Search Results (19)

The actinobacterial strain Kitasatospora griseola JNUCC 62 was isolated from volcanic wetland soil at Mulyeongari Oreum, Jeju Island, and taxonomically identified through 16S rRNA gene and whole-genome analyses. The complete genome, assembled from PacBio Sequel I reads, spans 8.31 Mb with a GC content of 72.8% and contains 7265 coding sequences. Comparative genomic indices (Average nucleotide identity, ANI 97.46%; digital DNA–DNA hybridization, dDDH 84.4%) confirmed its conspecific relationship with K. griseola JCM 3339^T. Genome mining using antiSMASH 8.0 revealed 30 biosynthetic gene clusters (BGCs), including polyketide synthase (PKS), non-ribosomal peptide synthetase (NRPS), ribosomally synthesized and post-translationally modified peptide (RiPP), lanthipeptide, and terpene types, accounting for 18.6% of the genome. Several BGCs displayed homology to known formicamycin-, lankacidin-, and lanthipeptide-type clusters, while others were novel or cryptic, reflecting adaptation to the nutrient-poor volcanic environment. Ethyl acetate extraction of the culture broth, especially under tryptophan-supplemented conditions, yielded four metabolites—1-acetyl-β-carboline, perlolyrine, tryptopol, and 1H-pyrrole-2-carboxylic acid—identified by UV and NMR spectroscopy. These compounds correspond to NRPS–PKS hybrid and arylpolyene-type gene clusters predicted in the genome, suggesting precursor-directed biosynthesis of indole and pyrrole alkaloids. The ethyl acetate extract (JNUCC62 EA) exhibited strong antioxidant capacity in the ABTS assay, anti-inflammatory activity via inhibition of nitric oxide (31.09 ± 3.69% of control) and cytokines (IL-6, IL-1β, TNF-α) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, and anti-melanogenic effects in α-melanocyte-stimulating hormone (MSH)-stimulated B16F10 melanoma cells, where melanin content and tyrosinase activity decreased to 61.49 ± 1.24% and 24.32 ± 0.31% of the control, respectively, without cytotoxicity. A human primary skin irritation test confirmed no irritation up to 50 µg/mL, establishing excellent dermal safety. Collectively, these findings highlight K. griseola JNUCC 62 from Mulyeongari Oreum as a volcanic wetland-derived actinomycete harboring rich biosynthetic potential for novel indole alkaloids with antioxidant, anti-inflammatory, and whitening properties, supporting its development as a safe and multifunctional cosmeceutical ingredient. Full article

Ethyl 3-formyl-1H-indol-2-carboxylate (FIC) and 2-(4-methoxyphenyl)-2,4-dihydropyrrolo [3,4-b]indol-3-ol (MPI) were synthesized as indole derivatives. The chemical structures of FIC and MPI were established through analytical and spectroscopic techniques. The inhibitory impacts of FIC and MPI on mild steel (MS) in an acidic environment (0.5 M H₂SO₄) were investigated by employing methodologies including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP). As the studied indole derivatives adsorbed on the surface of MS, they created a barrier to mass and charge movement, shielding the MS from dangerous ions. It was observed that the inhibitory efficiency (%EF) values increased with the molar concentration of indole derivatives (FIC and MPI). At all concentrations, the two indole derivatives being studied, FIC and MPI, had high efficiency values. The highest efficiencies at 90 ppm were 81.2% with MPI and 76.2% with FIC. The polarization curves also clearly showed that MPI and FIC function as mixed-type inhibitors. Additionally, this study used density functional theory (DFT) and molecular dynamics (MD) simulations to investigate how well the two indole derivatives prevented mild steel corrosion. Full article

