ABSTRACT
Here, we report wajeepeptin (1), a new cyclic depsipeptide isolated from a marine Moorena sp. cyanobacterium. The structure was elucidated by a combination of spectroscopic analyses, X-ray diffraction analysis, and degradation reactions. Wajeepeptin (1) showed moderate cytotoxicity (IC50 = 3.7 µM against HeLa cells) and potent antitrypanosomal activity (IC50 = 0.73 ± 0.14 µM against Trypanosoma brucei rhodesiense).
Subject(s)
Cyanobacteria , Depsipeptides , Depsipeptides/pharmacology , Depsipeptides/chemistry , Depsipeptides/isolation & purification , Humans , Molecular Structure , HeLa Cells , Cyanobacteria/chemistry , Trypanosoma brucei rhodesiense/drug effects , Marine Biology , Trypanocidal Agents/pharmacology , Trypanocidal Agents/chemistry , Drug Screening Assays, Antitumor , Crystallography, X-Ray , Nuclear Magnetic Resonance, BiomolecularABSTRACT
In our continuing search for biologically active new chemical entities from marine organisms, we have isolated a new cyclic depsipeptide, PM170453 (1), from a cyanobacterium of the genus Lyngbya sp., collected in the Indo-Pacific Ocean. Structure elucidation of the isolated compound was determined by spectroscopic methods including MS, 1H, 13C and 2D-NMR. To solve the supply problem for 1 and progress pharmaceutical development, the total synthesis of 1 that involves a total of 20 chemical steps in a convergent process was carried out. Its in vitro cytotoxic activity against four human tumor cell lines, as well as the inhibition of the interaction between the programmed cell death protein 1 PD-1 and its ligand PD-L1 were also evaluated.
Subject(s)
Antineoplastic Agents , Cyanobacteria , Depsipeptides , Depsipeptides/pharmacology , Depsipeptides/isolation & purification , Depsipeptides/chemistry , Depsipeptides/chemical synthesis , Humans , Cyanobacteria/chemistry , Cell Line, Tumor , Antineoplastic Agents/pharmacology , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/chemistry , Antineoplastic Agents/chemical synthesis , Aquatic Organisms , B7-H1 Antigen/antagonists & inhibitors , Pacific Ocean , Peptides, Cyclic/pharmacology , Peptides, Cyclic/chemistry , Peptides, Cyclic/isolation & purificationABSTRACT
Kavaratamide A (1), a new linear lipodepsipeptide possessing an unusual isopropyl-O-methylpyrrolinone moiety, was discovered from the tropical marine filamentous cyanobacterium Moorena bouillonii collected from Kavaratti, India. A comparative chemogeographic analysis of M. bouillonii collected from six different geographical regions led to the prioritized isolation of this metabolite from India as distinctive among our data sets. AI-based structure annotation tools, including SMART 2.1 and DeepSAT, accelerated the structure elucidation by providing useful structural clues, and the full planar structure was elucidated based on comprehensive HRMS, MS/MS fragmentation, and NMR data interpretation. Subsequently, the absolute configuration of 1 was determined using advanced Marfey's analysis, modified Mosher's ester derivatization, and chiral-phase HPLC. The structures of kavaratamides B (2) and C (3) are proposed based on a detailed analysis of their MS/MS fragmentations. The biological activity of kavaratamide A was also investigated and found to show moderate cytotoxicity to the D283-medullablastoma cell line.
