Bond Linkage Research Articles

Self-assembled 5-fluorouracil-cinnamaldehyde nanodrugs for greatly improved chemotherapy in vivo.

The preferred cancer treatment is to achieve a high therapeutic effect as well as reduce side effects. In this study, we developed carrier-free nano drugs based on 5-fluorouracil (5FU) and cinnamaldehyde (CA) to meet the above goals. Two model drugs were spliced by acetal linkage and ester bond, which could self-assemble into nano drug particles (5FU-CA NPs) with a size of ∼170 nm. In vitro cell experiments showed 5FU-CA NPs were efficiently internalized by HepG2 cells. They then quickly exerted dual drug activities by the cleavage of acetal and ester bond, resulting in enhanced cell-killing efficacy and apoptosis. Synergistic mechanisms were achieved via the anti-metabolic effects mediated by 5FU-COOH and the oxidative damage induced by CA. In vivo anti-tumor evaluation further indicated that 5FU-CA NPs had higher tumor growth inhibition than 5FU-COOH/CA mixture (5FU-COOH + CA) and exhibited lower systemic toxicity under the same reducing dose of each drug. Overall, this is a successful synergistic anti-tumor attempt through rational self-assembly of drugs with different mechanisms and it can be extrapolated to other agents.

Two-Dimensional Conjugated Covalent Organic Framework Films via Oxidative C–C Coupling Reactions at a Liquid–Liquid Interface

The construction of conjugated covalent organic frameworks (COFs) with strong C–C bond linkage remains a big challenge. Herein, we report a new strategy by using an oxidative C–C coupling reaction between electron-rich pyrrole rings at a liquid–liquid interface. Two threefold symmetric monomers containing three terminal pyrrole units were tested, and both gave two-dimensional conjugated COF films with good crystallinity. The bipyrrole units in the as-formed COFs are partially doped, which can be reduced to the neutral form by hydrazine and redoped by I2 vapor. The I2-doped films showed high conductivity (1.35 S/m). Meanwhile, the unpaired electrons exhibited moderate interlayer antiferromagnetic coupling.

Degradation of a Lignin Model Compound by ROS Generated In Situ through Controlled ORR in Ionic Liquid

The cleavage of the linkage bonds among the C9 units in lignin molecules via selective oxidation method to obtain small-weight aromatic compounds is an important way to lignin valorisation. In this study, the cleavage pathways of bonds in a lignin model compound, GGE (guaiacylglycerol-β-guaiacyl ether), by the reactive oxygen species (ROS) in situ generated through electrochemical oxygen reduction reaction (ORR) in an aprotic ionic liquid ([BMIM]BF4) was investigated. The results indicated that when the main ROS was ·OOH, coniferyl alcohol, guaiacol and vanillin were detected as the degradation products which is supposed to be caused by β-O-4 bonds cleavage; Otherwise, when HO2 − was the main ROS, coniferyl alcohol could not be detected and the degradation reaction is believed to be trigerred by C α -C β bonds cleavage.

Electrochemical Degradation of Lignin by ROS

Lignin is a unique renewable aromatic resource in nature. In the past decades, researchers have attempted to breakdown the linkage bonds in lignin to provide aromatic platform chemicals that used to come from the petrochemical industry. In recent years, electrochemical lignin degradation under mild conditions has drawn much attention from the scientific community owing to its potential to scale up and its environmental friendliness. Sustainable electrochemical degradation of lignin consumes less energy and usually requires mild conditions, but low degradation efficiency and insufficient product selectivity are still significant challenges. The method for lignin degradation by reactive oxygen species (ROS) generated through the water oxidation reaction (WOR) at the anode and oxygen reduction reaction (ORR) at the cathode are more attractive for sustainable electrochemical degradation. The present contribution aims to review advancements in electrochemical degradation of lignin in aqueous or non-aqueous supporting electrolytes, focusing on the regulation of ROS in situ generated on the electrode.

PH-Sensitive Biomaterials for Drug Delivery.