Bacterial antibiotic resistance represents a major healthcare problem. In 2019, 4.95 million deaths were associated with antibiotic resistance, and it is estimated that, by 2050, up to 3.8% of the global gross domestic product could be lost due to this problem. Methicillin-resistant Staphylococcus aureus is one of the leading sources of hospital-acquired infections associated with increased mortality, length of hospital stay, and higher cost of treatment. Here, we describe the de novo synthesis of a library of 22 triazeneindole derivatives with high activity against a wide panel of multidrug-resistant MRSA clinical isolates. Leading compound BX-SI043 (ethyl 6-fluoro-3-[pyrrolidin-1-yl-azo]-1H-indole-2-carboxylate) showed high activity (minimal inhibitory concentration range, 0.125–0.5 mg/L) against 41 multidrug-resistant MRSA strains, as well as relatively low in vitro cytotoxicity (selectivity index, 76) and in vivo acute toxicity (maximum tolerated dose, 600 mg/kg), via intragastric administration in rats. These data suggest that BX-SI043 is a promising drug candidate for the development a novel MRSA treatment. Full article

This study aimed to provide novel information on the impact of indigenous non-Saccharomyces yeasts, including Metschnikowia chrysoperlae, Metschnikowia sinensis/shanxiensis, Metschnikowia pulcherrima, Lachancea thermotolerans, Hanseniaspora uvarum, Hanseniaspora guilliermondii, and Pichia kluyveri, on metabolites related to the metabolism of tryptophan, phenylalanine, and tyrosine. The experiment included two fermentation practices: monoculture and sequential fermentation with commercial Saccharomyces cerevisiae, using sterile Maraština grape juice. A targeted approach through ultrahigh-resolution liquid chromatography associated with mass spectrometry was used to quantify 38 metabolites. All the indigenous yeasts demonstrated better consumption of tryptophan in monoculture than in interaction with S. cerevisiae. M. sinensis/shanxiensis was the only producer of indole-3-carboxylic acid, while its ethyl ester was detected in monoculture fermentation with H. guilliermondii. H. guilliermondii consumed the most phenylalanine among the other isolates. 5-hydroxy-L-tryptophan was detected in fermentations with M. pulcherrima and M. sinensis/shanxiensis. M. pulcherrima significantly increased tryptophol content and utilised tyrosine in monoculture fermentations. Sequential fermentation with M. sinensis/shanxiensis and S. cerevisiae produced higher amounts of N-acetyl derivatives of tryptophan and phenylalanine, while H. guilliermondii-S. cerevisiae fermentation resulted in wines with the highest concentrations of L-kynurenine and 3-hydroxyanthranilic acid. P. kluyveri produced the highest concentration of N-acetyl-L-tyrosine in monoculture fermentations. These findings highlight the different yeast metabolic pathways. Full article

Indole ring is widely represented in natural compounds, as well as in a great variety of drugs. In this paper, the synthesis of a 5-hydroxybenzoindole derivative carrying a pyridyl substituent on position 1 is reported. The method involved no chromatography for purification and used solvents and catalysts of very low toxicity. Full article

Secondary metabolites, bioactive compounds produced by living organisms, can unveil symbiotic relationships in nature. In this study, soilborne entomopathogenic nematodes associated with symbiotic bacteria (Xenorhabdus stockiae and Photorhabdus luminescens) were extracted from solvent supernatant containing secondary metabolites, demonstrating significant inhibitory effects against E. coli, S. aureus, B. subtilus, P. mirabilis, E. faecalis, and P. stutzeri. The characterization of these secondary metabolites by Fourier transforms infrared spectroscopy revealed amine groups of proteins, hydroxyl and carboxyl groups of polyphenols, hydroxyl groups of polysaccharides, and carboxyl groups of organic acids. Furthermore, the obtained crude extracts were analyzed by high-performance liquid chromatography for the basic identification of potential bioactive peptides. Gas chromatography–mass spectrometry analysis of ethyl acetate extracts from Xenorhabdus stockiae identified major compounds including nonanoic acid derivatives, proline, paromycin, octodecanal derivatives, trioxa-5-aza-1-silabicyclo, 4-octadecenal, methyl ester, oleic acid, and 1,2-benzenedicarboxylicacid. Additional extraction from Photorhabdus luminescens yielded functional compounds such as indole-3-acetic acid, phthalic acid, 1-tetradecanol, nemorosonol, 1-eicosanol, and unsaturated fatty acids. These findings support the potential development of novel natural antimicrobial agents for future pathogen suppression. Full article

