Chemical Structure Research Articles

An in-depth review of thalidomide's basic moieties

Thalidomide, also referred to as N-phthalimido glutarimide, was initially made available as a sedative by Chemie Grunelthal GmbH in West Germany in 1957. Thalidomide's chemical structure primarily consists of two rings: the phthalimide ring and the glutarimide ring. Although small substitutions in one or both rings might be tolerated without a reduction in toxicity, both of these groups were necessary for embryopathic action. A cyclic chemical structure that is a component of thalidomide is the phthalimide ring. The phthalimide ring is thought to contribute to both the teratogenic (causes birth defects) and some therapeutic aspects of the medication. Another cyclic structure seen in the chemical makeup of thalidomide is the Glutarimide Ring. The pharmacological characteristics of thalidomide are also connected to this portion of the molecule. Based on their activities and structural connections, this review study gives an overview of the interaction between phalidimide and the glutarimide ring for teratogenicity of the thalidomide type. Understanding how thalidomide interacts with the human body, both for its intended therapeutic effects and its negative side effects, especially when taken during pregnancy, is important given the combination of these rings in the drug's chemical structure.

SYNTHESIS, CHARACTERIZATION & BIOLOGICAL EVALUATION OF SOME FLUOROQUINOLONE DERIVATIVES AS ANTIMICROBIAL AGENTS

Fluoroquinolones, a class of synthetic antibacterial agents, have gained significant attention due to their broad-spectrum activity against various bacterial pathogens. However, the emergence of resistance to conventional fluoroquinolones underscores the necessity for novel derivatives with enhanced efficacy and reduced resistance profiles. The synthesis of fluoroquinolone derivatives involves structural modifications aimed at improving antimicrobial activity, pharmacokinetic properties, and minimizing adverse effects. Various synthetic routes, including modification of the quinolone core structure, substitution of fluorine atoms, and introduction of diverse functional groups, have been explored to tailor the properties of these derivatives. Characterization techniques such as infrared spectroscopy (IR) has been employed to elucidate the chemical structures and confirm the purity of synthesized compounds. Biological evaluation encompasses in vitro and in vivo studies to assess the antimicrobial activity, cytotoxicity, and pharmacological profiles of fluoroquinolone derivatives. These evaluations provide crucial insights into the therapeutic potential, mechanism of action, and safety profile of novel compounds.

New nor-lignans from the leaves of styrax annamensis guillaumin.

Phytochemical study of the leaves of Styrax annamensis Guillaumin resulted in the isolation of a new natural product egonol-3''-sulphate (1), and two new derivatives egonol-3-methyl-D-galactopyranoside (2) and 7-methoxy-2-(3',4'-methylenedioxyphenyl)-benzofuran-5-carboxamide (3). Their chemical structures were -elucidated by spectroscopic data. Compounds 1 and 3 significantly established a great role for the chemotaxonomic aspect. Compound 1 showed cytotoxicity against four cancer cell lines KB, HepG2, Lu, and MCF7 with the IC50 values of 84.90-101.69 µg/mL, and exhibited acetylcholinesterase (AChE) inhibitory activity with the IC50 value of 97.08 µg/mL.

Insights into the Biological Activities and Substituent Effects of Pyrrole Derivatives: The Chemistry-Biology Connection.

Pyrrole, with its versatile heterocyclic ring structure, serves as a valuable template for generating a diverse range of lead compounds with various pharmacophores. Researchers and scientists globally are intrigued by pyrrole and its analogues for their broad pharmacological potential, prompting thorough investigations aimed at advancing human welfare. This comprehensive review delves into the diverse activities exhibited by pyrrole compounds, encompassing their synthesis, reactions, and pharmacological properties alongside their derivatives. In addition to detailing the characteristics of pyrrole and its derivatives within the context of green chemistry, the review also examines microwave-assisted reactions. It provides insights into their chemical structures, natural occurrences, and potential applications across various domains. Furthermore, the article investigates structural alterations of pyrrole compounds and their implications on their functionality, highlighting their versatility as foundational elements for both functional materials and bioactive compounds. Ultimately, the review underscores the imperative for continued research and development in the realm of pyrrole compounds to unearth novel activities and advantages.

