benzofurans and cercosporamide

To identify natural inhibitors against MCT8 for Allan-Herndon-Dudley Syndrome.. Monocarboxylate Transporter 8 (MCT8) is a Thyroid Hormone (TH) transporter which is highly expressed in the liver and brain. Mutations in the MCT8 gene (SLC16A2) cause a syndrome of psychomotor retardation in humans, known as Allan-Herndon-Dudley syndrome (AHDS). Currently, no treatment is available for AHDS. Therefore, there is a need to discover new inhibitors of MCT8 for treating AHDS.. Considering the importance of natural compounds in drug discovery, this study aimed to identify potential natural inhibitors against MCT8.. As Protein-ligand interactions play a key role in structure based drug design, this study screened 24 natural kinase inhibitors and investigated their binding affinity against MCT8 by using molecular docking. The modelled 3D structure of MCT8 docked with 24 compounds using PyRX through Autodock Vina. Drug-likeness studies were made using Swiss ADME and Lipinski's rule of five was performed. Triac, desipramine and silychristin were used as the positive controls. Binding energies of the selected compounds were compared with that of positive controls.. The results showed that emodin exhibited best binding energy of -8.6 kcal/mol followed by helenaquinol, cercosporamide and resveratrol. Moreover, it was observed that emodin and helenaquinol exhibit higher binding energy than the positive controls. Cercosporamide and resveratrol exhibited higher binding energy than triac and desipramine and showed the binding energy similar to silychristin.. This study reveals that these compounds could be promising candidates for further evaluation for AHDS prevention.

Topics: Benzofurans; Biological Transport; Drug Discovery; Emodin; Humans; Mental Retardation, X-Linked; Molecular Docking Simulation; Monocarboxylic Acid Transporters; Muscle Hypotonia; Muscular Atrophy; Mutation; Phytochemicals; Protein Kinase Inhibitors; Resveratrol; Symporters; Thyroid Hormones

Eukaryotic translation initiation factor 4E (eIF4E) is activated in cancers in response to stress. This is regulated by MAP kinase interacting serine/threonine kinase (MNK) in cancerous but not normal cells. Chemoresistance causes treatment failure in advanced cervical cancer. In this study, we addressed chemotherapy effects on eIF4E for cervical cancer and reversal effects by MNK inhibitor cercosporamide for chemo-resistance mitigation.. Cell assays and mouse tumour models were used to determine the efficacy of cercosporamide. Western blotting was applied to understand the affected cell signaling after cercosporamide treatment.. Cercosporamide spared normal cervical epithelial cells. On cervical cancer cell lines, it showed inhibition of cell growth and migration, and induced apoptosis. Cercosporamide was effective on chemoresistant cancer cells and augmented the efficiency of doxorubicin and cisplatin both in vitro and in vivo. Cercosporamide suppressed eIF4E signaling. Of note, chemotherapy increased p-eIF4E. Cercosporamide abolished chemotherapy-induced eIF4E activation. The higher level of p-eIF4E in cancer cells compared with normal cervical epithelial cells explains the preferential toxicity of cercosporamide.. This work demonstrates the ability of cercosporamide to overcome chemoresistance and highlight preferential inhibition of eIF4E via MNK inhibition in cervical cancer.

Topics: Animals; Antineoplastic Agents; Benzofurans; Cell Line, Tumor; Drug Resistance, Neoplasm; Eukaryotic Initiation Factor-4E; Female; Humans; Intracellular Signaling Peptides and Proteins; Mice, Nude; Molecular Targeted Therapy; Protein Serine-Threonine Kinases; Uterine Cervical Neoplasms; Xenograft Model Antitumor Assays

Topics: Animals; Benzofurans; Biological Assay; Bone Morphogenetic Protein Receptors, Type I; Bone Morphogenetic Proteins; Embryo, Nonmammalian; HEK293 Cells; Hep G2 Cells; Humans; Protein Kinase Inhibitors; Signal Transduction; Time Factors; Zebrafish; Zebrafish Proteins

