ABSTRACT
A new polyene macrolide, machidamycin (1), and a known compound YS-822A (2), were obtained by physicochemical screening from a culture broth of Streptomyces sp. K22-0017. The structures were elucidated using MS and 1D/2D NMR analyses. Compound 1 exhibited weak antifungal activity against Candida albicans and Mucor racemosus. Furthermore, 1 showed stronger antileishmanial activity than the existing drug paromomycin.
Subject(s)
Antifungal Agents , Candida albicans , Macrolides , Magnetic Resonance Spectroscopy , Polyenes , Streptomyces , Streptomyces/metabolism , Candida albicans/drug effects , Macrolides/pharmacology , Macrolides/chemistry , Macrolides/isolation & purification , Antifungal Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/isolation & purification , Polyenes/pharmacology , Polyenes/chemistry , Polyenes/isolation & purification , Mucor/drug effects , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Microbial Sensitivity Tests , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/chemistry , Mass SpectrometryABSTRACT
Polyene macrolactams are a special group of natural products with great diversity, unique structural features, and a wide range of biological activities. Herein, a cryptic gene cluster for the biosynthesis of putative macrolactams was disclosed from a sponge-associated bacterium, Streptomyces sp. DSS69, by genome mining. Cloning and heterologous expression of the whole biosynthetic gene cluster led to the discovery of weddellamycin, a polyene macrolactam bearing a 23/5/6 ring skeleton. A negative regulator, WdlO, and two positive regulators, WdlA and WdlB, involved in the regulation of weddellamycin production were unraveled. The fermentation titer of weddellamycin was significantly improved by overexpression of wdlA and wdlB and deletion of wdlO. Notably, weddellamycin showed remarkable antibacterial activity against various Gram-positive bacteria including MRSA, with MIC values of 0.10-0.83 µg/mL, and antifungal activity against Candida albicans, with an MIC value of 3.33 µg/mL. Weddellamycin also displayed cytotoxicity against several cancer cell lines, with IC50 values ranging from 2.07 to 11.50 µM.
Subject(s)
Anti-Bacterial Agents , Lactams, Macrocyclic , Microbial Sensitivity Tests , Multigene Family , Streptomyces , Streptomyces/genetics , Streptomyces/metabolism , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/biosynthesis , Anti-Bacterial Agents/chemistry , Humans , Lactams, Macrocyclic/pharmacology , Lactams, Macrocyclic/chemistry , Lactams, Macrocyclic/isolation & purification , Polyenes/pharmacology , Polyenes/isolation & purification , Polyenes/chemistry , Candida albicans/drug effects , Cell Line, Tumor , Antarctic Regions , Animals , Porifera/microbiology , Antifungal Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/isolation & purificationABSTRACT
Six new fusarin derivatives, fusarins G-L (1-6), together with five known compounds (5-11) were isolated from the marine-derived fungus Fusarium solani 7227. The structures of the new compounds were elucidated by means of comprehensive spectroscopic methods (1D and 2D NMR, HRESIMS, ECD, and ORC) and X-ray crystallography. Compounds 5-11 exhibited potent anti-inflammatory activity by inhibiting the production of NO in RAW264.7 cells activated by lipopolysaccharide, with IC50 values ranging from 3.6 to 32.2 µM. The structure-activity relationships of the fusarins are discussed herein.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Fusarium , Lactams/pharmacology , Nitric Oxide/antagonists & inhibitors , Polyenes/pharmacology , Animals , Anti-Inflammatory Agents/isolation & purification , Fermentation , Fusarium/chemistry , Fusarium/metabolism , Lactams/isolation & purification , Lipopolysaccharides/pharmacology , Mice , Nitric Oxide/metabolism , Polyenes/isolation & purification , RAW 264.7 Cells , Secondary Metabolism , Structure-Activity RelationshipABSTRACT
A marine actinomycete strain C1-2 was taxonomically characterized as the genus Streptomyces, based on whole-genome sequence analysis. The highest average nucleotide identity (ANI) value (98.96%) and digital DNA-DNA hybridization (DDH) value (90.4%) were observed between Streptomyces sp. C1-2 and Streptomyces griseoaurantiacus. Thus, Streptomyces sp. C1-2 could be identified as S. griseoaurantiacus. Genome analysis revealed that Streptomyces sp. C1-2 contained 22 biosynthetic gene clusters (BGCs) for secondary metabolites, where among them, 54% have low similarities with known BGCs. The chemical investigation led to the isolation of three new manumycin-type derivatives and two known analog antibiotics named SW-B and cornifronin B. All compounds showed antioxidant activity with the half-maximal inhibitory concentration (IC50) values in a range of 50.82 ± 0.8-112.04 ± 1.0 µg/mL with no cytotoxicity against Vero cells. This is the first report of the antioxidant property of manumycin-type derivatives. Moreover, two known compounds exhibited antifungal activity against Phytophthora capsici, Fusarium oxysporum f. sp. cucumerinum, and Magnaporthe grisea, with the minimum inhibitory concentration (MIC) values in a range of 125-500 µg/mL.
