s,
2H), 3.32 (d, J = 6.4 Hz, 1H), 2.34 (s, 3H), 2.27 (p, J = 8.7, 7.6
Hz, 1H), 2.17 (m, 2H), 2.07 (s, 1H), 2.06 – 1.99 (m, 1H), 1.73 (d,
J = 14.4 Hz, 1H), 1.61 (q, J = 11.7, 10.9 Hz, 3H), 1.49 (q, J =
Unless otherwise stated, all chemicals were obtained
commercially and were used without special treatment. Thin-
layerchromatography (TLC) analysis (silica gel 60 GF254
aluminum foil plate, Merck) was used to monitor the reaction

13.9, 12.8 Hz, 1H), 1.41 (s, 3H), 1.31 (t, J = 17.5 Hz, 2H), 1.13
(s, 3H), 1.09 (m, 1H), 0.84 (d, J = 6.9 Hz, 3H), 0.70 (d, J = 7.0
Hz, 3H). 13C NMR (151 MHz, CDCl3) δ 216.89 , 193.42 , 167.23
, 138.87 , 117.07 , 74.48 , 70.00 , 58.03 , 53.47 , 45.37 , 44.60 ,
43.92 , 41.81 , 36.66 , 35.93 , 34.39 , 32.13 , 30.34 , 30.03 ,
26.77 , 26.41 , 24.75 , 16.68 , 14.74 , 11.41 . HRMS: calcd for
C24H36O5S [M - H]-：435.2205，found: 435.2213.
(151 MHz, CDCl3) δ 174.39 , 60.02 , 51.36 , 50.33 , 37.60 ,
26.03 , 23.83 , 20.85 , 13.92 .HRMS: calcd for C9H14O3 [M +
Na]+：193.0841，found: 193.0845.
4.1.7. (1S, 3R, 4R)-3-((tert-butoxycarbonyl)amino)-4-hydroxy
cyclohexane-1-carboxylate ethyl (F). To (1S,3S,6R)-7-
oxabicyclo[4.1.0]heptane-3-carboxylate ethyl (17 g, 0.1 mmol)
was added 175 ml of aqueous ammonia and the reaction was
stirred at 45 °C. After completion of the reaction (confirmed by
TLC),concentrated in vacuo and then 175 ml of EtOH was
added. A solution of di-tert-butyl dicarbonate (44.0 g, 201
mmol) in ethanol(175ml) was added dropwise to the above
reaction and the reaction was stirred at room temperature. After
completion of the reaction (confirmed by 1H NMR),
concentrated in vacuo. Add 300 ml of water to the residue, and
the aqueous layer was extracted twice with EtOH (300 ml). The
organic phases were combined and dried over anhydrous sodium
sulfate. concentrated in vacuo and the residue was purified by
column chromatography on silica gel to give the white solid F
4.1.4. 14-O-[(mercapto)acetyl]motilin (C). 14-O-[(acetylthio)
acetyl]mutilin (3.0 g, 6.87 mmol) was dissolved in 30 mL
dichloromethane under argon. Then, 80% hydrazine
monohydrate (0.3 g, 1.05 mmol) was added dropwise to the
above reaction. The reaction was stirred at room temperature for
3 h. After completion of the reaction (confirmed by TLC).Then
concentrated in vacuo to dryness.The residue was purified by
column chromatography on silica gel to give a white solid C
2.2g. Yield: 81.5%. 1H NMR (600 MHz, CDCl3) δ 6.45 (dd, J =
17.4, 11.0 Hz, 1H), 5.72 (d, J = 8.4 Hz, 1H), 5.37 – 5.27 (m,
1H), 5.19 (d, J = 17.4 Hz, 1H), 3.35 (d, J = 6.4 Hz, 1H), 3.22 –
3.11 (m, 2H), 2.35 – 2.29 (m, 1H), 2.21 – 2.20 (m, 2H), 2.10 (s,
1H), 2.09 – 2.04 (m, 1H), 1.89 (t, J = 8.2 Hz, 1H), 1.76 (d, J =
14.5 Hz, 1H), 1.64 (q, J = 11.0 Hz, 2H), 1.54 (dd, J = 26.8, 13.0
Hz, 2H), 1.44 (s, 3H), 1.34 (dd, J = 25.2, 15.2 Hz, 2H), 1.16 (s,
3H), 1.11 (d, J = 14.0 Hz, 1H), 0.87 (d, J = 7.0 Hz, 3H), 0.72 (d,
J = 7.0 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ 216.94 , 169.25 ,
138.89 , 117.19 , 74.55 , 69.70 , 58.12 , 45.41 , 44.68 , 43.93 ,
41.78 , 36.72 , 35.97 , 34.42 , 30.38 , 27.20 , 26.79 , 26.37 ,
24.80 , 16.88 , 14.83 , 11.48 . HRMS: calcd for C22H34O4S [M -
H]-：393.2100，found: 393.2109.
1
16g. Yield:50.0% H NMR (600 MHz, CDCl3) δ 4.69 (s, 1H),
4.15 (m, 2H), 3.58 (s, 1H), 3.43 (t, J = 8.3 Hz, 1H), 2.62 (s, 1H),
2.31 (d, J = 12.7 Hz, 1H), 2.09 (d, J = 10.7 Hz, 1H), 1.86 (d, J =
10.1 Hz, 1H), 1.51 (s, 4H), 1.43 (s, 9H), 1.25 (t, J = 7.1 Hz, 3H).
13C NMR (151 MHz, Chloroform-d) δ 174.15 , 156.68 , 85.11,
79.82 , 72.92 , 60.53 , 38.64 , 29.75 , 27.33 , 24.60 , 14.17
.HRMS: calcd for C14H25NO5 [M + Na]+ ： 310.1630 ， found:
310.1644.
4.1.8. (1S, 3R, 4R)-3-((tert-butoxycarbonyl) amino)-4-(tosyloxy)
cyclohexane-1-carboxylate ethyl (G). Phenylsulfonyl chloride
(8.76 g, 46 mmol) and (1S, 3R, 4R)-3-((tert-
butoxycarbonyl)amino)-4-hydroxycyclohexane-1-carboxy late
ethyl (11 g, 38.3 mmol) were dissolved in 200 ml in methyl
chloride. 8 ml of triethylamine was added dropwise to the above
reaction at -5 ° C, and after 15 minutes of dropwise addition, the
temperature was raised to 25 °C. After completion of the
reaction (confirmed by 1H NMR), the reaction solution was
washed with citric 200ml 5%, washed with saturated sodium
bicarbonate, dried over anhydrous sodium sulfate. concentrated
in vacuo and the crude mixture was purified by column
chromatography on silica gel to give the white solid product G
8g. Yield: 60.0% 1H NMR (600 MHz, CDCl3) δ 7.81 (d, J = 8.1
Hz, 2H), 7.33 (d, J = 8.0 Hz, 2H), 4.55 (d, J = 29.6 Hz, 2H), 4.14
(q, J = 7.1 Hz, 2H), 3.78 – 3.70 (m, 1H), 2.53 (td, J = 7.7, 7.2,
4.1 Hz, 1H), 2.44 (s, 3H), 2.27 (d, J = 18.6 Hz, 1H), 1.96 (d, J =
13.0 Hz, 1H), 1.68 – 1.56 (m, 2H), 1.43 (s, 9H), 1.25 (t, J = 7.1
Hz, 3H). 13C NMR (151 MHz, Chloroform-d) δ 173.77, 154.74 ,
144.64, 134.08, 129.78 , 127.65 , 79.55, 60.64 , 49.29 , 37.78 ,
30.57 , 28.28 , 27.20, 26.99, 23.78 , 21.59, 14.16 . HRMS: calcd
for C21H31NO7S [M + Na]+：464.1719，found: 464.1734.