Eukaryotic translation initiation factor 4E (eIF4E) is deregulated in patients with renal cell carcinoma (RCC) and associated with poor prognosis, and is activated and regulated by Mnk kinases. In this study, we investigated the anti-RCC potential of a unique Mnk inhibitor cercosporamide. We showed that cercosporamide is active against RCC cells via suppressing growth, survival and migration. Combination indices value indicated that the combination of cercosporamide with sunitinib or temsirolimus are synergistic in RCC. In two independent RCC xenograft mouse models, complete tumor growth arrest or reverse was observed throughout the duration of drug treatment in the combination of cercosporamide with sunitinib or temsirolimus groups. Of note, cercosporamide inhibited RCC angiogenesis via negatively regulating a number of RCC endothelial cellular events including morphogenesis, migration, growth and survival. Mechanistically, we found that cercosporamide suppressed pro-angiogenic factors VEGF and HIFα, inhibited EMT and reduced pro-survival and cell cycle proteins; and furthermore this was attributed to cercosporamide's ability in inhibiting eIF4E. This work demonstrates the anti-RCC activity of cercosporamide through targeting both RCC tumor cells and angiogenesis, and provides the first preclinical proof-of-concept of evidence of Mnk inhibition for RCC treatment.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Benzofurans; Carcinoma, Renal Cell; Cell Line, Tumor; Drug Synergism; Eukaryotic Initiation Factor-4E; Humans; Intracellular Signaling Peptides and Proteins; Kidney Neoplasms; Mice, SCID; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Sirolimus; Sunitinib; TOR Serine-Threonine Kinases

To investigate the bioactive metabolite of endophytic fungus from Kalimeris indica.. A strain ZJLQ336 was separated from the leaves of K. indica. It was identified as Cadophora orchidicola based on the phylogenetic analysis of ITS-rDNA sequences. From the fermentation broth a metabolite cercosporamide (compound 1) was isolated, and its structure was determined by spectroscopic analysis. Additionally, this compound was subjected to bioactivity assays, including antifungal activity against seven plant pathogenic fungi, as well as its potential immunoregulatory effects on HEK-BLUE™-hTLR4 cells, splenocytes and macrophages. The results showed that cercosporamide had strong growth inhibition against five common plant pathogenic fungi, including Pestalotia diospyri, Botrytis cinerea, Fusarium oxysporum, Sclerotium rolfsii and Penicillum digitatum with EC. This is the first report of endophytic C. orchidicola from K. indica and its metabolite cercosporamide. The results of pharmacological tests highlight the potential fungicide and TLR4 agonist of cercosporamide.. This study indicates endophytic fungi are good resources for natural bioactive metabolites. It also suggests that cercosporamide is a potential fungicide and TLR4 agonist.

Topics: Animals; Antifungal Agents; Ascomycota; Aster Plant; Benzofurans; Cytokines; Female; HEK293 Cells; Humans; Mice; Phylogeny; RAW 264.7 Cells; Toll-Like Receptor 4

Histone demethylases are known to play important roles in the determination of the fate of stem cells and in cancer progression. In this study, we show that the lysine 4 of histone H3 (H3K4), lysine-specific demethylase 5A (KDM5A) is essential for the repression of astrocyte differentiation in neural progenitor cells (NPCs), and its expression is regulated by translational machinery. Knockdown of KDM5A in NPCs increased astrocytogenesis, and conversely, KDM5A overexpression reduced the transcriptional activity of the Gfap promoter. Induction of astrocytogenesis by ciliary neurotrophic factor (CNTF) or small interfering RNA-induced knockdown of KDM5A decreased KDM5A recruitment to the Gfap promoter and increased H3K4 methylation. The transcript level of Kdm5a was high, whereas KDM5A protein level was low in CNTF induced astrocytes. During astroglial differentiation, translational activity indicated by the phosphorylation of eukaryotic translation initiation factor (eIF)4E was decreased. Treatment of NPCs with the cercosporamide, a MAPK-interacting kinases inhibitor, reduced eIF4E phosphorylation and KDM5A protein expression, increased GFAP levels, and enhanced astrocytogenesis. These data suggest that KDM5A is a key regulator that maintains NPCs in an undifferentiated state by repressing astrocytogenesis and that its expression is translationally controlled during astrocyte differentiation. Thus, KDM5A is a promising target for the modulation of NPC fate.-Kong, S.-Y., Kim, W., Lee, H.-R., Kim, H.-J. The histone demethylase KDM5A is required for the repression of astrocytogenesis and regulated by the translational machinery in neural progenitor cells.

