Alleviating Cellular Oxidative Stress through Treatment with Superoxide-Triggered Persulfide Prodrugs

Article abstract of DOI:10.1002/anie.202006656

Overproduction of superoxide anion (O₂^.?), the primary cellular reactive oxygen species (ROS), is implicated in various human diseases. To reduce cellular oxidative stress caused by overproduction of superoxide, we developed a compound that reacts with O₂^.? to release a persulfide (RSSH), a type of reactive sulfur species related to the gasotransmitter hydrogen sulfide (H₂S). Termed SOPD-NAC, this persulfide donor reacts specifically with O₂^.?, decomposing to generate N-acetyl cysteine (NAC) persulfide. To enhance persulfide delivery to cells, we conjugated the SOPD motif to a short, self-assembling peptide (Bz-CFFE-NH₂) to make a superoxide-responsive, persulfide-donating peptide (SOPD-Pep). Both SOPD-NAC and SOPD-Pep delivered persulfides/H₂S to H9C2 cardiomyocytes and lowered ROS levels as confirmed by quantitative in vitro fluorescence imaging studies. Additional in vitro studies on RAW 264.7 macrophages showed that SOPD-Pep mitigated toxicity induced by phorbol 12-myristate 13-acetate (PMA) more effectively than SOPD-NAC and several control compounds, including common H₂S donors.

Full text of DOI:10.1002/anie.202006656

A Journal of the Gesellschaft Deutscher Chemiker
Angewandte
Chemie
International Edition
www.angewandte.org
Accepted Article
Title: Alleviating cellular oxidative stress through treatment with
superoxide-triggered persulfide prodrugs
Authors: Yin Wang, Kearsley Dillon, Zhao Li, Ethan Winckler, and John
B Matson
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Angew. Chem. Int. Ed. 10.1002/anie.202006656
Link to VoR: https://doi.org/10.1002/anie.202006656

10.1002/anie.202006656
Angewandte Chemie International Edition
RESEARCH ARTICLE
Alleviating cellular oxidative stress through treatment with
superoxide-triggered persulfide prodrugs
Yin Wang#, Kearsley M. Dillon#, Zhao Li, Ethan W. Winckler, and John B. Matson*
[*]
Dr. Y. Wang, K. M. Dillion, Z. Li, E. W. Winckler, Prof. J. B. Matson
Department of of Chemistry, Virginia Tech Center for Drug Discovery, and Macromolecules Innovation Institute
Virginia Tech
Blacksburg, VA 24061, United States
E-mail: jbmatson@vt.edu
# These authors contributed to this work equally.
Supporting information for this article is given via a link at the end of the document.
Abstract: Overproduction of superoxide anion (O2∙–), the primary
cellular reactive oxygen species (ROS), is implicated in various
human diseases. To reduce cellular oxidative stress caused by
overproduction of superoxide, we developed a compound that reacts
with O2∙– to release a persulfide (RSSH), a type of reactive sulfur
species related to the gasotransmitter hydrogen sulfide (H2S). Termed
SOPD-NAC, this persulfide donor reacts specifically with O2∙–,
decomposing to generate N-acetyl cysteine (NAC) persulfide. To
enhance persulfide delivery to cells, we conjugated the SOPD motif
to a short, self-assembling peptide (Bz-CFFE-NH2) to make a
superoxide-responsive, persulfide-donating peptide (SOPD-Pep).
Both SOPD-NAC and SOPD-Pep delivered persulfides/H2S to H9C2
cardiomyocytes and lowered ROS levels as confirmed by quantitative
in vitro fluorescence imaging studies. Additional in vitro studies on
RAW 264.7 macrophages showed that SOPD-Pep mitigated toxicity
induced by phorbol 12-myristate 13-acetate (PMA) more effectively
than SOPD-NAC and several control compounds, including common
H2S donors.
some cancers (e.g., prostate cancer).[5] Given the roles of O2∙– in
both cell signaling and disease, turn-on fluorescence probes
capable of detecting O2∙– have been developed.[6]-[7] Surprisingly,
no compounds exist that react specifically with O2∙– to both reduce
O2∙– levels and release a molecule capable of further alleviating
oxidative stress.
One signaling species that may be capable of regulating
redox balance in cells with high levels of O2∙– is a persulfide
(RSSH).[8] Persulfides are related to the signaling gas
(gasotransmitter) hydrogen sulfide (H2S), a reactive sulfur species
crucial to many (patho)physiological processes.[9] Because of
their potentially dominant roles in H2S-related signaling pathways,
combined with their ability to persulfidate biological targets
(conversion of RSH into RSSH) under conditions where H2S
cannot, persulfides have recently gained attention.[10] Key
reactivities of persulfides are their nucleophilicity and reducing
abilities; both small molecule and protein-bound persulfides
regulate redox signaling through direct and indirect routes.[11] For
example, glutathione persulfide quickly scavenges the biological
oxidant H2O2,[12] and persulfidation of p66Shc, a protein involved
in mitochondrial redox signaling, inhibits mitochondrial ROS
production.[13] Therefore, we envisioned that a persulfide donor
that could be triggered by O2∙– might be a powerful tool for
reducing its deleterious effects. Beyond decreasing O2∙– levels, a
superoxide-triggered persulfide donor might help uncover the
roles and connections among O2∙– and persulfides in the reactive
species interactome.[4]
The difficulty in developing persulfide donors comes from
the instability of persulfides, which react quickly with various
species, including themselves, oxidants, and free thiol groups.[14]
Therefore, protected persulfides (i.e., prodrugs), in which a
specific stimulus activates the removal of the protecting group to
release the persulfide, are needed to achieve controlled delivery.
Accordingly, persulfide donors exist that respond to biologically
relevant stimuli, including enzymes,[15] light,[16] and H2O2.[17] We
envisioned that a superoxide-triggered persulfide donor could be
constructed by linking a diphenylphosphinate ester, which can be
oxidized by O2∙– in a bond cleaving reaction,[18] to a 4-
(RSSCH2)phenoxy group. In a cascade of reactions, O2∙– should
Introduction
Superoxide anion (O2∙–), the product of a one-electron reduction
of O2 generated primarily in mitochondria during cellular
respiration, is a reactive oxygen species (ROS) implicated in
various diseases related to mitochondrial dysfunction.[1] While a
minimum level of O2∙– is essential for cell survival, excessive
production leads to damage to proteins, lipids, and nucleic
acids.[2] Beyond the harm that superoxide can inflict directly, it is
also a key precursor for other even more damaging ROS; for
example, it reacts with nitric oxide (NO) to produce peroxynitrite
(ONOO–), a powerful and destructive oxidant.[3] Superoxide
dismutases, enzymes that deactivate O2∙–, exist in nearly all cells
and have evolved over 2 billion years to limit the extent of cell
damage from O2∙–.[4] Despite this cellular defense against O2∙–, its
overproduction is ascribed to many oxidative stress-induced
diseases, including degenerative disorders, ischemia-reperfusion
(IR) injury resulting from surgery, cardiovascular disease, and
1
This article is protected by copyright. All rights reserved.

10.1002/anie.202006656
Angewandte Chemie International Edition
RESEARCH ARTICLE
react at phosphorous to cleave the 4-(RSSCH2)phenoxy group,
which would then undergo a 1,6-elimination reaction to reveal a
persulfide anion (RSS–). Such a persulfide donor would serve two
functions—capturing O2∙– and releasing a persulfide. Additionally,
we aimed to develop a delivery system for this donor that would
enhance its water solubility, bioavailability, and provide a potential
mechanism for eventual targeting to specific cells or tissues.
Therefore, we detail here our efforts to develop a small molecule
superoxide-triggered persulfide donor that could be used on its
own and could also be easily conjugated to a self-assembling
One promising strategy to address limitations in prodrug
solubility and bioavailability is appending drugs or prodrugs to
self-assembling peptides. Due to their inherent biodegradability
and biocompatibility in most contexts, peptides capable of self-
assembly into nanostructures and/or hydrogels are powerful
materials for biomedical applications.[20] Previously, we have
shown that conjugation of H2S-donating S-aroylthiooximes
(SATOs) to short peptides not only extended H2S release profiles,
but also modulated release behaviors as a result of their different
self-assembled morphologies.[21] In this regard, conjugating
peptide-based delivery vehicle to improve solubility and bioactivity. SOPD to a self-assembling peptide scaffold would endow the
resultant conjugate with new properties, including improved water
solubility and the potential for cell targeting.
Therefore, we conjugated 4-(mercaptomethyl)phenyl
diphenylphosphinate to a tetrapeptide Bz-Cys-Phe-Phe-Glu (Bz-
Results and Discussion
CFFE) (Bz = benzoyl) through a disulfide linkage (Scheme 2A). In
this two-step synthesis, the 2-thiopyridyl-activated disulfide of Bz-
We chose the diphenylphosphinate group as the stimuli-
responsive unit because of its ability to selectively react with
O2∙–.[18] We conjugated this group to N‐acetyl cysteine (NAC),
which we selected because of its powerful antioxidant
capability[17b, 19] and its free thiol group for conjugation to a thiol-
containing diphenylphosphinate. Synthesis was carried out as
shown in Scheme 1A. Briefly, diphenylphosphinic chloride was
treated with p-cresol under basic conditions. The resulting tolyl
diphenylphosphinate (1) was then brominated by using NBS to
generate a benzyl bromide (2). Bromide displacement was
achieved by treating compound 2 with thiourea followed by
hexylamine, resulting in a benzyl thiol (3). Finally, we treated thiol
3 with the activated disulfide of NAC (NACpyDS) in a disulfide
exchange reaction to afford the target persulfide donor termed
SOPD-NAC (SOPD = superoxide-triggered persulfide donor). A
proposed mechanism for persulfide release is shown in Scheme
1B.
CFFE
was
prepared
and
then
treated
with
4-
(mercaptomethyl)phenyl diphenylphosphinate to afford the target
superoxide responsive peptide (SOPD-Pep). We also
synthesized a control peptide termed SOPD-Pep-Cont, which
included the same peptide sequence conjugated to the
diphenylphosphinate group through a thioether linkage instead of
a disulfide. SOPD-Pep-Cont was synthesized in one step by
reacting
Bz-CFFE
with
4-(bromomethyl)phenyl
diphenylphosphinate (Scheme 2B). We chose Bz-CFFE not only
because of the free thiol group in the sequence, but also because
of its propensity to form discrete one-dimensional
nanostructures.[22]
Next, we investigated whether SOPD-NAC and SOPD-Pep
could specifically react with O2∙– to release persulfides by 1,6-
elimination (self-immolation), a strategy used in several ROS-
triggered H2S donors.[23] Because very few persulfide-specific
chemical probes exist, we first evaluated persulfide release by
relying on the ability of persulfides to rapidly react with cysteine
(Cys) to generate H2S.[10] To this end, we evaluated the reactivity
of SOPD-NAC and SOPD-Pep with several potential triggers by
monitoring the fluorescence increase of an H2S-selective
fluorescent probe WSP-2 reported previously[24] (Figures S10 and
1A). The experiment probed whether persulfide donors react with
the triggers by monitoring the fluorescence intensity at em=455
nm, the characteristic wavelength of 7-hydroxycoumarin (Figure
1B).
The results revealed that neither SOPD-NAC nor SOPD-
Pep alone showed any fluorescence increase in the absence of a
trigger (control groups in Figures 1A (SOPD-Pep) and S10
(SOPD-NAC)). However, adding excess Cys and O2∙– led to a 16-
fold and 12-fold increase in fluorescence intensity for SOPD-Pep
and SOPD-NAC, respectively (red bars, Figures 1A and S10).
Incubating SOPD-NAC or SOPD-Pep with either Cys alone or
O2∙– alone generated a limited increase in fluorescence intensity,
significantly lower than that of the treatment group containing both
triggers. These results implied that H2S liberation from SOPD-
NAC or SOPD-Pep requires both Cys and O2∙–. Consistent with
previous reports on superoxide-responsive probes,[6] other
common reactive sulfur, oxygen, and nitrogen species
(RSONS)—hypochlorite (ClO–), peroxynitrite (ONOO–), sulfate
(SO42–), and glutathione (GSH)—failed to trigger release of H2S.
More importantly, H2O2 did not enhance the fluorescence intensity,
suggesting that SOPD-NAC and SOPD-Pep are selective to O2∙–.
In summary, this screening assay validated that SOPD-NAC and
Scheme 1. A) Synthesis of SOPD-NAC. Reaction conditions: i) NEt3, DMAP,
THF, 16 h, rt, 82% yield; ii) AIBN, C6H6, 16 h, reflux, 91% yield; iii) CH3OH, 16
h, rt; iv) hexylamine, CHCl3, 24 h, rt, 90% yield; v) CH2Cl2, 24 h, rt, 56% yield.
B) Proposed mechanism of superoxide-triggered persulfide release from
SOPD-NAC (R=NAC).
2
This article is protected by copyright. All rights reserved.

10.1002/anie.202006656
Angewandte Chemie International Edition
RESEARCH ARTICLE
SOPD-Pep possess good selectivity for O2∙– and that both
persulfide donors could release H2S in the presence of Cys
(Figure 1B). For direct verification, we also confirmed persulfide
release through mass spectrometry (Figure S11).
Scheme 2. A) Synthesis of SOPD-Pep and B) SOPD-Pep-Cont.
Figure 1. (A) Relative response of 1 mM SOPD-Pep and 50 μM WSP-2 to each potential trigger (4 mM) or combination of triggers or control (no trigger added)
represented as the ratio of the final fluorescence intensity (If) after 30 min to the initial fluorescence intensity (I0), showing an increased selectivity for Cys + O2∙–
over other potential triggers (KO2 was used as the superoxide source). The results were expressed as the mean ± SD (n = 3). (B) Proposed mechanism for
fluorescence turn-on of WSP-2 by H2S released from SOPD-Pep in the presence of Cys and O2∙–. (C) Conventional TEM characterization of twisted nanoribbons
formed by SOPD-Pep in 10 mM phosphate buffer (pH=7.4). The concentration was 100 μM, diluted from 1 mM pre-assembled stock solution. The TEM grid was
stained with 2 wt % uranyl acetate prior to imaging. (D) CD spectrum of SOPD-Pep in 10 mM phosphate buffer (pH=7.4) at 100 μM.
Given the amphiphilic nature of SOPD-Pep, we next studied
the morphology of SOPD-Pep after dissolution in 10 mM
phosphate buffer (pH 7.4) by conventional transmission electron
microscopy (TEM). TEM imaging showed that SOPD-Pep self-
assembled into twisted nanoribbons as indicated by the varying
thickness and grayscale intensity (Figure 1C). Average widths
were 10 ± 2 nm, and lengths were on the scale of a few
micrometers. The molecular packing within these nanoribbons
was then assessed by circular dichroism (CD) spectroscopy
(Figure 1D). CD revealed that SOPD-Pep had a primarily random
3
This article is protected by copyright. All rights reserved.

10.1002/anie.202006656
Angewandte Chemie International Edition
RESEARCH ARTICLE
coil structure with some β-sheet contribution. The minimum at 206
nm may result from π−π interactions of the aromatic side chains
in nanostructures and the distortion of β-sheets, which have been
previously observed in aromatic peptide amphiphile systems.[25]
The negative peak near 250 nm was attributed to the absorption
of diphenylphosphinate group.
We then focused on biological applications of SOPD-NAC
and SOPD-Pep. Cell viability assays indicated that both SOPD-
NAC and SOPD-Pep were nontoxic to H9C2 cardiomyocytes, a
widely used cell line for testing how compounds may affect heart
function, at concentrations up to 200 μM (Figure S15).
Fluorescence microscopy was then used to investigate whether
H2S could be liberated from SOPD-NAC and SOPD-Pep and
delivered to cells in the presence of O2∙–. We used L-buthionine-
(S,R)-sulfoximine (BSO), which induces oxidative stress in cells
by depleting glutathione (GSH),[26] to generate superoxide in
vitro.[27] WSP-5,[24] an H2S-selective fluorescent probe, was used
to monitor H2S accumulation in H9C2 cells. No additional Cys was
added, relying instead on endogenous thiols to convert
persulfides into detectable H2S.
the production of ROS, and that SOPD-Pep suppresses more
effectively than SOPD-NAC.
As expected, BSO alone provided a negligible fluorescent
signal (Figure 2, first row). Treating cells with SOPD-NAC or
SOPD-Pep without BSO generated a weak fluorescent signal.
This most likely resulted from a small amount of H2S liberated
from SOPD-NAC or SOPD-Pep triggered by endogenous O2∙–
within cells (Figure 2, second and third rows). Co-incubation of
SOPD-NAC with BSO generated a slightly stronger signal
compared to SOPD-NAC alone (Figure 2, fourth row), indicating
some amount of H2S production from this small molecule
persulfide donor. In sharp contrast, co-incubation of SOPD-Pep
nanoribbons and BSO produced a significant increase in WSP-5
fluorescence (Figure 2, fifth row), demonstrating that SOPD-Pep
can be successfully activated to release H2S in vitro. Given the
identical conditions and equimolar amounts of SOPD-NAC and
SOPD-Pep, the difference in H2S-release levels likely stems from
different cellular accumulations of these two persulfide donors.
We speculate that SOPD-Pep enters and remains in cells to a
greater extent than SOPD-NAC due to its nanoscale size, a
phenomenon that has been observed for other self-assembled
peptide drug-delivery vehicles.[28]
Given that both SOPD-NAC and SOPD-Pep are triggered
by O2∙– in vitro, we then asked whether these persulfide donors
could decrease ROS production. BSO was used as a superoxide
inducer with dihydroethidium (DHE) as an ROS-sensing
fluorescent probe.[29] As shown in row 1 of Figure 3, the control
group (H9C2 cells without any treatments) showed a dim red
fluorescent signal, indicating that a certain amount of ROS was
naturally generated within H9C2 cells as a product of normal
metabolism of oxygen, consistent with previous reports.[30]
However, after treatment with BSO, the red fluorescent signal
from DHE increased, implying that ROS had accumulated in cells
(Figure 3, second row). We found that H9C2 cells co-incubated
with BSO and SOPD-Pep-Cont showed a lower red fluorescence
compared to those treated only with BSO because SOPD-Pep-
Cont possesses a diphenylphosphinate group that scavenges
O2∙–, but it lacks the capacity to release a persulfide (Figure 3,
third row). Co-incubation of BSO with persulfide donors SOPD-
NAC or SOPD-Pep decreased the red fluorescence signal
(Figure 3 fourth and fifth rows), with SOPD-Pep showing a similar
fluorescence intensity to the control group. These results agree
with the H2S production studies (Figure 2), indicating that
persulfides released from SOPD-NAC and SOPD-Pep suppress
Figure 2. Bright field, fluorescence, and merged images showing fluorescence
in H9C2 cells pre-incubated with SOPD-NAC or SOPD-Pep (200 μM) for 6 h,
and subsequently treated with WSP-5 (50 μM) and BSO (5 mM) or an equal
volume of PBS for 30 min. Cells were then washed, and fluorescence images
were taken in PBS. Scale bars are 50 μm. Averaged fluorescence intensities of
these five respective treatment groups were quantified by ImageJ (cell counts
are > 30 for each group from three separate wells).
As
SOPD-NAC
and
SOPD-Pep
both
deliver
persulfides/H2S into cells and further quench ROS production, we
next explored their anti-inflammatory activities on RAW 264.7
macrophages. RAW 264.7 cells were chosen as a model because
they generate a considerable amount of O2∙– when incubated with
31]
phorbol 12-myristate 13-acetate (PMA).[23d,
H2S alleviates
inflammation caused by ROS,[32] but the protective capacity of
4
This article is protected by copyright. All rights reserved.

10.1002/anie.202006656
Angewandte Chemie International Edition
RESEARCH ARTICLE
persulfide donors has not been tested in cells treated with PMA.
Thus, we envisioned that SOPD-NAC and SOPD-Pep might
NAC showed a moderate ability to rescue cells; this result may be
related to a small amount of persulfide/H2S accumulated within
cells, consistent with results shown in Figures 2 and 3. SOPD-
Pep-Cont showed a similar cell protective ability to SOPD-NAC.
This small but significant protective capacity likely resulted from
•–
the diphenylphosphinate group scavenging O2 and, thus,
lowering intracellular ROS levels. Under the same conditions, we
also compared SOPD-Pep to sodium sulfide (Na2S), a fast-
releasing H2S donor, and GYY4137,[33] a slow-releasing H2S
donor. Na2S had limited ability to rescue cells, while GYY4137
had no effect. Therefore, SOPD-Pep more effectively rescued
cells than did Na2S and GYY4137.
rescue RAW 264.7 macrophages from induced oxidative stress.
Figure 3. Bright field, fluorescence, and merged images showing fluorescence
in H9C2 cells pre-incubated with SOPD-Pep-Cont or SOPD-NAC or SOPD-
Pep (200 μM) for 6 h and then treated with DHE (10 μM) and BSO (5 mM) or
an equal volume of DMSO for 30 min. Cells were then washed, and
fluorescence images were taken in PBS. Scale bars are 50 μm. Averaged
fluorescence intensities of these five respective treatment groups were
quantified by ImageJ (cell counts are > 30 for each group from three separate
wells).
