Nitro Derivatives Research Articles

Non-thermal plasma modulated l-tyrosine self-assemblies: a potential avenue for fabrication of supramolecular self-assembled biomaterials.

Aromatic amino acids (AAs) have garnered particular interest due to their pivotal roles in numerous biological processes and disorders. Variations in AA self-assembly not only affect protein structures and functions, but their non-covalent interactions such as hydrogen bonding, van der Waals forces, and π-π stacking, yield versatile assemblies vital in bio-inspired material fabrication. Tyrosine (Tyr), a non-essential aromatic amino acid, holds multifaceted significance in the body as a protein building block, neurotransmitter precursor, thyroid hormone contributor, and melanin synthesis regulator. The proficiency of Cold Atmospheric Plasma (CAP) in generating a spectrum of reactive oxygen and nitrogen species has spurred innovative research avenues in the studies of biomolecular components, including its potential for targeted cancer cell ablation and biomolecule modification. In this work, we have assessed the chemical as well as the structural changes in Tyrosine-derived self-assembled structures arising from the CAP-induced reactive species. For a comprehensive understanding of the mechanism, different treatment times, feed gases, and the role of solvent acidification are compared using various spectroscopic and microscopic techniques. LC-ESI-QQQ mass spectra unveiled the emergence of oxygenated and nitro derivatives of l-tyrosine following its interaction with CAP-derived ROS/RNS. SEM and TEM images demonstrated an enhanced surface size of self-assembled structures and the formation of novel nanomaterial-shaped assemblies following CAP treatment. Overall, this study aims to explore CAP's interaction with a single-amino acid, hypothesizing the creation of novel supramolecular structures and scrutinizing CAP-instigated transformations in l-tyrosine self-assembled structures, potentially advancing biomimetic-attributed nanomaterial fabrication which might present a novel frontier in the field of designing functional biomaterials.

Инактивация ксенобиотиков: некоторых азокрасителей, нитропроизводных фенола и тетрациклинов

The problem of environmental pollution by human waste products is currently critically relevant. Organic fragments undergo degradation slowly and as a result accumulate in ecosystems. Many studies confirm the presence of various pollutants in rivers, soils, atmosphere. Despite a large body of work on the search for methods of inactivation and purification of such pollutants, there is no universal method, applicable to various classes of xenobiotics. The purpose of this work has been to study the destructive processes of model systems of xenobiotics of various nature. UV irradiation has been used as a method of destruction. The destruction of model substances has been studied in the work: two dyes, two pharmaceuticals and two nitro derivatives of phenol. Destructive processes of model systems of various pollutants have been studied. It is shown that many substrates undergo photodestruction within the first hour. Kinetic characteristics of these processes are calculated. The results obtained indicate that UV irradiation can be considered as a promising method of inactivation of various pollutants.

Synthesis and voltammetric studies of azo dye compounds derived from 3-hydroxyquinolin-2-one in aqueous media

Azo dye derived from 3-hydroxyquinolin-2-one were synthesized and characterized by IR and 1HNMR. DC-polarography and cyclic voltammetry behavior of these compounds is considered in Britton-Robinson buffer solutions in the range of pH 2–12. The investigated azo compounds gave an irreversible dc-polarographic wave owing to the reduction of azo center with the consumption of four electrons controlled by diffusion, through the splitting of the N = N center to the amine group. For nitro derivative a single 8-elctron wave is observed. In cyclic voltammetry a cathodic peak was obtained for all compounds in the entire pH range. The kinetic data of the reduction process was determined and examined in view of the influence of medium and substitutes and the reduction mechanism was found to be H+, e, e, H+. The free energy of activation ∆G* was observed to increase whereas the rate constant kf,h diminishes with rise of the pH of the electrolysis medium. The effect of substituents was studied based on Hammett constants and showed that the electron withdrawing group facilitate the electrode reaction whereas the electron donating ones hinder it.