The development of precise and personalized medicine requires novel formulation strategies to deliver the therapeutic payloads to the pathological tissues, producing enhanced therapeutic outcome and reduced side effects. As many diseased tissues are feathered with acidic characteristics microenvironment, pH-sensitive biomaterials for drug delivery present great promise for the purpose, which could protect the therapeutic payloads from metabolism and degradation during in vivo circulation and exhibit responsive release of the therapeutics triggered by the acidic pathological tissues, especially for cancer treatment. In the past decades, many methodologies, such as acidic cleavage linkage, have been applied for fabrication of pH-responsive materials for both in vitro and in vivo applications. In this review, we will summarize some pH-sensitive drug delivery system for medical application, mainly focusing on the pH-sensitive linkage bonds and pH-sensitive biomaterials.

Analysis of disulphide bond linkage between CoA and protein cysteine thiols during sporulation and in spores of Bacillus species.

ABSTRACTSpores of Bacillus species have novel properties, which allow them to lie dormant for years and then germinate under favourable conditions. In the current work, the role of a key metabolic integrator, coenzyme A (CoA), in redox regulation of growing cells and during spore formation in Bacillus megaterium and Bacillus subtilis is studied. Exposing these growing cells to oxidising agents or carbon deprivation resulted in extensive covalent protein modification by CoA (termed protein CoAlation), through disulphide bond formation between the CoA thiol group and a protein cysteine. Significant protein CoAlation was observed during sporulation of B. megaterium, and increased largely in parallel with loss of metabolism in spores. Mass spectrometric analysis identified four CoAlated proteins in B. subtilis spores as well as one CoAlated protein in growing B. megaterium cells. All five of these proteins have been identified as moderately abundant in spores. Based on these findings and published studies, protein CoAlation might be involved in facilitating establishment of spores’ metabolic dormancy, and/or protecting sensitive sulfhydryl groups of spore enzymes.

Covalent attachment of 2D graphene oxide (GO) sheets with poly allylamine (PAA) for enhanced mechanical performance: Theoretical and experimental study

2D graphene and its derivatives are used as potent high strength filler materials contributing in the enhanced mechanical properties of resulting polymer composites. However, the full potential of these filler reinforcement materials has not been explored yet due to the weak interface interactions between the filler and polymer matrix. Various functionalities can be introduced during the synthesis of graphene to improve interface interactions but strong covalent bonding between the filler and matrix is still a nascent area. Present report proposes a new route to covalently attach 2D graphene oxide (GO) sheets with poly allylamine (PAA) resulting in a multifold improvement in the mechanical performance of PAA. A theoretical study in this work has been performed to identify possible functionalities on GO sheet and bonding with PAA. The study has proposed a possible route of covalent amide bond linkage of –COOH groups (at GO edges) with free –NH2 (groups on PAA polymer). The molecular dynamics model has shown enhancement in mechanical properties of the resulting composite. Next in the experimental synthesis, GO has been covalently attached to PAA through covalent amide bonding between of –COOH group (on GO) with –NH2 group (on PAA) using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC)/N-Hydroxysuccinimide (NHS) chemistry. The chemical bonds in the synthesized samples were characterized using FTIR and UV–vis spectroscopy. Mechanical properties of the composite samples have been studied using nanoindentation technique. The proposed scheme has great potential of enhancing the mechanical performance of other polymers through covalent cross-linking.

Covalent binding of glutathione on magnetic nanoparticles: Application for immobilizing small fragment ubiquitin-like-specific protease 1

Magnetic nanoparticles bound with glutathione (GSH) are useful for diagnostics, enzyme immobilization, and affinity precipitation by using the strong and specific interaction of GSH with glutathione S-transferase (GST)-fused proteins. Our studies revealed that GSH-bound magnetic nanoparticles could be obtained using the covalent bond linkage of GSH and nanoparticles to promote the stability of bound GSH. To yield this conjugate, superparamagnetic iron oxide nanoparticles (SPIONs) were prepared and modified using tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES), which introduced amino groups that were then activated with maleic anhydride (MA) for covalent binding of GSH. After MA was used to activate the amino-grafted SPION for 24 h, the yield of GSH conjugation increased over 4 days from 37 % to 74 % of the original amine density on the surface as the incubation of GSH with MA-activated SPION. These GSH-bound magnetic nanoparticles, designated as SPION@silica-GSH with approximately 103 nmol GSH/mg particles, were ready for coupling with GST-fused protein through the GSH–GST affinity interaction. A GST-tagged small fragment of ubiquitin-like-specific protease 1 (sfULP1) was used as the model protein for immobilization on SPION@silica-GSH. ULP1 is a small ubiquitin-like modifier (SUMO) protease. Results indicated that this immobilized GST-sfULP1 could retain 87 % ± 5 % enzyme activity of free protease before immobilization and could catalyze the cleavage of the SUMO-fused peptide (SUMO-GLP-1) to obtain glucagon-like peptide-1, a peptide hormone for type 2 diabetes therapy.