Subject(s)
Cyanobacteria , Depsipeptides , Cyanobacteria/chemistry , Depsipeptides/chemistry , Depsipeptides/pharmacology , Depsipeptides/isolation & purification , Molecular Structure , India , Nuclear Magnetic Resonance, Biomolecular , Marine Biology , Humans , Drug Screening Assays, Antitumor , Chromatography, High Pressure LiquidABSTRACT
Exploring the chemical diversity present in cyanobacterial mats increasingly frequent in fresh and marine waters is imperative for both evaluating risks associated with these diverse biofilms and their potential for biodiscovery. During a project aimed at the study of the (eco)toxicity of benthic cyanobacteria blooming in some lakes of the West of Ireland, three previously undescribed ahp-cyclodepsipeptides micropeptin LOF941 (1), micropeptin LOF925 (2) and micropeptin LOF953 (3) were isolated from the Microcoleus autumnalis-dominated benthic cyanobacterial biofilm collected from the shore of Lough O'Flynn, Co. Roscommon, Ireland. Their structures remain consistent in their amino acid sequence with the presence of an unusual methionine, and differ by their exocyclic side chains. The planar structures of the previously undescribed micropeptins were elucidated by 1D and 2D NMR and HRESIMS analyses, and their 3D configurations assessed by ROESY NMR and Marfey's analyses. The three isolated compounds showed no cytotoxic effects and all three compounds were shown to exhibit antioxidant properties, with 1 showing the highest bioactivity. Additionally, several micropeptin analogues are proposed from the methanolic fraction of the biofilm extract by UHPLC-HRESIMS/MS analysis and molecular networking. Notably, the known cyanotoxins anatoxin-a and dihydroanatoxin-a were annotated in the molecular network therefore raising issues about the toxicity of this cyanobacterial mat.
Subject(s)
Antioxidants , Cyanobacteria , Depsipeptides , Cyanobacteria/chemistry , Antioxidants/chemistry , Antioxidants/pharmacology , Antioxidants/isolation & purification , Ireland , Depsipeptides/chemistry , Depsipeptides/isolation & purification , Depsipeptides/pharmacology , Biofilms/drug effects , Molecular Structure , HumansABSTRACT
Serratiomycin (1) is an antibacterial cyclic depsipeptide, first discovered from a Eubacterium culture in 1998. This compound was initially reported to contain l-Leu, l-Ser, l-allo-Thr, d-Phe, d-Ile, and hydroxydecanoic acid. In the present study, 1 and three new derivatives, serratiomycin D1-D3 (2-4), were isolated from a Serratia sp. strain isolated from the exoskeleton of a long-horned beetle. The planar structures of 1-4 were elucidated by using mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Comparison of the NMR chemical shifts and the physicochemical data of 1 to those of previously reported serratiomycin indeed identified 1 as serratiomycin. The absolute configurations of the amino units in compounds 1-4 were determined by the advanced Marfey's method, 2,3,4,6-tetra-O-acetyl-ß-d-glucopyranosyl isothiocyanate derivatization, and liquid chromatography-mass spectrometric (LC-MS) analysis. Additionally, methanolysis and the modified Mosher's method were used to determine the absolute configuration of (3R)-hydroxydecanoic acid in 1. Consequently, the revised structure of 1 was found to possess d-Leu, l-Ser, l-Thr, d-Phe, l-allo-Ile, and d-hydroxydecanoic acid. In comparison with the previously published structure of serratiomycin, l-Leu, l-allo-Thr, and d-Ile in serratiomycin were revised to d-Leu, l-Thr, and l-allo-Ile. The new members of the serratiomycin family, compounds 2 and 3, showed considerably higher antibacterial activities against Staphylococcus aureus and Salmonella enterica than compound 1.
Subject(s)
Anti-Bacterial Agents , Microbial Sensitivity Tests , Serratia , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Serratia/chemistry , Molecular Structure , Animals , Peptides, Cyclic/chemistry , Peptides, Cyclic/pharmacology , Coleoptera , Depsipeptides/pharmacology , Depsipeptides/chemistry , Depsipeptides/isolation & purification , Staphylococcus aureus/drug effectsABSTRACT
Three unique linear oligomeric depsipeptides, designated as cavomycins A-C (1-3), were identified from Streptomyces cavourensis, a gut bacterium associated with the annelid Paraleonnates uschakovi. The structures of these depsipeptides were determined through a combination of spectroscopic methods and chemical derivatization techniques, including methanolysis, the modified Mosher's method, advanced Marfey's methods, and phenylglycine methyl ester derivatization. The unique dipeptidyl residue arrangements in compounds 1-3 indicate that they are not degradation products of valinomycin. Compound 2 and its methylation derivative 2a exhibited antiproliferative activity against PANC-1 pancreatic cancer cells with IC50 values of 1.2 and 1.7 µM, respectively.