The discovery of aryl-2-nitroethyl triamino pyrimidines as anti-Trypanosoma brucei agents

Pteridine reductase 1 (PTR1) is a catalytic protein belonging to the folate metabolic pathway in Trypanosmatidic parasites. PTR1 is a known target for the medicinal chemistry development of antiparasitic agents against Trypanosomiasis and Leishmaniasis. In previous studies, new nitro derivatives were elaborated as PTR1 inhibitors. The compounds showing a diamino-pyrimidine core structure were previously developed but they showed limited efficacy. Therefore, a new class of phenyl-, heteroaryl- and benzyloxy-nitro derivatives based on the 2-nitroethyl-2,4,6-triaminopyrimidine scaffold were designed and tested. The compounds were assayed for their ability to inhibit T. brucei and L. major PTR1 enzymes and for their antiparasitic activity towards T. brucei and L. infantum parasites. To understand the structure-activity relationships of the compounds against TbPTR1, the X-ray crystallographic structure of the 2,4,6-triaminopyrimidine (TAP) was obtained and molecular modelling studies were performed. As a next step, only the most effective compounds against T. brucei were then tested against the amastigote cellular stage of T. cruzi, searching for a broad-spectrum antiprotozoal agent. An early ADME-Tox profile evaluation was performed. The early toxicity profile of this class of compounds was investigated by measuring their inhibition of hERG and five cytochrome P450 isoforms (CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4), cytotoxicity towards A549 cells and mitochondrial toxicity. Pharmacokinetic studies (SNAP-PK) were performed on selected compounds using hydroxypropyl-β-cyclodextrins (50 % w/v) to preliminarily study their plasma concentration when administered per os at a dose of 20 mg/kg. Compound 1p, showed the best pharmacodynamic and pharmacokinetic properties, can be considered a good candidate for further bioavailability and efficacy studies.

Experimental (NMR) and Theoretical (DFT Method) Studies of the Nucleophilic Substitution Reaction of 1-Methyl-4-, 6- and 7-NitroIndazoles by 2-(p-Tolyl) Acetonitrile

Theoretical and experimental study of the reactivity between alkyl nitroindazole molecules and aryl acetonitrile molecules was evaluated by Density Functional Theory (DFT) using a basis set of B3LYP/6-311G (d, p) level and experimental Nuclear Magnetic Resonance (NMR) data. Global quantum chemical parameters derived from DFT showed that these compounds are reactive while NMR data indicated the influence of nitro group on ortho, meta and para positions. The distinction atoms capable of undergoing nucleophilic and electrophilic attacks at the level of each molecule were spread by Fukui functions and dual descriptor. This distinction has helped to explain the mechanism of some nitro derivatives formation. Experimental and theoretical results are convergent and consistent.

Green Ultrasound-Assisted Synthesis of Rare-Earth-Based MOFs.

Rare-earth (RE)-based metal organic frameworks (MOFs) are quickly gaining popularity as flexible functional materials in a variety of technological fields. These MOFs are useful for more than just conventional uses like gas sensors and catalyst materials; in fact, they also show significant promise in emerging technologies including photovoltaics, optical, and biomedical applications. Using yttrium and europium as ionic host centres and dopants, respectively, and 1,3,5-benzenetricarboxylic acid (H3-BTC) as an organic linker, we describe a simple and green approach for the fabrication of RE-MOFs. Specifically, Y-BTCs and Eu-doped Y-BTCs MOFs have been synthesised in a single step using an eco-friendly method that makes use of ultrasound technology. To establish a correlation between the morphological and structural properties and reaction conditions, a range of distinct reaction periods has been employed for the synthetic processes. Detailed analyses of the synthesised samples through powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FT-IR) have confirmed the phase formation. Furthermore, thermal analyses such as thermogravimetric analysis (TGA) have been employed to evaluate the thermal stability and structural modifications of the Y-BTC and Eu-doped Y-BTC samples. Finally, the luminescent properties of the synthesised samples doped with Eu3+ have been assessed, providing an evaluation of their characteristics. As a proof of concept, an Eu-doped Y-BTC sample has been applied for the sensing of nitrobenzene as a molecule test of nitro derivatives.