Topics: Animals; Astrocytes; Benzofurans; Cell Differentiation; Gene Expression Regulation, Enzymologic; Glial Fibrillary Acidic Protein; Histones; Methylation; Neural Stem Cells; Promoter Regions, Genetic; Rats; Rats, Sprague-Dawley; Retinoblastoma-Binding Protein 2

In a context of growing resistance to classical antifungal therapy, the design of new drugs targeting alternative pathways is highly expected. Benzofuro[3,2-d]pyrimidine derivatives, derived from (-)-cercosporamide, were synthesized and evaluated as potential Candida albicans PKC inhibitors in the aim of restoring susceptibility to azole treatment. Co-administration assay of benzofuropyrimidinedione 23 and fluconazole highlighted a synergistic effect on inhibition of cell growth of a Candida albicans resistant strain.

Topics: Antifungal Agents; Ascomycota; Benzofurans; Biofilms; Candida albicans; Drug Resistance, Fungal; Drug Synergism; Fluconazole; HeLa Cells; Humans; Protein Kinase C; Protein Kinase Inhibitors; Pyrimidinones

Topics: Animals; Antidepressive Agents; Anxiety; Behavior, Animal; Benzofurans; Citalopram; Depression; Depressive Disorder, Major; Eukaryotic Initiation Factor-4E; Female; Fluoxetine; Inflammation; Ketamine; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-KappaB Inhibitor alpha; Phosphorylation; Protein Biosynthesis; Protein Serine-Threonine Kinases; Serotonin and Noradrenaline Reuptake Inhibitors; Synaptic Transmission; Tumor Necrosis Factor-alpha

Mnk kinase is required for the phosphorylation and activation of the eukaryotic initiation factor 4E (eIF4E), which regulates translation of proteins involve in important aspects of hepatocellular carcinoma (HCC). Here we investigated whether an antifungal agent, cercosporamide, which had been recently identified as a potent Mnk inhibitor, is active against HCC and angiogenesis. We showed that cercosporamide significantly inhibited growth and induced caspase-dependent apoptosis on numerous HCC cell lines, while sparing normal liver cells. In addition, cercosporamide impaired HCC angiogenesis via inhibiting HCC-endothelial cells (HCC-EC) capillary network formation, migration, proliferation and survival. Importantly, cercosporamide sensitized HCC cells to cisplatin in in vitro cell culture and in vivo HCC xenograft mouse model. Cercosporamide blocked the phosphorylation of eIF4E but not Erk or p38 in a dose- and time-dependent manner in HCC and HCC-EC cells, suggesting that suppression of eIF4E phosphorylation was the result of inhibition of Mnk but not Mnk upstream pathways. Overexpression of constitutively active eIF4E (S209D) but not the nonphosphorylatable eIF4E (S209A) abolished the inhibitory effects of cercosporamide in HepG2 cells. Altogether, our work demonstrates that cercosporamide acts as a Mnk inhibitor through blockage of eIF4E phosphorylation and selectively exhibits anti-HCC activities. Our work suggests that targeting MNK-eIF4E pathway represents a therapeutic strategy to overcome chemo-resistance for HCC treatment.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzofurans; Carcinoma, Hepatocellular; Cell Proliferation; Cell Survival; Cisplatin; Dose-Response Relationship, Drug; Drug Synergism; Eukaryotic Initiation Factor-4E; Hep G2 Cells; Humans; Intracellular Signaling Peptides and Proteins; Liver Neoplasms; Mice, SCID; Neovascularization, Pathologic; Phosphorylation; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Signal Transduction; Time Factors; Transfection; Xenograft Model Antitumor Assays