4.1.5. (1S, 4S, 5S)-4-iodo-6-oxabicyclo[3.2.1]octan-7-one (D).
250 ml of a NaHCO3 solution (15.2 g, 181 mmol) was added to
(S)-cyclohex-3-ene-1-carboxylic acid (7.6 g, 60.2 mmol) in an
ice bath (0-5 °C). After stirring to dissolve the suspension, 150
ml of an aqueous solution of KI (60 g, 361 mmol) and I (16.1 g,
63.3 mmol) was added. After completion of the reaction
(confirmed by TLC), 300 ml of dichloromethane was added and
the aqueous layer was extracted with CHCl2 (2×50 ml). The
organic layer was collected and washed with saturated Na2SO3
(250 ml), then dried over anhydrous MgSO4, the solvent was
evaporated in vacuo to give a white solid product D 13.05g.
Yield:86%, 1H NMR (600 MHz,CDCl3) δ 4.80 (s, 1H), 4.49 (s,
1H), 2.77 (d, J = 11.9 Hz, 1H), 2.65 (s, 1H), 2.40 (d, J = 21.2 Hz,
2H), 2.09 (d, J = 15.6 Hz, 1H), 1.97 – 1.70 (m, 2H).13C NMR
(151 MHz, CDCl3) δ 177.71 , 80.19 , 38.58 , 34.49 , 29.70 ,
23.80 , 23.11 . HRMS: calcd for C7H9IO2 [M + H]+ ：
252.9725，found: 252.9735.
4.1.6. (1S, 3S, 6R)-7-oxabicyclo[4.1.0]heptane-3-carboxylate
ethyl (E). (1S, 4S, 5S)-4-iodo-6-oxabicyclo[3.2.1]octan-7-one
(25.2 g, 0.1 mmol) was added to EtOH (250 ml) and stirred
rapidly to disperse in ethanol. Then 50 ml of an aqueous solution
of NaOH (4.0 g, 0.1 mmol) was added dropwise to the above
solution and the reaction was stirred at room temperature. After
completion of the reaction (confirmed by 1H NMR). The
reaction was concentrated at 40 ℃, the residue was added 300ml
of water, then extracted with 300 ml of dichloromethane layered,
aqueous layer was extracted once with 300 ml of methylene
chloride, the organic phases were combined and dried overnight
over Na2SO4, and concentrated in vacuo to give the product
4.1.9. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-tert-butoxycar
bonylamino-cyclohexyl-sulfanyl]acetyl}-mutilin (H). 14-O-
[(mercapto) acetyl] mutilin (C) (1.0 g, 2.53 mmol) and sodium
ethoxide (207 mg, 3.04 mmol) were dissolved in THF and stirred
for 30 min under argon protection. A solution of (1S, 3R, 4R)-3-
((tert-butoxycarbonyl) amino) - 4 - ( tosyloxy ) cyclohexane-1-
carboxylate ethyl (G) (1.3 g, 2.94 mmol) in THF was added
dropwise to the above reaction and the reaction was stirred at
room temperature. After completion of the reaction (confirmed
by TLC), the reaction was concentrated in vacuo and the residue
was added 30ml EtOH. The organic phase was washed with 30
ml of saturated sodium chloride and dried over anhydrous
sodium sulfate. The crude mixture was purified by column
1
Yellow liquid E 16.00g. Yield:94.0%, H NMR (600 MHz,
CDCl3) δ 3.88 (q, J = 7.1 Hz, 2H), 2.91 (s, 2H), 2.01 – 1.99 (m,
1H), 1.98 – 1.91 (m, 2H), 1.87 (dd, J = 15.2, 11.0 Hz, 1H), 1.56
(m, 1H), 1.43 – 1.28 (m, 2H), 1.01 (t, J = 7.2 Hz, 3H). 13C NMR

chromatography on silica gel to give the white solid product H
735 mg. Yield: 44.0% 1H NMR (600 MHz, CDCl3) δ 6.48 (dd, J
= 17.3, 11.0 Hz, 1H), 5.76 (d, J = 8.4 Hz, 1H), 5.35 (d, J = 11.0
Hz, 1H), 5.21 (d, J = 17.4 Hz, 1H), 4.70 (s, 1H), 4.13 – 4.01 (m,
3H), 3.75 (s, 1H), 3.36 (d, J = 6.5 Hz, 1H), 3.29 – 3.16 (m, 2H),
2.93 (s, 1H), 2.52 (s, 1H), 2.34 – 2.27 (m, 2H), 2.22 – 2.18 (m,
2H), 2.12 – 2.06 (m, 2H), 2.04 (s, 1H), 1.96 (td, J = 9.5, 4.3 Hz,
1H), 1.93 – 1.86 (m, 1H), 1.76 (s, 2H), 1.65 – 1.51 (m, 4H), 1.45
(d, J = 4.5 Hz, 12H), 1.39 – 1.32 (m, 2H), 1.26 (t, J = 7.1 Hz,
4H), 1.18 (s, 3H), 1.14 – 1.08 (m, 1H), 0.88 (d, J = 6.9 Hz, 3H),
0.74 (d, J = 6.9 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ 217.00 ,
174.24 , 168.99 , 154.94 , 139.21 , 117.21 , 74.67 , 69.22 , 60.58
, 60.38 , 58.23 , 49.76 , 46.71 , 45.47 , 44.81 , 43.92 , 41.77 ,
38.55 , 36.81 , 36.04 , 34.47 , 33.50 , 30.46 , 28.43 , 27.33 ,
26.87 , 26.39 , 25.15 , 24.87 , 21.05 , 16.84 , 14.93 , 14.24 ,
11.50 . HRMS: calcd for C36H57NO8S [M - H]- ： 662.3727 ，
found: 662.3720.
16.65 , 15.02 , 11.98 . HRMS: calcd for C29H45NO6S [M - H]-：
534.2890，found: 534.2879.