Subject(s)
Genome, Bacterial , Polyenes/pharmacology , Polyunsaturated Alkamides/pharmacology , Streptomyces/classification , Animals , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Antifungal Agents/isolation & purification , Antifungal Agents/pharmacology , Antioxidants/isolation & purification , Antioxidants/pharmacology , Aquatic Organisms/classification , Chlorocebus aethiops , DNA, Bacterial/genetics , Multigene Family , Nucleic Acid Hybridization , Phylogeny , Polyenes/isolation & purification , Polyunsaturated Alkamides/isolation & purification , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Streptomyces/isolation & purification , Vero Cells , Whole Genome SequencingABSTRACT
The dotted white geometrid moth, Naxa seriaria Motschulsky (Lepidoptera: Geometridae), is a pest of Oleaceae in Korea, Japan, and China. In this study, we identified (3Z,6Z,9Z,12Z,15Z)-heneicosapentaene (C-21 pentaene) as the only compound in extracts of the pheromone glands of female N. seriaria causing a response from receptors on the antennae of males in analyses by gas chromatography with electroantennographic detection. The synthetic sex pheromone elicited dose-dependent electrophysiological responses from antennae of male N. seriaria. In field tests, more male moths were captured in traps baited with synthetic C-21 pentaene than in unbaited traps, and increasing the loading of C-21 pentaene in the lure increased catches of male moths. Significantly more male N. seriaria moths were caught in delta traps than in bucket traps. Based on these results, C-21 pentaene is proposed to be the major, if not the only, component of the sex pheromone of N. seriaria.
Subject(s)
Moths/physiology , Polyenes/isolation & purification , Scent Glands/chemistry , Sex Attractants/isolation & purification , Animals , Female , Gas Chromatography-Mass Spectrometry , Oleaceae/growth & developmentABSTRACT
The conspicuous bright golden to orange-reddish coloration of species of the basidiomycete genus Laetiporus is a hallmark feature of their fruiting bodies, known among mushroom hunters as the "chicken of the woods". This report describes the identification of an eight-domain mono-modular highly reducing polyketide synthase as sole enzyme necessary for laetiporic acid biosynthesis. Heterologous pathway reconstitution in both Aspergillus nidulans and Aspergillus niger verified that LpaA functions as a multi-chain length polyene synthase, which produces a cocktail of laetiporic acids with a methyl-branched C26-C32 main chain. Laetiporic acids show a marked antifungal activity on Aspergillus protoplasts. Given the multiple products of a single biosynthesis enzyme, our work underscores the diversity-oriented character of basidiomycete natural product biosynthesis.