Subject(s)
Depsipeptides , Streptomyces , Streptomyces/chemistry , Depsipeptides/pharmacology , Depsipeptides/chemistry , Depsipeptides/isolation & purification , Humans , Molecular Structure , Animals , Drug Screening Assays, Antitumor , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purificationABSTRACT
The antimicrobial activity of tumescenamide C against the scab-forming S. scabiei NBRC13768 was confirmed with a potent IC50 value (1.5 µg/mL). Three tumescenamide C-resistant S. scabiei strains were generated to compare their gene variants. All three resistant strains contained nonsynonymous variants in genes related to cellobiose/cellotriose transport system components; cebF1, cebF2, and cebG2, which are responsible for the production of the phytotoxin thaxtomin A. Decrease in thaxtomin A production and the virulence of the three resistant strains were revealed by the LC/MS analysis and necrosis assay, respectively. Although the nonsynonymous variants were insufficient for identifying the molecular target of tumescenamide C, the cell wall component wall teichoic acid (WTA) was observed to bind significantly to tumescenamide C. Moreover, changes in the WTA contents were detected in the tumescenamide C-resistant strains. These results imply that tumescenamide C targets the cell wall system to exert antimicrobial effects on S. scabiei.
Subject(s)
Anti-Bacterial Agents , Depsipeptides , Peptides, Cyclic , Streptomyces , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Cell Wall/drug effects , Depsipeptides/pharmacology , Depsipeptides/chemistry , Depsipeptides/isolation & purification , Drug Resistance, Bacterial , Indoles , Microbial Sensitivity Tests , Peptides, Cyclic/pharmacology , Peptides, Cyclic/chemistry , Peptides, Cyclic/isolation & purification , Piperazines , Streptomyces/chemistry , Streptomyces/drug effects , Streptomyces/genetics , Teichoic Acids/metabolismABSTRACT
The skyllamycins are a class of heavily modified, non-ribosomal peptides, first isolated from Streptomyces sp. KY11784. A Streptomyces strain with potent antibiotic activity against Bacillus subtilis was isolated from a sample of the New Zealand lichen Pseudocyphellaria dissimilis. Whole genome sequencing and biosynthetic gene cluster genetic analysis coupled with GNPS LCMS/MS molecular networking revealed that this strain had the capacity to produce skyllamycins, including previously undescribed congeners, and that these were likely the source of the observed biological activity. Guided by the results of the molecular networking, we isolated the previously reported skyllamycins A-C (1-3), along with two new congeners, skyllamycins D (4) and E (5). The structures of these compounds were elucidated using comprehensive 1D and 2D NMR analyses, along with HRESIMS fragmentation experiments. Antibacterial assays revealed that skyllamycin D possessed improved activity against B. subtilis E168 compared to previously reported congeners.
Subject(s)
Anti-Bacterial Agents/pharmacology , Depsipeptides/pharmacology , Streptomyces/chemistry , Anti-Bacterial Agents/isolation & purification , Bacillus subtilis/drug effects , Depsipeptides/isolation & purification , Lichens/microbiology , Molecular Structure , New Zealand , Peptides, CyclicABSTRACT
Pithohirolide (1), a new depsipeptide, was isolated from an ascomycetous fungus Pithomyces chartarum TAMA 581. The planar structure of 1 was elucidated on the basis of NMR and MS analyses and the absolute configuration was determined by the advanced Marfey's analysis, chiral-phase HPLC analysis, and synthesis of degradation product. Compound 1 possesses a cyclic structure comprising (S)-2-hydroxy-3-phenylpropanoic acid, (S)-3-hydroxy-3-phenylpropanoic acid, (S)-2-hydroxyisovaleric acid, and N-methyl-L-alanine, connected via three ester and one amide linkages. Compound 1 exhibited antimicrobial activity against Staphylococcus aureus and Saccharomyces cerevisiae at MIC 3.1 µg ml-1.