Fragile X syndrome (FXS) is the leading genetic cause of autism. Mutations in Fmr1 (fragile X mental retardation 1 gene) engender exaggerated translation resulting in dendritic spine dysmorphogenesis, synaptic plasticity alterations, and behavioral deficits in mice, which are reminiscent of FXS phenotypes. Using postmortem brains from FXS patients and Fmr1 knockout mice (Fmr1(-/y)), we show that phosphorylation of the mRNA 5' cap binding protein, eukaryotic initiation factor 4E (eIF4E), is elevated concomitant with increased expression of matrix metalloproteinase 9 (MMP-9) protein. Genetic or pharmacological reduction of eIF4E phosphorylation rescued core behavioral deficits, synaptic plasticity alterations, and dendritic spine morphology defects via reducing exaggerated translation of Mmp9 mRNA in Fmr1(-/y) mice, whereas MMP-9 overexpression produced several FXS-like phenotypes. These results uncover a mechanism of regulation of synaptic function by translational control of Mmp-9 in FXS, which opens the possibility of new treatment avenues for the diverse neurological and psychiatric aspects of FXS.

Topics: Adenosine Triphosphatases; Animals; Autistic Disorder; Benzofurans; Brain; Cation Transport Proteins; Cells, Cultured; Copper-Transporting ATPases; Dendritic Spines; Enzyme Induction; Eukaryotic Initiation Factor-4E; Female; Fragile X Syndrome; Humans; Male; Matrix Metalloproteinase 9; Mice, Inbred C57BL; Mice, Transgenic; Phenotype; Phosphorylation; Protein Biosynthesis; Protein Processing, Post-Translational; Receptors, Metabotropic Glutamate

Mnk kinases regulate the phosphorylation and activation of the eukaryotic initiation factor 4E (eIF4E), a protein that plays key roles in the initiation of messenger RNA translation and whose activity is critical for various cellular functions. eIF4E is deregulated in acute myeloid leukemia (AML), and its aberrant activity contributes to leukemogenesis. We determined whether cercosporamide, an antifungal agent that was recently shown to act as a unique Mnk inhibitor, exhibits antileukemic properties. Treatment of AML cells with cercosporamide resulted in a dose-dependent suppression of eIF4E phosphorylation. Such suppression of Mnk kinase activity and eIF4E phosphorylation by cercosporamide resulted in dose-dependent suppressive effects on primitive leukemic progenitors (CFU-L) from AML patients and enhanced the antileukemic properties of cytarabine (Ara-C) or mammalian target of rapamycin (mTOR) complex 1 inhibition. Similarly, the combination of cercosporamide with cytarabine resulted in enhanced antileukemic responses in a xenograft mouse model in vivo. Altogether, this work demonstrates that the unique Mnk inhibitor cercosporamide suppresses phosphorylation of eIF4E and exhibits antileukemic effects, in support of future clinical-translational efforts involving combinations of Mnk inhibitors with cytarabine and/or mTOR inhibitors for the treatment of AML.

Topics: Adenosine Triphosphatases; Animals; Antineoplastic Agents; Benzofurans; Cation Transport Proteins; Cell Line, Tumor; Cell Proliferation; Copper-Transporting ATPases; Down-Regulation; Humans; K562 Cells; Leukemia, Myeloid, Acute; Mice; Neoplastic Stem Cells; Protein Kinase Inhibitors; U937 Cells; Xenograft Model Antitumor Assays

A novel series of 3-methyl-1-benzofuran derivatives were synthesized and screened in vitro for their antiproliferative activity against two human NSCLC cell lines (NSCLC-N6 mutant p53 and A549 wild type p53). Most promising compounds presented a structural analogy with the west part of cercosporamide, a natural product of biological interest. In particular, compounds 10, 12 and 31 showed cytotoxic activities at micromolar concentrations (IC₅₀ < 9.3 μM) and compounds 13, 18 and 32 displayed moderate IC₅₀ values (25-40 μM).

