Synthesis, carbonic anhydrase inhibition studies and modelling investigations of phthalimide-hydantoin hybrids.

A novel series of hydantoins incorporating phthalimides has been synthesised by condensation of activated phthalimides with 1-aminohydantoin and investigated for their inhibitory activity against a panel of human (h) carbonic anhydrase (CA, EC 4.2.1.1): the cytosolic isoforms hCA I, hCA II, and hCA VII, secreted isoform hCA VI, and the transmembrane hCA IX, by a stopped-flow CO2 hydrase assay. Although all newly developed compounds were totally inactive on hCA I and mainly ineffective towards hCA II, they generally exhibited moderate repressing effects on hCA VI, VII, and IX with KIs values in the submicromolar to micromolar ranges. The salts 3a and 3b, followed by derivative 5, displayed the best inhibitory activity of all the evaluated compounds and their binding mode was proposed in silico. These compounds can also be considered interesting starting points for the development of novel pharmacophores for this class of enzyme inhibitors.

Binding Mode and Molecular Mechanism of the Two-Component Histidine Kinase Bos1 of Botrytis cinerea to Fludioxonil and Iprodione.

Gray mold caused by Botrytis cinerea is among the 10 most serious fungal diseases worldwide. Fludioxonil is widely used to prevent and control gray mold due to its low toxicity and high efficiency; however, resistance caused by long-term use has become increasingly prominent. Therefore, exploring the resistance mechanism of fungicides provides a theoretical basis for delaying the occurrence of diseases and controlling gray mold. In this study, fludioxonil-resistant strains were obtained through indoor drug domestication, and the mutation sites were determined by sequencing. Strains obtained by site-directed mutagenesis were subjected to biological analysis, and the binding modes of fludioxonil and iprodione to Botrytis cinerea Bos1 BcBos1 were predicted by molecular docking. The results showed that F127S, I365S/N, F127S + I365N, and I376M mutations on the Bos1 protein led to a decrease in the binding energy between the drug and BcBos1. The A1259T mutation did not lead to a decrease in the binding energy, which was not the cause of drug resistance. The biological fitness of the fludioxonil- and point mutation-resistant strains decreased, and their growth rate, sporulation rate, and pathogenicity decreased significantly. The glycerol content of the sensitive strains was significantly lower than that of the resistant strains and increased significantly after treatment with 0.1 µg/ml of fludioxonil, whereas that of the resistant strains decreased. The osmotic sensitivity of the resistant strains was significantly lower than that of the sensitive strains. Positive cross-resistance was observed between fludioxonil and iprodione. These results will help to understand the resistance mechanism of fludioxonil in Botrytis cinerea more deeply.

Discovery of novel benzimidazole derivatives as potent HDACs inhibitors against leukemia with (Thio)Hydantoin as zinc-binding moiety: Design, synthesis, enzyme inhibition, and cellular mechanistic study.

Based on the well-established pharmacophoric features required for histone deacetylase (HDAC) inhibition, a novel series of easy-to-synthesize benzimidazole-linked (thio)hydantoin derivatives was designed and synthesized as HDAC6 inhibitors. All target compounds potently inhibited HDAC6 at nanomolar levels with compounds 2c, 2d, 4b and 4c (IC50s = 51.84-74.36 nM) being more potent than SAHA reference drug (IC50 = 91.73 nM). Additionally, the most potent derivatives were further assessed for their in vitro cytotoxic activity against two human leukemia cells. Hydantoin derivative 4c was equipotent/superior to SAHA against MOLT-4/CCRF-CEM leukemia cells, respectively and demonstrated safety profile better than that of SAHA against non-cancerous human cells. 4c was also screened against different HDAC isoforms. 4c was superior to SAHA against HDAC1. Cell-based assessment of 4c revealed a significant cell cycle arrest and apoptosis induction. Moreover, western blotting analysis showed increased levels of acetylated histone H3, histone H4 and α-tubulin in CCRF-CEM cells. Furthermore, docking study exposed the ability of title compounds to chelate Zn2+ located within HDAC6 active site. As well, in-silico evaluation of physicochemical properties showed that target compounds are promising candidates in terms of pharmacokinetic aspects.

Synthesis and biological evaluation of hydantoin derivatives as potent antiplasmodial agents.