4.1.12. 14-O-{[(1R, 2R, 4S)-4- ethylacetate -2-amino-
sulfanyl]acetyl}-mutilin (K). 14-O-{[(1R, 2R, 4S)-4-ethylacetate-
2-tert-butoxycarbonylamino-cyclohexyl-sulfanyl]acetyl}-mutilin
(200 mg, 0.21 mmol) was dissolved in 5 mL DCM. Then, HCl
gas was passed through the above reaction for about 1.5 hours.
Suction filtration to give the white solid product K 100 mg.
Yield:58%. 1H NMR (600 MHz, CDCl3) δ 8.62 (s, 2H), 6.34 (dd,
J = 17.3, 11.0 Hz, 1H), 5.67 (d, J = 8.4 Hz, 1H), 5.45 (d, J = 10.9
Hz, 1H), 5.24 – 5.08 (m, 1H), 4.03 (q, J = 7.0 Hz, 2H), 3.37 (s,
1H), 3.33 – 3.24 (m, 2H), 3.18 (d, J = 16.7 Hz, 1H), 3.05 (t, J =
9.0 Hz, 1H), 2.79 (s, 1H), 2.67 – 2.61 (m, 1H), 2.27 – 2.22 (m,
1H), 2.20 – 2.06 (m, 2H), 2.04 – 1.92 (m, 5H), 1.67 (dd, J =
27.1, 14.3 Hz, 2H), 1.57 – 1.50 (m, 3H), 1.48 – 1.41 (m, 1H),
1.35 (s, 3H), 1.27 (t, J = 16.8 Hz, 2H), 1.16 (t, J = 7.0 Hz, 3H),
1.10 (s, 3H), 1.04 – 0.99 (m, 1H), 0.81 (d, J = 6.8 Hz, 3H), 0.61
(d, J = 7.0 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ 216.92 ,
173.76 , 170.68 , 138.59 , 117.91 , 74.63 , 70.41 , 60.73 , 58.06 ,
53.42 , 51.17 , 46.74 , 45.39 , 44.86 , 43.89 , 41.73 , 37.97 ,
36.65 , 35.95 , 34.42 , 32.51 , 30.72 , 30.38 , 28.45 , 26.84 ,
26.33 , 24.82 , 16.85 , 14.83 , 14.23 , 11.59 . HRMS: calcd for
C31H49NO6S [M - H]-：562.3201，found: 562.3169.
4.1.10. 14-O-{[(1R, 2R, 4S)-4-acetate-2-tert-butoxycarbony
lamino-cyclohexyl-sulfanyl]acetyl} mutilin (I). 14-O-{[(1R,
2R,4S)-4-ethylacetate-2-tert-butoxycarbonylamino-cyclohexyl-
sulfanyl]acetyl}mutilin (350 mg, 0.53 mmol) was dissolved in
10 mL MeOH. Then 1 ml of LiOH (80 mg, 1.95 mmol) was
added dropwise and the reaction was stirred at room temperature.
After completion of the reaction (confirmed by TLC), the
reaction was concentrated in vacuo and the residue was added
10ml DCM. The organic layer was washed twice with 20 ml of
water and dried over anhydrous sodium sulfate. The crude
mixture was purified by column chromatography on silica gel to
give the white solid product I 135 mg. Yield: 41%.1H NMR (600
MHz, DMSO-d6) δ 12.12 (s, 1H), 6.97 (d, J = 7.4 Hz, 1H), 6.13
(dd, J = 17.7, 11.2 Hz, 1H), 5.75 (s, 1H), 5.55 (d, J = 8.1 Hz,
1H), 5.11 – 5.00 (m, 2H), 4.52 (d, J = 5.2 Hz, 1H), 3.57 (s, 1H),
3.43 (t, J = 5.5 Hz, 1H), 3.36 – 3.30 (m, 3H), 3.23 (d, J = 15.0
Hz, 1H), 2.79 (s, 1H), 2.65 (s, 1H), 2.50 (s, 1H), 2.41 (s, 1H),
2.19 (t, J = 9.7 Hz, 2H), 2.00 – 1.92 (m, 2H), 1.91 (s, 1H), 1.70 –
1.59 (m, 3H), 1.51 (d, J = 4.6 Hz, 2H), 1.39 (s, 9H), 1.36 (s, 2H),
1.27 (dd, J = 28.6, 15.9 Hz, 5H), 1.06 (s, 3H), 1.04 – 0.98 (m,
1H), 0.94 – 0.84 (m, 1H), 0.83 (d, J = 6.9 Hz, 3H), 0.63 (d, J =
6.8 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 217.60 , 176.35,
168.88 , 155.34 , 141.20 , 115.63 , 70.09, 73.04 , 69.80 , 57.70 ,
55.33, 49.64 , 45.40 , 44.44 , 44.14 , 41.89 , 37.92 , 36.80 , 34.44
, 33.49 , 30.56 , 29.01 , 28.71 , 27.63 , 27.01 , 25.54 , 24.92 ,
21.49, 16.55 , 14.99 , 11.97 . HRMS: calcd for C34H53NO8S [M -
H]-：634.3414，found: 634.3420.
4.1.13 General Procedure for the Synthesis of 2A-2J
Derivatives
4.1.13.1.
sulfonamide-sulfanyl]acetyl}-mutilin (2A). 14-O-{[(1R, 2R, 4S)-
4-ethylacetate -2-amino-sulfanyl]acetyl}-mutilin (200mg,
14-O-{[(1R,
2R,
4S)-4-ethylacetate-2-benzene
0.36mmol), Phenylsulfonyl chloride (88mg, 0.5mmol) and
DMAP (43 mg, 0.35 mmol) was dissolved in 5 mL DCM under
argon. To the reaction, (140 mg, 1.08 mmol) was added
dropwise, and the mixture was reacted to completion at 25 °C.