Subject(s)
Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Ascomycota/chemistry , Depsipeptides/chemistry , Animals , Cell Line, Tumor , Depsipeptides/isolation & purification , Depsipeptides/pharmacology , Drug Evaluation, Preclinical , Fungal Proteins/chemistry , Fungal Proteins/pharmacology , Leukemia/drug therapy , Leukemia/pathology , Magnetic Resonance Spectroscopy , Mice , Microbial Sensitivity Tests , Saccharomyces cerevisiae/drug effects , Staphylococcus aureus/drug effectsABSTRACT
Epithelial-mesenchymal transition (EMT), the epithelial cells transdifferentiation into the mesenchymal cells, has been involved in cancer metastasis. Nannocystin ax (NAN) is a cyclodepsipeptide initially isolated from Myxobacterial genus, Nannocystis sp. with anticancer activities. This study was designed to explore the effect of NAN on TGF-ß1-induced EMT in lung cancer cells. The morphological alteration was observed with a microscope. Western blotting and immunofluorescence assays were used to detect the protein expression and the localization. The adhesion and migration were evaluated by adhesion assay and wound healing assay. The mRNA expression of TGF-ß receptor type I (TßRI) was determined by real-time PCR. NAN significantly restrained TGF-ß1-induced EMT morphological changes, the protein expression of E-cadherin, N-cadherin, and Vimentin, etc. TGF-ß1 activated phosphorylation and nuclear translocation of Smad2/3 were inhibited by NAN. Furthermore, NAN suppressed adhesion and migration triggered by TGF-ß1. In addition, NAN significantly down-regulated TßRI on the transcriptional level directly. In summary, these results showed that NAN restrained TGF-ß1-induced epithelial-mesenchymal transition, migration, and adhesion in human lung cancer cells. The underlying mechanism involved the inhibition of Smad2/3 and the TßRI signaling pathway. This study reveals the new anticancer effect and mechanism of NAN.
Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung/drug therapy , Cell Adhesion/drug effects , Cell Movement/drug effects , Depsipeptides/pharmacology , Epithelial-Mesenchymal Transition/drug effects , Lung Neoplasms/drug therapy , Macrocyclic Compounds/pharmacology , Myxococcales/chemistry , Peptide Elongation Factor 1/antagonists & inhibitors , A549 Cells , Antineoplastic Agents/isolation & purification , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Depsipeptides/isolation & purification , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Macrocyclic Compounds/isolation & purification , Peptide Elongation Factor 1/metabolism , Phosphorylation , Receptor, Transforming Growth Factor-beta Type I/genetics , Receptor, Transforming Growth Factor-beta Type I/metabolism , Signal Transduction , Smad2 Protein/metabolism , Smad3 Protein/metabolismABSTRACT
The emetic Bacillus cereus toxin cereulide presents an enormous safety hazard in the food industry, inducing emesis and nausea after the consumption of contaminated foods. Additional to cereulide itself, seven structurally related isoforms, namely the isocereulides A-G, have already been elucidated in their chemical structure and could further be identified in B. cereus contaminated food samples. The newly performed isolation of isocereulide A allowed, for the first time, 1D- and 2D-NMR spectroscopy of a biosynthetically produced isocereulide, revealing results that contradict previous assumptions of an l-O-Leu moiety within its chemical structure. By furthermore applying posthydrolytical dipeptide analysis, amino acid and α-hydroxy acid analysis by means of UPLC-ESI-TOF-MS, as well as MSn sequencing, the structure of previously reported isocereulide A could be corrected. Instead of the l-O-Leu as assumed to date, one l-O-Ile unit could be verified in the cyclic dodecadepsipeptide, revising the structure of isocereulide A to [(d-O-Leu-d-Ala-l-O-Val-l-Val)2(d-O-Leu-d-Ala-l-O-Ile-l-Val)].
Subject(s)
Bacillus cereus/metabolism , Depsipeptides/chemistry , Depsipeptides/isolation & purification , Food Microbiology , Mass Spectrometry , Protein IsoformsABSTRACT
The latest chapter of the historic battle of humans against pathogenic microbes is the severe acute respiratory syndrome (SARS)-like coronavirus-2 (SARS-CoV-2), responsible for COVID-19, a respiratory disease declared a global pandemic by the WHO on March 11, 2020 [...].