Charge transfer complexes of nitroderivatives of 9,10-phenanthreqinone with 9-methyl-9<i>H</i>-carbazole: quantum chemical simulation, x-ray diffraction study

Within the framework of the density functional theory approximation, quantum-chemical calculations were performed and data on the structure and properties of charge-transfer complexes of 9,10-phenanthrenquinone nitro derivatives with 9-methyl-9 H -carbazole were obtained. The formation energies of complexes, the average distances between the donor and acceptor planes, and the values of charge transfer from the donor to the acceptor have been calculated. The crystal and molecular structure of the complex of 2,4,7-trinitro-9,10-phenanthrenquinone with 9-methyl-9 H -carbazole (C14H5N3O8·C13H11N) was determined by X-ray diffraction analysis. In the crystal of the complex, the donor and acceptor molecules form parallel stacks of the {-D-A-D-A-}∞ mixed type with average interplanar distances of 3.29 and 3.35 Å. Each acceptor molecule forms intermolecular hydrogen bonds C-H···O 2.42-2.69 Å.

Tert‐Butylnitrite Mediated Regioselective C(sp2)−3 Nitration of Substituted 4‐Quinolones and Its Late‐stage Manipulations

AbstractA novel and eco‐friendly technique for the synthesis of C‐3 nitro derivatives of 4‐quinolones via the regioselective C(sp2)−H bond functionalization employing tert‐butyl nitrite as nitrating agent in presence of TEMPO [(2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl] as an oxidant is unfolded herein. The protocol is scalable as well as high yielding with wide substrate scope and broad functional group tolerance. In‐depth mechanistic investigations revealed that the reaction occurred through a free radical pathway. The nitro derivatives of 4‐quinlones were selectively reduced to corresponding aminated 4‐quinolones. Finally, the photophysical properties of synthesized amine derivatives were also investigated, and some of them showed good fluorescence properties.

Плазмохимический синтез нитропроизводных аценафтена в поле токов высокой частоты при пониженном давлении

Plasma-chemical processing devices are widely used in practice and are an integral part in microelectronics, medicine, light industry and nanotechnology. In addition, they are used as methods for modifying the modern materials surfaces and in liquids processing. The paper considers preparation of the aromatic compound nitro derivatives under the action of capacitive high-frequency electrodeless discharge at the gas--liquid interface with the reduced pressure. During the plasma-chemical treatment of the reaction mixture containing the 1,2-dihydroacenaphthylene (acenaphthene), its complete conversion was observed, which was confirmed by detection of the acenaphthene mono- and dinitro-derivatives, as well as of the side chain oxidation products, in the reaction products. The proposed method of implementing nitration reaction of the aromatic substances, which belongs to the new instrumental methods of organic synthesis along with photochemistry and electrochemical synthesis, allows direct binding of the molecular nitrogen and oxygen into the valuable nitrogen-containing organic compounds. Study results demonstrate effective introduction of the plasma chemistry methods in chemical technology not only for the purposes of oxidative destruction of the organic substances, but also as the physicochemical tools for the fine organic synthesis allowing selective functionalization of the polynuclear aromatic compounds

Charge-Transfer Complexes of Nitro Derivatives of 9,10-Phenanthrenequinone with 9-Methyl-9H-carbazole: Quantum Chemical Simulation and X-Ray Diffraction Study

Charge-Transfer Complexes of Nitro Derivatives of 9,10-Phenanthrenequinone with 9-Methyl-9H-carbazole: Quantum Chemical Simulation and X-Ray Diffraction Study