The reaction solution was washed twice with 15 ml of water and
dried over anhydrous sodium sulfate. Column chromatography
1
gave a white solid product 180 mg.Yield:72%. H NMR (600
MHz, CDCl3) δ 7.90 (d, J = 8.0 Hz, 2H), 7.56 (t, J = 7.3 Hz, 1H),
7.49 (t, J = 7.6 Hz, 2H), 6.47 (dd, J = 17.4, 11.0 Hz, 1H), 5.72
(d, J = 8.5 Hz, 1H), 5.55 (s, 1H), 5.36 (d, J = 11.0 Hz, 1H), 5.28
(s, 1H), 5.21 (d, J = 17.4 Hz, 1H), 4.10 (q, J = 6.9 Hz, 2H), 3.35
(d, J = 6.4 Hz, 1H), 3.28 (s, 1H), 2.99 (s, 2H), 2.64 (s, 1H), 2.56
(s, 1H), 2.46 (d, J = 11.2 Hz, 1H), 2.32 (p, J = 6.8 Hz, 1H), 2.21
(dtd, J = 28.8, 19.3, 10.1 Hz, 3H), 2.11 – 2.06 (m, 2H), 1.98 –
1.93 (m, 1H), 1.90 – 1.85 (m, 1H), 1.79 – 1.74 (m, 1H), 1.64 (dt,
J = 18.9, 10.3 Hz, 3H), 1.55 (dd, J = 32.5, 12.4 Hz, 4H), 1.43 (s,
3H), 1.38 – 1.33 (m, 1H), 1.29 (d, J = 16.1 Hz, 1H), 1.23 (t, J =
6.8 Hz, 3H), 1.18 (s, 3H), 1.12 (td, J = 14.1, 4.1 Hz, 1H), 0.87 (d,
J = 6.9 Hz, 3H), 0.67 (d, J = 7.0 Hz, 3H). 13C NMR (151 MHz,
CDCl3) δ 216.98 , 173.93 , 169.03 , 139.86 , 138.96 , 132.63 ,
128.98 , 127.30 , 117.43 , 74.55 , 69.70 , 60.57 , 58.08 , 52.77 ,
48.20 , 45.41 , 44.81 , 43.91 , 41.71 , 38.16 , 36.66 , 35.96 ,
34.42 , 33.69 , 30.37 , 28.32 , 26.85 , 26.31 , 25.70 , 24.79 ,
21.03 , 16.84 , 14.84 , 14.21 , 11.50 . HRMS: calcd for
C37H53NO8S2 [M - H]-：702.3135，found: 702.3126.
4.1.11. 14-O-{[(1R, 2R, 4S)-4-acetate-2-amino-sulf anyl]acetyl}-
mutilin
(J).
14-O-{[(1R,
2R,
4S)-4-acetate-2-tert-
butoxycarbonylamino-cyclohexyl-sulfanyl]acetyl} -mutilin (135
mg, 0.21 mmol) was dissolved in 5 mL DCM. Then, HCl gas
was passed through the above reaction for about 1.5 hours.
Suction filtration to give a white solid product J 60 mg. Yield:
1
53%. H NMR (600 MHz, DMSO) δ 8.23 (s, 2H), 6.15 (dd, J =
17.7, 11.2 Hz, 1H), 5.76 (s, 1H), 5.57 (d, J = 8.3 Hz, 1H), 5.12 –
5.05 (m, 2H), 3.53 (d, J = 15.7 Hz, 1H), 3.46 – 3.43 (m, 1H),
3.35 (d, J = 15.7 Hz, 1H), 3.21 (s, 1H), 2.99 – 2.89 (m, 1H), 2.84
– 2.72 (m, 1H), 2.43 (s, 1H), 2.29 – 2.16 (m, 2H), 2.09 – 1.99
(m, 4H), 1.83 (d, J = 7.6 Hz, 1H), 1.65 – 1.62 (m, 3H), 1.60 –
1.47 (m, 3H), 1.38 (s, 3H), 1.35 – 1.22 (m, 4H), 1.07 (s, 3H),
1.02 (td, J = 14.0, 4.0 Hz, 1H), 0.83 (d, J = 6.9 Hz, 3H), 0.64 (d,
J = 7.0 Hz, 3H). 13C NMR (151 MHz, DMSO) δ 217.59 , 175.61
, 168.99 , 141.24 , 115.73 , 72.98 , 70.26 , 57.65 , 55.36 , 50.42 ,
45.40 , 44.50 , 44.13 , 41.93 , 37.34 , 36.87 , 36.78 , 34.44 ,
33.69 , 30.55 , 29.94 , 28.99 , 28.37 , 27.03 , 26.02 , 24.91 ,
4.1.13.2. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-p-toluenesul
fonamide-sulfanyl]acetyl}-mutilin (2B). Compound 2B was
prepared according to the general procedure from 14-O-{[(1R,
2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-mutilin(K)
and P-toluenesulfonyl chloride. The crude product was purified
over silica gel column chromatography to give white solid 200

mg.Yield：78%. 1H NMR (600 MHz, CDCl3) δ 7.79 (d, J = 8.0
Hz, 2H), 7.30 (d, J = 7.9 Hz, 2H), 6.49 (dd, J = 17.4, 11.0 Hz,
1H), 5.75 (d, J = 8.5 Hz, 1H), 5.42 – 5.32 (m, 2H), 5.23 (d, J =
17.4 Hz, 1H), 4.12 (q, J = 7.1 Hz, 2H), 3.37 (d, J = 6.5 Hz, 1H),
3.26 (s, 1H), 3.01 (s, 2H), 2.65 (s, 1H), 2.57 (s, 1H), 2.50 (d, J =
12.3 Hz, 1H), 2.42 (s, 3H), 2.33 (q, J = 7.1 Hz, 1H), 2.23 – 2.19
(m, 2H), 2.10 (q, J = 8.4 Hz, 2H), 2.00 – 1.94 (m, 1H), 1.94 –
1.87 (m, 1H), 1.81 – 1.75 (m, 1H), 1.70 – 1.60 (m, 4H), 1.57 –
1.49 (m, 3H), 1.45 (s, 3H), 1.40 – 1.35 (m, 1H), 1.31 (d, J = 16.1
Hz, 1H), 1.25 (t, J = 7.1 Hz, 4H), 1.20 (s, 3H), 1.14 – 1.10 (m,
1H), 0.89 (d, J = 7.0 Hz, 3H), 0.69 (d, J = 7.0 Hz, 3H). 13C NMR
(151 MHz, CDCl3) δ 216.93 , 173.92 , 169.01 , 143.39 , 138.94 ,
136.82 , 129.58 , 127.39 , 117.47 , 74.57 , 69.69 , 60.57 , 58.10 ,
52.69 , 48.25 , 45.42 , 44.82 , 43.91 , 41.72 , 38.20 , 36.67 ,
35.96 , 34.42 , 33.60 , 32.83 , 30.38 , 28.38 , 26.86 , 26.28 ,
25.78 , 24.80 , 21.55 , 16.84 , 14.85 , 14.21 , 11.50 . HRMS:
calcd for C38H55NO8S2 [M - H]-：716.3291，found: 716.3297.
48.61 , 45.41 , 44.84 , 43.93 , 41.71 , 38.28 , 36.63 , 35.95 ,
34.41 , 33.78 , 31.47 , 30.36 , 28.90 , 26.87 , 26.28 , 26.08 ,
24.78 , 16.85 , 14.81 , 14.21 , 11.49 . HRMS: calcd for
C37H52FNO8S2 [M - H]-：720.3040，found: 720.3044.