Subject(s)
Anti-Inflammatory Agents/pharmacology , Antiviral Agents/pharmacology , Aquatic Organisms/chemistry , Biological Products/pharmacology , COVID-19 Drug Treatment , Anti-Inflammatory Agents/isolation & purification , Anti-Inflammatory Agents/therapeutic use , Antimicrobial Cationic Peptides/isolation & purification , Antimicrobial Cationic Peptides/pharmacology , Antimicrobial Cationic Peptides/therapeutic use , Antiviral Agents/isolation & purification , Antiviral Agents/therapeutic use , Biological Products/isolation & purification , Biological Products/therapeutic use , COVID-19/epidemiology , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Depsipeptides/isolation & purification , Depsipeptides/pharmacology , Depsipeptides/therapeutic use , Humans , Pandemics/prevention & control , Peptides, Cyclic/isolation & purification , Peptides, Cyclic/pharmacology , Peptides, Cyclic/therapeutic use , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , Seawater/microbiology , Virus Attachment/drug effectsABSTRACT
The emetic toxin cereulide is a 1.2 kDa dodecadepsipeptide produced by the food pathogen Bacillus cereus. As cereulide poses a serious health risk to humans, sensitive and specific detection, as well as toxin purification and quantification, methods are of utmost importance. Recently, a stable isotope dilution assay tandem mass spectrometry (SIDA-MS/MS)-based method has been described, and an method for the quantitation of cereulide in foods was established by the International Organization for Standardization (ISO). However, although this SIDA-MS/MS method is highly accurate, the sophisticated high-end MS equipment required for such measurements limits the method's suitability for microbiological and molecular research. Thus, we aimed to develop a method for cereulide toxin detection and isolation using equipment commonly available in microbiological and biochemical research laboratories. Reproducible detection and relative quantification of cereulide was achieved, employing reversed phase chromatography (RPC). Chromatographic signals were cross validated by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS/MS). The specificity of the RPC method was tested using a test panel of strains that included non-emetic representatives of the B. cereus group, emetic B. cereus strains, and cereulide-deficient isogenic mutants. In summary, the new method represents a robust, economical, and easily accessible research tool that complements existing diagnostics for the detection and quantification of cereulide.
Subject(s)
Bacillus cereus/metabolism , Chromatography, Reverse-Phase , Depsipeptides/isolation & purification , Foodborne Diseases/microbiology , Gram-Positive Bacterial Infections/microbiology , Vomiting/microbiology , Bacillus cereus/genetics , Humans , Reproducibility of ResultsABSTRACT
Tubulin-targeted chemotherapy has proven to be a successful and wide spectrum strategy against solid and liquid malignancies. Therefore, new ways to modulate this essential protein could lead to new antitumoral pharmacological approaches. Currently known tubulin agents bind to six distinct sites at α/ß-tubulin either promoting microtubule stabilization or depolymerization. We have discovered a seventh binding site at the tubulin intradimer interface where a novel microtubule-destabilizing cyclodepsipeptide, termed gatorbulin-1 (GB1), binds. GB1 has a unique chemotype produced by a marine cyanobacterium. We have elucidated this dual, chemical and mechanistic, novelty through multidimensional characterization, starting with bioactivity-guided natural product isolation and multinuclei NMR-based structure determination, revealing the modified pentapeptide with a functionally critical hydroxamate group; and validation by total synthesis. We have investigated the pharmacology using isogenic cancer cell screening, cellular profiling, and complementary phenotypic assays, and unveiled the underlying molecular mechanism by in vitro biochemical studies and high-resolution structural determination of the α/ß-tubulin-GB1 complex.