Topics: Antineoplastic Agents; Benzofurans; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Lung Neoplasms; Molecular Structure; Structure-Activity Relationship

Through bioassay-guided fractionation, the EtOAc extract of a culture broth of the endophytic fungus Phoma species ZJWCF006 in Arisaema erubescens afforded a new α-tetralone derivative, (3S)-3,6,7-trihydroxy-α-tetralone (1), together with cercosporamide (2), β-sitosterol (3), and trichodermin (4). The structures of compounds were established on the basis of spectroscopic analyses. Compounds 1, 2, and 3 were obtained from Phoma species for the first time. Additionally, the compounds were subjected to bioactivity assays, including antimicrobial activity, against four plant pathogenic fungi (Fusarium oxysporium, Rhizoctonia solani, Colletotrichum gloeosporioides, and Magnaporthe oryzae) and two plant pathogenic bacteria (Xanthomonas campestris and Xanthomonas oryzae), as well as in vitro antitumor activities against HT-29, SMMC-772, MCF-7, HL-60, MGC80-3, and P388 cell lines. Compound 1 showed growth inhibition against F. oxysporium and R. solani with EC₅₀ values of 413.22 and 48.5 μg/mL, respectively. Additionally, compound 1 showed no cytotoxicity, whereas compound 2 exhibited cytotoxic activity against the six tumor cell lines tested, with IC₅₀ values of 9.3 ± 2.8, 27.87 ± 1.78, 48.79 ± 2.56, 37.57 ± 1.65, 27.83 ± 0.48, and 30.37 ± 0.28 μM, respectively. We conclude that endophytic Phoma are promising sources of natural bioactive and novel metabolites.

Topics: Anti-Bacterial Agents; Antifungal Agents; Antineoplastic Agents; Arisaema; Ascomycota; Benzofurans; Cell Line, Tumor; Culture Media, Conditioned; Endophytes; Fungi; HL-60 Cells; HT29 Cells; Humans; Medicine, Chinese Traditional; Plant Diseases; Sitosterols; Species Specificity; Tetralones; Trichodermin; Xanthomonas

Peroxisome proliferator-activated receptor gamma (PPARγ) is a potential drug target for treating type 2 diabetes. The selective PPARγ modulators (SPPARMs), which partially activate the PPARγ transcriptional activity, are considered to improve the plasma glucose level with attenuated PPARγ related adverse effects. However, the relationships between desired pharmacological profiles and ligand specific PPARγ transcriptional profiles have been unclear. And there is also little knowledge of how to control ligand specific PPARγ transcriptional profiles. Herein, we present synthesis of novel derivatives containing substituent at naphthalene C3 position of compound 1. The novel derivatives showed various maximal efficacies as PPARγ partial agonist.

Topics: Benzofurans; Crystallography, X-Ray; Gene Expression Regulation; Humans; Hypoglycemic Agents; Inhibitory Concentration 50; Models, Molecular; Molecular Structure; Naphthalenes; PPAR gamma

Selective peroxisome proliferator-activated receptor gamma (PPARγ) modulators are expected to be a novel class of drugs improving plasma glucose levels without PPARγ-related adverse effects. As a continuation of our studies for (-)-Cercosporamide derivatives as selective PPARγ modulators, we synthesized substituted naphthalene type compounds and identified the most potent compound 15 (EC(50) = 0.94 nM, E(max) = 38%). Compound 15 selectively activated PPARγ transcription and did not activate PPARα and PPARδ. The potassium salt of compound 15 showed a high solubility and a good oral bioavailability (58%). Oral administration of the potassium salt remarkably improved the plasma glucose levels of female Zucker diabetic fatty rats at 1 mg/kg. Moreover, it did not cause a plasma volume increase or a cardiac enlargement in Wistar-Imamichi rats, even at 100 mg/kg.