4.1.13.5. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-P-chlorobenzene
sulfonamide-sulfanyl]acetyl}-mutilin (2E). Compound 2D was
prepared according to the general procedure from 14-O-{[(1R,
2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-mutilin(K)
and P-chlorobenzenesulfonyl chloride. The crude product was
purified over silica gel column chromatography to give white
solid 195 mg.Yield：73%. 1H NMR (600 MHz, CDCl3) δ 7.84
(d, J = 8.4 Hz, 2H), 7.47 (d, J = 8.4 Hz, 2H), 6.50 (dd, J = 17.4,
11.0 Hz, 1H), 5.75 (d, J = 8.5 Hz, 1H), 5.66 (s, 1H), 5.39 (d, J =
11.0 Hz, 1H), 5.31 – 5.20 (m, 2H), 4.12 (qt, J = 7.6, 3.8 Hz, 2H),
3.36 (d, J = 6.5 Hz, 1H), 3.25 (s, 1H), 3.06 (s, 2H), 2.57 (dd, J =
26.0, 10.9 Hz, 3H), 2.32 – 2.29 (m, 1H), 2.22 – 2.19 (m, 2H),
2.10 (t, J = 12.3 Hz, 2H), 2.01 – 1.92 (m, 2H), 1.80 – 1.75 (m,
1H), 1.66 (q, J = 11.2 Hz, 2H), 1.59 – 1.50 (m, 4H), 1.44 (s, 3H),
1.40 – 1.35 (m, 1H), 1.30 (d, J = 16.2 Hz, 1H), 1.25 (t, J = 7.1
Hz, 3H), 1.19 (s, 3H), 1.13 – 1.10 (m, 1H), 0.89 (d, J = 7.0 Hz,
3H), 0.68 (d, J = 7.0 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ
216.88 , 173.81 , 169.33 , 139.02 , 138.95 , 138.35 , 129.18 ,
128.90 , 117.54 , 74.54 , 69.94 , 60.63 , 58.06 , 53.02 , 48.72 ,
45.41 , 44.85 , 43.93 , 41.71 , 38.29 , 36.63 , 35.95 , 34.42 ,
33.82 , 33.50 , 30.36 , 29.02 , 26.88 , 26.28 , 26.15 , 24.79 ,
16.87 , 14.82 , 14.22 , 11.51 . HRMS: calcd for C37H52ClNO8S2
[M - H]-：736.2745，found: 736.2726.
4.1.13.3. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-p-methoxy
benzenesulfonamide-sulfanyl]acetyl}-mutilin (2C). Compound
2C was prepared according to the general procedure from 14-O-
{[(1R, 2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-
mutilin(K) and P-methoxybenzenesulfonyl chloride. The crude
product was purified over silica gel column chromatography to
1
give white solid 210 mg.Yield ： 80%. H NMR (600 MHz,
CDCl3) δ 7.84 (d, J = 8.6 Hz, 2H), 6.97 (d, J = 8.4 Hz, 2H), 6.49
(dd, J = 17.4, 11.0 Hz, 1H), 5.74 (d, J = 8.5 Hz, 1H), 5.45 (s,
1H), 5.37 (d, J = 11.0 Hz, 1H), 5.31 (s, 1H), 5.23 (d, J = 17.4 Hz,
1H), 4.12 (q, J = 6.7 Hz, 2H), 3.87 (s, 3H), 3.37 (d, J = 6.5 Hz,
1H), 3.27 (s, 1H), 3.04 (s, 2H), 2.68 (s, 1H), 2.58 (s, 1H), 2.53 –
2.41 (m, 1H), 2.34 (p, J = 6.8 Hz, 1H), 2.23 – 2.20 (m, 2H), 2.14
– 2.07 (m, 2H), 2.05 (s, 1H), 2.01 – 1.95 (m, 1H), 1.92 – 1.86
(m, 1H), 1.78 (d, J = 14.3 Hz, 1H), 1.66 (p, J = 13.5, 12.7 Hz,
4H), 1.55 (dd, J = 14.4, 3.9 Hz, 2H), 1.45 (s, 3H), 1.38 (d, J =
14.1 Hz, 1H), 1.32 (d, J = 16.1 Hz, 1H), 1.26 (q, J = 6.9, 6.2 Hz,
4H), 1.20 (s, 3H), 1.14 (td, J = 14.3, 4.4 Hz, 1H), 0.89 (d, J = 6.9
Hz, 3H), 0.70 (d, J = 7.0 Hz, 3H). 13C NMR (151 MHz,
Chloroform-d) δ 216.98 , 173.99 , 168.99 , 162.83 , 138.95 ,
131.46 , 129.45 , 117.41 , 114.10 , 74.55 , 69.67 , 60.55 , 60.36 ,
58.09 , 55.55 , 53.43 , 52.63 , 48.11 , 45.41 , 44.79 , 43.90 ,
41.71 , 38.13 , 36.67 , 35.95 , 34.42 , 33.71 , 30.37 , 26.85 ,
26.30 , 24.79 , 21.02 , 16.82 , 14.83 , 14.20 , 11.49 . HRMS:
calcd for C38H55NO9S2 [M - H]-：732.3240，found: 732.3219.
4.1.13.6. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-p-bromobenzene
sulfonamide-sulfanyl]acetyl}-mutilin (2F). Compound 2E was
prepared according to the general procedure from 14-O-{[(1R,
2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-mutilin(K)
and P-bromobenzenesulfonyl chloride. The crude product was
purified over silica gel column chromatography to give white
solid 200 mg.Yield：72%. 1H NMR (600 MHz, CDCl3) δ 7.77
(d, J = 8.4 Hz, 2H), 7.62 (d, J = 8.4 Hz, 2H), 6.48 (dd, J = 17.3,
11.0 Hz, 1H), 5.82 (s, 1H), 5.73 (d, J = 8.4 Hz, 1H), 5.36 (d, J =
10.9 Hz, 1H), 5.30 – 5.18 (m, 1H), 4.12 – 4.08 (m, 2H), 3.36 (d,
J = 6.1 Hz, 1H), 3.29 (s, 1H), 3.09 – 3.02 (m, 2H), 2.60 (d, J =
20.6 Hz, 2H), 2.46 (d, J = 10.9 Hz, 1H), 2.32 (p, J = 7.7, 7.0 Hz,
1H), 2.20 – 2.15 (m, 2H), 2.12 – 2.06 (m, 2H), 2.02 (s, 2H), 1.97
(dd, J = 11.7, 5.3 Hz, 1H), 1.93 – 1.87 (m, 1H), 1.77 (d, J = 14.1
Hz, 1H), 1.65 (q, J = 11.2, 10.7 Hz, 2H), 1.57 – 1.49 (m, 4H),
1.43 (s, 3H), 1.36 (d, J = 13.8 Hz, 1H), 1.29 (d, J = 16.1 Hz, 1H),
1.24 (t, J = 7.1 Hz, 4H), 1.18 (s, 3H), 1.12 – 1.09 (m, 1H), 0.88
(d, J = 6.9 Hz, 3H), 0.68 (d, J = 7.0 Hz, 3H). 13C NMR (151
MHz, CDCl3) δ 216.95 , 173.88 , 171.12 , 169.29 , 138.97 ,
132.16 , 128.94 , 127.46 , 117.42 , 74.52 , 69.86 , 60.60 , 60.36 ,
58.05 , 52.96 , 48.47 , 45.40 , 44.81 , 43.92 , 41.70 , 38.17 ,
36.63 , 35.95 , 34.41 , 33.91 , 30.35 , 26.86 , 26.33 , 25.84 ,
24.78 , 21.02 , 16.85 , 14.82 , 14.21 , 11.50 . HRMS: calcd for
C37H52BrNO8S2 [M + H]+：782.2396，found: 782.2221.