Subject(s)
Antifungal Agents/metabolism , Polyenes/metabolism , Polyketide Synthases/metabolism , Polyporales/enzymology , Antifungal Agents/isolation & purification , Antifungal Agents/pharmacology , Aspergillus nidulans/drug effects , Aspergillus niger/drug effects , Microbial Sensitivity Tests , Polyenes/isolation & purification , Polyenes/pharmacology , Polyketide Synthases/genetics , Polyporales/chemistry , Polyporales/genetics , Polyporales/metabolismABSTRACT
BACKGROUND: Streptomycetes from the rhizospheric soils are a rich resource of novel secondary metabolites with various biological activities. However, there is still little information related to the isolation, antimicrobial activity and biosynthetic potential for polyketide and non-ribosomal peptide discovery associated with the rhizospheric streptomycetes of Panax notoginseng. Thus, the aims of the present study are to (i) identify culturable streptomycetes from the rhizospheric soil of P. notoginseng by 16S rRNA gene, (ii) evaluate the antimicrobial activities of isolates and analyze the biosynthetic gene encoding polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs) of isolates, (iii) detect the bioactive secondary metabolites from selected streptomycetes, (iv) study the influence of the selected isolate on the growth of P. notoginseng in the continuous cropping field. This study would provide a preliminary basis for the further discovery of the secondary metabolites from streptomycetes isolated from the rhizospheric soil of P. notoginseng and their further utilization for biocontrol of plants. RESULTS: A total of 42 strains representing 42 species of the genus Streptomyces were isolated from 12 rhizospheric soil samples in the cultivation field of P. notoginseng and were analyzed by 16S rRNA gene sequencing. Overall, 40 crude cell extracts out of 42 under two culture conditions showed antibacterial and antifungal activities. Also, the presence of biosynthesis genes encoding type I and II polyketide synthase (PKS I and PKS II) and nonribosomal peptide synthetases (NRPSs) in 42 strains were established. Based on characteristic chemical profiles screening by High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD), the secondary metabolite profiles of strain SYP-A7257 were evaluated by High Performance Liquid Chromatography-High Resolution Mass Spectrometry (HPLC-HRMS). Finally, four compounds actinomycin X2 (F1), fungichromin (F2), thailandin B (F7) and antifungalmycin (F8) were isolated from strain SYP-A7257 by using chromatography techniques, UV, HR-ESI-MS and NMR, and their antimicrobial activities against the test bacteria and fungus were also evaluated. In the farm experiments, Streptomyces sp. SYP-A7257 showed healthy growth promotion and survival rate improvement of P. notoginseng in the continuous cropping field. CONCLUSIONS: We demonstrated the P. notoginseng rhizospheric soil-derived Streptomyces spp. distribution and diversity with respect to their metabolic potential for polyketides and non-ribosomal peptides, as well as the presence of biosynthesis genes PKS I, PKS II and NRPSs. Our results showed that cultivatable Streptomyces isolates from the rhizospheric soils of P. notoginseng have the ability to produce bioactive secondary metabolites. The farm experiments suggested that the rhizospheric soil Streptomyces sp. SYP-A7257 may be a potential biological control agent for healthy growth promotion and survival rate improvement of P. notoginseng in the continuous cropping field.
Subject(s)
Panax notoginseng/microbiology , Peptide Synthases/genetics , Polyketide Synthases/genetics , Streptomyces/classification , Bacterial Proteins/genetics , Chromatography, High Pressure Liquid , DNA, Bacterial/genetics , DNA, Ribosomal/genetics , Dactinomycin/analogs & derivatives , Dactinomycin/isolation & purification , Drug Resistance, Bacterial , Macrolides/isolation & purification , Phylogeny , Polyenes/isolation & purification , RNA, Ribosomal, 16S/genetics , Rhizosphere , Secondary Metabolism , Soil Microbiology , Streptomyces/genetics , Streptomyces/isolation & purificationABSTRACT
Pink biofilms are multispecies microbial communities that are commonly found in moist household environments. The development of this pink stain is problematic from an aesthetic point of view, but more importantly, it raises hygienic concerns because they may serve as a potential reservoir of opportunistic pathogens. Although there have been several studies of pink biofilms using molecular analysis and confocal laser scanning microscopy, little is known about the spatial distributions of constituent microorganisms within pink biofilms, a crucial factor associated with the characteristics of pink biofilms. Here we show that Raman spectroscopic signatures of intracellular carotenoids and polyenes enable us to visualize pigmented microorganisms within pink biofilms in a label-free manner. We measured space-resolved Raman spectra of a pink biofilm collected from a bathroom, which clearly show resonance Raman bands of carotenoids. Multivariate analysis of the Raman hyperspectral imaging data revealed the presence of typical carotenoids and structurally similar but different polyenes, whose spatial distributions within the pink biofilm were found to be mutually exclusive. Raman measurements on individual microbial cells isolated from the pink biofilm confirmed that these distributions probed by carotenoid/polyene Raman signatures are attributable to different pigmented microorganisms. The present results suggest that Raman microspectroscopy with a focus on microbial pigments such as carotenoids is a powerful nondestructive method for studying multispecies biofilms in various environments.