Subject(s)
Antineoplastic Agents/chemical synthesis , Bacterial Proteins/chemical synthesis , Biological Products/chemical synthesis , Depsipeptides/chemical synthesis , Microtubules/drug effects , Tubulin Modulators/chemical synthesis , Tubulin/chemistry , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Bacterial Proteins/isolation & purification , Bacterial Proteins/pharmacology , Binding Sites , Biological Products/isolation & purification , Biological Products/pharmacology , Cell Line, Tumor , Colchicine/chemistry , Colchicine/pharmacology , Crystallography, X-Ray , Cyanobacteria/chemistry , Depsipeptides/isolation & purification , Depsipeptides/pharmacology , Drug Discovery , HCT116 Cells , Humans , Maytansine/chemistry , Maytansine/pharmacology , Microtubules/metabolism , Microtubules/ultrastructure , Models, Molecular , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Pyrones/chemistry , Pyrones/pharmacology , Taxoids/chemistry , Taxoids/pharmacology , Tubulin/genetics , Tubulin/metabolism , Tubulin Modulators/isolation & purification , Tubulin Modulators/pharmacology , Vinca Alkaloids/chemistry , Vinca Alkaloids/pharmacologyABSTRACT
Two potential non-ribosomal peptide synthetases (NRPSs) were identified in the genome of a guanophilic fungus Amphichorda guana by bioinformatics analysis and gene knockout experiments. Liquid chromatography coupled with mass spectrometry (LC-MS) guided isolation led to the discovery of a new cyclodepsipeptide isaridin H (1) and seven known analogs, desmethylisaridin E (2), isaridin E (3), isariin A (4), iso-isariin B (5), iso-isariin D (6), isariin E (7), and nodupetide (8). The absolute configuration of isaridin H (1) was achieved by Marfey's method. Isaridin H (1) showed significant antifungal activity against Botrytis cinerea and Alternaria solani.
Subject(s)
Depsipeptides/isolation & purification , Hypocreales/chemistry , Alternaria/drug effects , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/isolation & purification , Antifungal Agents/pharmacology , Bacillus subtilis/drug effects , Botrytis/drug effects , Computational Biology , Depsipeptides/chemistry , Depsipeptides/pharmacology , Escherichia coli/drug effects , Gene Knockout Techniques , Genomics , Hypocreales/genetics , Microbial Sensitivity Tests , Peptide Synthases/genetics , Staphylococcus aureus/drug effectsABSTRACT
The potent and selective Gq protein inhibitor depsipeptide FR900359 (FR), originally discovered as the product of an uncultivable plant endosymbiont, is synthesized by a complex biosynthetic system comprising two nonribosomal peptide synthetase (NRPS) assembly lines. Here we characterize a cultivable bacterial FR producer, enabling detailed investigations into biosynthesis and attachment of the functionally important FR side chain. We reconstitute side chain assembly by the monomodular NRPS FrsA and the non-heme monooxygenase FrsH, and characterize intermolecular side chain transesterification to the final macrocyclic intermediate FR-Core, mediated by the FrsA thioesterase domain. We harness FrsA substrate promiscuity to generate FR analogs with altered side chains and demonstrate indispensability of the FR side chain for efficient Gq inhibition by comparative bioactivity, toxicity and docking studies. Finally, evolution of FR and side chain biosynthesis is discussed based on bioinformatics analyses. Side chain transesterification boosts potency and target affinity of selective Gq inhibitor natural products.
Subject(s)
Bacterial Proteins/pharmacology , Chromobacterium/metabolism , Depsipeptides/pharmacology , GTP-Binding Protein alpha Subunits, Gq-G11/antagonists & inhibitors , Animals , Bacterial Proteins/biosynthesis , Bacterial Proteins/chemistry , Bacterial Proteins/isolation & purification , Depsipeptides/biosynthesis , Depsipeptides/chemistry , Depsipeptides/isolation & purification , Esterases/metabolism , GTP-Binding Protein alpha Subunits, Gq-G11/genetics , GTP-Binding Protein alpha Subunits, Gq-G11/metabolism , Gene Knockout Techniques , HEK293 Cells , Hemiptera , Humans , Molecular Docking Simulation , Molecular Structure , Signal Transduction/drug effects , Signal Transduction/geneticsABSTRACT
New chymotrypsin inhibitory peptides named streptopeptolins B and C were isolated from Streptomyces olivochromogenes. Structures of streptopeptolins B and C were determined to be cyclic depsipeptides possessing 3-amino-6-hydroxy-2-piperidone unit by interpretation of NMR spectra and ESI-MS. Streptopeptolins B and C showed inhibitory activities to chymotrypsin with IC50 of 8.0 and 12.0 µg/mL, respectively.