4.1.13.4.
14-O-{[(1R,
2R,
4S)-4-ethylacetate-2-P-fluoro
benzenesulfonamide-sulfanyl]acetyl}-mutilin (2D). Compound
2C was prepared according to the general procedure from 14-O-
{[(1R, 2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-
mutilin(K) and P-fluorobenzenesulfonyl chloride. The crude
product was purified over silica gel column chromatography to
1
give white solid 190 mg.Yield ： 74%. H NMR (600 MHz,
CDCl3) δ 8.06 – 7.92 (m, 2H), 7.24 – 7.11 (m, 2H), 6.51 (dd, J =
17.4, 11.0 Hz, 1H), 5.75 (d, J = 8.5 Hz, 1H), 5.66 (s, 1H), 5.40
(dd, J = 10.9, 1.6 Hz, 1H), 5.24 (dd, J = 17.4, 1.6 Hz, 1H), 4.13 –
4.19 (m, 2H), 3.37 (d, J = 6.5 Hz, 1H), 3.27 – 3.24 (m, 1H), 3.06
(s, 2H), 2.97 (s, 1H), 2.89 (s, 1H), 2.61 (s, 2H), 2.54 (d, J = 13.0
Hz, 1H), 2.38 – 2.32 (m, 2H), 2.23 – 2.19 (m, 2H), 2.14 – 2.08
(m, 2H), 2.02 – 1.94 (m, 2H), 1.79 (d, J = 14.4 Hz, 1H), 1.71 –
1.64 (m, 2H), 1.61 – 1.50 (m, 4H), 1.45 (s, 4H), 1.41 – 1.36 (m,
1H), 1.31 (d, J = 16.1 Hz, 1H), 1.26 (t, J = 7.1 Hz, 3H), 1.20 (s,
3H), 1.14 – 1.10 (m, 1H), 0.90 (d, J = 7.0 Hz, 3H), 0.69 (d, J =
7.0 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ 216.88 , 173.85 ,
169.25 , 165.85 , 164.16 , 138.97 , 130.15 , 130.09 , 117.50 ,
116.18 , 116.03 , 77.22 , 74.54 , 69.89 , 60.61 , 58.06 , 52.96 ,
4.1.13.7. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-p-nitrobenzene
sulfonamide-sulfanyl]acetyl}-mutilin (2G). Compound 2F was
prepared according to the general procedure from 14-O-{[(1R,
2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-mutilin(K)
and P-nitrobenzenesulfonyl chloride. The crude product was
purified over silica gel column chromatography to give white
solid 160 mg.Yield：60%. 1H NMR (600 MHz, CDCl3) δ 8.31
(d, J = 8.7 Hz, 2H), 8.08 (d, J = 8.7 Hz, 2H), 6.52 (dd, J = 17.4,
11.0 Hz, 1H), 6.20 (s, 1H), 5.74 (d, J = 8.5 Hz, 1H), 5.42 (d, J =

11.0 Hz, 1H), 5.24 (d, J = 17.3 Hz, 1H), 4.15 – 4.07 (m, 2H),
3.36 (d, J = 6.4 Hz, 1H), 3.26 (s, 1H), 3.08 (s, 2H), 2.67 – 2.57
(m, 2H), 2.45 (s, 1H), 2.36 – 2.27 (m, 2H), 2.20 – 2.15 (m, 2H),
2.10 (q, J = 8.4 Hz, 2H), 2.03 – 1.94 (m, 3H), 1.80 – 1.75 (m,
1H), 1.65 (q, J = 10.9, 10.4 Hz, 2H), 1.49 – 1.44 (m, 4H), 1.42
(s, 3H), 1.39 – 1.34 (m, 1H), 1.24 (p, J = 7.4, 6.8 Hz, 4H), 1.19
(s, 3H), 1.12 (td, J = 14.2, 4.3 Hz, 1H), 0.88 (d, J = 7.0 Hz, 3H),
0.66 (d, J = 7.0 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ 216.81 ,
173.75 , 169.82 , 149.91 , 145.60 , 138.99 , 128.76 , 124.07 ,
117.60 , 74.51 , 70.35 , 60.69 , 60.37 , 57.98 , 53.48 , 49.35 ,
45.40 , 44.89 , 43.98 , 41.70 , 38.39 , 36.56 , 35.94 , 34.40 ,
34.18 , 30.32 , 29.82 , 26.90 , 26.59 , 26.31 , 24.76 , 16.91 ,
14.77 , 14.23 , 11.50 . HRMS: calcd for C37H52N2O10S2 [M -
H]-：747.2895，found: 747.2974.
3.1.13.10. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-p-acetylbenzene
sulfonamide-sulfanyl]acetyl}-mutilin (2J). Compound 2I was
prepared according to the general procedure from 14-O-{[(1R,
2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-mutilin(K)
and P-acetylbenzenesulfonyl chloride. The crude product was
purified over silica gel column chromatography to give white
solid 160 mg.Yield：60%.1H NMR (600 MHz, CDCl3) δ 8.05
(d, J = 8.2 Hz, 2H), 7.99 (d, J = 8.2 Hz, 2H), 6.49 (dd, J = 17.4,
11.0 Hz, 1H), 5.93 (s, 1H), 5.73 (d, J = 8.5 Hz, 1H), 5.38 (d, J =
11.0 Hz, 1H), 5.34 – 5.18 (m, 2H), 4.13 – 4.08 (m, 2H), 3.36 (d,
J = 6.4 Hz, 1H), 3.29 (s, 1H), 3.06 (d, J = 3.4 Hz, 2H), 2.64 (s,
3H), 2.62 – 2.56 (m, 2H), 2.51 (d, J = 12.5 Hz, 1H), 2.32 (p, J =
7.0 Hz, 1H), 2.21 – 2.19 (m, 2H), 2.09 (q, J = 8.6, 7.9 Hz, 2H),
2.02 (s, 1H), 2.00 – 1.91 (m, 2H), 1.77 (d, J = 12.8 Hz, 1H), 1.64
(dd, J = 13.6, 7.0 Hz, 2H), 1.56 – 1.50 (m, 3H), 1.42 (s, 3H),
1.40 – 1.34 (m, 1H), 1.29 (d, J = 16.1 Hz, 1H), 1.24 (d, J = 7.1
Hz, 3H), 1.19 (s, 3H), 1.16 – 1.08 (m, 1H), 0.88 (d, J = 7.0 Hz,
3H), 0.67 (d, J = 7.0 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ
216.92 , 196.86 , 173.83 , 169.36 , 143.85 , 139.81 , 138.97 ,
128.76 , 127.66 , 117.46 , 74.52 , 69.98 , 60.62 , 60.36 , 58.03 ,
53.15 , 48.72 , 45.40 , 44.84 , 43.93 , 41.70 , 38.25 , 36.61 ,
35.94 , 34.40 , 33.96 , 30.34 , 28.93 , 26.86 , 26.33 , 26.06 ,
24.77 , 21.02 , 16.86 , 14.80 , 14.21 , 11.49 . HRMS: calcd for
C39H55NO9S2 [M - H]-：744.3240，found: 744.3212.