Topics: Animals; Benzofurans; Cell Line, Tumor; Chemistry Techniques, Synthetic; Diabetes Mellitus, Type 2; Female; Genes, Reporter; Humans; Hypoglycemic Agents; Models, Molecular; PPAR gamma; Protein Conformation; Rats

Activation of the translation initiation factor 4E (eIF4E) promotes malignant transformation and metastasis. Signaling through the AKT-mTOR pathway activates eIF4E by phosphorylating the inhibitory 4E binding proteins (4E-BP). This liberates eIF4E and allows binding to eIF4G. eIF4E can then be phosphorylated at serine 209 by the MAPK-interacting kinases (Mnk), which also interact with eIF4G. Although dispensable for normal development, Mnk function and eIF4E phosphorylation promote cellular proliferation and survival and are critical for malignant transformation. Accordingly, Mnk inhibition may serve as an attractive cancer therapy. We now report the identification of a potent, selective and orally bioavailable Mnk inhibitor that effectively blocks 4E phosphorylation both in vitro and in vivo. In cultured cancer cell lines, Mnk inhibitor treatment induces apoptosis and suppresses proliferation and soft agar colonization. Importantly, a single, orally administered dose of this Mnk inhibitor substantially suppresses eIF4E phosphorylation for at least 4 hours in human xenograft tumor tissue and mouse liver tissue. Moreover, oral dosing with the Mnk inhibitor significantly suppresses outgrowth of experimental B16 melanoma pulmonary metastases as well as growth of subcutaneous HCT116 colon carcinoma xenograft tumors, without affecting body weight. These findings offer the first description of a novel, orally bioavailable MNK inhibitor and the first preclinical proof-of-concept that MNK inhibition may provide a tractable cancer therapeutic approach.

Topics: Animals; Antineoplastic Agents; Apoptosis; Base Sequence; Benzofurans; Blotting, Western; Cell Proliferation; Eukaryotic Initiation Factor-4E; Female; Humans; Inhibitory Concentration 50; Intracellular Signaling Peptides and Proteins; Lung Neoplasms; Mice; Mice, Nude; Molecular Sequence Data; Neoplasm Metastasis; Phosphorylation; Polymerase Chain Reaction; Protein Serine-Threonine Kinases; Xenograft Model Antitumor Assays

Peroxisome proliferator-activated receptor γ (PPARγ; NR1C3) is known as a key regulator of adipocytogenesis and the molecular target of thiazolidinediones (TZDs), also known as antidiabetic agents. Despite the clinical benefits of TZDs, their use is often associated with adverse effects including peripheral edema, congestive heart failure, and weight gain. Here we report the identification and characterization of a non-thiazolidinedione PPARγ partial agonist, Cerco-A, which is a derivative of the natural product, (-)-cercosporamide. Cerco-A was found to be a binder of the PPARγ ligand-binding domain in a ligand competitive binding assay and showed a unique cofactor recruitment profile compared to rosiglitazone. A crystal structure analysis revealed that Cerco-A binds to PPARγ without direct hydrogen bonding to helix12. In PPARγ transcriptional activation assay and an adipocyte differentiation assay, Cerco-A was a potent partial agonist of PPARγ. After a 14-day oral administration, once per day of Cerco-A in Zucker diabetic fatty (ZDF) rats, an apparent decrease of plasma glucose and triglyceride was observed, as with pioglitazone. To evaluate drug safety, Cerco-A was administered for 13 days orally in non-diabetic Zucker fatty (ZF) rats. Each of the hemodilution parameters (hematocrit, red blood cells number, and hemoglobin), which are considered as undesirable effects of TZDs, was improved significantly compared to pioglitazone. While Cerco-A showed body weight gain, as with pioglitazone, Cerco-A had significantly lower effects on heart and white adipose tissues weight gain. The results suggest that Cerco-A offers beneficial effects on glycemic control with attenuated undesirable side effects.

