Radical Cation Research Articles

Magnetic Properties of Self-Assemble Naphthalene Diimide Radical Aggregates.

The concept of creating room-temperature ferromagnets from organic radicals proposed nearly sixty years ago, has recently experienced a resurgence due to advances in organic radical chemistry and materials. However, the lack of definitive design paradigms for achieving stable long-range ferromagnetic coupling between organic radicals presents an uncertain future for this research. Here, an innovative strategy is presented to achieve room-temperature ferromagnets by assembling π-conjugated radicals into π-π stacking aggregates. These aggregates, with ultra-close π-π distances and optimal π-π overlap, provide a platform for strong ferromagnetic (FM) interaction. The planar aromatic naphthalene diimide (NDI) anion radicals form nanorod aggregates with a π-π distance of just 3.26 Å, shorter than typical van der Waals distances. The suppressed electron paramagnetic resonance (EPR) signal and emergent near-infrared (NIR) absorption of the aggregates confirm strong interactions between the radicals. Magnetic measurements of NDI anion radical aggregates demonstrate room-temperature ferromagnetism with a saturated magnetization of 1.1 emug-1, the highest among pure organic ferromagnets. Theoretical calculations reveal that π-stacks of NDI anion radicals with specific interlayer translational slippage favor ferromagnetic coupling over antiferromagnetic coupling.

Near UV and Visible Light Photodegradation in Solid Formulations: Generation of Carbon Dioxide Radical Anions from Citrate Buffer and Fe(III).

Near UV and visible light photodegradation can target therapeutic proteins during manufacturing and storage. While the underlying photodegradation pathways are frequently not well-understood, one important aspect of consideration is the formulation, specifically the formulation buffer. Citrate is a common buffer for biopharmaceutical formulations, which can complex with transition metals, such as Fe(III). In an aqueous solution, the exposure of such complexes to light leads to the formation of the carbon dioxide radical anion (•CO2-), a powerful reductant. However, few studies have characterized such processes in solid formulations. Here, we show that solid citrate formulations containing Fe(III) lead to the photochemical formation of •CO2-, identified through DMPO spin trapping and HPLC-MS/MS analysis. Factors such as buffers, the availability of oxygen, excipients, and manufacturing processes of solid formulations were evaluated for their effect on the formation of •CO2- and other radicals such as •OH.

Organocatalyzed Carbonylation of Alkyl Halides Driven by Visible Light.

Herein, we describe a new strategy for the carbonylation of alkyl halides with different nucleophiles to generate valuable carbonyl derivatives under visible light irradiation. This method is mild, robust, highly selective, and proceeds under metal-free conditions to prepare a range of structurally diverse esters and amides in good to excellent yields. In addition, we highlight the application of this activation strategy for 13C isotopic incorporation. We propose that the reaction proceeds by a photoinduced reduction to afford radical anions from alkyl halides, which undergo subsequent single electron-oxidation to form a carbocationic intermediate. Carbon monoxide is trapped by the carbocation to generate an acylium cation, which can be attacked by a series of nucleophiles to give a range of carbonyl products.

Contrasting Photosensitized Processes of Ru(II) Polypyridyl Structural Isomers Containing Linear and Hooked Intercalating Ligands Bound to Guanine-Rich DNA.

The DNA binding and cellular uptake of the lambda enantiomer of two bis-tetraazaphenanthrene (TAP) Ru(II) polypyridyl complexes containing either a linear dppn (1) or a hooked bdppz (2) benzodipyridophenazine ligand are reported, and the role of different charge-transfer states of the structural isomers in the photo-oxidation of guanine is explored. Both complexes possess characteristic metal-to-ligand charge-transfer (MLCT) bands between 400 and 500 nm and emission at ca. 630 nm in an aerated aqueous solution. Transient visible absorption (TrA) spectroscopy reveals that 400 nm excitation of 1 yields a dppn-based metal-to-ligand charge-transfer (MLCT) state, which in turn populates a dppn intraligand (3IL) state. In contrast, photoexcitation of 2 results in an MLCT state on the TAP ligand and not the intercalating bdppz ligand. Both 1 and 2 bind strongly to double-stranded guanine-rich DNA with a loss of emission. Combined TrA and time-resolved infrared (TRIR) spectroscopy confirms formation of the guanine radical cation when 2 is bound to the d(G5C5)2 duplex, which is not the case when 1 is bound to the same duplex and indicates a different mechanism of action in DNA. Utilizing the long-lived triplet excited lifetime, we show good uptake and localization of 2 in live cells as well as isolated chromosomes. The observed shortening of the excited-state lifetime of 2 when internalized in cell chromosomes is consistent with DNA binding and luminescent quenching due to guanine photo-oxidation.