PH-sensitive curcumin conjugated micelles for tumor triggered drug delivery

Development of new drugs are confronted with some barriers and challenges, since these projects are mainly expensive, complex, time consuming with lack of success, there is an urgent need to reformulate the current poorly water soluble anti-cancer drugs. In this study, a new type of polymer–curcumin conjugates based on glycidyl azide polymer (GAP) was developed for cancer therapy. The copolymer was used for delivery of curcumin (CUR) as an anticancer drug to cancer cells. Our method is based on the facile conjugation of CUR to amine-containing polymeric vehicles through imine linkage bonds, which could remain stable in normal physiological condition while readily dissociate by an acidic environment and make the prodrug active to liberate its payload CUR to inhibit cell growth. The results demonstrated that fabricated amphiphilic PDCs were self-assembled into nanosized micelles in aqueous solution and the micelles showed an average size of 180 nm with a good polydispersity index. Drug release studies demonstrated that this nano-conjugate is fairly stable at physiologic environments but prone to mild acidic conditions which would trigger the release of conjugated CUR. Moreover, the PDCs micelles exhibited excellent cytotoxicity effect on 4T1 mouse breast cancer cell line but no significant toxicity was observed for the copolymer. In addition, the copolymer did not display remarkable toxicity against A. salina even at high doses of copolymer. In addition, the synthesized PDCs exhibited hemolysis lowers than 6%. The safety of copolymers as a drug vehicle was also confirmed by LD50, since all mice which treated with 5000 mg/Kg (limited dose) were still alive after one week. Our findings revealed that these unique pH-sensitive PDCs may provide a promising approach for delivery of the anticancer drugs to cancer cells.

Antioxidant, Antitumor and Bactericidal Activities of Ethyl Gallate Quinoxalines

Background: Quinoxaline, a fused heterocycle of benzene and pyrazine rings are becoming recognized as a potent class of anti-cancer compounds, such as, in a wide array of pharmacological activities. Methods: We evaluate the three gallate quinoxalines (G-A1, G-A2, and G-A3) as c-Met kinase inhibitors using a docking study, in vitro anticancer potential measurements, antioxidant and bactericidal activities. Results: The docking study showed hydrogen bond linkage of quinoxalines with amino acids at active site of c-Met kinase structures, indicating a possible cancer inhibition cell proliferation. Therefore, the three quinoxalines were analyzed against four in vitro cancer cell lines, and G-A1 demonstrated cytotoxicity against HL-60 and HCT116 cell lines (IC50= 9.55 and IC50= 16.67 μmol L-1, respectively). In HepG2 and MCF-7 cells, the IC50 were 22.48 and 33.42 μmol L-1, respectively. For G-A2 and G-A3, cytotoxic activity ranged from 61.22 to >101.21 μmol L-1. Potent antioxidant activities were also obtained for G-A2>G-A1>G-A3 (IC50= 4.5-8.4 μmol L-1 and AAI= 8.8-17.8). Six different Bacillius strains showed growth inhibition (11.33 to 13.33 mm) in the presence of quinoxaline G-A1 (500 μg). Conclusion: The present work showed the biological potential of quinoxalines G-A1, G-A2 and G-A3 in inhibiting four cancer cells proliferation, in addition to a very strong antioxidant activity.

Simulation of differential structure and dynamics of disulfide bond isoforms of conopeptide AuIB in presence of human α3β4nAChR