Subject(s)
Biofilms , Carotenoids/isolation & purification , Polyenes/isolation & purification , Rhodococcus/isolation & purification , Carotenoids/chemistry , Humans , Microbiota , Microscopy, Confocal , Pigments, Biological/chemistry , Pigments, Biological/isolation & purification , Polyenes/chemistry , Rhodococcus/growth & development , Spectrum Analysis, RamanABSTRACT
Produced by a newly isolated Streptomycetes strain, meijiemycin is a gigantic linear polyene-polyol that exhibits structural features not seen in other members of the polyene-polyol family. We propose a biosynthetic mechanism and demonstrate that meijiemycin inhibits hyphal growth by inducing the aggregation of ergosterol and restructuring of the fungal plasma membrane.
Subject(s)
Antifungal Agents/pharmacology , Fatty Alcohols/pharmacology , Polyenes/pharmacology , Antifungal Agents/isolation & purification , Antifungal Agents/metabolism , Candida albicans/drug effects , Drug Discovery , Fatty Alcohols/isolation & purification , Fatty Alcohols/metabolism , Genes, Bacterial , Genomics , Microbial Sensitivity Tests , Multigene Family , Polyenes/isolation & purification , Polyenes/metabolism , Polyketide Synthases/genetics , Streptomyces/chemistryABSTRACT
Burkholderia thailandensis has emerged as a model organism for investigating the production and regulation of diverse secondary metabolites. Most of the biosynthetic gene clusters encoded in B. thailandensis are silent, motivating the development of new methods for accessing their products. In the current work, we add to the canon of available approaches using phenotype-guided transposon mutagenesis to characterize a silent biosynthetic gene cluster. Because secondary metabolite biosynthesis is often associated with phenotypic changes, we carried out random transposon mutagenesis followed by phenotypic inspection of the resulting colonies. Several mutants exhibited intense pigmentation and enhanced expression of an iterative type I polyketide synthase cluster that we term org. Disruptions of orgA, orgB, and orgC abolished the biosynthesis of the diffusible pigment, thus linking it to the org operon. Isolation and structural elucidation by HR-MS and 1D/2D NMR spectroscopy revealed three novel, cryptic metabolites, thailandene A-C. Thailandenes are linear formylated or acidic polyenes containing a combination of cis and trans double bonds. Variants A and B exhibited potent antibiotic activity against Staphylococcus aureus and Saccharomyces cerevisiae but not against Escherichia coli. One of the transposon mutants that exhibited an enhanced expression of org contained an insertion upstream of a σ54-dependent transcription factor. Closer inspection of the org operon uncovered a σ54 promoter consensus sequence upstream of orgA, providing clues regarding its regulation. Our results showcase the utility of phenotype-guided transposon mutagenesis in uncovering cryptic metabolites encoded in bacterial genomes.
Subject(s)
Anti-Bacterial Agents/biosynthesis , Biological Products/chemistry , Burkholderia/genetics , Polyenes/metabolism , Anti-Bacterial Agents/isolation & purification , Biological Products/isolation & purification , Burkholderia/chemistry , DNA Transposable Elements , Escherichia coli/drug effects , Gene Expression Regulation, Bacterial/drug effects , Genome, Bacterial , Multigene Family , Mutagenesis , Phenotype , Polyenes/isolation & purification , Polyketide Synthases/metabolism , Saccharomyces cerevisiae/drug effects , Secondary Metabolism , Transcription Factors/metabolismABSTRACT
Heterologous expression of a unique biosynthetic gene cluster (BGC) comprising a highly reducing polyketide synthase and stand-alone thioesterase genes in Aspergillus oryzae enabled us to isolate a novel 34-membered polyene macrolide, phaeospelide A (1). This is the first isolation of a fungal polyene macrolide and the first demonstration of fungal aliphatic macrolide biosynthetic machinery. In addition, sequence similarity network analysis demonstrated the existence of a large number of BGCs for novel fungal macrolides.