According to data provided by the World Health Organization (WHO), a total of 2.3 million women across the globe received a diagnosis of breast cancer in the year 2020, and among these cases, 685,000 resulted in fatalities. As the incidence of breast cancer statistics continues to rise, it is imperative to explore new avenues in the ongoing battle against this disease. Therefore, a number of new indolyl-hydrazones were synthesized by reacting the ethyl 3-formyl-1H-indole-2-carboxylate 1 with thiosemicarbazide, semicarbazide.HCl, 4-nitrophenyl hydrazine, 2,4-dinitrophenyl hydrazine, and 4-amino-5-(1H-indol-2-yl)-1,2,4-triazole-3-thione to afford the new hit compounds, which were assigned chemical structures as thiosemicarbazone 3, bis(hydrazine derivative) 5, semicarbzone 6, Schiff base 8, and the corresponding hydrazones 10 and 12 by NMR, elemental analysis, and X-ray single-crystal analysis. The MTT assay was employed to investigate the compounds’ cytotoxicity against breast cancer cells (MCF-7). Cytotoxicity results disclosed potent IC₅₀ values against MCF-7, especially compounds 5, 8, and 12, with IC₅₀ values of 2.73 ± 0.14, 4.38 ± 0.23, and 7.03 ± 0.37 μM, respectively, compared to staurosproine (IC₅₀ = 8.32 ± 0.43 μM). Consequently, the activities of compounds 5, 8, and 12 in relation to cell migration were investigated using the wound-healing test. The findings revealed notable wound-healing efficacy, with respective percentages of wound closure measured at 48.8%, 60.7%, and 51.8%. The impact of the hit compounds on cell proliferation was assessed by examining their apoptosis-inducing properties. Intriguingly, compound 5 exhibited a significant enhancement in cell death within MCF-7 cells, registering a notable increase of 39.26% in comparison to the untreated control group, which demonstrated only 1.27% cell death. Furthermore, the mechanism of action of compound 5 was scrutinized through testing against kinase receptors. The results revealed significant kinase inhibition, particularly against PI3K-α, PI3K-β, PI3K-δ, CDK2, AKT-1, and EGFR, showcasing promising activity, compared to standard drugs targeting these receptors. In the conclusive phase, through in vivo assay, compound 5 demonstrated a substantial reduction in tumor volume, decreasing from 106 mm³ in the untreated control to 56.4 mm³. Moreover, it significantly attenuated tumor proliferation by 46.9%. In view of these findings, the identified leads exhibit promises for potential development into future medications for the treatment of breast cancer, as they effectively hinder both cell migration and proliferation. Full article

Pyrimidines play an important role in modern medical fields. They have a wide spectrum of biological activities such as antimicrobial, anticancer, anti-allergic, anti-leishmanial, antioxidant agents and others. Moreover, in recent years, 3,4-dihydropyrimidin-2(1H)ones have attracted researchers to synthesize them via Biginelli reaction and evaluate their antihypertensive activities as bioisosters of Nifedipine, which is a famous calcium channel blocker. Our new target compounds were prepared through one-pot reaction of thiourea 1, ethyl acetoacetate 2 and/or 1H-indole-2-carbaldehyde, 2-chloroquinoline-3-carbaldehyde, 1,3-diphenyl-1H-pyrazole-4-carbaldehyde, 3a–c in acid medium (HCl) yielding pyrimidines 4a–c, which in turn were hydrolyzed to carboxylic acid derivatives 5a–c which were chlorinated by SOCl₂ to give acyl chlorides 6a–c. Finally, the latter were reacted with some selected aromatic amines, namely, aniline, p-toluidine and p-nitroaniline, producing amides 7a–c, 8a–c, and 9a–c. The purity of the prepared compounds was examined via TLC monitoring, and structures were confirmed by different spectroscopic techniques such as IR, ¹HNMR, ¹³CNMR, and mass spectroscopy. The in vivo evaluation of the antihypertensive activity revealed that compounds 4c, 7a, 7c, 8c, 9b and 9c had comparable antihypertensive properties with Nifedipine. On the other hand, the in vitro calcium channel blocking activity was evaluated by IC₅₀ measurement and results revealed that compounds 4c, 7a, 7b, 7c, 8c, 9a, 9b, and 9c had comparable calcium channel blocking activity with the reference Nifedipine. Based on the aforementioned biological results, we selected compounds 8c and 9c to be docked onto Ryanodine and dihydropyridine receptors. Furthermore, we developed a structure–activity relationship. The designed compounds in this study show promising activity profiles in reducing blood pressure and as calcium channel blockers, and could be considered as new potential antihypertensive and/or antianginal agents. Full article