Radical Cation Diels–Alder Reaction by Photocatalysis at a Dye Sensitized Photoanode

Radical Cation Diels–Alder Reaction by Photocatalysis at a Dye Sensitized Photoanode

Synthesis, molecular docking, drug‐likeness analysis, and ADMET prediction of nickel and zinc tetraphenyl‐porphyrin complexes as possible antioxidant agents

AbstractNickel tetraphenyl‐porphyrin (NiTPPH₂) and zinc tetra(4‐methophenyl)‐porphyrin (ZnTPPH₂(p‐methyl)) were successfully synthesized and characterized using 1H NMR spectroscopy. Their antioxidant activities and interactions with the superoxide anion radical () were evaluated using cyclic voltammetry. Remarkably, NiTPPH₂ displayed superior antioxidant activity with an IC50 value of 54.57 μg mL−1, significantly outperforming α‐tocopherol (IC50 = 353.27 μg mL−1), indicating its potential as a potent antioxidant. Binding free energy calculations demonstrated that electrostatic interactions predominantly govern the binding, with values of −23.47 kJ mol−1 for NiTPPH₂ and −22.50 kJ mol−1 for ZnTPPH₂(p‐methyl). These values suggest robust binding affinities with . Quantum chemical parameters, obtained through density functional theory (DFT), showed a strong correlation with experimental results, validating the computational approach. Additionally, ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) and drug‐likeness assessments, alongside molecular docking studies, highlighted favorable pharmacokinetic profiles and binding affinities. These findings underscore the potential of NiTPPH₂ and ZnTPPH₂(p‐methyl) as promising candidates for antioxidant therapy, exhibiting drug‐like properties and favorable pharmacokinetics. This research advances the understanding of these porphyrin derivatives and their application in the development of novel antioxidant therapeutics.

Heating mode transitions in Capacitively Coupled CF4 Plasmas at low pressure

Abstract Capacitively coupled plasmas operated in CF4 at low pressure are frequently used for dielectric plasma etching. For such applications the generation of different ion and neutral radical species by energy dependent electron impact ionization and dissociation of the neutral background gas is important. These processes are largely determined by the space and time dependent electron energy distribution function and, thus, by the electron power absorption dynamics. In this work and based on a PIC/MCC model, we show that the electron heating mode in such plasmas is sensitive to changes of the gap at a constant pressure of 3 Pa. At a gap of 1.5 cm, the dominant mode is found to be a hybrid combination of the Drift-Ambipolar (DA) and the α-mode. As the gap is increased to 2 cm and 2.5 cm, the bulk power absorption and ambipolar power absorption decreases, and the DA mode decays. When the gap reaches 3 cm, the α-mode becomes more prominent, and at a gap of 3.75 cm the α-mode is dominant. These mode transitions are caused by a change of the electronegativity and are found to affect the discharge characteristics. The presence of the DA-mode leads to significant positive electron power absorption inside the bulk region and negative power absorption within the sheaths on time average, as electrons are accelerated from the bulk towards the collapsed sheath. The heating mode transitions result in a change from negative to positive total electron power absorption within the sheaths as the gap increases. When accounting for secondary electron emission (SEE), the transition of the heating mode can occur at shorter gaps due to the enhanced plasma density and decreased electronegativity.

Visible-Light-Promoted Cascade Carboxylation/Arylation of Unactivated Alkenes with CO2 for the Synthesis of Carboxylated Indole-Fused Heterocycles.

Described here is a visible-light-promoted cascade carboxylation/arylation of indole-tethered unactivated alkenes with CO2 to access various carboxylated indole-fused heterocycles. This reaction is initiated by the addition of a CO2 radical anion to the alkene motif toward an alkyl carbon radical, followed by its addition to the aromatic ring, and then rearomatization to afford the final products. This reaction provides a facile and sustainable protocol for the construction of carboxylated indole-fused heterocycles using CO2 as the carboxylic source.