Subject(s)
Macrolides/metabolism , Polyenes/metabolism , Polyketides/metabolism , Thiolester Hydrolases/metabolism , Trans-Activators/metabolism , Aspergillus oryzae/enzymology , Cyclization , Macrolides/chemistry , Macrolides/isolation & purification , Molecular Conformation , Polyenes/chemistry , Polyenes/isolation & purification , Polyketides/chemistry , Thiolester Hydrolases/genetics , Trans-Activators/chemistryABSTRACT
In our screening program for new biologically active secondary metabolites, a new strain, Nocardiopsis CG3 (DSM 106572), isolated from the saltpan of Kenadsa, was found to produce five new polyene macrolactams, the kenalactams A-E (1-5). Their structures were elucidated by spectral methods (NMR and HRESIMS), and the absolute configuration was derived by chemical derivatization (Mosher's method). Through a feeding experiment, alanine was proven to be the nitrogen-bearing starter unit involved in biosynthesis of the polyketide kenalactam A (1). Kenalactam E (5) was cytotoxic against human prostate cancer PC-3 cells with an IC50 value of 2.1 µM.
Subject(s)
Actinobacteria/chemistry , Lactams/isolation & purification , Polyenes/isolation & purification , Cell Line, Tumor , Humans , Lactams/chemistry , Lactams/pharmacology , Polyenes/chemistry , Polyenes/pharmacology , Polyketides/chemistry , Polyketides/isolation & purification , Polyketides/pharmacologyABSTRACT
The present study explores the UVB protective role of Asperyellone (AY), a secondary metabolite of Aspergillus niger strain AN01. The in vitro UVB protective efficacy of AY was studied using the Human Epidermal keratinocytes cells (HaCaT) cell line. The results suggest the appreciable scavenging of UVB-induced reactive oxygen species in the AY-pretreated cells compared with UVB control. Experimental results on the antioxidant enzymes (Catalase, SOD, LPO, and GPx) profile, histochemical, and molecular analyses support the UVB protective effect of AY in HaCaT cells. Further, the in vivo UVB protective efficacy of AY was studied using animal models and compared with that of commercially available UVB protective agents. Physical, biochemical, and molecular analyses of skin samples emphasized the UVB protective role of AY. Thus, the important beneficial effects of AY have been explored in the present study.
Subject(s)
Keratinocytes/drug effects , Polyenes/pharmacology , Radiation-Protective Agents/pharmacology , Reactive Oxygen Species/antagonists & inhibitors , Skin/drug effects , Animals , Aspergillus niger/chemistry , Aspergillus niger/metabolism , Catalase/genetics , Catalase/metabolism , Cell Line , Gene Expression Regulation/drug effects , Glutathione Peroxidase/genetics , Glutathione Peroxidase/metabolism , Humans , Keratinocytes/radiation effects , Lipid Peroxidation/drug effects , Lipoxygenase/genetics , Lipoxygenase/metabolism , Mice , Oxidative Stress , Polyenes/isolation & purification , Radiation-Protective Agents/isolation & purification , Reactive Oxygen Species/metabolism , Secondary Metabolism , Skin/radiation effects , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism , Treatment Outcome , Ultraviolet RaysABSTRACT
A new polyene compound (1) and a new diketopiperazine (2), as well as three known compounds (3-5), were isolated from the Antarctic marine-derived fungus Penicillium crustosum HDN153086. The structures of 1-5 were deduced based on MS, NMR and TD-DFT calculations of specific ECD spectra. These compounds were evaluated for their cytotoxic activities against K562 cell line and only compound 2 exhibited cytotoxicity against K562 cell, with IC50 value of 12.7 µM.