AbstractThe structure and function of conopeptides are usually strongly modulated by disulfide bond linkage patterns. Conopeptide AuIB is a selective inhibitor of the mammalian α3β4 nicotinic acetylcholine receptor (nAChR), found in the neuromuscular junctions. The non‐native ribbon isoform of α‐conotoxin, AuIB, is reported to be significantly more potent than the native globular isoform. However, experiments show that their binding sites on mammalian nAChR are different. The difference in the structure and dynamics of these two isoforms when bound to the globular isoform binding site in homology modeled human (α3)3‐(β4)2 nAChR is explored in this work. The isoforms are compared in their unbound and bound states through equilibrium and replica exchange molecular dynamics simulations. Interaction energy map between the key peptide and the receptor residues involved in binding, secondary structures of the peptide and intra‐peptide H‐bonding patterns bring out the difference in non‐bonding interactions and structure of the isoforms while being bound to the receptor. Dynamics exhibited by the isoforms as followed by principal component analysis (PCA), using internal coordinates of backbone dihedral angles, reveal that the ribbon isoform is significantly more flexible as compared to the globular isoform, when bound to the latter's binding site, near the Cys‐loop of the α3(+)β4(−) junction of human (α3)3(β4)2 nAChR. The works brings out differences in the structure and dynamical modes exhibited by the isoforms as it explores the receptor surface.

Catalytic Cleavage of the C-O Bond in 2,6-dimethoxyphenol Without External Hydrogen or Organic Solvent Using Catalytic Vanadium Metal.

Hydrogenolysis of the C-O bonds in lignin, which promises to be able to generate fuels and chemical feedstocks from biomass, is a particularly challenging and important area of investigation. Herein, we demonstrate a vanadium-catalyzed cleavage of a lignin model compound (2,6-dimethoxyphenol). The impact of the catalyst in the context of the temperature, reaction time, and the solvent, was examined for the cleavage of the methyl ethers in 2,6-dimethoxyphenol. In contrast to traditional catalytic transfer hydrogenolysis, which requires high pressure hydrogen gas or reductive organic molecules, such as an alcohol and formic acid, the vanadium catalyst demonstrates superior catalytic activity on the cleavage of the C-O bonds using water as a solvent. For example, the conversion of 2,6-dimethoxyphenol is 89.5% at 280°C after 48 h using distilled water. Notably, the vanadium-catalyzed cleavage of the C-O bond linkage in 2,6-dimethoxyphenol affords 3-methoxycatechol, which undergoes further cleavage to afford pyrogallol. This work is expected to provide an alternative method for the hydrogenolysis of lignin and related compounds into valuable chemicals in the absence of external hydrogen and organic solvents.

Facile synthesis of magnetite nanocubes using deep eutectic solvent: an insight to anticancer and photo-Fenton efficacy

Iron oxide nanoparticles (IONPs) with cubic shape was synthesized using a non-toxic solvent comprising of choline chloride (ChCl) and citric acid (CA). From the Tauc plot, the direct and indirect optical band gaps were found to be 2.53 eV and 1.7 eV respectively. Characteristic peaks in the Fourier transform infrared spectrum at 633 cm−1 and 587 cm−1 proved the presence of Fe-O bond linkage. XRD peaks evidenced the formation of a pure cubic magnetite (Fe3O4) without the presence of any other phases. From TEM analysis confirmed the nanoparticles to be in cubic shape with an average particle size 6.91 nm. Superparamagnetic behaviour was identified with saturation magnetization value of 0.97697 emu/g. From BET surface area analysis the pore diameter, pore volume and surface area were found to be 10.009 nm, 0.107 cm3/g and 27.313 m²/g respectively. EDAX analysis revealed the presence of only iron and oxygen, suggesting that the synthesized IONPs are highly pure. Rhodamine B was photo degraded upto 94 % under UV light irradiation. A dose dependent anticancer activity was envisioned from MTT assay. IC50 was found to be 14.14 µg/mL. The DES capped magnetite showed enhanced photo degradation of organic pollutant and showed excellent anticancer effect against CCL 241 human gastric cancer cells, hence it can be used in the treatment of industrial effluent and cancer.

The effect of reducing agent DTT on pasting, hydration and microstructure properties of foxtail millet

Protein-protein crosslinks, especially disulfide bonds, widely exist and influence the quality of cereal-based food. In order to investigate the effect of disulfide bonds on pasting properties of foxtail millet, ten typical varieties were selected and separated into three groups according to their eating quality, and then reducing agent dithiothreitol (DTT) was used to disrupt disulfide bonds. Disulfide and sulfhydryl groups’ variations, pasting, and hydration properties were determined. Scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM) were also used to analyze the microstructure of foxtail millet paste. Results showed that foxtail millet with poor eating quality was more prone to form disulfide bond linkage at a higher rate and degree during cooking. Disrupting disulfide bonds increased peak viscosity, breakdown, water absorption, and swelling power of granules. Meanwhile, pasting temperature, setback, and final viscosity decreased significantly. The larger size of swollen starch granules and breakage of protein networks were found under CLSM, and firmer lamellar structures with less connections and pores were illustrated under SEM in DTT-treated paste. After DTT-treatment, disulfide bonds were believed to restrict hydration and pasting properties of foxtail millet, and strengthen the swollen granules and paste rigidity as well as a high level of starch reassociation.