Labunicolamine: A Rare Penillic Acid Congener from the Nematode Cyst-Associated Fungus Laburnicola nematophila.

A chemical investigation of a methanol extract derived from a solid-state rice culture of the nematode-cyst associated fungus Laburnicola nematophila K01 led to the isolation and characterization of a previously undescribed penillic acid analogue named laburnicolamine (1). The chemical structure was elucidated through comprehensive 1D and 2D NMR spectroscopic analyses in methanol-d4 and DMSO-d6, alongside with HR-ESI-MS spectrometry. The absolute configuration of 1 was concluded through the electronic circular dichroism (ECD) and time-dependent density functional theory-ECD (TDDFT-ECD) computations compared to its acquired spectrum. Biological assays revealed that compound 1 exhibited no significant cytotoxic, antimicrobial, or nematicidal activity.

Graphiumisides A-D, Monoterpene Glycosides from an Animal-Derived Endophytic Fungus Graphium sp. GD-11.

Four new monoterpene rhamnosides, graphiumisides A-D (1-4), along with fourknown steroid compounds (5-8)were isolated from the fermentation extract of animal-derived endophytic fungus, Graphiumsp. GD-11. The chemical structures of all compounds were elucidated using 1D and 2D NMR, HRESIMS spectroscopic analyses, and other spectroscopic methods. Compounds 1-4exhibit a distinctive structure connected by one p-menthane type monoterpene and one L-rhamnose.This is the first report of monoterpene glycosides from Graphiumsp. All compounds (1-8) were tested for cytotoxic activities against four cancer cell lines (HepG2, SMMC7721, SW480,and A549), and only compound 1showedweak anti-tumor activity against SMMC7721 cells.

Elevated water transport of polyamide nanofiltration membranes via aqueous organophosphorus mediated interfacial polymerization

As interfacial polymerization (IP) is a reaction-diffusion process, rational regulation of diamine diffusion rate is effective to heighten the nanofiltration (NF) performance of polyamide (PA) membranes. Herein, we propose an aqueous organophosphorus-regulated IP strategy that promotes the formation of thinner and moderately crosslinked films toward improved water transport. Two similar compounds tetrakis (hydroxymethyl) phosphonium chloride (THPC) and tetrakis (hydroxymethyl) phosphonium sulfate (THPS) were utilized as functional additives to physically interact with piperazine via hydrogen bonding and thus retard piperazine diffusion rate during an IP process. The resultant polyamide membranes have been analyzed in terms of surface morphologies, chemical structures, hydrophilicity, and separation performance in detail. Surface temperature monitoring results revealed that heat release from regulated IP was less than that from unmodified IP, which was ascribed to retard monomer diffusion toward organic boundary in the presence of THPC or THPS. Molecular dynamics simulation further confirmed that the addition of THPC and THPS could efficiently decline the monomer diffusion rate via hydrogen bonds and increased solution viscosity. The modified PA membranes exhibited a reduced film thickness, moderate crosslinking degree, as well as increased average pore size, as revealed by a series of characterizations. Furthermore, the incorporation of THPC or THPS resulted the PA membranes with higher surface hydrophilicity and stronger negative charges. These improved physicochemical features synergically conferred a two-fold water permeance while maintaining a high divalent salt rejection (THPC-0.01: 18.3 L m-2 h−1 bar−1, 99.0 %, THPS-0.015: 20.2 L m−2 h−1 bar−1, 98 %). This aqueous organophosphorus regulated IP offers a simple and feasible approach to the preparation of low-transport-resistance PA membranes for enhanced NF performance.