4.1.13.8. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-p-cyanobenzene
sulfonamide-sulfanyl]acetyl}-mutilin (2H). Compound 2G was
prepared according to the general procedure from 14-O-{[(1R,
2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-mutilin(K)
and P-cyanobenzenesulfonyl chloride. The crude product was
purified over silica gel column chromatography to give white
solid 180 mg.Yield：70%. 1H NMR (600 MHz, CDCl3) δ 8.00
(d, J = 3.3 Hz, 2H), 7.77 (d, J = 8.0 Hz, 2H), 6.54 – 6.39 (m,
2H), 5.73 (d, J = 8.5 Hz, 1H), 5.38 (d, J = 11.0 Hz, 1H), 5.31 –
5.18 (m, 2H), 4.11 (p, J = 6.9 Hz, 2H), 3.36 (d, J = 6.4 Hz, 1H),
3.29 (s, 1H), 3.13 – 3.03 (m, 2H), 2.65 – 2.60 (m, 1H), 2.55 (s,
1H), 2.48 (d, J = 13.2 Hz, 1H), 2.34 – 2.26 (m, 2H), 2.20-2.23
(m, 2H), 2.09 (q, J = 8.7 Hz, 2H), 2.01 – 1.90 (m, 3H), 1.77 (d, J
= 12.6 Hz, 1H), 1.65 (q, J = 11.8, 10.9 Hz, 2H), 1.52 – 1.49 (m,
4H), 1.39 – 1.34 (m, 1H), 1.28 (d, J = 16.2 Hz, 1H), 1.24 (t, J =
7.0 Hz, 3H), 1.18 (s, 3H), 1.12 – 1.09 (m, 1H), 0.88 (d, J = 7.0
Hz, 3H), 0.67 (d, J = 7.0 Hz, 3H). 13C NMR (151 MHz, CDCl3) δ
216.86 , 173.85 , 169.56 , 162.57 , 144.39 , 139.04 , 132.66 ,
128.02 , 117.46 , 116.02 , 74.48 , 70.12 , 60.61 , 58.01 , 53.35 ,
48.92 , 45.39 , 44.85 , 43.95 , 41.70 , 38.24 , 36.58 , 36.50 ,
35.95 , 34.40 , 34.16 , 31.43 , 30.32 , 26.88 , 26.37 , 26.17 ,
24.75 , 16.87 , 14.79 , 14.21 , 11.48 . HRMS: calcd for
C38H52N2O8S2 [M - H]-：727.3081，found: 727.3053.
4.1.13.11. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-p-acetamidoben
zenesulfonamide-sulfanyl]acetyl}mutilin (2K). Compound 2J was
prepared according to the general procedure from 14-O-{[(1R,
2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-mutilin(K)
and P-acetamidobenzenesulfonyl chloride. The crude product
was purified over silica gel column chromatography to give
white solid 170 mg.Yield：63%. 1H NMR (600 MHz, CDCl3) δ
8.18 (s, 1H), 7.80 (d, J = 8.6 Hz, 2H), 7.69 (d, J = 8.2 Hz, 2H),
6.47 (dd, J = 17.4, 11.0 Hz, 1H), 5.77 – 5.67 (m, 2H), 5.36 (d, J
= 11.0 Hz, 1H), 5.30 (s, 1H), 5.22 (d, J = 17.4 Hz, 1H), 4.11 (q, J
= 7.1 Hz, 2H), 3.37 (d, J = 6.2 Hz, 1H), 3.28 (s, 1H), 3.08 (q, J =
15.6 Hz, 2H), 2.71 – 2.64 (m, 1H), 2.59 (s, 1H), 2.44 (d, J = 11.9
Hz, 1H), 2.36 – 2.28 (m, 1H), 2.20 (s, 3H), 2.13 – 2.06 (m, 2H),
2.03 – 1.94 (m, 2H), 1.90 (d, J = 11.7 Hz, 1H), 1.77 (d, J = 12.9
Hz, 1H), 1.69 – 1.61 (m, 2H), 1.59 – 1.49 (m, 4H), 1.43 (d, J =
6.1 Hz, 3H), 1.36 (d, J = 12.1 Hz, 1H), 1.31 (d, J = 16.1 Hz, 1H),
1.24 (t, J = 7.1 Hz, 3H), 1.18 (s, 3H), 1.12 – 1.09 (m, 1H), 0.88
(d, J = 6.9 Hz, 3H), 0.69 (d, J = 7.0 Hz, 3H). 13C NMR (151
MHz, CDCl3) δ 217.21 , 174.06 , 169.16 , 169.00 , 142.21 ,
138.97 , 134.37 , 128.45 , 119.17 , 117.42 , 74.56 , 73.43 , 69.80
, 60.65 , 58.11 , 52.87 , 48.28 , 48.24 , 45.43 , 44.80 , 43.93 ,
41.73 , 38.19 , 36.69 , 35.95 , 34.46 , 33.89 , 30.38 , 28.34 ,
26.85 , 26.34 , 25.49 , 24.78 , 24.68 , 16.84 , 14.85 , 14.21 ,
11.50 . HRMS: calcd for C39H56N2O9S2 [M - H]- ：759.3349，
found: 759.3308.