Subject(s)
Diketopiperazines/isolation & purification , Penicillium/metabolism , Polyenes/isolation & purification , Antarctic Regions , Aquatic Organisms , Diketopiperazines/chemistry , Diketopiperazines/pharmacology , Drug Screening Assays, Antitumor , Humans , K562 Cells , Magnetic Resonance Spectroscopy , Molecular Structure , Penicillium/chemistry , Polyenes/chemistry , Polyenes/pharmacologyABSTRACT
Through serial promoter exchanges, we isolated several novel polyenes, the aspernidgulenes, from Aspergillus nidulans and uncovered their succinct biosynthetic pathway involving only four enzymes. An enoyl reductase (ER)-less highly reducing polyketide synthase (HR-PKS) putatively produces a 5,6-dihydro-α-pyrone polyene, which undergoes bisepoxidation, epoxide ring opening, cyclization, and hydrolytic cleavage by three tailoring enzymes to generate aspernidguleneâ A1 and A2. Our findings demonstrate the prowess of fungal-tailoring enzymes to transform a polyketide scaffold concisely and efficiently into complex structures. Moreover, comparison with citreoviridin and aurovertin biosynthesis suggests that methylation of the α-pyrone hydroxy group by methyltransferase (CtvB or AurB) is the branching point at which the biosynthesis of these two classes of compounds diverge. Therefore, scanning for the presence or absence of the gatekeeping α-pyrone methyltransferase gene in homologous clusters might be a potential way to classify the product bioinformatically as belonging to methylated α-pyrone polyenes or polyenes containing rings derived from the cyclization of the unmethylated 5,6-dihydro-α-pyrone, such as 2,3-dimethyl-γ-lactone and oxabicyclo[2.2.1]heptane.
Subject(s)
Aspergillus nidulans/chemistry , Aspergillus nidulans/genetics , Polyenes/metabolism , Promoter Regions, Genetic , Aspergillus nidulans/metabolism , Biosynthetic Pathways , Methyltransferases/genetics , Methyltransferases/metabolism , Molecular Conformation , Oxidoreductases/genetics , Oxidoreductases/metabolism , Polyenes/chemistry , Polyenes/isolation & purification , Polyketide Synthases/genetics , Polyketide Synthases/metabolism , Promoter Regions, Genetic/geneticsABSTRACT
An essential oil from the brown alga Sargassum thunbergii, prepared by a simultaneous distillation extraction method, contained in two types of volatile polyenes with a terminal double bond such as (6Z,9Z,12Z,15Z,18Z)-1,6,9,12,15,18-henicosahexaene and (6Z,9Z,12Z,15Z)-1,6,9,12,15-henicosapentaene and with their saturated terminal structures such as (3Z,6Z,9Z,12Z,15Z,18Z)-3,6,9,12,15,18-henicosahexaene and (3Z,6Z,9Z,12Z,15Z)-3,6,9,12,15-henicosapentaene. These volatile polyenes were identified by comparison with the GC-MS and NMR spectra of synthetics. The polyenes with the saturated terminal structures were found in the brown algae for the first time.
Subject(s)
Oils, Volatile/isolation & purification , Polyenes/isolation & purification , Sargassum/chemistry , Distillation , Gas Chromatography-Mass Spectrometry , Liquid-Liquid Extraction/methods , Magnetic Resonance Spectroscopy , Oils, Volatile/chemistry , Phaeophyceae/chemistry , Polyenes/chemistryABSTRACT
An essential oil from dried "wakame" (Undaria pinnatifida), prepared by a simultaneous distillation extraction method, was analyzed by GC-MS, indicating the presence of one major component of volatiles. The volatile component was identified as (6Z,9Z,12Z,15Z,18Z)-1,6,9,12,15,18-henicosahexaene by comparison with the GC-MS and NMR spectra of synthetic. The henicosahexaene showed a subtly marine aroma. (6Z,9Z,12Z,15Z)-1,6,9,12,15-Henicosapentaene was also detected as a minor polyene in the essential oils. It was suggested that these polyenes contribute to the characteristic aroma of the dried wakame.