Experimental and computational studies of novel cyclic ammonium based ionic liquids as corrosion inhibitors for carbon steel in acid medium

The challenge of corrosion posed as a result of acidic sittings is considered as a major industrial concern, wherein ionic liquids serve as crucial in addressing the corrosive impacts on metals. In this study, five selected cyclic ammonium based ionic liquids were synthesized; IL-1MPyrBr, IL-1MPipBr, IL-2PyBr, IL-3MPyBr and IL-4MPyBr and their chemical structures were characterized using a variety of spectroscopic techniques (FT-IR, IH-NMR, 13C-NMR, Elemental analysis and thermal gravimetric analysis (TGA). Their corrosion inhibition efficiency was studied on carbon steel in 1 M HCl via different concentrations at 298 K using chemical and electrochemical parameters (PDP and EIS). DFT quantum parameters were computed, and the noted results were in complete compatible with the experimental. The synthesized ILs recorded excellent inhibition on the carbon steel corrosion in acidic media with increasing efficiency by increasing the inhibitor concentrations from 20 to 100 ppm. Different cations in the synthesized ILs affect the anti-corrosion effect and IL-3MPyBr showed the highest inhibition (ηR); 96.12% using the lowest concentration. Kinetic and thermodynamic considerations were studied and illustrated.

Chemoreactomic analysis of the antioxidant properties of vitamin B12 derivatives

Background. Synthetic derivatives of vitamin B12 exhibit various physical, chemical and pharmacological properties. The development of methods for predicting the properties of these molecules based on their chemical structure is important for the targeted organic synthesis of corrins with the desired properties and range of applications in pharmacology.Objective: chemoreactomic assessment of the antioxidant effects of vitamin B12 and its derivatives: aquacobalamin, diaquacobinamide, aquacyano-forms of heptaethanolamine-, heptaethylenediamine-, heptamethyl- and heptabutylcobyrinates.Material and methods. The study was conducted using the method of chemoreactomic analysis, implemented within the framework of the algebraic theory of recognition and topological data analysis and based on the theory of isomorphism of labeled graphs and modern methods for predicting numerical target variables. To carry out chemoinformatic chemoreactome analysis, a special problem-oriented theory was developed within the boundaries of the combinatorial theory of solvability and the antioxidant properties of vitamin B12 derivatives were assessed (140 activities in total).Results. Significant differences were found in the properties of the studied substances in relation to oxidative stress. In test systems based on the oxidant 1,1-diphenyl-2-picrylhydrazyl, at different exposure times to molecules (15–60 min) in different concentrations (10–125 μM, 50–3000 μg/ml), aquacobalamin exhibited the most pronounced antioxidant properties at lower concentrations (up to 100 µM). At higher concentrations of substances (125 μM), the antioxidant activity of other vitamin B12 derivatives was higher. All studied molecules had a moderate antimicronutrient effect (total score of about 3.0; for most synthetic drugs, this score is higher than 3.6). Aquacobalamin was characterized by еhe least pronounced antimicronutrient effect (total score less than 0.8), which indicates an almost complete absence of antivitamin and antimineral action, corresponding to an average increase in the risk of a particular micronutrient excretion by no more than 5%.Conclusion. All the studied compounds exert antioxidant properties to one degree or another. Regardless of the choice of simulated test systems for assessing oxidative stress, aquacobalamin demonstrated antioxidant effects to the greatest extent and practically did not stimulate the loss of other micronutrients.