3′-Nitro- and 3′-Aminofluoresceins: Appearance of Previously Missing Dyes

Contrary to the 4′- and 5′-nitro- and aminofluoresceins, the corresponding 3′-derivatives are practically unexplored. In this paper, we describe the synthesis and spectral properties of 3′-nitrofluorescein and 3′-aminofluorescein, as well as their methyl esters. Among other methods, X-ray analysis, 13C NMR spectroscopy, and ESI mass spectrometry made it possible to establish the molecular structure of the target compounds as well as intermediates and by-products. Some unexpected products, though in small amounts, were revealed within the course of study. Whereas the fluorescence of the double-charged R2− ion of 3′-nitrofluorescein in both aqueous and organic solvents is weak, the R2− anion of 3′-aminofluorescein in a non-hydrogen bonding donor solvent, but not in water, exhibits intensive fluorescence, analogous to the case of 4′- and 5′-aminofluoresceins. Interestingly, the λmax values in water of the R2− ions bearing an NO2 group in the 3′- and 6′-positions are 7 to 10 nm higher than those of the 4′- and 5′-nitro derivatives. The difference was also observed in dimethyl sulfoxide. This correlates with the angles between the xanthene and phthalic planes of the dyes. The dye 3′-aminofluorescein could be used as a fluorescent indicator sensitive to hydrogen bonding ability of the solvent. It could also serve as a platform for synthesizing fluorescent molecular probes for biochemical research, analogous to the very popular application of 4′- and 5′-amino derivatives.

Co(OAc)2/TBHP as a Highly Active Catalytic System for the Selective Oxidation of Aromatic Amines to Nitro Derivatives

AbstractAn efficient cobalt-catalyzed protocol for the selective oxidation of anilines using a combination of inexpensive tert-butyl hydroperoxide and Co(OAc)2·4H2O without any ligand has been developed, providing the nitroarene products in good to excellent yields (up to 96%).

Hybridization of the effective pharmacophores for treatment of epilepsy: design, synthesis, in vivo anticonvulsant activity, and in silico studies of phenoxyphenyl-1,3,4-oxadiazole-thio-N-phenylacetamid hybrids

BackgroundEpilepsy is a common neurological disorder. The available drugs for this disease only control convulsions in nearly 70% of patients, while bearing many side effects. In this study, a new series of phenoxyphenyl-1,3,4-oxadiazole-thio-N-phenylacetamid hybrids 8a-m was designed, synthesized, and evaluated as potent anticonvulsant agents.MethodsPhenoxyphenyl-1,3,4-oxadiazole-thio-N-phenylacetamid derivatives 8a-m were synthesized with well-known chemical reactions and anticonvulsant activity of them was determined by pentylenetetrazole (PTZ) and maximal electroshock (MES) induced seizures in mice. Phenoxyphenyl-1,3,4-oxadiazole-thio-N-phenylacetamid scaffold has the necessary pharmacophores to be a benzodiazepine (BZD) receptor agonist, thus, the most potent anticonvulsant compounds were assayed in vivo and in silico as BZD receptor agonist. Furthermore, in vivo neurotoxicity evaluation and in silico physicochemical, pharmacokinetic, and toxicity study on the most potent compounds were also performed.ResultsObtained results demonstrated that two compounds among the title new compounds have anticonvulsant activity in PTZ test while all of the new compounds are active in the MES test. The best anticonvulsant activities were obtained with nitro derivatives 8k and 8L. In vivo evaluation of flumazenil effect (a BZD receptor antagonist) on anticonvulsant activity of compound 8k confirmed that this compound is a BZD receptor agonist. The most potent compounds 8k and 8L interacted with the important residues of BZD-binding site of GABAA receptor. Furthermore, neurotoxicity of the latter compounds was lower than positive control diazepam.ConclusionAccording to these results, our designed scaffold can be a valuable lead structure for further structural developments and assessments to obtain a new potent anticonvulsant agent.

Towards understanding of stepwise acid-base dissociation in systems inclined to tautomerism: Nitro derivatives of fluorescein in dimethyl sulfoxide

Understanding the dissociation of polyprotic acids in solution is important for many branches of chemistry and related sciences. A most important and at the same time knotty problem is the relation between the values of the stepwise dissociation constants. Sometimes even in a series of compounds that belong to the same family, the ratio of these constants varies in a wide range. This paper is aimed at disclosing the (unusual) relations between the first and second dissociation constants of the nitro derivatives of fluorescein in dimethyl sulfoxide. Some of the compounds were synthesized for the first time and characterized. The thermodynamic pKa values for 8 dyes were determined using the spectrophotometric method in buffer solutions and compared with the data for 12 earlier examined compounds; the Ka1/Ka2 ratio varies within an extremely wide range of 0.2 to 4 × 107. It is demonstrated that the peculiarities of the tautomerism of molecules, single-, and double-charged anions play a decisive role in this case. Neutral species, H2R, are represented by the quinonoid and lactonic tautomers. The fraction of the latter is higher for all the dyes with the free carboxylic group. For the single-charged anions, HR–, of the 4′- and 5′-mononitrofluoresceins, i.e., dyes with the NO2 group in the phthalic acid residue, the carboxylic group is dissociated (COO–) while the OH group not. In contrast, for the dyes bearing the NO2 group in the 4,5-; 4,5,4′-; 4,5,5′-; or 2,4,5,7-positions the HR– ions exist mainly as a tautomer with the dissociated hydroxyl group (O–) and un-dissociated COOH group. To the dianions, R2–, of fluorescein dyes a structure with the COO– and O– groups is normally ascribed. However, for the 4,5-dinitro-2,7-dibromofluorescein in DMSO, the fraction of the dianion existing as a lactonic tautomer is substantial; previously, it was shown that this tautomer of the R2– ion predominates for the 2,4,5,7-tetranitrofluorescein, 2,4,5,7,4′-, and 2,4,5,7,5′-pentanitrofluoresceins. After assessing the tautomeric relationships and singling out the so-called microscopic constants, the order of dissociating functional groups and the influence of the substituents in the xanthenes moiety became easy to understand. The values for the microscopic dissociation constants were confirmed by the pKa s of the model compounds with blocked carboxylic groups, COOCH3 or COOC2H5.

Chemoselective Nitro Reduction Using Nitrogen‐Doped Carbon‐Encapsulated Ni Catalyst and Y‐Type Packed Bed Column for Continuous Flow Reaction

AbstractSelective reduction of nitro‐containing arenes and heteroarenes was achieved in 5 minutes at room temperature utilizing inexpensive NaBH4 as a hydrogen source and a newly developed Ni@N−C catalyst, obtained via a simple carbon coating process without the need for an external carbon source. A wide variety of nitro derivatives, including pharmaceutical molecules, was successfully reduced to the corresponding amines in yields ranging from 45% to 99% using the Ni@N−C catalyst under general batch conditions. The reactivity and selectivity of the nitro reduction were further enhanced by a continuous flow reaction system, especially when a newly designed Y‐type column was used, and the Osimertinib intermediate was produced on gram scale after 24 hours without any nickel metal contamination or silica gel chromatography purification.

Transition Metal-free Selenium-mediated Synthesis of Aryl amines via Reduction of Nitroarenes.

A scalable and operationally simple on water seleno-mediated reduction of nitroarenes to the respective aryl amines with NaBH4 is described. The reaction proceeds under transition metal-free conditions and is promoted by the formation of Na2Se, which is the effective reducing agent involved in the mechanism. This mechanistic information enabled the development of a mildNaBH4-free protocol for the selective reduction of nitro derivatives bearing labile moieties, including nitrocarbonyl compounds. The selenium-containing aqueous phase can be successfully reused up to four reduction cycles, thus further improving the efficiency of the protocol disclosed herein.