Malaria, a devastating disease, has claimed numerous lives and caused considerable suffering, with young children and pregnant women being the most severely affected group. However, the emergence of multidrug-resistant strains of Plasmodium and the adverse side effects associated with existing antimalarial drugs underscore the urgent need for the development of novel, well-tolerated, and more efficient drugs to combat this global health threat. To address these challenges, six new hydantoins derivatives were synthesized and evaluated for their in vitro antiplasmodial activity. Notably, compound 2c exhibited excellent inhibitory activity against the tested Pf3D7 strain, with an IC50 value of 3.97 ± 0.01 nM, three-fold better than chloroquine. Following closely, compound 3b demonstrated an IC50 value of 27.52 ± 3.37 µM against the Pf3D7 strain in vitro. Additionally, all the hydantoins derivatives tested showed inactive against human MCR-5 cells, with an IC50 value exceeding 100 µM. In summary, the hydantoin derivative 2c emerges as a promising candidate for further exploration as an antiplasmodial compound.

Multifunctional polymeric guanidine and hydantoin halamines with broad biocidal activity.

Prolonged and excessive use of biocides during the coronavirus disease era calls for incorporating new antiviral polymers that enhance the surface design and functionality for existing and potential future pandemics. Herein, we investigated previously unexplored polyamines with nucleophilic biguanide, guanidine, and hydantoin groups that all can be halogenated leading to high contents of oxidizing halogen that enables enhancement of the biocidal activity. Primary amino groups can be used to attach poly(N-vinylguanidine) (PVG) and poly(allylamine-co-4-aminopyridine-co-5-(4-hydroxybenzylidene)hydantoin) (PAH) as well as a broad-spectrum commercial biocide poly(hexamethylene biguanide) (PHMB) onto a solid support. Halogenation of polymer suspensions was conducted through in situ generation of excess hypobromous acid (HBrO) from bromine and sodium hydroxide or by sodium hypochlorite in aqueous solutions, resulting in N-halamines with high contents of active > N-Br or > N-Cl groups. The virucidal activity of the polymers against human respiratory coronavirus HCoV-229E increased dramatically with their halogenation. Brominated PHMB-Br showed activation activity value > 5 even at 1 mg/L, and complete virus inhibition was observed with either PHMB-Br or PAH-Br at 10 mg/mL. Brominated PVG-Br and PAH-Br possessed fungicidal activity against C. albicans, while PHMB was fungistatic. PHMB, PHMB-Br and PAH polymers demonstrated excellent bactericidal activity against the methicillin-resistant S. aureus and vancomycin-resistant E. faecium. Brominated polymers (PHMB-Br, PVG-Br, PAH-Br) were not toxic to the HeLa monolayers, indicating acceptable biocompatibility to cultured human cells. With these features, the N-halamine polymers of the present study are a worthwhile addition to the arsenal of biocides and are promising candidates for development of non-leaching coatings.

Highly biocidal poly(vinyl alcohol)-hydantoin/starch hybrid gels: A "Trojan Horse" for Bacillus subtilis.

HYPOTHESIS: Poly (vinyl alcohol) (PVA) cryogels can be functionalized with n-Halamines to confer biocidal features useful for their application as wound-dressing tools. Their efficacy can be boosted by stably embedding a polymeric bacterial food source (e.g., starch) in the gel matrix. The bioavailability of the food source lures bacteria inside the gel network via chemotactic mechanisms, promoting their contact with the biocidal functionalities and their consequent inactivation. EXPERIMENTS: The synthesis of a novel hydantoin-functionalized PVA (H-PVA-hyd) is proposed. The newly synthesized H-PVA-hyd polymer was introduced in the formulation of H-PVA-based cryogels. To promote the cryogelation of the systems we exploited phase-separation mechanisms employing either a PVA carrying residual acetate groups (L-PVA) or starch as phase-segregating components. The permanence of the biocidal functionality after swelling was investigated via proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FT-IR) microscopy. The activated H-PVA-hyd cryogels have been tested against bacteria with amylolytic activity (Bacillus subtilis) and the outcomes were analyzed by direct observation via confocal laser scanning microscopy (CLSM). FINDINGS: The cryogels containing starch resulted in being the most effective (up to 90% bacterial killing), despite carrying a lower amount of hydantoin groups than their starch-free counterparts, suggesting that their improved efficacy relies on a "Trojan Horse" type of mechanism.

Investigation of tetrasubstituted heterocycles reveals hydantoins as a promising scaffold for development of novel antimicrobials with membranolytic properties.