The Nature and Origin of Plant Viruses with an Incursion into Virus Nomenclature

Eversince, the chemical nature of not only the anisometric tobacco mosaic virus (TMV) but also the crystalline viruses like bushy stunt of tomato, tobacco necrosis virus, turnip yellow mosaic virus and others have been characterized, sap transmissible viruses have been shown to be good antigens and that their antisera had group specificity aiding identification. Whilst symptomatology alone was found unreliable and of insufficient means for diagnosis and classification of viruses, serology, chemical and physical structure of viruses and the modes of transmission have played an important role in virus nomenclature. However, it is premature to think of orthodox binomial and trinomial nomenclature as practised in fungal classification playing a role in virus terminology, Anisometric and crystalline viruses are comparatively simple chemical entities (as compared with animal viruses) and are essentially nucleoproteins where the RNA (ribonucleic acid) core has a shell of protein in a helical pattern serving as a protective coating. The infectivity of the nucleic acid alone (which is hardly 6% of the nucleoproteiri) has been proved beyond doubt whereas, the protein (which is the bulk of the virus) does not count for infectivity but plays an important role in serological reactions and consequently is of immense value in grouping viruses. Nevertheless, size, shapes and structure of viruses are of considerable significance as a tool in virus classification of rodshaped particles. Spherical virus particles, however, have not lent themselves to this approach. A somewhat similar approach to classification has been made by using specific vector-virus relationships.In the speculative field of origin of viruses, the free gene or plasmagene theory of Darlington seems to find little support at present. Nonetheless, a biochemical approach is still valid and as all the ribonucleic acid (RNA) in the TMV appears to be present in a single polynucleotide chain, a break in this chain has to be transmitted intact to the recipient cell to enable reduplication. That the RNA may be replicated in the cells is, therefore, not to be regarded as a shortlived messenger carrying genetic information from nuclear deoxyribonucleic acid (DNA) to protein. Stretching this argument one could conceive of a further step to the self-perpetuating RNA molecule capable of directing protein synthetic mechanisms in recipient cells to specific products.

Experimental Study on Evolution of Chemical Structure Defects and Secondary Contaminative Deposition during HF-Based Etching

Post-processing based on HF etching has become a highly preferred technique in the fabrication of fused silica optical elements in various high-power laser systems. Previous studies have thoroughly examined and confirmed the elimination of fragments and contamination. However, limited attention has been paid to nano-sized chemical structural defects and secondary precursors that arise during the etching process. Therefore, in this paper, a set of fused silica samples are prepared and undergo the etching process under different parameters. Subsequently, an atomic force microscope, scanning electron microscope and fluorescence spectrometer are applied to analyze sample surfaces, and then an LIDT test based on the R-on-1 method is applied. The findings revealed that appropriate etching configurations will lead to certain LIDT improvement (from initial 7.22 J/cm2 to 10.76 J/cm2), and HF-based etching effectively suppresses chemical structural defects, while additional processes are recommended for the elimination of micron- to nano-sized secondary deposition contamination.

The use of thioxopyrimidine derivatives for the regulation of vegetative growth of wheat

The work is devoted to the screening of new effective wheat plant growth regulators based on synthetic compounds, thioxopyrimidine derivatives. The wheat (Triticum aestivum L.) variety Oksamit Mironivskyi was used as the object of the study. Morphometric parameters (average length of shoots and roots (mm), and average biomass of 10 plants (g)) of 4-week-old wheat plants were measured. Treatment of wheat plants with thioxopyrimidine derivatives at a concentration of 10-6 M contributed to the growth and development of shoots and roots compared to control wheat plants treated with distilled water. The regulatory effect of thioxopyrimidine derivatives on the vegetative growth of wheat plants was similar to the regulatory effect of auxin IAA (1H-indol-3-yl)acetic acid) or synthetic compounds, derivatives of sodium and potassium salts of 6-methyl-2-mercapto-4-hydroxypyrimidine (Methyur, Kamethur) and N-oxide-2,6-dimethylpyridine (Ivin) used in the same concentration of 10-6 M. The correlation between the growth regulatory effect and the chemical structure of synthetic compounds, thioxopyrimidine derivatives was established. The selected most active synthetic compounds, thioxopyrimidine derivatives, are proposed to be used to improve the vegetative growth of wheat (T. aestivum L.) variety Oksamit Mironivskyi.