4.1.13.9. 14-O-{[(1R, 2R, 4S)-4-ethylacetate-2-p-trifluoromethyl
benzenesulfonamide-sulfanyl]acetyl}-mutilin (2I). Compound 2H
was prepared according to the general procedure from 14-O-
{[(1R, 2R, 4S)-4- ethylacetate -2-amino-sulfanyl]acetyl}-
mutilin(K) and P-trifluoromethylbenzenesulfonyl chloride. The
crude product was purified over silica gel column
1
chromatography to give white solid 150 mg.Yield ： 55%. H
NMR (600 MHz, CDCl3) δ 8.03 (d, J = 8.1 Hz, 2H), 7.75 (d, J =
8.2 Hz, 2H), 6.50 (dd, J = 17.4, 11.0 Hz, 1H), 5.90 (s, 1H), 5.74
(d, J = 8.5 Hz, 1H), 5.37 (d, J = 11.0 Hz, 1H), 5.22 (d, J = 17.3
Hz, 1H), 4.11 – 4.08 (m, 2H), 3.35 (d, J = 6.4 Hz, 1H), 3.28 (s,
1H), 3.05 (s, 2H), 2.57 (d, J = 33.8 Hz, 3H), 2.35 – 2.27 (m, 2H),
2.20 – 2.10 (m, 2H), 2.09 (t, J = 12.3 Hz, 2H), 2.03 – 1.92 (m,
3H), 1.80 – 1.74 (m, 1H), 1.65 (q, J = 11.0, 10.4 Hz, 3H), 1.59 –
1.47 (m, 4H), 1.42 (s, 3H), 1.39 – 1.33 (m, 1H), 1.29 (d, J = 16.1
Hz, 1H), 1.23 (t, J = 7.1 Hz, 4H), 1.18 (s, 3H), 1.12 – 1.09 (m,
1H), 0.87 (d, J = 7.0 Hz, 3H), 0.67 (d, J = 7.0 Hz, 3H). 13C NMR
(151 MHz, CDCl3) δ 216.87 , 173.78 , 169.50 , 143.45 , 138.96 ,
134.07 , 127.95 , 126.03 , 126.00 , 122.36 , 117.51 , 74.53 ,
70.06 , 60.65 , 60.37 , 58.04 , 53.19 , 48.93 , 45.40 , 44.85 ,
43.94 , 41.70 , 38.31 , 36.61 , 35.95 , 34.41 , 33.95 , 30.34 ,
29.21 , 26.87 , 26.27 , 24.77 , 21.03 , 16.86 , 14.79 , 14.20 ,
11.48 . HRMS: calcd for C38H52F3NO8S2 [M - H]-：770.3008，
found: 770.3004.
MIC Testing
Minimum inhibitory concentrations (MIC) of the
compounds were determined by using the agar dilution method
described by the Clinical Laboratory Standards Institute. The
stocks solutions of the compounds were prepared in 0.2%DMSO
and the concentrations are 1920 μg/ml. The drug stock solution
is diluted twice with the corresponding diluent to various desired
concentrations. 1 ml of different concentrations of the dilutions
were sequentially taken and added to the well-marked 90 mm

8.
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sterile dishes. Then, 14 ml of MH agar at 45 to 50 °C was added
using a graduated pipette. After thoroughly mixing the drug
solution with the culture medium, it was placed on a horizontal
test bench. After the agar naturally solidifies, it is ready for use.
The final concentrations of compounds ranged from 0.03 to 128
μg/mL. The concentration of the bacterial solution was adjusted
to 0.5 turbidity (about 108 CFU/ml) using a turbidimeter.
Further, it was diluted 10 times (about 107 CFU/ml), and after
mixing, an appropriate amount (about 0.3 ml) was added to the
inoculated plate in order. The above-mentioned bacterial solution
was inoculated to a series of plates containing different
concentrations of the drug using a multi-point inoculation
instrument (inoculation needle diameter 3 mm, dispensing
amount 1-2 μl) within 30 minutes, and the inoculum amount per
inoculation point was about 104 CFU. Culture plates were
incubated at 35 ±2°C for 18 h, and MICs were then recorded.
The MIC was defined as the lowest concentration that prevented
visible growth of the bacteria.
10. Shang, R. F.; Liu, Y.; Xin, Z. J.; Guo, W. Z.; Guo, Z. T.; Hao, B.
C.; Liang, J. P. Synthesis and antibacterial evaluation of novel
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Acknowledgments
The research was supported by the National Natural Science
Foundation of China (grant number 81703366), The National
Mega-Project
for
drug
renovation
(grant
number
2019ZX09721001-004-006), CAMS innovation fund for
Medical Sciences (grant numbers 2016-I2M-3-014，2016-I2M-
1-011, and 2017-I2M-3-019), the Fundamental Research Funds
for the Central Universities (grant number 332017078), and
Fundamental Research Funds for Jinzhou Medical University
(grant number JYTQN201731).
18. Riedl, K. Studies on pleuromutilin and some of its derivatives. J.
Antibiot. 1976, 29, 132–139.
19. Novak, R.; Shlaes, D.M. The pleuromutilin antibiotics: A new
class for human use. Curr. Opin. Investig. Drugs 2010, 11, 182–
191.
20. Bacque, E.; Pautrat, F.; Zard, S.Z. A Flexible Strategy for the
Divergent Modification of Pleuromutilin. Chem. Commun. 2002,
34, 2312–2313.
Author Contribution Statement
21. Novak, R.; Shlaes, D. M. The pleuromutilin antibiotics: a new
class for human use. Curr. Opin. Invest. Drugs 2010, 11,
182−191.
22. Novak, R. Are pleuromutilin antibiotics finally fit for human use?
Ann. N.Y. Acad. Sci. 2011, 1241, 71−81.
23. Nabriva Therapeutics: Nabriva Therapeutics Announces
Acceptance of New Drug Applications by the FDA for
Intravenous and Oral Lefamulin to Treat Community-Acquired
Bacterial Pneumonia in Adults. February 19, 2019,
https://investors.nabriva.com/news-releases/news-release-
details/nabriva-therapeutics-announces-acceptance-new-drug-
applications Accessed May, 1, 2019.
Yun-Ge Li, Fan Zhang, and Yu-Cheng Wang designed and
planned the experiments. Yun-Ge Li and Mei Zhu synthesized
the compounds. Xue-Fu You tested the antibacterial activity.
Yun-Ge Li wrote the manuscript with support from Guo-Ning
Zhang, Ju-Xian Wang, and Fan Zhang. Yu-Cheng Wang
supervised the project.
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Graphical Abstract
O
O
O
O
S
OH
MIC=0.25μg/ml(MSSE)
MIC=0.5μg/ml(MRSE)
MIC=0.5μg/ml(MSSA)
MIC=0.25μg/ml(MRSA)
MIC=0.06μg/ml(VSE)
MIC=0.12μg/ml(VRE)
O
N
H
O
S
O
O
O
H
OH
O
H2N
O
S
Compound 2C
O
H
O
O
O
O
Compound K
MIC=0.25μg/ml(MSSE)
MIC=0.25μg/ml(MRSE)
MIC=1μg/ml(MSSA)
MIC=1μg/ml(MRSA)
MIC=0.25μg/ml(VSE)
MIC=0.25μg/ml(VRE)
O
S
OH
MIC=0.25μg/ml(MSSE)
MIC=0.25μg/ml(MRSE)
MIC=0.25μg/ml(MSSA)
MIC=0.25μg/ml(MRSA)
MIC=≤0.03μg/ml(VSE)
MIC=0.25μg/ml(VRE)
O
N
H
O
S
O
H
O
Compound 2J
Declaration of interests
☑The authors declare that they have no known
competing financial interests or personal
relationships that could have appeared to influence
t√he work reported in this paper.
☒The authors declare the following financial
interests/personal relationships which may be
considered as potential competing interests: