9 research outputs found
Lithium–Sulfur Battery Cathode Enabled by Lithium–Nitrile Interaction
Lithium sulfide is a promising cathode material for high-energy
lithium ion batteries because, unlike elemental sulfur, it obviates
the need for metallic lithium anodes. Like elemental sulfur, however,
a successful lithium sulfide cathode requires an inherent mechanism
for preventing lithium polysulfide dissolution and shuttling during
electrochemical cycling. A new scheme is proposed to create composites
based on lithium sulfide uniformly dispersed in a carbon host, which
serve to sequester polysulfides. The synthesis methodology makes use
of interactions between lithium ions in solution and nitrile groups
uniformly distributed along the chain backbone of a polymer precursor
(e.g., polyacrylonitrile), to control the distribution of lithium
sulfide in the host material. The Li<sub>2</sub>S–carbon composites
obtained by carbonizing the precursor are evaluated as cathode materials
in a half-cell lithium battery, and are shown to yield high galvanic
charge/discharge capacities and excellent Coulombic efficiency, demonstrating
the effectiveness of the architecture in homogeneously distributing
Li<sub>2</sub>S and in sequestering lithium polysulfides
Discovery and Characterization of Moracin C as an Anti-Gouty Arthritis/Hyperuricemia Candidate by Docking-Based Virtual Screening and Pharmacological Evaluation
In
the present study, a natural product database of compounds associated
with herbs traditionally verified to treat gout/hyperuricemia/arthritis
was constructed. 3D-shape and docking-based virtual screening was
conducted. To identify potential xanthine oxidase (XOD) inhibitors
in the database, eight compounds with commercial availability were
identified as high 3D-shape similarity with febuxostat (1), a known XOD inhibitor. Docking was used to further predict the
possible interactions between XOD and these compounds. Moracin C (2), moracin D (3), and isoformononetin (8) exhibited higher docking scores and binding energies than
other compounds. In vitro, 2 inhibited XOD with an IC50 value of 0.25 ± 0.14 μM, which is similar to
that of 1 (0.16 ± 0.08 μM). In a hyperuricemic
mouse model, 5–20 mg/kg 2 exhibited satisfying
urate-lowering and XOD inhibitory effects. Compound 2 also exhibited antiarthritis activities. In RAW264.7 cells, 2 at 1–10 μM inhibited the expression of IL-1β
and TNF-α induced by MSU. In an acute gouty arthritis model
in SD rats, 5–20 mg/kg 2 significantly alleviated
the toe swelling, inflammatory response, and dysfunction disorder
caused by monosodium urate (MSU). Compound 2 inhibited
serum IL-1β and TNF-α cytokines as well as reduced the
expression of the NLRP3/ASC/caspase-1 inflammasome in joints. In summary, 2 was an effective compound for the treatment of hyperuricemia/gouty
arthritis
X‑ray Crystal Structure-Guided Discovery of Novel Indole Analogues as Colchicine-Binding Site Tubulin Inhibitors with Immune-Potentiating and Antitumor Effects against Melanoma
A series of novel indole analogues were discovered as
colchicine-binding
site inhibitors of tubulin. Among them, 3a exhibited
the highest antiproliferative activity (average IC50 =
4.5 nM), better than colchicine (IC50 = 65.3 nM). The crystal
structure of 3a in complex with tubulin was solved by
X-ray crystallography, which explained the improved binding affinity
of 3a to tubulin and thus its higher anticancer activity
(IC50 = 4.5 nM) than the lead compound 12b (IC50 = 32.5 nM). In vivo, 3a (5 mg/kg) displayed significant antitumor efficacy against B16-F10
melanoma with a TGI of 62.96% and enhanced the antitumor efficacy
of a small-molecule PD-1/PD-L1 inhibitor NP19 (TGI = 77.85%). Moreover, 3a potentiated the antitumor immunity of NP19 by activating
the tumor immune microenvironment, as demonstrated by the increased
tumor-infiltrating lymphocytes (TIL). Collectively, this work shows
a successful example of crystal structure-guided discovery of a novel
tubulin inhibitor 3a as a potential anticancer and immune-potentiating
agent
X‑ray Crystal Structure-Guided Discovery of Novel Indole Analogues as Colchicine-Binding Site Tubulin Inhibitors with Immune-Potentiating and Antitumor Effects against Melanoma
A series of novel indole analogues were discovered as
colchicine-binding
site inhibitors of tubulin. Among them, 3a exhibited
the highest antiproliferative activity (average IC50 =
4.5 nM), better than colchicine (IC50 = 65.3 nM). The crystal
structure of 3a in complex with tubulin was solved by
X-ray crystallography, which explained the improved binding affinity
of 3a to tubulin and thus its higher anticancer activity
(IC50 = 4.5 nM) than the lead compound 12b (IC50 = 32.5 nM). In vivo, 3a (5 mg/kg) displayed significant antitumor efficacy against B16-F10
melanoma with a TGI of 62.96% and enhanced the antitumor efficacy
of a small-molecule PD-1/PD-L1 inhibitor NP19 (TGI = 77.85%). Moreover, 3a potentiated the antitumor immunity of NP19 by activating
the tumor immune microenvironment, as demonstrated by the increased
tumor-infiltrating lymphocytes (TIL). Collectively, this work shows
a successful example of crystal structure-guided discovery of a novel
tubulin inhibitor 3a as a potential anticancer and immune-potentiating
agent
Largely Improved Creep Resistance and Thermal-Aging Stability of Eco-Friendly Polypropylene High-Voltage Insulation by Long-Chain Branch-Induced Interfacial Constraints
Polypropylene (PP)-based composites have attracted numerous
attention
as a replacement of prevailing cross-linked polyethylene (XLPE) for
high-voltage insulation due to their ease of processing, recyclability,
and excellent electrical performance. However, the poor resistances
against high-temperature creep and thermal aging are obstacles to
practical applications of PP-based thermoplastic high-voltage insulation.
To address these problems, in this Letter, we synthesized an impact
polypropylene copolymer (IPC) containing multifold long-chain branched
(LCB) structures in phases, especially the interfaces between the
PP matrix and the rubber phase. The results indicated that the structural
stability of LCBIPC was significantly enhanced under extreme conditions.
In comparison to IPC (without LCB structures), 24.1% less creep strain
and 75.2% less unrecoverable deformation are achieved in LCBIPC at
90 °C. In addition, the thermal aging experiments were performed
at 135 °C for 48 and 88 days for IPC and LCBIPC, respectively.
The results show that the resistance against thermal aging was also
enhanced in LCBIPC, which showed a 133% longer thermal aging life
compared to IPC. Further results revealed that the interfacial layer
between the PP matrix and the rubber phase was constructed in LCBIPC.
The two phases are tightly linked by chemical bonds in LCB structures,
leading to enforced constraints of the rubber phase at the micro level
and better resistance performance against creep and thermal aging
at the macro level. Evidently, the reported eco-friendly LCBIPC thermoplastic
insulation shows great potential for applications in high-voltage
cable insulation
Discovery and Computational Studies of Potent Covalent Kinase Inhibitors with α‑Substituent Electrophiles Targeting Cysteine
Both reversible noncovalent inhibitors and irreversible
covalent
inhibitors targeting tyrosine kinases have their disadvantages. The
reversible covalent inhibitors with electrophilic group cyanoacrylamide
as warheads reacting with cysteine residues could solve the dilemmas.
However, there are still several unresolved issues regarding the electrophilic
groups. In this manuscript, a series of EGFR inhibitors with double
electron-withdrawing substituents introduced into the Cα position on the olefin bond were designed and synthesized. The binding
structures and characteristics of inhibitors with the kinase in both
the first noncovalent binding phase and the second covalent binding
step were explored and combined with molecular docking and molecular
dynamics simulations. Then, the reverse β-elimination reactions
of the thiol-Michael adducts were investigated by applying density
functional theory calculations. In addition, the effects of different
electrophilic substituents of Cα on the binding between
the inhibitors and kinase were elucidated. The results suggested that
the electrophilicity and size of the electron-withdrawing groups play
an important role in the specific interactions during the reaction.