A hollow mesoporous iron oxide nanoparticle to strengthen Fenton reaction and weaken antioxidant defense systems for high efficacy tumor ferroptosis therapy

Traditional drug delivery system (DDS) such as hollow mesoporous organosilica nanoparticle (HMON) can achieve efficient delivery of ferroptosis-inducing agents for tumor therapy due to its high drug loading content (DLC), but is limited by their slow degradation and the uselessness of their silicon-based compounds. In this study, a novel hollow mesoporous superparamagnetic iron oxide nanoparticle (HMSPION) was developed with 100 nm of hollow core and 40 nm of mesoporous shell with a high DLC (up to 22.9 %) of β-Lapachone (LAP), doxorubicin (DOX), sorafenib (SFN) and/or Zn2+. Furthermore, we propose a new strategy to strengthen Fenton reaction and weaken antioxidant defense systems in tumors by co-loading Zn2+ and LAP into HMSPION to generate LAP@HMSPION@Zn. Specifically, i) LAP@HMSPION@Zn is degraded into Fe2+/3+, Zn2+, and LAP in acidic tumor microenvironment. ii) LAP catalyzes O2 to be superoxide anion radical (O2•−) and Zn2+ raises the O2•− production in mitochondria. iii) The O2•− can be catalyzed into hydrogen peroxide (H2O2) via superoxide dismutase. iv) H2O2 and the released Fe2+ accelerate the Fenton reaction, generating highly toxic hydroxyl radical (•OH). v) The Fe3+ consumes GSH and LAP downregulates GSH level by NADPH consumption, thereby relieving the antioxidant defense systems in tumor cells.

Development of Methods to Generate Radical Species and Synthetic Applications

Radicals are chemical species bearing an isolated single electron. They have developed in a complementary manner to the two-electron species such as anions and cations. Radical species are classified into different groups according to their electronic states, such as cation radicals, neutral radicals, anion radicals, and biradicals, each of which has high reactivity and induces specific reactions. The authors have been developing studies on radical species to establish the generation methods and to control their reactivity. The author has found that heavy atom-containing compounds can undergo photochemical reactions that generate radical species through direct S0→Tn transitions. The S0→Tn absorption band exists in a longer wavelength region than the corresponding S0→Sn band, and thus light in the near-visible light region can be used for the reactions. Although the absorption efficiency of the S0→Tn transition is not high, it is possible to selectively excite heavy atom-containing molecules by irradiation of near-visible light, thus making it possible to control the generation and reactivity of radical species. The author also succeeded in developing a ligand that is activated by visible light irradiation to generate the monovalent palladium radical species. By using this ligand, it was possible to efficiently generate radical species of transition metals. Furthermore, depending on the valence of the palladium used, radical species with opposite properties could be generated.

Implications of Ultrasonication-assisted Extraction with Response Surface Methodology on Phytochemical Compositions and Antioxidant Activity of Polysaccharide Extract from Phellinus rimosus (Berk.) Pilát Cultivated Mycelia in Northeastern Thailand

Background: Polysaccharides from the medicinal mushroom Phellinus rimosus (Berk.) Pilát (PR) are the major functional bioactive ingredients. However, there has been a marked natural decrease in the number of PR fruit bodies, leading to their increased cost. Moreover, the natural growth and development of mature PR fruit bodies takes several decades. Objective: The objective of this study was to produce a polysaccharide extract from cultured PR mycelia (PEPRM) by using ultrasonic-assisted extraction with response surface methodology (RSM), and determine its physicochemical composition and antioxidant potential. Methods: Polysaccharide and monosaccharide composition analyses were carried out by Fouriertransform infrared spectroscopy (FT-IR) and High-performance liquid chromatography (HPLC). Total contents of polysaccharides, beta-glucans, phenolic compounds, and flavonoids were investigated utilizing the phenol-sulfuric acid method, enzymatic-based commercial test kit, Folin-Ciocalteu method, and aluminium chloride colorimetric method, respectively. Antioxidant activity was determined by using 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) radical scavenging assay and 2,2- azino-bis (3-ethylbenzothiazol-6-sulfonic acid) (ABTS) radical cation decolorization assay. Results: Optimal conditions for the production of PEPRM included a ratio of 51.29 mL water to 1 g PR mycelia and an extraction time of 46.23 minutes, resulting in a total polysaccharide content of 577.5 mg/g of PEPRM. FT-IR spectra of PEPRM showed two broad bands at 3272.08 cm-1 and 2924.8 cm-1 in the carbohydrate region and the peaks at 1078.44, 1019.05, and 853.0 cm-1 indicated the presence of the pyranose ring skeleton, glycosidic linkage, and glucans. PEPRM had molar ratios of glucose: mannose: rhamnose: fucose, i.e., 21.86: 1.00: 2.08: 3.40, respectively. PEPRM had total contents of beta-glucans, phenolic compounds, and flavonoids as percentages of dry weight, i.e., 21.22, 2.51, and 5.71, respectively. PEPRM showed better inhibitory activity against ABTS radicals than DPPH radicals. result: Optimal conditions for the production of PEPRM were a ratio of 51.29 ml water to 1 g PR mycelia and extraction time of 46.23 min, yielding a total polysaccharide content of 577.5 mg/g of PEPRM. FT-IR spectra of PEPRM showed two broad bands at 3272.08 cm-1 and 2924.8 cm-1 in the carbohydrate region and the peaks at 1078.44, 1019.05, and 853.0 cm-1 indicated the presence of the pyranose ring skeleton, glycosidic linkage, and glucans. PEPRM had molar ratios of glucose: mannose: rhamnose: fucose, i.e., 21.86: 1.00: 2.08: 3.40, respectively. PEPRM had total contents of beta-glucan, phenolic compounds, and flavonoids as percentages of dry weight, i.e., 21.22, 2.51, and 5.71, respectively. PEPRM showed better inhibitory activity against ABTS radicals than DPPH radicals. Conclusion: This is the first finding to reveal that ultrasonic-assisted extraction with RSM was an environmentally friendly alternative to produce antioxidant polysaccharides from cultured PR mycelia. conclusion: This is the first finding to reveal that ultrasonic-assisted extraction with RSM was an environmentally friendly alternative to produce antioxidant polysaccharides from cultured PR mycelia.