Exploring the Interfacial Phase and π-π Stacking in Aligned Carbon Nanotube/Polyimide Nanocomposites.

To characterize the interfacial microstructure and interaction at a nanoscale has a significant meaning for the interface improvement of the nanocomposites. In this study, the interfacial microstructure and features of aligned multiwalled carbon nanotube (MWNT) and conjugated polymer polyimide (PI) with three molecular structures were investigated using small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD), and fluorescence emission spectroscopy. It was found that aligned MWNT/PI nanocomposites had a nonideal two-phase system with the interfaces belonging to long period stacking ordered structure. Attributed to the π–π stacking effect, MWNT/BTDA-MPD presented the most regular arrangement verified by fractal dimension. By adopting a one-dimension correlation function, each phase dimension in aligned MWNT/PI nanocomposites was calculated and verified by high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The π–π stacking was demonstrated to be an important interaction between MWNT and PI via WAXD and fluorescence emission spectroscopy, and it was influenced by the linkage bond between benzene rings in PIs. This work is of significance to reveal the interfacial features between conjugated polymer and carbon nanotubes (CNTs), which is favorable for the interface design of CNT-based high performance nanocomposites.

Pb Stabilization by a New Chemically Durable Orthophosphate Phase: Insights into the Molecular Mechanism with X-ray Structural Analysis.

The rapid progression of piezoelectric technology and the upgradation of electronic devices have resulted in a global increase in Pb-based piezoelectric ceramic materials. In this study, the feasibility of incorporating Pb into a PbZr(PO4)2 double orthophosphate structure was evaluated by investigating the interaction mechanism of the perovskite with phosphate. The unique combination of X-ray absorption spectroscopy, selected area electronic diffraction, and Pawley refinement revealed that Pb was incorporated into a hexagonal structure and tetra-coordinated with oxygen in the phosphate-treated product. The chemical durability was enhanced through the structural alterations via Zr-O-P and Pb-O-P bond linkages. The stable phase encapsulating both Pb and phosphate showed effectiveness not only in stabilizing Pb but also in inhibiting P release as a secondary pollution risk within a wide pH range (1 ≤ pH ≤ 13). Despite the excellent chemical durability of the robust PbZr(PO4)2 crystalline phase, the increased Ti doping amounts at the Zr site resulted in a slight decrease in the lattice parameters and further enhanced the Pb stabilization effect through the formation of PbZrxTi(1-x)(PO4)2 solid solutions. This study demonstrates that the newly robust crystalline structure, developed through a well-designed thermal treatment scheme, provides an effective strategy for the treatment of Pb frequently encountered in electronic wastes.

Structural characterization and comparison of enzymatic and deep eutectic solvents isolated lignin from various green processes: Toward lignin valorization

In this work, several representative green processes were developed to extract the enzymatic lignin and deep eutectic solvents (DESs) isolated lignin from corn straw. The results revealed that enzymatic lignin and DESs isolated lignin had a relatively low and homogeneous molecular weight and DESs isolated lignin shown a higher purity. Enzymatic and DESs isolated lignin showed good representativeness and similar to original herbal lignin structures accompany few aryl ether linkage cleavages and oxidation phenomenon. Among them, the subcritical CO2-assisted autohydrolysis and ChCl/Lac DESs treatment exhibited a higher severity for lignin preparation, and sequence DESs isolated lignin had a better reactivity. The β-O-4 ether bonds and carbon-carbon bonds linkage were further broken up during the Lac and DESs sequence treatment. In short, the described processes showed practical significance for lignin extraction and potential valorization, as well as help to develop more novel strategies for the current biorefinery process.