Cancer cells frequently develop drug resistance, which leads to chemotherapeutic treatment failure. Additionally, chemotherapies are hindered by their high toxicity. Therefore, the development of new chemotherapeutic drugs with improved clinical outcomes and low toxicity is a major priority. Several indole derivatives exhibit distinctive anti-cancer mechanisms which have been associated with various molecular targets. In this study, target compounds 4a–q were obtained through the reaction of substituted benzyl chloride with hydrazine hydrate, which produces benzyl hydrazine. Subsequently, the appropriate substituted benzyl hydrazine was allowed to react with 1H-indole-2-carboxylic acid or 5-methoxy-1H-indole-2-carboxylic acid using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide as a coupling agent. All compounds exhibited cytotoxicity in three cell lines, namely, MCF-7, A549, and HCT. Compound 4e exhibited the highest cytotoxicity, with an average IC50 of 2 µM. Moreover, a flow cytometry study revealed a significantly increased prevalence of Annexin-V and 7-AAD positive cell populations. Several derivatives of 4a–q showed moderate to high cytotoxicity against the tested cell lines, with compound 4e having the highest cytotoxicity, indicating that it may possess potential apoptosis-inducing capabilities. Full article

A general approach towards the synthesis of tetrahydro-4H-pyrazolo[1,5-a][1,4]diazepin-4-one, tetrahydro[1,4]diazepino[1,2-a]indol-1-one and tetrahydro-1H-benzo[4,5]imidazo[1,2-a][1,4]diazepin-1-one derivatives was introduced. A regioselective strategy was developed for synthesizing ethyl 1-(oxiran-2-ylmethyl)-1H-pyrazole-5-carboxylates from easily accessible 3(5)-aryl- or methyl-1H-pyrazole-5(3)-carboxylates. Obtained intermediates were further treated with amines resulting in oxirane ring-opening and direct cyclisation—yielding target pyrazolo[1,5-a][1,4]diazepin-4-ones. A straightforward two-step synthetic approach was applied to expand the current study and successfully functionalize ethyl 1H-indole- and ethyl 1H-benzo[d]imidazole-2-carboxylates. The structures of fused heterocyclic compounds were confirmed by ¹H, ¹³C, and ¹⁵N-NMR spectroscopy and HRMS investigation. Full article

Halymenia durvillei is a red alga distributed along the coasts of Southeast Asian countries including Thailand. Previous studies have shown that an ethyl acetate fraction of H. durvillei (HDEA), containing major compounds including n-hexadecanoic acid, 2-butyl-5-hexyloctahydro-1H-indene, 3-(hydroxyacetyl) indole and indole-3-carboxylic acid, possesses high antioxidant and anti-lung cancer activities. The present study demonstrated that HDEA could protect mouse skin fibroblasts (L929) and human immortalized keratinocytes (HaCaT) against photoaging due to ultraviolet A and B (UVA and UVB) by reducing intracellular reactive oxygen species (ROS) and expressions of matrix metalloproteinases (MMP1 and MMP3), as well as increasing Nrf2 nuclear translocation, upregulations of mRNA transcripts of antioxidant enzymes, including superoxide dismutase (SOD), heme oxygenase (HMOX) and glutathione S-transferase pi1 (GSTP1), and procollagen synthesis. The results indicate that HDEA has the potential to protect skin cells from UV irradiation through the activation of the Nrf2 pathway, which leads to decreasing intracellular ROS and MMP production, along with the restoration of skin collagen. Full article