Simple Method for Predicting the Heats of Formation of Energetic Metal–Organic Frameworks

Abstract The heats of formation (HOF) of energetic materials is crucial in determining their performance. A novel approach has been introduced to accurately predict the condensed phase HOF of energetic metal-organic frameworks (EMOFs). The experimental condensed phase HOF data of 63 EMOFs were utilized to develop and evaluate the model. This model relies on particular chemical bonds, elemental composition, and some of the specific structural parameters that can be obtained from the chemical structures of EMOFs. This model can be easily applied to EMOFs with intricate compositions and structures, without the need for complicated computer codes. Statistical parameters along with the internal and external validation approaches were employed to assess the accuracy, precision, goodness-of-fit, and goodness-of-prediction of the model. Values of the coefficients of determination in training set, as well as internal and external validation, i.e., R2, $${\text{Q}}_{{{\text{LOO}}}}^{2}$$, $${\text{Q}}_{{5{\text{-fold}}}}^{2}$$, and $$R_{{{\text{External}}}}^{2}$$ are 0.96, 0.93, 0.91, and 0.94, respectively.

Effect of holmium oxide nanoparticle on the mechanical properties of epoxy resin composites

In this study, holmium oxide/epoxy resin (Ho2O3/EP) nanocomposites were prepared by using different additions of Ho2O3 nanoparticles as nanofiller. The surface-modification treatment of Ho2O3 was applied with a silane coupling agent (SCA) to improve the interfacial combination between Ho2O3 and EP. The effect of SCA treatment on the chemical structure of Ho2O3 was investigated using Fourier transform infrared spectroscopy (FTIR). The effects of Ho2O3 nanoparticle and SCA treatment on the mechanical properties of the nanocomposites were studied. The fracture morphology of the EP nanocomposites was observed by scanning electron microscopy (SEM) to explore the failure mechanism of the EP nanocomposites with Ho2O3 nanoparticle. The experimental results show the tensile and flexural strengths of the nanocomposites are improved when Ho2O3 content is 1 wt. %. The tensile and flexural strengths were increased to 73.42 MPa and 130.85 MPa, respectively. But on further increase in Ho2O3 content of 1.5 wt. %, the tensile and flexural strengths were reduced. The SCA treatment could increase the interfacial bonding by containing C-H and Si-O functional groups, promoting the tensile properties, flexural properties, impact toughness, and fracture properties of the nanocomposites.

Non‐isocyanate polyurethane‐acrylate as UV‐ and thermo‐responsive plasticizer for thermoplastic elastomer

AbstractA UV‐ and thermo‐responsive polyurethane‐acrylate prepolymer was synthesized from palm olein (POo) via a non‐isocyanate route. The process included epoxidation of POo, carbonation of epoxidized palm olein (EPOo) into polycyclic carbonate in a solvent‐free and mild condition (100°C, 1 atm), followed by reacting with ethylene diamine and acrylic acid. The chemical structure of the non‐isocyanate polyurethane‐acrylate (NIPUA) prepolymer was elucidated by 1H and 13C nuclear magnetic resonance (NMR) and Fourier transform‐infrared spectroscopy (FTIR), while weight average molecular weight of NIPUA was determined by gel permeation chromatography (GPC). The NIPUA (0–20 wt%) was incorporated with thermoplastic elastomer (TPE) as a plasticizer and cured under UV light and thermal stimulations. The cured NIPUA/TPE films were characterized by FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile strength test. Under UV and thermal stimulations, the NIPUA/TPE demonstrated enhanced tensile properties (elongation at break >1280%, Young's modulus ~25 MPa), thermal properties (lower Tg), lower water contact angle, and shortened curing time as compared with the blank TPE. The 20 wt% NIPUA/TPE films exhibited susceptibility to enzymatic biodegradation and noncytotoxic to HEK 293 cells in vitro, demonstrated it's potential as a UV‐ and thermo‐responsive plasticizer for TPE in manufacturing of medical devices.

Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE) after administration of corticosteroids: Case series and review of literature.