Subject(s)
Chymotrypsin/antagonists & inhibitors , Depsipeptides , Peptides, Cyclic , Streptomyces , Depsipeptides/chemistry , Depsipeptides/isolation & purification , Magnetic Resonance Spectroscopy , Peptides, Cyclic/chemistry , Peptides, Cyclic/isolation & purification , Streptomyces/chemistryABSTRACT
In this study, screening by LC-MS and cytotoxicity-guided isolation led to the identification of ulleungamide C (1), a previously unknown pipecolic acid-rich branched cyclic depsipeptide, from a soil actinobacterium Streptomyces sp. KCB13F003. The structure of 1 was determined by interpretation of spectroscopic and spectrometric data from 1D and 2D NMR and HRESIMS experiments. Antiproliferative assays using mammalian cancerous cells revealed that 1 inhibits the proliferation of HL-60 human promyelocytic leukemia cells. Cell cycle analysis showed an increased accumulation of cells in the G0/G1 phase after treatment with 1. Results of immunoblotting assays revealed that 1 reduced the expression levels of cyclin-dependent kinase 4 (CDK4), CDK6, retinoblastoma protein (Rb), and phosphorylated Rb, whereas it induced cyclin-dependent kinase inhibitor 1B (p27/Kip1) expression.
Subject(s)
Depsipeptides/isolation & purification , G1 Phase Cell Cycle Checkpoints/drug effects , Leukemia, Promyelocytic, Acute/drug therapy , Streptomyces/metabolism , Cell Proliferation/drug effects , Chromatography, Liquid , Depsipeptides/chemistry , Depsipeptides/pharmacology , HL-60 Cells , Humans , Leukemia, Promyelocytic, Acute/pathology , Mass Spectrometry , Pipecolic Acids/chemistry , Resting Phase, Cell Cycle/drug effectsABSTRACT
Four new cyclodepsipeptides, trichodestruxins A-D (1-4), together with destruxin E2 chlorohydrin (5) and destruxin A2 (6), were isolated from the plant endophytic fungus Trichoderma harzianum by a bioassay-guided fractionation method. Their planar structures were elucidated on the basis of 1D and 2D NMR and MS/MS spectroscopic analyses. The stereochemical configuration was established by application of the advanced Marfey's method, J-based configuration analysis, Mosher's method, and chemical derivatizations. Trichodestruxin B contains hydroxy acid fragments of the THPA unit, while trichodestruxins A and C contain the ß-methylproline moiety. All cyclodepsipeptides displayed cytotoxicity against HT-29, A549, and/or P388 cell lines with IC50 values of 0.7-19.1 µM.
Subject(s)
Antineoplastic Agents/isolation & purification , Depsipeptides/isolation & purification , Hypocreales/chemistry , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Depsipeptides/chemistry , Depsipeptides/pharmacology , Humans , Molecular Structure , Spectrum Analysis/methodsABSTRACT
Cryptophycin-1 is a cyanotoxin produced by filamentous cyanobacteria. It has been evaluated as an anticancer agent with great potential. However, its synthesis provides insufficient yield for industrial use. An alternative solution for metabolite efficient production is to stress cyanobacteria by modifying the environmental conditions of the culture (Nostoc sp. ATCC 53789). Here, we examined the effects of light photoperiod, wavelength, and intensity. In light photoperiod, photoperiods 24:0 and 16:8 (light:dark) were tested while in wavelength, orange-red light was compared with blue. Medium, high, and very high light intensity experiments were performed to test the effect of light stress. For a 10-day period, growth was measured, metabolite concentration was calculated through HPLC, and the related curves were drawn. The differentiation of light wavelength had a major effect on the culture, as orange-red filter contributed to noticeable increase in both growth and doubled the cyanotoxin concentration in comparison to blue light. Remarkably, constant light provides higher cryptophycin yield, but slightly lower growth rate. Lastly, the microorganism prefers medium light intensities for both growth and metabolite expression. The combination of these optimal conditions would contribute to the further exploitation of cryptophycin.