Methicillin-resistant Staphylococcus aureus (MRSA) infections are increasingly causing morbidity and mortality; thus, drugs with multifunctional efficacy against MRSA are needed. We extracted a novel compound from the halophilic Pseudomonas aeruginosa using an ethyl acetate (HPAEtOAcE). followed by purification and structure elucidation through HPLC, LCMS, and ¹H and ¹³C NMR, revealing the novel 5-(1H-indol-3-yl)-4-pentyl-1,3-oxazole-2-carboxylic acid (Compound 1). Molecular docking of the compound against the MRSA PS (pantothenate synthetase) protein was confirmed using the CDOCKER algorithm in BDS software with specific binding to the amino acids Arg (B:188) and Lys (B:150) through covalent hydrogen bonding. Molecular dynamic simulation of RMSD revealed that the compound–protein complex was stabilized. The proficient bioactivities against MRSA were attained by the HPAEtOAcE, including MIC and MBCs, which were 0.64 and 1.24 µg/mL, respectively; 100% biomass inhibition and 99.84% biofilm inhibition were observed with decayed effects by CLSM and SEM at 48 h. The hla, IrgA, and SpA MRSA genes were downregulated in RT-PCR. Non-hemolytic and antioxidant potential in the DPPH assay were observed at 10 mg/mL and IC₅₀ 29.75 ± 0.38 by the HPAEtOAcE. In vitro growth inhibition assays on MRSA were strongly supported by in silico molecular docking; Lipinski’s rule on drug-likeness and ADMET toxicity prediction indicated the nontoxic nature of compound. Full article

The cardioprotective effects of nitric oxide (NO) have been described through S-nitrosylation of several important proteins in the mitochondria of the cardiomyocyte. S-nitrosoglutathione reductase (GSNOR) is an enzyme involved in the metabolism of S-nitrosothiols by producing denitrosylation, thus limiting the cardioprotective effect of NO. The effect of GSNOR inhibition on the damage by cardiac ischemia–reperfusion is still unclear. We tested the hypothesis that pharmacological inhibition of GSNOR promotes cardioprotection by increasing the levels of protein S-nitrosylation. In a model of ischemia–reperfusion in isolated rat heart, the effect of a GSNOR inhibitor, 5-chloro-3-(2-[4-ethoxyphenyl) (ethyl) amino]-2-oxoethyl)-1H-indole-2-carboxylic acid (C2), was investigated. Ventricular function and hemodynamics were determined, in addition to tissue damage and S-nitrosylation of mitochondrial proteins. Hearts treated with C2 showed a lower release of myocardial damage marker creatine kinase and a reduction in the infarcted area. It also improved post-ischemia ventricular function compared to controls. These results were associated with increasing protein S-nitrosylation, specifically of the mitochondrial complexes III and V. The pharmacological inhibition of GSNOR showed a concentration-dependent cardioprotective effect, being observed in functional parameters and myocardial damage, which was maximal at 1 µmol/L, associated with increased S-nitrosylation of mitochondrial proteins. These data suggest that GSNOR is an interesting pharmacological target for cardiac reperfusion injury. Full article

Successful alkylations of the nitrogen of ethyl indol-2-carboxylate were carried out using aq. KOH in acetone. The respective N-alkylated acids could be obtained without separating the N-alkylated esters by increasing the amount of KOH and water. The use of NaOMe in methanol led to transesterification instead of the alkylation, while the use of NaOEt led to low yields of the N-alkylated acids. Hydrazinolysis of the ester gave indol-2-carbohydrazide which then was allowed to react with different aromatic aldehydes and ketones in ethanol catalyzed by acetic acid. Indol-2-thiosemicarbazide was used in a heterocyclization reaction to form thiazoles. The new structures were confirmed using NMR, mass spectrometry and X-ray single crystal analysis. Full article