Mimics of antimicrobial peptides (AMPs) have been proposed as a promising class of antimicrobial agents. We report the analysis of five tetrasubstituted, cationic, amphipathic heterocycles as potential AMP mimics. The analysis showed that the heterocyclic scaffold had a strong influence on the haemolytic activity of the compounds, and the hydantoin scaffold was identified as a promising template for drug lead development. Subsequently, a total of 20 hydantoin derivatives were studied for their antimicrobial potency and haemolytic activity. We found 19 of these derivatives to have very low haemolytic toxicity and identified three lead structures, 2dA, 6cG, and 6dG with very promising broad-spectrum antimicrobial activity. Lead structure 6dG displayed minimum inhibitory concentration (MIC) values as low as 1 µg/mL against Gram-positive bacteria and 4-16 µg/mL against Gram-negative bacteria. Initial mode of action (MoA) studies performed on the amine derivative 6cG, utilizing a luciferase-based biosensor assay, suggested a strong membrane disrupting effect on the outer and inner membrane of Escherichia coli. Our findings show that the physical properties and structural arrangement induced by the heterocyclic scaffolds are important factors in the design of AMP mimics.

A metalloporphyrin and hydantoin functionalized nanozyme with synergistically enhanced bacterial inhibition.

An elaborate design of multimodal antibacterial agents has been revealed to be a promising strategy to address bacterial resistance, originating from the abuse of antibiotics. In this work, we have developed a positively charged and porous material, FePPOPHydantoin, as a disinfectant via introducing 1,3-dibromo-5,5-dimethylhydantoin (Hydantoin) and porphyrin iron units into a polymer framework. The extended π conjugated networks of FePPOPHydantoin endowed the material with strong near-infrared (NIR) absorption, high density of surface catalytic active centers, superior stability, and reproducibility. FePPOPHydantoin exhibits high peroxidase mimetic and photo-Fenton activity, which can catalyze the biologically allowable maximum concentrations of hydrogen peroxide (100 µM) to produce a vast amount of hydroxyl radicals. Simultaneously, the effective electrostatic interaction between the positively charged FePPOPHydantoin and the negatively charged bacteria facilitates the binding of FePPOPHydantoin on the bacterial membrane, restricting bacteria within the destruction range of hydroxyl radicals and thus making the bacteria more vulnerable. Finally, further close contact between bacteria and Hydantoin units in FePPOPHydantoin gave the material an antibacterial efficiency of over 99.999%. Compared with chemical therapy, photo-Fenton therapy, or peroxidase catalytic therapy alone, FePPOPHydantoin had a noteworthy multi-amplified antibacterial efficiency. Furthermore, FePPOPHydantoin exhibited good biocompatibility and negligible cytotoxicity. The in vivo antibacterial therapy on the Staphylococcus aureus (S. aureus) infected mouse wound model clearly proved the effectiveness of FePPOPHydantoin for fighting bacterial infections. This work highlights opportunities for the design of nanozymes with enhanced bacteriostatic activity, providing a new avenue for the construction of novel antibiotics.

Biologically Oriented Hybrids of Indole and Hydantoin Derivatives.

Indoles and hydantoins are important heterocycles scaffolds which present in numerous bioactive compounds which possess various biological activities. Moreover, they are essential building blocks in organic synthesis, particularly for the preparation of important hybrid molecules. The series of hybrid compounds containing indoles and imidazolidin-2-one moiety with direct C-C bond were synthesized using an amidoalkylation one-pot reaction. All compounds were investigated as a growth regulator for germination, growth and development of wheat seeds (Triticum aestivum L). Their effect on drought resistance at very low concentrations (4 × 10-5 M) was evaluated. The study highlighted identified the leading compounds, 3a and 3e, with higher growth-regulating activity than the indole-auxin analogues.

Benzenesulfonamides Incorporating Hydantoin Moieties Effectively Inhibit Eukaryoticand Human Carbonic Anhydrases.

A series of novel 1-(4-benzenesulfonamide)-3-alkyl/benzyl-hydantoin derivatives were synthesized and evaluated for the inhibition of eukaryotic and human carbonic anhydrases (CAs, EC 4.2.1.1). The prepared compounds were screened for their hCA inhibitory activities against three cytosolic isoforms as well as two ß-CAs from fungal pathogens. The best inhibition was observed against hCA II and VII as well as Candida glabrata enzyme CgNce103. hCA I and Malassezia globosa MgCA enzymes were, on the other hand, less effectively inhibited by these compounds. The inhibitory potency of these compounds against CAs was found to be dependent on the electronic and steric effects of substituent groups on the N3-position of the hydantoin ring, which included alkyl, alkenyl and substituted benzyl moieties. The interesting results against CgNce103 make the compounds of interest for investigations in vivo as potential antifungals.