Inherently Chiral Oligomers Based on Indole-Benzothiophene Core.

In recent years, transductors of chiral information based on conducting polymers have gained considerable attention. In particular, inherently chiral materials, which allow differentiation between the antipodes of a chiral analyte in terms of energetic variations, are highly desired. In this work, we successfully synthesized a novel inherently chiral oligomer based on an indole-benzothiophene core, namely, 2-([2,2'-bithiophen]-5-yl)-3-(2-([2,2'-bithiophen]-5-yl)benzo[b]thiophen-3-yl)-N-methylindole (BTIndT4). The electrochemical characterization evidences a stabilization of electrogenerated radical cations due to the presence of the indole group, which guides the oligomerization, producing well-ordered polymeric matrices. Furthermore, the insitu electrochemical conductance analysis demonstrates a simultaneous intrachain and interchain transfer of charge carriers. Finally, the highly efficient enantiorecognition capabilities of the antipodes of the oligo-BTIndT4 films toward the enantiomers of tryptophan and 3,4-dihydroxyphenylalanine (DOPA), as model chiral analytes, were demonstrated.

N-Halosuccinimide-CeCl3 Transient Charge-Transfer Complexes as Semi Heterogeneous Photocatalyst in Cyclization of N-Propargylamides.

In this work, we used photoinert anhydrous cerium(III) chloride, to form a transient charge-transfer (CT) complex with NXS (N-bromosuccinimide or NBS and N-iodosuccinimide or NIS) in acetonitrile. These transient CT complexes acted as a semi-heterogeneous photocatalyst. These complexes allowed the Ce(III) ions to absorb light, turning them into strong electron donors that transferred electrons to NXS. This created halide radicals from NXS radical anions, helping to turn N-propargylamides into oxazole aldehydes. Experiments with DMPO and spin-trapping showed that a radical-based mechanism followed a single electron transfer (SET) pathway. Notably, CeCl3 was reused after the reaction without much decomposition, as it was regenerated and separated through simple filtration.

Solid-State Laser-Assisted Synthesis of Cobalt Single-Atom Catalysts for Detecting Superoxide Radical Anions

Solid-State Laser-Assisted Synthesis of Cobalt Single-Atom Catalysts for Detecting Superoxide Radical Anions

A Redox‐Active Phenothiazine‐based Pd2L4‐Type Coordination Cage and Its Isolable Crystalline Polyradical Cations

AbstractPolyradical cages are of great interest because they show very fascinating physical and chemical properties, but many challenges remain, especially for their synthesis and characterization. Herein, we present the synthesis of a polyradical cation cage 14⋅+ through post‐synthetic oxidation of a redox‐active phenothiazine‐based Pd2L4‐type coordination cage 1. It′s worth noting that 1 exhibits excellent reversible electrochemical and chemical redox activity due to the introduction of a bulky 3,5‐di‐tert‐butyl‐4‐methoxyphenyl substituent. The generation of 14⋅+ through reversible electrochemical oxidation is investigated by in situ UV/Vis‐NIR and EPR spectroelectrochemistry. Meanwhile, chemical oxidation of 1 can also produce 14⋅+ which can be reversibly reduced back to the original cage 1, and the process is monitored by EPR and NMR spectroscopies. Eventually, we succeed in the isolation and single crystal X‐ray diffraction analysis of 14⋅+, whose electronic structure and conformation are distinct to original 1. The magnetic susceptibility measurements indicate the predominantly antiferromagnetic interactions between the four phenothiazine radical cations in 14⋅+. We believe that our study including the facile synthesis methodology and in situ spectroelectrochemistry will shed some light on the synthesis and characterization of novel polyradical systems, opening more perspectives for developing functional supramolecular cages.