Subject(s)
Odorants/analysis , Oils, Volatile/isolation & purification , Plant Oils/isolation & purification , Polyenes/analysis , Undaria/chemistry , Volatile Organic Compounds/isolation & purification , Distillation , Gas Chromatography-Mass Spectrometry , Liquid-Liquid Extraction/methods , Magnetic Resonance Spectroscopy , Oils, Volatile/analysis , Plant Oils/analysis , Polyenes/isolation & purificationABSTRACT
Polyene macrolides such as nystatin A1 and amphotericin B belong to a large family of very valuable antifungal polyketide compounds typically produced by soil actinomycetes. Recently, nystatin-like Pseudonocardia polyene (NPP) A1 has been identified as a unique disaccharide-containing tetraene antifungal macrolide produced by Pseudonocardia autotrophica. Despite its significantly increased water solubility and decreased hemolytic activity, its antifungal activity remains limited compared with that of nystatin A1. In this study, we developed NPP B1, a novel NPP A1 derivative harboring a heptaene core structure, by introducing two amino acid substitutions in the putative NADPH-binding motif of the enoyl reductase domain in module 5 of the NPP A1 polyketide synthase NppC. The low level NPP B1 production yield was successfully improved by eliminating the native plasmid encoding a polyketide biosynthetic gene cluster present in P. autotrophica. In vitro and in vivo antifungal activity and toxicity studies indicated that NPP B1 exhibited comparable antifungal activity against Candida albicans and was less toxic than the most potent heptaene antifungal, amphotericin B. Moreover, NPP B1 showed improved pharmacokinetic parameters compared to those of amphotericin B, suggesting that NPP B1 could be a promising candidate for development into a pharmacokinetically improved and less-toxic polyene antifungal antibiotic.
Subject(s)
Actinobacteria/genetics , Antifungal Agents/pharmacology , Candidiasis/drug therapy , Macrolides/pharmacology , Metabolic Engineering/methods , Polyenes/pharmacology , Actinobacteria/chemistry , Actinobacteria/metabolism , Amino Acid Sequence , Amino Acid Substitution , Animals , Antifungal Agents/chemistry , Antifungal Agents/isolation & purification , Antifungal Agents/metabolism , Binding Sites , Candida albicans/drug effects , Candida albicans/growth & development , Candidiasis/microbiology , Candidiasis/mortality , Disaccharides/chemistry , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression , Macrolides/chemistry , Macrolides/isolation & purification , Macrolides/metabolism , Male , Mice , Mice, Inbred ICR , Microbial Sensitivity Tests , NADP/chemistry , NADP/metabolism , Nystatin/pharmacology , Plasmids/chemistry , Plasmids/metabolism , Polyenes/chemistry , Polyenes/isolation & purification , Polyenes/metabolism , Polyketide Synthases/genetics , Polyketide Synthases/metabolism , Sequence Alignment , Structure-Activity Relationship , Survival AnalysisABSTRACT
Chemical investigation of a marine-derived actinomycete strain Micromonospora sp. FIM05328 isolated from a soil sample collected from the East China Sea, resulted in the discovery of a new 26-membered polyene macrolactam metabolite FW05328-1 (1), together with a known polyene with pyridone ring compound aurodox (2). The structures of compounds 1 and 2 were determined by the detailed analysis of 1D, 2D NMR and HR-TOF-MS data, along with literature data analysis. 1 and 2 exhibited excellent antiproliferative activities against KYSE30, KYSE180 and EC109 human tumour cell lines, but displayed no antibacterial activities against bacteria or fungi were tested.
Subject(s)
Antineoplastic Agents/isolation & purification , Micromonospora/chemistry , Polyenes/chemistry , Actinobacteria/metabolism , Anti-Bacterial Agents , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , China , Humans , Magnetic Resonance Spectroscopy , Molecular Structure , Polyenes/isolation & purificationABSTRACT
In this study, we identified a new Bacillus strain isolated from an Algerian salty lake that produces metabolites that are active against Gram-positive and Gram-negative bacteria, as well as fungal pathogens. The draft genome sequence of the strain is presented herein. Genome sequence analysis identified the strain to be B. amyloliquefaciens subspecies plantarum F11, and showed that the strain carries the gene clusters for the production of a number of bioactive and surface-active compounds. These include the lipopeptides surfactin and fengycin, antibacterial polyketides macrolactin and bacillaene, and a putative novel lanthipeptide, among others. Through an activity-guided purification method using hydrophobic interaction chromatographic techniques, we confirmed the ability of the strain to produce fengycin lipopeptides. The identities of the isolated fengycin homologs were ascertained through tandem mass spectrometry.