Hydantoin based dual inhibitors of ALR2 and PARP-1: Design, synthesis, in-vitro and in-vivo evaluation.

Diabetic nephropathy is one of the most dreadful diabetic complications (DCs). The polyol pathway and unified mechanism are two important pathways implicated in the progression of DCs. In this regard, targeting the key enzymes i.e., aldose reductase (ALR2) and poly (ADP-ribose) polymerase-1 (PARP-1), of these pathways can be a relevant strategy. Thus, in this study, the pharmacophoric requirements necessary for the dual inhibition of these two enzymes i.e., ALR2 and PARP-1 were identified and consequently, some hydantoin based molecules were designed. The designed molecules were subjected to structure-based molecular modelling analysis including molecular docking analysis and molecular dynamic simulations. The promising molecules were duly synthesized and examined for their ALR2 and PARP-1 dual inhibitory activities and selectivity over aldehyde reductase (ALR1) using in vitro enzymatic assays. Based on the results of in silico analysis and in vitro assays, the best three molecules were evaluated in vivo for their nephroprotective effect and antioxidant potential in the high-fat diet-streptozotocin induced diabetic rat model. The results showed that the compounds FM6B, FM7B and FM9B were having low micromolar inhibitory potential against ALR2 (IC50; 1.02, 1.14 and 1.08 µM, respectively) and PARP-1 (IC50; 0.95, 0.81 and 1.42 µM, respectively) with selectivity over ALR1 (selectivity index; 43.63, 37.03 and 45.14, respectively).

Synthesis of Hydantoin Androgen Receptor Antagonists and Study on Their Antagonistic Activity.

Hydroxymethylthiohydantoin, hydroxymethylthiohydantoin, and hydantoin, containing a pyridine group, were synthesized to study their androgen receptor antagonistic activities. Among them, compounds 6a/6c/7g/19a/19b exhibited excellent androgen receptor antagonistic activity, which was consistent with or even superior to enzalutamide. In addition, compounds 19a and 19b exhibited better antiproliferative activity than enzalutamide in prostate cancer cells. The results show that compound 19a has great potential as a new AR antagonist.

Thiohydantoins and hydantoins derived from amino acids as potent urease inhibitors: Inhibitory activity and ligand-target interactions.

We report the investigation of hydantoins and thiohydantoins derived from L and d-amino acids as inhibitors against the Canavalia ensiformis urease (CEU). The biochemical in vitro assay against CEU revealed a promising inhibitory potential for most thiohydantoins with six of them showing %I higher than the reference inhibitor thiourea (56.5%). In addition, thiohydantoin derived from l-valine, 1b, as well as the hydantoin 2d, derived from l-methionine, were identified as the most potent inhibitors with %I = 90.5 and 85.9 respectively. Enzyme kinetic studies demonstrated a mixed and uncompetitive inhibition profile for these compounds with Ki values of 0.42 mM for 1b and 0.99 mM for 2d. These kinetic parameters, obtained from traditional colorimetric assay, were strictly related to the KD values measured spectroscopically by the Saturation Transfer Difference (STD) technique for the urease complex. STD was also used to evince the moieties of the ligands responsible for the binding with the enzyme. Molecular docking studies showed that the thiohydantoin and hydantoin rings can act as a pharmacophoric group due to their binding affinity by hydrogen bonding interactions with critical amino acid residues in the enzyme active and/or allosteric site. These findings agreed with the experimental alpha values, demonstrating that 1b has affinity by free enzyme, and 2d derivative, an uncompetitive inhibitor, has great binding affinity at the allosteric site. The results for the thiohydantoin 1a, derived from d-valine, demonstrated a drastic stereochemical influence on inhibition, kinetics, and binding parameters in comparison to its enantiomer 1b.

Evaluation of Two Novel Hydantoin Derivatives Using Reconstructed Human Skin Model EpiskinTM: Perspectives for Application as Potential Sunscreen Agents.