Chemical and photophysical studies on the interaction of reactive oxygen species with carbonylated diazo derivatives: Their chromogenic, fluorescent detection and mechanistic investigation

Reactive oxygen species (ROS) like H2O2 and singlet oxygen (1O2) have an important role in living systems. A particular concentration of H2O2 is very necessary to regulate the physiological activities of cells. Both lower concentrations as well accumulation of H2O2 trigger varieties of diseases. Likewise, excessive 1O2 causes many dysfunctions and leads to many kinds of diseases. So, it is necessary to know the accurate concentration of H2O2 and 1O2 in a different system for safety. Here, we present a chemodosimeter approach to investigate the interactions of H2O2 and 1O2 by the use of diazo compounds through spectroscopy and investigate the reaction mechanism. Dakin and oxidative addition reactions were used respectively where probes showed a good color change and significant changes in absorbance and emission bands. Difluoride substituted diazo compound appeared to show a better limit of detection (4.75 μM at pH = 7.4) for H2O2, and the nitro derivative is found good for 1O2 (36 μM at pH = 9). For the validity of the result, we also carried out DFT quantum chemical studies. Raman and IR spectroscopy were used to investigate the reaction mechanism. Finally, we isolated the final products and characterized which interestingly showed an unusual de-nitration reaction during interactions of the probe with the H2O2 solution and an interesting blue-colored para-quinone derivative of the compound was also isolated.

Nitrobenzoates and Nitrothiobenzoates with Activity against M. tuberculosis.

Esters of weak acids have shown improved antimycobacterial activity over the corresponding free acids and nitro benzoates in particular have previously shown to have a very intriguing activity. To expand the potential of nitro-derivatives of benzoic acid as antimycobacterial drugs and explore the effects of various structural features on the activity of these compounds, we have obtained a library of 64 derivatives containing esters and thioesters of benzoates and studied their activity against M. tuberculosis, the stability of the compounds, their activation by mycobacterial enzymes and the potential cytotoxicity against human monocytic THP-1 cell line. Our results showed that the most active compounds are those with an aromatic nitro substitution, with the 3,5-dinitro esters series being the most active. Also, the greater antitubercular activity for the nitro derivatives was shown to be unrelated to their pKa values or hydrolysis rates. Given the conventional relationship between nitro-containing substances and toxicity, one might anticipate that the great antimicrobial activity of nitro compounds would be associated with high toxicity; yet, we have not found such a relationship. The nitrobenzoate scaffold, particularly the 3,5-dinitrobenzoate scaffold, merits further investigation, because it has the potential to generate future antimycobacterial agents with improved activity.

Synthesis, Anticancer, Antimicrobial and Antioxidant Potential of Novel 4-(Substituted phenyl-1,3,4-oxadiazol/thiadiazol-2-yl)-4-(4-substituted phenyl) Azetidin-2-One Derivatives.