Photo-cross-linked poly(N-allylisatin biphenyl)-co-poly(alkylene biphenyl)s with pendant N-cyclic quaternary ammonium as anion exchange membranes for direct borohydride/hydrogen peroxide fuel cells

The slightly crosslinked poly(N-allylisatin biphenyl)-co-poly(alkylene biphenyl)s (PIB-co-PAB) based anion exchange membranes are prepared by super-acid catalyst polycondensation and thiol-ene click chemistry in situ. The hydrophilic crosslinked structure improves the hydroxide conductivity due to enhanced the water uptake and well-developed microphase separation. Furthermore, the introduction of N-spirocyclic quaternization ammonium groups promotes the chemical stability of the prepared membranes. Among them, the crosslinked PIB-co-PAB membrane with high ion exchange capacity exhibit high ion conductivity of 24.7 and 39.1 mS·cm−1 at 30 °C for chloride and hydroxide ionic conduction, respectively. Moreover, it possesses an acceptable alkaline stability, which remains the 65.19% of original hydroxide conductivity after storage in 1 M NaOH solution at 80 °C for 1000 h. Meanwhile, the crosslinked membranes exhibit lower permeability for borohydride anion than un-crosslinked membranes. Additionally, the peak power density of direct borohydride/hydrogen peroxide fuel cells using the crosslinked membrane as separator is 76.1 mW·cm−2 at 149.2 mA·cm−2, which is higher than un-crosslinked membranes (17.3 mW·cm−2 at 48.2 mA·cm−2) Therefore, all the results reveal that the prepared free aryl-ether bonds linkage membranes with hydrophilic crosslinked structure provide potential application in fuel cells.

New Insights into the Microbial Degradation of D-Cyphenothrin in Contaminated Water/Soil Environments.

Persistent use of the insecticide D-cyphenothrin has resulted in heavy environmental contamination and public concern. However, microbial degradation of D-cyphenothrin has never been investigated and the mechanism remains unknown. During this study, for the first time, an efficient D-cyphenothrin-degrading bacterial strain Staphylococcus succinus HLJ-10 was identified. Response surface methodology was successfully employed by using Box-Behnken design to optimize the culture conditions. At optimized conditions, over 90% degradation of D-cyphenothrin (50 mg·L−1) was achieved in a mineral salt medium within 7 d. Kinetics analysis revealed that its half-life was reduced by 61.2 d, in comparison with the uninoculated control. Eight intermediate metabolites were detected in the biodegradation pathway of D-cyphenothrin including cis-D-cyphenothrin, trans-D-cyphenothrin, 3-phenoxybenzaldehyde, α-hydroxy-3-phenoxy-benzeneacetonitrile, trans-2,2-dimethyl-3-propenyl-cyclopropanol, 2,2-dimethyl-3-propenyl-cyclopropionic acid, trans-2,2-dimethyl-3-propenyl-cyclopropionaldehyde, and 1,2-benzenedicarboxylic acid, dipropyl ester. This is the first report about the degradation of D-cyphenothrin through cleavage of carboxylester linkage and diaryl bond. In addition to degradation of D-cyphenothrin, strain HLJ-10 effectively degraded a wide range of synthetic pyrethroids including permethrin, tetramethrin, bifenthrin, allethrin, and chlorempenthrin, which are also widely used insecticides with environmental contamination problems. Bioaugmentation of D-cyphenothrin-contaminated soils with strain HLJ-10 substantially enhanced its degradation and over 72% of D-cyphenothrin was removed from soils within 40 d. These findings unveil the biochemical basis of a highly efficient D-cyphenothrin-degrading bacterial isolate and provide potent agents for eliminating environmental residues of pyrethroids.

2D sp2Carbon‐Conjugated Porphyrin Covalent Organic Framework for Cooperative Photocatalysis with TEMPO

Abstract2D covalent organic frameworks (COFs) are receiving ongoing attention in semiconductor photocatalysis. Herein, we present a photocatalytic selective chemical transformation by combining sp2carbon‐conjugated porphyrin‐based covalent organic framework (Por‐sp2c‐COF) photocatalysis with TEMPO catalysis illuminated by 623 nm red light‐emitting diodes (LEDs). Highly selective conversion of amines into imines was swiftly afforded in minutes. Specifically, the π‐conjugation of porphyrin linker leads to extensive absorption of red light; the sp2−C=C− double bonds linkage ensures the stability of Por‐sp2c‐COF under high concentrations of amine. Most importantly, we found that crystalline framework of Por‐sp2c‐COF is pivotal for cooperative photocatalysis with (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO). This work foreshadows that the outstanding hallmarks of COFs, particularly crystallinity, could be exploited to address energy and environmental challenges by cooperative photocatalysis.