Cutaneous manifestations of drug-induced type IV reactions vary widely, with symmetrical drug-related intertriginous and flexural exanthema (SDRIFE) being a less common presentation. Corticosteroids (CS), primarily known for their anti-inflammatory effects, rarely induce hypersensitivity reactions. The aim of this case series is to report four cases of SDRIFE following systemic prednisolone therapy and to review existing CS classification proposals to better understand cross-reactivity of CS. Patients recruited at a German dermatology centre underwent allergologic evaluation including prick and patch testing with various CS. Positive cases underwent oral challenge testing with alternative agents. The classification systems of Coopman et al. and Baeck et al. were taken into account. Despite a paucity of literature, CS-induced type IV reactions do occur, including SDRIFE. Classification systems based on chemical structure provide insight into cross-reactivity patterns. Provocation tests with alternative CS highlight the complexity of managing CS hypersensitivity. SDRIFE may develop following systemic prednisolone therapy. Classification systems are helpful in understanding cross-reactivity and help in the selection of alternative preparations but are not always reliable. Individualised assessment is crucial for managing CS hypersensitivity, with consideration of alternative agents and emergency use of CS when necessary.

Quinuclidine N-oxygenation mediated by flavin-containing monooxygenase (FMO) 1 and FMO3 in kidney and liver microsomes from humans, monkeys, dogs, and pigs.

Flavin-containing monooxygenases (FMOs) are a family of enzymes that are involved in the oxygenation of heteroatom-containing molecules. In humans, FMO3 is the major hepatic form, whereas FMO1 is predominant in the kidneys. FMO1 and FMO3 were also identified in monkeys, dogs, and pigs. The predicted contribution of human FMO3 to drug candidate N-oxygenation could be estimated using the classic base dissociation constants of the N-containing moiety. A basic quinuclidine moiety was found in the natural quinine and medicinal products. Consequently, N-oxygenation of quinuclidine was evaluated using liver and kidney microsomes from humans, monkeys, dogs, and pigs as well as recombinant FMO1, FMO3, and FMO5 enzymes. Experiments using simple reversed-phase liquid chromatography with fluorescence monitoring revealed that recombinant FMO1 mediated quinuclidine N-oxygenation with a high capacity in humans. Moreover, recombinant FMO1, FMO3, and/or FMO5 in monkeys, dogs, and pigs exhibited relatively broad substrate specificity toward quinuclidine N-oxygenation. Kinetic analysis showed that human FMO1 efficiently, and pig FMO1 moderately, mediated quinuclidine N-oxygenation with high capacity, which is consistent with the reported findings for larger substrates readily accepted by pig FMO1 but excluded by human FMO1. In contrast, human FMO3-mediated quinuclidine N-oxygenation was slower than that of the typical FMO3 substrate trimethylamine. These results suggest that some species differences exist in terms of FMO-mediated quinuclidine N-oxygenation in humans and some animal models (monkeys, dogs, and minipigs); however, the potential for quinuclidine, which has a simple chemical structure, to be inhibited clinically by co-administered drugs should be relatively low, especially in human livers. Significance Statement The high capacity of human flavin-containing monooxygenase (FMO) 1 to mediate quinuclidine N-oxygenation, a basic moiety in natural products and medicines, was demonstrated by simple reversed-phase liquid chromatography using fluorescence monitoring. The substrate specificity of FMO1 and FMO3 toward quinuclidine N-oxygenation in monkeys, dogs, and pigs was suggested to be relatively broad. Human FMO3-mediated quinuclidine N-oxygenation was slower than trimethylamine N-oxygenation. The likelihood of quinuclidine, with its simple chemical structure, being clinically inhibited by co-administered drugs is relatively low.