This study aimed to assess two novel 5-arylideneimidazolidine-2,4-dione (hydantoin) derivatives (JH3 and JH10) demonstrating photoprotective activity using the reconstructed human skin model EpiskinTM. The skin permeability, irritation, and phototoxicity of the compounds was evaluated in vitro. Moreover, the in vitro genotoxicity and human metabolism of both compounds was studied. For skin permeation and irritation experiments, the test compounds were incorporated into a formulation. It was shown that JH3 and JH10 display no skin irritation and no phototoxicity. Both compounds did not markedly enhance the frequency of micronuclei in CHO-K1 cells in the micronucleus assay. Preliminary in vitro studies with liver microsomes demonstrated that hydrolysis appears to constitute their important metabolic pathway. EpiskinTM permeability experiments showed that JH3 permeability was lower than or close to currently used UV filters, whereas JH10 had the potential to permeate the skin. Therefore, a restriction of this compound permeability should be obtained by choosing the right vehicle or by optimizing it, which should be addressed in future studies.

Design, synthesis and biological evaluation of hydantoin derivatives as Mcl-1 selective inhibitors.

As a member of Bcl-2 protein family, myeloid cell leukemia-1 (Mcl-1) plays a critical role in cell apoptosis and has become a promising anti-cancer drug target. Herein, we designed and synthesized a series of hydantoin derivatives as novel Mcl-1 inhibitors based on our previously developed lead compound. Among them, compound M23 and M24 exhibited good binding affinities against Mcl-1 with Ki values of 0.49 µM and 0.33 µM respectively. Especially, compound M23 exhibited good selectivity over Bcl-xL, whereas compound M24 possessed good selectivity over both Bcl-2 and Bcl-xL. Furthermore, we also investigated the effects of these new Mcl-1 inhibitors on cell proliferation, apoptosis and mitochondrial membrane potential, as well as the stability in plasma.

Wide distribution of resistance to the fungicides fludioxonil and iprodione in Penicillium species.

Fludioxonil and iprodione are effective fungicides widely used for crop protection and are essential for controlling plant pathogenic fungi. The emergence of fungicide-resistant strains of targeted pathogens is regularly monitored, and several cases have been reported. Non-targeted fungi may also be exposed to the fungicide residues in agricultural fields. However, there are no comprehensive reports on fungicide-resistant strains of non-targeted fungi. Here, we surveyed 99 strains, representing 12 Penicillium species, that were isolated from a variety of environments, including foods, dead bodies, and clinical samples. Among the Penicillium strains, including non-pathogenic P. chrysogenum and P. camembertii, as well as postharvest pathogens P. expansum and P. digitatum, 14 and 20 showed resistance to fludioxonil and iprodione, respectively, and 6 showed multi-drug resistance to the fungicides. Sequence analyses revealed that some strains of P. chrysogenum and Penicillium oxalicum had mutations in NikA, a group III histidine kinase of the high-osmolarity glycerol pathway, which is the mode of action for fludioxonil and iprodione. The single nucleotide polymorphisms of G693D and T1318P in P. chrysogenum and T960S in P. oxalicum were only present in the fludioxonil- or iprodione-resistant strains. These strains also exhibited resistance to pyrrolnitrin, which is the lead compound in fludioxonil and is naturally produced by some Pseudomonas species. This study demonstrated that non-targeted Penicillium strains distributed throughout the environment possess fungicide resistance.

Synthesis and biological activity of novel hydantoin cyclohexyl sulfonamide derivatives as potential antimicrobial agents in agriculture.

BACKGROUND: Plant disease is one of the most serious problems in agriculture that can damage crops. Chemical fungicides are widely used to control plant diseases, but have led to resistance and a series of environmental problems. It is, therefore, necessary to develop highly effective and eco-friendly antimicrobial compounds with novel structures. RESULTS: A series of novel hydantoin cyclohexyl sulfonamide derivatives were synthesized through an intramolecular condensation reaction. The bioassay results indicated that a majority of the title compounds displayed potent inhibitory activity against Botrytis cinerea, Sclerotinia sclerotiorum and Erwinia carotorora. The in vivo inhibition rate of compound 3h was 91.01% against B. cinerea, which was higher than that of iprodione (84.07%). Compound 3w showed excellent antifungal activity against B. cinerea with a half-maximal effective concentration (EC50 ) of 4.80 µg ml-1 , which is lower than that of iprodione. Compound 3q had an EC50 value of 1.44 µg ml-1 against S. sclerotiorum, which was close to that of iprodione (1.39 µg ml-1 ), and the inhibition rate was also similar to that of iprodione. Compounds 3i and 3w had the best inhibition efficacy against S. sclerotiorum, both on growth of the mycelium and sclerotia and in the greenhouse pot test in vitro. Further study showed that compounds 3h, 3r and 3s have superb antibacterial activity against E. carotorora with EC50 values of 2.65, 4.24 and 4.29 µg ml-1 respectively, and were superior to streptomycin sulfate (5.96 µg ml-1 ). CONCLUSION: Because of their excellent antifungal and antibacterial activity against B. cinerea, S. sclerotiorum and E. carotorora, these hydantoin cyclohexyl sulfonamide derivatives could be considered as suitable candidates for new antimicrobial agents. © 2021 Society of Chemical Industry.