A Redox-Active Phenothiazine-based Pd2L4-Type Coordination Cage and Its Isolable Crystalline Polyradical Cations.

Polyradical cages are of great interest because they show very fascinating physical and chemical properties, but many challenges remain, especially for their synthesis and characterization. Herein, we present the synthesis of a polyradical cation cage 14⋅+ through post-synthetic oxidation of a redox-active phenothiazine-based Pd2L4-type coordination cage 1. It's worth noting that 1 exhibits excellent reversible electrochemical and chemical redox activity due to the introduction of a bulky 3,5-di-tert-butyl-4-methoxyphenyl substituent. The generation of 14⋅+ through reversible electrochemical oxidation is investigated by in situ UV/Vis-NIR and EPR spectroelectrochemistry. Meanwhile, chemical oxidation of 1 can also produce 14⋅+ which can be reversibly reduced back to the original cage 1, and the process is monitored by EPR and NMR spectroscopies. Eventually, we succeed in the isolation and single crystal X-ray diffraction analysis of 14⋅+, whose electronic structure and conformation are distinct to original 1. The magnetic susceptibility measurements indicate the predominantly antiferromagnetic interactions between the four phenothiazine radical cations in 14⋅+. We believe that our study including the facile synthesis methodology and in situ spectroelectrochemistry will shed some light on the synthesis and characterization of novel polyradical systems, opening more perspectives for developing functional supramolecular cages.

A DFT study on the heterolytic bond cleavage of hydrazones under cathodic conditions in acetonitrile.

Hydrazones have been studied for a myriad of chemical and physiochemical properties, such as sensors, chelators and numerous biological activities. Experimental data indicates that hydrazones are unstable under cathodic potentials irrespective of the solvent. The single electron reduction of hydrazones to produce radical anions result in unstable species that cleaves at the N-N bond in a heterolytic manner. The literature has proposed a mechanism favouring the radical on the imine moiety, however in this study DFT calculations suggest the radical on the amine product is more likely upon bond cleavage. This has implications on electrochemical mechanisms, and the active molecule in biological studies viz the method of delivery to target areas. Density functional theory calculations were carried out using the GAMESS software package. The structures were optimized in the gas phase (B3LYP/6-31G(d,p)) as indicated by the absence of imaginary frequencies in the Hessian, and in CH3CN (B3LYP/6-31G(d,p)/SMD) with the Pople polarization functions. As a comparison, selected pathways were fully optimized using PBE0/6-31G(d,p) and PBE0/6-31G(d,p)/SMD for gas phase and CH3CN, respectively with the Pople polarization functions. The values were not significantly different (< 5% difference). As such only the B3LYP is evaluation is discussed.

Size-dependent influences of nano- and micro-plastics exposure on feeding, antioxidant systems, and organic sulfur compounds in ciliate Uronema marinum

Protozoa play a pivotal role in the microbial cycle, and ciliated protozoan grazing habits are associated with dimethyl sulfide (DMS) cycle. Many studies have explored the impacts of nanoplastics (NPs) and microplastics (MPs) on ecotoxicological effects of ciliates. However, limited research exists on NPs and MPs influences on the production of organic sulfur compounds. The impact of NPs and MPs on the production of dimethyl sulfoxide (DMSO) and carbonyl sulfide (COS) remains unclear. Therefore, we examined the impacts of three concentrations (1 × 105, 5 × 105, and 1 × 106 items/mL) of polystyrene (PS) NPs (50 nm) and MPs (1 and 5 μm) on the ecotoxicology and DMS/dimethylsulfoniopropionate (DMSP)/DMSO/COS production in the ciliate Uronema marinum. NPs and MPs exposure were found to reduce the abundance, growth rate, volume, and biomass of U. marinum. Additionally, NPs and MPs increased the superoxide anion radical (O2˙─) production rates and malondialdehyde (MDA) contents (24 h), leading to a decline in glutathione (GSH) content and an ascend in superoxide dismutase (SOD) activity to mitigate the effects of reactive oxygen species (ROS). Exposure to PS NPs and MPs decreased the ingestion rates of algae by 7.5–14.4%, resulting in decreases in DMS production by 56.8–85.4%, with no significant impact on DMSO production. The results suggest a distinct pathway for the production of DMSO or COS compared to DMS. These findings help us to understand the NPs and MPs impacts on the marine ecosystem and organic sulfur compound yield, potentially influencing the global climate.