By exploiting the ample biological potential of 1,3,4-oxadiazole/thiadiazole ring, 4-substitutedphenyl-1,3,4-oxadiazol/Thiadiazol-2-yl)-4-(4-substitutedphenyl) azetidin-2-one derivatives were prepared. Various substituted azetidin-2-one derivatives have been identified as immunostimulating and antimicrobial, as well as their antioxidant activity. 2-amino 1,3,4 oxadiazole/thiadiazole conjugates were synthesized by mixing semi/thio carbazides and sodium acetate with water and stirring well, followed by adding aldehydes in methanol at room temperature. Acetate (glacial) was used as the catalyst to produce Schiff's bases (intermediates) by treating substituted aldehydes with 2-amino 1,3,4 oxadiazole/thiadiazole(s). Using the mixture of triethylamine (dropwise) and chloroacetylchloride with vigorous stirring, 4-substitutedphenyl-1,3,4-oxadiazol/Thiadiazol-2-yl)-4-(4-substitutedphenyl) azetidin-2-one derivatives were prepared. The newly synthesized conjugates were evaluated for their anticancer potential using MCF-7 cell lines. Amoxicillin and fluconazole were used as reference drugs to determine their antimicrobial activity. Synthesized derivatives were evaluated for their antioxidant properties using 2-diphenyl-1-picrylhydrazyl (DPPH). In vitro cytotoxicity screening (MTTS assay) revealed that derivatives AZ-5, 9, 10, 14 and 19 demonstrated high efficacy with the percentage of inhibition at different concentration ranges (0.1 μM, 0.5 μM, 1 μM, 2 μM) of 89% to 94% μM as compared to doxorubicin as standard drug. The antimicrobial study indicated that compounds AZ-10, 19, and AZ-20 were found to have significant antimicrobial potential with MIC ranges of 3.34 µM to 3.71 µM in comparison to reference drugs having 4.29 µM to 5.10 µM. Based on antioxidant screening, most of the synthetic derivatives showed greater stability and effectiveness than the standard drug. According to the antioxidant screening, compounds AZ-5 and AZ-15 (IC50 = 45.02 μg/mL and 42.88 μg/mL, respectively) showed the greatest potency, as compared to ascorbic acid (IC50 = 78.63 μg/mL). Structure-activity relationship (SAR) studies of synthesized novel derivatives revealed that para-substituted halogen and nitro derivatives have remarkable potential against MCF-7 cancer cell lines and different microbial strains. Current evidence indicates that the synthesized derivatives may be promising candidates for use in the prevention and treatment of these infections. These synthesized compounds require further mechanism-based research to understand how they interact with the cells.

Analytical Toolbox to Unlock the Diversity of Oxidized Lipids.

ConspectusLipids are diverse class of small biomolecules represented by a large variety of chemical structures. In addition to the classical biosynthetic routes, lipids can undergo numerous modifications via introduction of small chemical moieties forming hydroxyl, phospho, and nitro derivatives, among others. Such modifications change the physicochemical properties of a parent lipid and usually result in new functionalities either by mediating signaling events or by changing the biophysical properties of lipid membranes. Over the last decades, a large body of evidence indicated the involvement of lipid modifications in a variety of physiological and pathological events. For instance, lipid (per)oxidation for a long time was considered as a hallmark of oxidative stress and related proinflammatory signaling. Recently, however, with the burst in the development of the redox biology field, oxidative modifications of lipids are also recognized as a part of regulatory and adaptive events that are highly specific for particular cell types, tissues, and conditions.The initial diversity of lipid species and the variety of possible lipid modifications result in an extremely large chemical space of the epilipidome, the subset of the natural lipidome formed by enzymatic and non-enzymatic lipid modifications occurring in biological systems. Together with their low natural abundance, structural annotation of modified lipids represents a major analytical challenge limiting the discovery of their natural variety and functions. Furthermore, the number of available chemically characterized standards representing various modified lipid species remains limited, making analytical and functional studies very challenging. Over the past decade we have developed and implemented numerous analytical methods to study lipid modifications and applied them in the context of different biological conditions. In this Account, we outline the development and evolution of modern mass-spectrometry-based techniques for the structural elucidation of modified/oxidized lipids and corresponding applications. Research of our group is mostly focused on redox biology, and thus, our primary interest was always the analysis of lipid modifications introduced by redox disbalance, including lipid peroxidation (LPO), oxygenation, nitration, and glycation. To this end, we developed an array of analytical solutions to measure carbonyls derived from LPO, oxidized and nitrated fatty acid derivatives, and oxidized and glycated complex lipids. We will briefly describe the main analytical challenges along with corresponding solutions developed by our group toward deciphering the complexity of natural epilipdomes, starting from in vitro-oxidized lipid mixtures, artificial membranes, and lipid droplets, to illustrate the diversity of lipid modifications in the context of metabolic diseases and ferroptotic cell death.