3-Imino derivative-sulfahydantoins: Synthesis, in vitro antibacterial and cytotoxic activities and their DNA interactions.

Sulfahydantoins are five-membered rings found in the structure of chemicals that exhibit antibacterial, anti-inflammatory, and anticonvulsant properties. They also activate serine protease enzymes that catalyze the hydrolysis of peptide bonds. Five 3-imino sulfahydantoin compounds were synthesized by using Strecker synthesis reaction with minor modifications. We used reflux of various aldehydes with excess sulfamide in 85% methanol in the presence of sodium cyanide. The spectroscopic properties of these compounds were studied in detail. Antibacterial activities of all synthesized new compounds against four Gram-positive (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Streptococcus mutans) and four Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella Enteritidis) bacteria were investigated by disc diffusion and microdilution method. pBR322 plasmid DNA binding abilities of compounds were investigated in vitro by agarose gel electrophoresis. In addition, the cytotoxic activities of the compounds against the human malignant pleural mesothelioma (SPC212) cell line were determined by the MTT method. The remarkable result in this study is that the synthesized compounds, especially 4b, 4d, and 4e, have significant biological activities. It has been demonstrated that these compounds, which cause DNA damage, also have an important antibacterial effect on both Gram-negative and Gram-positive bacteria when results compared with the control group antibiotics. Compound 4e exhibited the highest antibacterial potency against Streptococcus mutans (24.33 ± 0.57) from Gram-positive bacteria and Pseudomonas aeruginosa (24.66 ± 1.15) from Gram-negative bacteria. At the same time, MTT results determined that compounds 4b, 4d, and 4e showed cytotoxic activity against the SPC212 cells. In particular, compound 4b had a high cytotoxic effect, and the IC50 value was determined as 6.25 µM.

Structure-Activity Relationship Studies of Hydantoin-Cored Ligands for Smoothened Receptor.

An underside binding site was recently identified in the transmembrane domain of smoothened receptor (SMO). Herein, we report efforts in the exploration of new insights into the interactions between the ligand and SMO. The hydantoin core in the middle of the parent compound was found to be highly conservative in chirality, ring size, and substituents. On each benzene at two ends, a plethora of variations, particularly halogen substitutions, were introduced and investigated. Analysis of the structure-activity relationship revealed miscellaneous halogen effects. The ligands with double halogen substituents exhibit remarkably enhanced potency, providing promising candidates that potentially overcome the common drug resistance and useful heavy-atom labeled chemical tools for co-crystallization studies of SMO.

The indole-hydantoin derivative exhibits anti-inflammatory activity by preventing the transactivation of NF-κB through the inhibition of NF-κB p65 phosphorylation at Ser276.

Indole- and hydantoin-based derivatives both exhibit anti-inflammatory activity, suggesting that the structures of indole and hydantoin are functional for this activity. In the present study, we synthesized two types of indole-hydantoin derivatives, IH-1 (5-(1H-indole-3-ylmethylene) imidazolidine-2,4-dione) and IH-2 (5-(1H-indole-3-ylmethyl) imidazolidine-2,4-dione) and examined their effects on LPS-induced inflammatory responses in murine macrophage-like RAW264.7 cells. LPS-induced inflammatory responses were not affected by indole, hydantoin, or IH-2. In contrast, IH-1 significantly inhibited the LPS-induced production of nitric oxide (NO) and secretion of CCL2 and CXCL1 by suppressing the mRNA expression of inducible NO synthase (iNOS), CCL2, and CXCL1. IH-1 markedly inhibited the LPS-induced activation of NF-κB without affecting the degradation of IκBα or nuclear translocation of NF-κB. IH-1 markedly attenuated the transcriptional activity of NF-κB by suppressing the LPS-induced phosphorylation of the NF-κB p65 subunit at Ser276. Furthermore, IH-1 prevented the LPS-induced interaction of NF-κB p65 subunit with a transcriptional coactivator, cAMP response element-binding protein (CBP). Collectively, these results revealed the potential of the novel indole-hydantoin derivative, IH-1 as an anti-inflammatory drug.