Antioxidant Activities and Laxative Effect of Bioactive Compounds from Cynara cardunculus var. sylvestris

The present study aims to investigate the antioxidant and anti-constipation activities of the derived phenolic extracts in ribs wild cardoon (Cynara sylvestris). Analysed extracts (acetone, methanol and aqueous) exhibited high level of phenolic compounds and excellent antioxidant activities with significant IC50 values (p ≤0.05), as assessed by the DPPH radical-scavenging activity (0.84±0.08 - 2.44±0.007 μg/mL), ABTS cationic radical test (0.96 ±0.01- 136.67±6.75 μg/mL) and β-carotene bleaching assay (2.09±0.02-51.12±1.32 μg/mL). Also, higher levels of insoluble dietary fibers were found (56.18 ± 0.91% DW of neutral detergent fiber). The in vivo investigation was performed on Wistar rats to explore the ability of C. sylvestris aqueous extract (CSAE) in the enhancement of the gastrointestinal transit and the treatment of induced constipation by Loperamide (commercialized as Idium). A significant increase of 15, 24.5 and 32.4% in gastrointestinal motility was recordedwhen doses of CSAE increased (75, 150 and 300 mg/kg b.w, respectively). Food intake, water consumption, number and weight of stools were also increased in a dose-dependent manner, compared to the positive control (untreated). Moreover, CSAE provided significantly (p ≤0.05) and dose-dependently protection against oxidative stress by preserving normal antioxidant enzymes activities (SOD and GPx) in intestinal and colonic mucosa, and resorted hepatic enzymes (AST and ALT) and renal (urea and creatinine) levels to normal values. These results can be explained by the abundance of phenolic compounds and insoluble fibers in this plant. Therefore, its use can be encouraged in alimentary and pharmaceutical applications as antioxidant and laxative food supplements.

Hierarchical multi-task deep learning-assisted construction of human gut microbiota reactive oxygen species-scavenging enzymes database.

In the process of oxygen reduction, reactive oxygen species (ROS) are generated as intermediates, including superoxide anion (O2-), hydrogen peroxide (H2O2), and hydroxyl radicals (OH-). ROS can be destructive, and an imbalance between oxidants and antioxidants in the body can lead to pathological inflammation. Inappropriate ROS production can cause oxidative damage, disrupting the balance in the body and potentially leading to DNA damage in intestinal epithelial cells and beneficial bacteria. Microorganisms have evolved various enzymes to mitigate the harmful effects of ROS. Accurately predicting the types of ROS-scavenging enzymes (ROSes) is crucial for understanding the oxidative stress mechanisms and formulating strategies to combat diseases related to the "gut-organ axis." Currently, there are no available ROSes databases (DBs). In this study, we propose a systematic workflow comprising three modules and employ a hierarchical multi-task deep learning approach to collect, expand, and explore ROSes-related entries. Based on this, we have developed the human gut microbiota ROSes DB (http://39.101.72.186/), which includes 7,689 entries. This DB provides user-friendly browsing and search features to support various applications. With the assistance of ROSes DB, various communication-based microbial interactions can be explored, further enabling the construction and analysis of the evolutionary and complex networks of ROSes DB in human gut microbiota species.IMPORTANCEReactive oxygen species (ROS) is generated during the process of oxygen reduction, including superoxide anion, hydrogen peroxide, and hydroxyl radicals. ROS can potentially cause damage to cells and DNA, leading to pathological inflammation within the body. Microorganisms have evolved various enzymes to mitigate the harmful effects of ROS, thereby maintaining a balance of microorganisms within the host. The study highlights the current absence of a ROSes DB, emphasizing the crucial importance of accurately predicting the types of ROSes for understanding oxidative stress mechanisms and developing strategies for diseases related to the "gut-organ axis." This research proposes a systematic workflow and employs a multi-task deep learning approach to establish the human gut microbiota ROSes DB. This DB comprises 7,689 entries and serves as a valuable tool for researchers to delve into the role of ROSes in the human gut microbiota.