Figure 4. (A) Cell viability of RAW 264.7 macrophage cells pretreated with
different concentrations of PMA for 1 h followed by exposure to SOPD-Pep (100
μM) for 4 h. * indicates p < 0.01 vs PMA-only groups. (B) Cell viability of RAW
264.7 macrophage cells pretreated with PMA (2 μg/mL) for 1 h followed by
exposure to different groups (100 μM) for 4 h: GYY4137, SOPD-Pep-Cont,
Na2S, SOPD-NAC, and SOPD-Pep. * indicates p < 0.01. Error bars indicate
standard deviation of three separate experiments with five replicates per
experiment. Group comparisons are indicated as determined by a one-way
analysis of variance (ANOVA) with a Student−Newman−Keuls comparisons
post-hoc test.
First, we demonstrated that both SOPD-NAC and SOPD-Pep
were nontoxic to RAW 264.7 cells at concentrations up to 200 μM
(Figure S16). In contrast, PMA induced significant cytotoxicity at
concentrations as low as 1 μg/mL (Figure 4A). In treatment
studies, RAW 264.7 cells were pretreated with PMA for 1 h, a
period consistent with previous reports,[23d] then SOPD-Pep was
added without removing PMA solution, and cells were
subsequently cultured for another 4 h before analyzing viability.
Compared to the PMA-only treatment group, cell viability
increased significantly when cells were co-incubated with SOPD-
Pep and PMA (Figure 4A). For example, exposure of PMA to cells
at 2 μg/mL decreased viability to 51% while viability increased to
81% when co-incubated with 100 µM SOPD-Pep.
Conclusion
In summary, we report a new dual-acting compound that
scavenges O2∙– and then decomposes to release a persulfide.
This motif, based on a small molecule (SOPD-NAC), was
conjugated to a self-assembling peptide (SOPD-Pep). In the
presence of O2∙–, both donors released persulfides, decreasing
ROS levels in cells. Further, SOPD-Pep showed pronounced anti-
inflammatory activity on macrophages, greater than SOPD-NAC,
SOPD-Pep-Cont (a control peptide incapable of persulfide
To further ensure that persulfide release was responsible
for imparting protection to the macrophages in the presence of
PMA, several control studies were carried out (Figure 4B). SOPD-
5
This article is protected by copyright. All rights reserved.

10.1002/anie.202006656
Angewandte Chemie International Edition
RESEARCH ARTICLE
[14] S. Kawamura, T. Horii, J. Tsurugi, J. Org. Chem. 1971, 36, 3677-3680.
[15] a)Z. N. Yuan, Y. Q. Zheng, B. C. Yu, S. M. Wang, X. X. Yang, B. H. Wang,
Org Lett 2018, 20, 6364-6367; b)Y. Q. Zheng, B. C. Yu, Z. Li, Z. N. Yuan, C. L.
Organ, R. K. Trivedi, S. M. Wang, D. J. Lefer, B. H. Wang, Angew. Chem. Int.
Ed. 2017, 56, 11749-11753; c)K. M. Dillon, R. J. Carrazzone, Y. Wang, C. R.
Powell, J. B. Matson, ACS Macro Lett. 2020, 9, 606-612.
release), and common H2S donors. These results highlight the
potential of SOPD-NAC and SOPD-Pep for persulfide-based
therapies and demonstrate their power to initiate complex
changes in cell behavior. Broadly, this dual superoxide-
scavenging–persulfide-donating scaffold could potentially find
use to regulate the redox balance within cells, which may alleviate
oxidative stress-induced diseases caused by upregulation of O2∙–.
[16] A. Chaudhuri, Y. Venkatesh, J. Das, M. Gangopadhyay, T. K. Maiti, N. D.
P. Singh, J. Org. Chem. 2019, 84, 11441-11449.
[17] a)P. Bora, P. Chauhan, S. Manna, H. Chakrapani, Org. Lett. 2018, 20,
7916-7920; b)C. R. Powell, K. M. Dillon, Y. Wang, R. J. Carrazzone, J. B.
Matson, Angew. Chem. Int. Ed. 2018, 57, 6324-6328.
[18] S. C. Lim, Y. H. Kim, Heteroatom Chem. 1990, 1, 261-265.
[19] a)D. Ezerina, Y. Takano, K. Hanaoka, Y. Urano, T. P. Dick, Cell Chem. Biol.
2018, 25, 447-459; b)M. Zafarullah, W. Q. Li, J. Sylvester, M. Ahmad, CMLS-
Cell. Mol. Life Sci. 2003, 60, 6-20; c)N. P. Murphy, K. J. Lampe, Biotechnol.