Detection, detoxification, and anti-counterfeiting applications of pullulan-modified nitrogen-doped carbon dots

Nitrogen-doped carbon dots (N-CDs) modified with pullulan were prepared using a hydrothermal method for use in sensing, detoxification, and anti-counterfeiting applications. The excitation-independent N-CDs demonstrated selectivity for hydroquinone and 4-nitrophenol (4-NP) with detection limits of 58 and 13 nM. The N-CD-based detection method was extended to environmental samples such as bottled water, tap water, and river water, and acceptable relative standard deviations (RSDs) and good recoveries were found. In the presence of NaBH4, N-CDs converted the toxic MB to colorless leuco-methylene blue in 10.5 minutes, confirming that the catalytic ability of N-CDs can be evaluated using MB as a model pollutant. With an excellent quantum yield of 31%, the N-CDs had the potential as a fluorescent ink for anti-counterfeiting applications by helping to visualize fingerprints, drawings, and chemical structures under 365 nm UV light while being completely invisible in daylight and sunlight. The N-CDs have significant potential for industrial use as fluorescent inks, detoxification catalysts, and pollutant sensors.

The Influence of the Alkylamino Group on the Solvatochromic Behavior of 5-(4-substituted-arylidene)-1,3-dimethylpyrimidine-2,4,6-triones: Synthesis, Spectroscopic and Computational Studies

Advances in electronics and medical diagnostics have made organic dyes extremely popular as key functional materials. From a practical viewpoint, it is necessary to assess the spectroscopic and physicochemical properties of newly designed dyes. In this context, the condensation of 1,3-dimethylbarbituric acid with electron-rich alkylaminobenzaldehyde derivatives has been described, resulting in a series of merocyanine-type dyes. These dyes exhibit intense blue-light absorption but weak fluorescence. An electron-donating alkylamino group at position C4 is responsible for the solvatochromic behavior of the dyes since the lone electron pair of the nitrogen atom is variably delocalized toward the barbituric ring, which exhibits electron-withdrawing properties. This was elucidated, taking into account the different geometry of the amino group. The intramolecular charge transfer in the molecules is responsible for the relatively high redshift in absorption and fluorescence spectra. Additionally, an increase in solvent polarity moves the absorption and fluorescence to lower energy regions. The observed solvatochromism is discussed in terms of the four-parameter Catalán solvent polarity scale. The differences in the behavior of the dyes were quantified with the aid of time-dependent density functional theory calculations. The obtained results made it possible to find regularities linking the basic spectroscopic properties of the compounds with their chemical structure. This is important in the targeted search for new, practically important dyes.

Actinomycetes are a natural resource for sustainable pest control and safeguarding agriculture.

Actinomycetes, a diverse group of bacteria with filamentous growth characteristics, have long captivated researchers and biochemists for their prolific production of secondary metabolites. Among the myriad roles played by actinomycete secondary metabolites, their historical significance in the field of biocontrol stands out prominently. The fascinating journey begins with the discovery of antibiotics, where renowned compounds like streptomycin, tetracycline, and erythromycin revolutionized medicine and agriculture. The history of biocontrol traces its roots back to the early twentieth century, when scientists recognized the potential of naturally occurring agents to combat pests and diseases. The emergence of synthetic pesticides in the mid-twentieth century temporarily overshadowed interest in biocontrol. However, with growing environmental concerns and the realization of the negative ecological impacts of chemical pesticides, the pendulum swung back towards exploring sustainable alternatives. Beyond their historical role as antibiotics, actinomycete-produced secondary metabolites encompass a rich repertoire with biopesticide potential. The classification of these compounds based on chemical structure and mode of action is highlighted, demonstrating their versatility against both plant pathogens and insect pests. Additionally, this review provides in-depth insights into how endophytic actinomycete strains play a pivotal role in biocontrol strategies. Case studies elucidate their effectiveness in inhibiting Spodoptera spp. and nematodes through the production of bioactive compounds. By unraveling the multifunctional roles of endophytic actinomycetes, this review contributes compelling narrative knowledge to the field of sustainable agriculture, emphasizing the potential of these microbial allies in crafting effective, environmentally friendly biocontrol strategies for combating agricultural pests.