Topics: Adipocytes; Animals; Base Sequence; Benzofurans; Cell Differentiation; Cell Line, Tumor; DNA Primers; Fluorescence Polarization; Humans; Ligands; Molecular Structure; PPAR gamma; Rats; Rats, Zucker

Fungi are well known for their vast diversity of secondary metabolites that include many life-saving drugs and highly toxic mycotoxins. In general, fungal cultures producing such metabolites are immune to their toxic effects. However, some are known to produce self-toxic compounds that can pose production optimization challenges if the metabolites are needed in large amounts for chemical modification. One such culture, LV-2841, was identified as the lead for one of our exploratory projects. This culture was found to be a slow grower that produced trace amounts of a known metabolite, cercosporamide, under the standard flask fermentation conditions, and extensive medium optimization studies failed to yield higher titers. Poor growth of the culture in liquid media was attributed to the self-toxicity of cercosporamide to the producing organism, and the minimum inhibitory concentration (MIC) of cercosporamide was estimated to be in the range of 8-16 microg/ml. Fermentations carried out in media containing Diaion HP20 resin afforded significantly higher titers of the desired compound. While several examples of resin-based fermentations of soil streptomyces have been published, this approach has rarely been used for fungal fermentations. Over a 100-fold increase in the production titer of cercosporamide, a self-toxic secondary metabolite, was achieved by supplementing the production medium with a commercially available neutral adsorbent resin.

Topics: Antifungal Agents; Benzofurans; Culture Media; Fermentation; Fungi; Ion Exchange Resins; Microbial Sensitivity Tests; Polystyrenes

In an investigation of (-)-Cercosporamide derivatives with a plasma glucose-lowering effect, we found that N-benzylcarboxamide derivative 4 was a partial agonist of PPARgamma. A SAR study of the substituents on carboxamide nitrogen afforded the N-(1-naphthyl)methylcarboxamide derivative 23 as the most potent selective PPARgamma modulator. An X-ray crystallography study revealed that compound 23 bounded to the PPARgamma ligand binding domain in a unique way without any interaction with helix12. Compound 23 displayed a potent plasma glucose-lowering effect in db/db mice without the undesirable increase in body fluid and heart weight that is typically observed when PPARgamma full agonists are administrated.

Topics: Animals; Benzofurans; Crystallography, X-Ray; Diabetes Mellitus; Glucose; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Mice; Models, Molecular; PPAR gamma

In our exploratory campaign for an antihyperglycemic agent with a novel mechanism of action, (-)-Cercosporamide 1, which is known as an antifungal agent, showed a potent plasma glucose lowering effect in hyperglycemic KK/Ta mice. The trouble was that it was accompanied by a decrease in food intake and a loss of body weight. We synthesized some (-)-Cercosporamide derivatives and succeeded to separate these actions. N,O-ketal type derivatives, especially compound 10, had the most potent plasma glucose lowering effect without affecting the food consumption or body weight.

Topics: Animals; Antifungal Agents; Benzofurans; Blood Glucose; Body Weight; Chemistry, Pharmaceutical; Drug Design; Eating; Feeding Behavior; Humans; Hypoglycemic Agents; Inhibitory Concentration 50; Mice; Mice, Transgenic; Models, Chemical

Phomodione, [(4aS(*),9bR(*))-2,6-diacetyl-7-hydroxy-4a,9-dimethoxy-8,9b-dimethyl-4a.9b-dihydrodibenzo[b,d]furan-1,3(2H,4H)-dione], an usnic acid derivative, was isolated from culture broth of a Phoma species, discovered as an endophyte on a Guinea plant (Saurauia scaberrinae). It was identified using NMR, X-ray crystallography, high resolution mass spectrometry, as well as infrared and Raman spectroscopy. In addition to phomodione, usnic acid and cercosporamide, known compounds with antibiotic activity, were also found in the culture medium. Phomodione exhibited a minimum inhibitory concentration of 1.6 microg/mL against Staphylococcus aureus using the disk diffusion assay, and was active against a representative oomycete, ascomycete and basidiomycete at between three and eight micro-grams per mL.