The compounds with the electron-withdrawing groups that had medium
electrostatic and steric complementarity to the kinase active site
could cooperatively stabilize the complexes and showed relatively
good potent activities in the kinase assay experiment. The mechanical
and structural information in this study could enhance our understanding
of the functioning of the electron-withdrawing groups in the covalent
inhibitors. The results might help to design efficient cysteine targeting
inhibitors in the future
Discovery and Computational Studies of Potent Covalent Kinase Inhibitors with α‑Substituent Electrophiles Targeting Cysteine
Both reversible noncovalent inhibitors and irreversible
covalent
inhibitors targeting tyrosine kinases have their disadvantages. The
reversible covalent inhibitors with electrophilic group cyanoacrylamide
as warheads reacting with cysteine residues could solve the dilemmas.
However, there are still several unresolved issues regarding the electrophilic
groups. In this manuscript, a series of EGFR inhibitors with double
electron-withdrawing substituents introduced into the Cα position on the olefin bond were designed and synthesized. The binding
structures and characteristics of inhibitors with the kinase in both
the first noncovalent binding phase and the second covalent binding
step were explored and combined with molecular docking and molecular
dynamics simulations. Then, the reverse β-elimination reactions
of the thiol-Michael adducts were investigated by applying density
functional theory calculations. In addition, the effects of different
electrophilic substituents of Cα on the binding between
the inhibitors and kinase were elucidated. The results suggested that
the electrophilicity and size of the electron-withdrawing groups play
an important role in the specific interactions during the reaction.
The compounds with the electron-withdrawing groups that had medium
electrostatic and steric complementarity to the kinase active site
could cooperatively stabilize the complexes and showed relatively
good potent activities in the kinase assay experiment. The mechanical
and structural information in this study could enhance our understanding
of the functioning of the electron-withdrawing groups in the covalent
inhibitors. The results might help to design efficient cysteine targeting
inhibitors in the future
Discovery of Novel Potent and Fast BTK PROTACs for the Treatment of Osteoclasts-Related Inflammatory Diseases
Bruton’s
tyrosine kinase (BTK) is an attractive target in
inflammatory and autoimmune diseases. However, the effectiveness of
BTK inhibitors is limited by side effects and drug resistance. In
this study, we report the development of novel BTK proteolysis targeting
chimeras (PROTACs) with different classes of BTK-targeting ligands
(e.g., spebrutinib) other than ibrutinib. Compound 23 was identified as a potent and fast BTK PROTAC degrader, exhibiting
outstanding degradation potency and efficiency in Mino cells (DC50, 4 h = 1.29 ± 0.3 nM, t1/2, 20 nM = 0.59 ± 0.20 h). Furthermore, compound 23 forms a stable ternary complex, as confirmed by the HTRF
assay. Notably, 23 down-regulated the BTK-PLCγ2-Ca2+-NFATc1 signaling pathway activated by RANKL, thus inhibiting
osteoclastogenesis and attenuating alveolar bone resorption
in a mouse periodontitis model. These findings suggest that compound 23 is a potent and promising candidate for osteoclast-related
inflammatory diseases, expanding the potential of BTK PROTACs
Discovery of Novel Potent and Fast BTK PROTACs for the Treatment of Osteoclasts-Related Inflammatory Diseases
Bruton’s
tyrosine kinase (BTK) is an attractive target in
inflammatory and autoimmune diseases. However, the effectiveness of
BTK inhibitors is limited by side effects and drug resistance. In
this study, we report the development of novel BTK proteolysis targeting
chimeras (PROTACs) with different classes of BTK-targeting ligands
(e.g., spebrutinib) other than ibrutinib. Compound 23 was identified as a potent and fast BTK PROTAC degrader, exhibiting
outstanding degradation potency and efficiency in Mino cells (DC50, 4 h = 1.29 ± 0.3 nM, t1/2, 20 nM = 0.59 ± 0.20 h). Furthermore, compound 23 forms a stable ternary complex, as confirmed by the HTRF
assay. Notably, 23 down-regulated the BTK-PLCγ2-Ca2+-NFATc1 signaling pathway activated by RANKL, thus inhibiting
osteoclastogenesis and attenuating alveolar bone resorption
in a mouse periodontitis model. These findings suggest that compound 23 is a potent and promising candidate for osteoclast-related
inflammatory diseases, expanding the potential of BTK PROTACs