Bioeng. 2018, 115, 246-256.
Acknowledgements
This work was supported by the National Science Foundation
(DMR‐1454754) and the National Institutes of Health
(R01GM123508). We also acknowledge the Dreyfus foundation
for supporting these studies through a Camille Dreyfus Teacher-
Scholar Award to J.B.M. We acknowledge Prof. Padmavathy
Rajagopalan (Virginia Tech) for sharing RAW 264.7 macrophage
cells, Prof. Mark Van Dyke (Virginia Tech) and Prof. Amanda J.
Morris (Virginia Tech) for instrumental assistance, Dr. Chadwick
R. Powell for synthesizing GYY4137, and Samantha J. Scannelli
and Prof. Richard D. Gandour for careful readings of the
manuscript. The authors also acknowledge use of facilities within
the Nanoscale Characterization and Fabrication Laboratory at
Virginia Tech.
[20] J. B. Matson, S. I. Stupp, Chem. Commun. 2012, 48, 26-33.
[21] a)J. M. Carter, Y. Qian, J. C. Foster, J. B. Matson, Chem. Commun. 2015,
51, 13131-13134; b)A. Longchamp, K. Kaur, D. Macabrey, C. Dubuis, J. M.
Corpataux, S. Deglise, J. B. Matson, F. Allagnat, Acta Biomater. 2019, 97, 374-
384; c)Y. Qian, K. Kaur, J. C. Foster, J. B. Matson, Biomacromolecules 2019,
20, 1077-1086; d)Y. Wang, K. Kaur, S. J. Scannelli, R. Bitton, J. B. Matson, J.
Am. Chem. Soc. 2018, 140, 14945-14951; e)Y. Wang, J. B. Matson, ACS Appl.
Bio Mater. 2019, 2, 5093-5098.
[22] a)S. Fleming, R. V. Ulijn, Chem. Soc. Rev. 2014, 43, 8150-8177; b)M.
Reches, E. Gazit, Science 2003, 300, 625-627.
[23] a)Y. Zhao, M. D. Pluth, Angew. Chem. Int. Ed. 2016, 55, 14638-14642; b)Y.
Zhao, H. A. Henthorn, M. D. Pluth, J. Am. Chem. Soc. 2017, 139, 16365-16376;
c)P. Chauhan, S. Jos, H. Chakrapani, Org. Lett. 2018, 20, 3766-3770; d)Y. M.
Hu, X. Y. Li, Y. Fang, W. Shi, X. H. Li, W. Chen, M. Xian, H. M. Ma, Chem. Sci.
2019, 10, 7690-7694; e)N. Zhang, P. Hu, Y. F. Wang, Q. Tang, Q. Zheng, Z. L.
Wang, Y. He, ACS Sens. 2020, 5, 319-326.
Keywords: Drug Delivery • Oxidative Stress • Peptides •
Prodrugs • Stimuli-Responsive
[24] B. Peng, W. Chen, C. R. Liu, E. W. Rosser, A. Pacheco, Y. Zhao, H. C.
Aguilar, M. Xian, Chem.-Eur. J. 2014, 20, 1010-1016.
[1] I. Fridovich, J. Biol. Chem. 1997, 272, 18515-18517.
[2] U. Bandyopadhyay, D. Das, R. K. Banerjee, Curr. Sci. 1999, 77, 658-666.
[3] C. Szabo, H. Ischiropoulos, R. Radi, Nat. Rev. Drug Discov. 2007, 6, 662-
680.
[25] a)Y. Hu, R. Lin, P. C. Zhang, J. Fern, A. G. Cheetham, K. Patel, R.
Schulman, C. Y. Kan, H. G. Cui, ACS Nano 2016, 10, 880-888; b)E. L. Bakota,
O. Sensoy, B. Ozgur, M. Sayar, J. D. Hartgerink, Biomacromolecules 2013, 14,
1370-1378.
[4] M. M. Cortese-Krott, A. Koning, G. G. C. Kuhnle, P. Nagy, C. L. Bianco, A.
Pasch, D. A. Wink, J. M. Fukuto, A. A. Jackson, H. van Goor, K. R. Olson, M.
Feelisch, Antioxid. Redox Signal. 2017, 27, 684-712.
[26] R. Reliene, R. H. Schiestl, Carcinogenesis 2006, 27, 240-244.