Topics: Actinidiaceae; Ascomycota; Basidiomycota; Benzofurans; Crystallography, X-Ray; Magnetic Resonance Spectroscopy; Mass Spectrometry; Microbial Sensitivity Tests; Microscopy, Electron, Scanning; Molecular Structure; Oomycetes; Staphylococcus

The Pkc1-mediated cell wall integrity-signaling pathway is highly conserved in fungi and is essential for fungal growth. We thus explored the potential of targeting the Pkc1 protein kinase for developing broad-spectrum fungicidal antifungal drugs through a Candida albicans Pkc1-based high-throughput screening. We discovered that cercosporamide, a broad-spectrum natural antifungal compound, but previously with an unknown mode of action, is actually a selective and highly potent fungal Pkc1 kinase inhibitor. This finding provides a molecular explanation for previous observations in which Saccharomyces cerevisiae cell wall mutants were found to be highly sensitive to cercosporamide. Indeed, S. cerevisiae mutant cells with reduced Pkc1 kinase activity become hypersensitive to cercosporamide, and this sensitivity can be suppressed under high-osmotic growth conditions. Together, the results demonstrate that cercosporamide acts selectively on Pkc1 kinase and, thus, they provide a molecular mechanism for its antifungal activity. Furthermore, cercosporamide and a beta-1,3-glucan synthase inhibitor echinocandin analog, by targeting two different key components of the cell wall biosynthesis pathway, are highly synergistic in their antifungal activities. The synergistic antifungal activity between Pkc1 kinase and beta-1,3-glucan synthase inhibitors points to a potential highly effective combination therapy to treat fungal infections.

Topics: Amphotericin B; Animals; Antifungal Agents; Benzofurans; beta-Glucans; Biological Assay; Candida albicans; Drug Synergism; Enzyme Activation; Fungal Proteins; Gene Expression Regulation, Fungal; Glucosyltransferases; Humans; Isoenzymes; Microbial Sensitivity Tests; Molecular Structure; Phosphatidylserines; Protein Kinase C; Protein Kinase Inhibitors

k9 killer toxin from Hansenula mrakii was used to select a number of resistant mutants from Saccharomyces cerevisiae. Preliminary biochemical and genetic studies showed that some of them acquired structural defects in the cell wall. One of these mutants, the knr4-1 mutant, displays a number of cell wall defects, including osmotic sensitivity; sensitivity to cercosporamide, a known antifungal agent; and resistance to Zymolyase, a (1,3)-beta-glucanase. We report here the isolation and analysis of the KNR4 gene. DNA sequence analysis revealed an uninterrupted open reading frame which contains five potential start codons. The longest coding template encodes a protein of 505 amino acids with a calculated molecular mass of 57,044 Da. A data base search revealed 100% identity with a nuclear protein, SMI1p. Disruption of the KNR4 locus does not result in cell death; however, it leads to reduced levels of both (1,3)-beta-glucan synthase activity and (1,3)-beta-glucan content in the cell wall. The gene was mapped to the right arm of chromosome VII.

Topics: Amino Acid Sequence; Base Sequence; Benzofurans; beta-Glucans; Blotting, Western; Chromosomes, Fungal; Cloning, Molecular; DNA, Fungal; Drug Resistance, Microbial; Fungal Proteins; Genes, Fungal; Glucans; Glucosyltransferases; Hydrolases; Killer Factors, Yeast; Kinetics; Membrane Proteins; Molecular Sequence Data; Molecular Weight; Open Reading Frames; Pichia; Protein Biosynthesis; Proteins; Recombinant Proteins; Restriction Mapping; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Schizosaccharomyces pombe Proteins; Sequence Homology, Amino Acid; Transcription Factors