[27] D. J. Adams, Z. V. Boskovic, J. R. Theriault, A. J. Wang, A. M. Stern, B. K.
Wagner, A. F. Shamji, S. L. Schreiber, ACS Chem. Biol. 2013, 8, 923-929.
[28] a)J. Zhan, Y. B. Cai, S. S. He, L. Wang, Z. M. Yang, Angew. Chem. Int. Ed.
2018, 57, 1813-1816; b)C. H. Liang, X. R. Yan, R. S. Zhang, T. Y. Xu, D. B.
Zheng, Z. Q. Tan, Y. X. Chen, Z. F. Gao, L. Wang, X. Y. Li, Z. M. Yang, J.
Control. Release 2020, 317, 109-117; c)D. Mumcuoglu, M. S. Ekiz, G. Gunay,
T. Tekinay, A. B. Tekinay, M. O. Guler, ACS Appl. Mater. Interfaces 2016, 8,
11280-11287.
[5] P. Pacher, J. S. Beckman, L. Liaudet, Physiol. Rev. 2007, 87, 315-424.
[6] X. Y. Gao, G. X. Feng, P. N. Manghnani, F. Hu, N. Jiang, J. Z. Liu, B. Liu, J.
Z. Sun, B. Z. Tang, Chem. Commun. 2017, 53, 1653-1656.
[7] J. J. Zhang, C. W. Li, R. Zhang, F. Y. Zhang, W. Liu, X. Y. Liu, S. M. Y. Lee,
H. X. Zhang, Chem. Commun. 2016, 52, 2679-2682.
[8] E. Cuevasanta, M. N. Moller, B. Alvarez, Arch. Biochem. Biophys. 2017, 617,
9-25.
[29] K. M. Robinson, M. S. Janes, M. Pehar, J. S. Monette, M. F. Ross, T. M.
Hagen, M. P. Murphy, J. S. Beckman, Proc. Natl. Acad. Sci. U. S. A. 2006, 103,
15038-15043.
[9] R. Wang, Physiol. Rev. 2012, 92, 791-896.
[10] M. R. Filipovic, J. Zivanovic, B. Alvarez, R. Banerjee, Chem. Rev. 2018,
118, 377-461.
[30] M. Schieber, N. S. Chandel, Curr. Biol. 2014, 24, R453-R462.
[31] J. Xu, Y. Zhang, H. Yu, X. D. Gao, S. J. Shao, Anal. Chem. 2016, 88, 1455-
1461.
[11] S. Kasamatsu, A. Nishimura, M. Morita, T. Matsunaga, H. A. Hamid, T.
Akaike, Molecules 2016, 21, 1721.
[12] T. Ida, T. Sawa, H. Ihara, Y. Tsuchiya, Y. Watanabe, Y. Kumagai, M.
Suematsu, H. Motohashi, S. Fujii, T. Matsunaga, M. Yamamoto, K. Ono, N. O.
Devarie-Baez, M. Xian, J. M. Fukuto, T. Akaike, Proc. Natl. Acad. Sci. U. S. A.
2014, 111, 7606-7611.
[32] a)Y. Y. Han, Q. W. Shang, J. Yao, Y. Ji, Cell Death Dis. 2019, 10, 293; b)J.
L. Wallace, Trends Pharmacol. Sci. 2007, 28, 501-505.
[33] L. Li, M. Whiteman, Y. Y. Guan, K. L. Neo, Y. Cheng, S. W. Lee, Y. Zhao,
R. Baskar, C. H. Tan, P. K. Moore, Circulation 2008, 117, 2351-2360.
[13] Z. Z. Xie, M. M. Shi, L. Xie, Z. Y. Wu, G. Li, F. Hua, J. S. Bian, Antioxid.
Redox Signal. 2014, 21, 2531-2542.
6
This article is protected by copyright. All rights reserved.

10.1002/anie.202006656
Angewandte Chemie International Edition
RESEARCH ARTICLE
Entry for the Table of Contents
Taming superoxide! Reported here are two dual-acting compounds (SOPD-NAC and SOPD-Pep) that scavenge superoxide and
then decompose to release persulfides (RSSH). Both donors deliver persulfides to cardiomyocytes, lowering intracellular reactive
oxygen species levels. Additionally, SOPD-Pep shows anti-inflammatory activity in macrophages, greater than SOPD-NAC and
several H2S‐ releasing control compounds.
7
This article is protected by copyright. All rights reserved.