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1.
Org Lett ; 24(32): 5941-5945, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35938920

RESUMO

Prenylemestrins A and B (1 and 2, respectively), two unusual epipolythiodioxopiperazines featuring a thioethanothio bridge instead of a polysulfide bridge, were isolated from the fungus Emericella sp. CPCC 400858 guided by genomic analysis. Their structures were determined by extensive spectroscopic data, NMR and ECD calculations, and X-ray diffraction analysis. A plausible biosynthetic pathway for 1 and 2 was proposed on the basis of gene cluster analysis. Prenylemestrins A and B exhibited cytotoxicities against human chronic myelocytic leukemia cell lines K562 and MEG-01.


Assuntos
Emericella , Cristalografia por Raios X , Emericella/química , Fungos , Genômica , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular
2.
Phytochemistry ; 202: 113303, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35787351

RESUMO

The fungus Emericella sp. XL029 isolated from leaves of Panax notoginseng was investigated for agents with potential antibacterial and antifungal activities using a one strain-many compounds (OSMAC) strategy. Fifteen compounds, including seven undescribed structures, were obtained from this species. Their structures were confirmed by extensive spectroscopic data, single-crystal X-ray crystallography and quantum chemistry calculations. Emerlactam A exhibited better antibacterial activity against multidrug-resistant Enterococcus faecium and antifungal activity against Helminthosporium maydis, with an MIC value of 12.5 µg/mL. Quiannulatic acid displayed significant antibacterial activity against multidrug-resistant Enterococcus faecium and multidrug-resistant Enterococcus faecalis with MIC values of 1.56 µg/mL and 3.13 µg/mL, respectively. 5-alkenylresorcinol exhibited significant antifungal activity against all tested phytopathogenic fungi with MIC values ranging from 6.25 to 12.5 µg/mL.


Assuntos
Emericella , Antibacterianos/química , Antifúngicos/química , Emericella/química , Fungos , Testes de Sensibilidade Microbiana , Estrutura Molecular
3.
Nat Prod Res ; 35(21): 3830-3838, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32189530

RESUMO

The crystal structure and unambiguous absolute configuration of meleagrin (1) isolated from fungus Emericella dentata Nq45 is reported herein to first time on the bases of single crystal X-ray diffraction. Together with 1, haenamindole (2), isorugulosuvine (3), secalonic acid D (4), ergosterol (5) and cerebroside A (6) were obtained and their structures were determined by ESI MS and NMR data analysis. Diverse biological activity of meleagrin (1) was investigated. Compound 1 pronounced potent cytotoxicity against the human cervix carcinoma cell line KB-3-1 and its multidrug resistant sub-clone KB-V1 of IC50 3.07 and 6.07 µM, respectively, in comparison with the reference (+) - griseofulvin (IC50 19, 19.5 µM). Based on the antibiofilm activity, compound 1 displayed as well potent activity against Staphylococcus aureus with an MIC of 0.25 mg/mL. Isolation of the producing fungus and taxonomical characterization is stated as well.


Assuntos
Emericella , Ovomucina/farmacologia , Organismos Aquáticos/química , Linhagem Celular Tumoral , Emericella/química , Humanos , Estrutura Molecular , Ovomucina/química , Staphylococcus aureus/efeitos dos fármacos
4.
Bioorg Med Chem Lett ; 29(24): 126686, 2019 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-31678008

RESUMO

The asteltoxin-producing fungus Emericella variecolor IFM42010 possesses 22 highly-reducing polyketide synthase (HR-PKS) genes. Of these, an HR-PKS with a methyltransferase domain but lacking an enoylreductase domain could be involved in the biosynthesis of asteltoxin and related compounds. From six such candidate HR-PKS genes, Ev460pks was analyzed by gene disruption in E. variecolor and heterologous expression in Aspergillus oryzae. The Ev460pks-disrupted strain retained asteltoxin production ability, indicating that Ev460pks is not involved in asteltoxin biosynthesis. The A. oryzae transformant harboring the Ev460pks gene produced compounds 1 and 2, along with several unidentified products possibly decomposed from 2. Spectroscopic analyses revealed that 1 was a 4-methyl-ß-ketolactone with a methylheptatriene side-chain at the C-5 position, and 2 was also a 4-methyl-ß-ketolactone, bearing a dimethyltetradecahexaene side-chain at the same position. The relative configuration at C-4 in compounds 1 and 2 was opposite.


Assuntos
Emericella/genética , Policetídeo Sintases/metabolismo , Estereoisomerismo
5.
Org Lett ; 21(13): 5091-5095, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31247789

RESUMO

Emeriones A-C (1-3), three highly methylated polyketides with bicyclo[4.2.0]octene and 3,6-dioxabicyclo[3.1.0]hexane functionalities, were isolated from Emericella nidulans. An additional peroxide bridge in compound 3 led to the construction of an unexpected 7,8-dioxatricyclo[4.2.2.02,5]decene scaffold. The structures of 1-3 were elucidated by comprehensive spectroscopic techniques, and their absolute configurations were confirmed by single-crystal X-ray crystallographic analyses and ECD calculations. Compound 1 shows weak inhibitory effects on NO production in LPS-induced RAW264.7 cells.


Assuntos
Alcenos/química , Emericella/química , Hexanos/química , Policetídeos/química , Metilação , Modelos Moleculares , Conformação Molecular
6.
Enzyme Microb Technol ; 124: 41-53, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30797478

RESUMO

Peptidylarginine deiminases (PADs) are a group of hydrolases, mediating the deimination of peptidylarginine residues into peptidyl-citrulline. Equivocal protein citrullination by PADs of fungal pathogens has a strong relation to the progression of multiple human diseases, however, the biochemical properties of fungal PADs remain ambiguous. Thus, this is the first report exploring the molecular properties of PAD from thermotolerant fungi, to imitate the human temperature. The teleomorph Emericella dentata and anamorph Aspergillus nidulans have been morphologically and molecularly identified, with observed robust growth at 37-40 °C, and strong PAD productivity. The physiological profiles of E. dentata and A. nidulans for PADs production in response to carbon, nitrogen sources, initial medium pH and incubation temperature were relatively identical, emphasizing the taxonomical proximity of these fungal isolates. PADs were purified from E. dentata and A. nidulans with apparent molecular masses 41 and 48 kDa, respectively. The peptide fingerprints of PADs from E. dentata and A. nidulans have been analyzed by MALDI-TOF/MS, displaying a higher sequence similarity to human PAD4 by 18% and 31%, respectively. The conserved peptide sequences of E. dentata and A. nidulans PADs displayed a higher similarity to human PAD than A. fumigatus PADs clade. PADs from both fungal isolates have an optimum pH and pH stability at 7.0-8.0, with putative pI 5.0-5.5, higher structural denaturation at pH 4.0-5.5 and 9.5-12 as revealed from absorbance at λ280nm. E. dentata PAD had a higher conformationally thermal stability than A. nidulans PAD as revealed from its lower Kr value. From the proteolytic mapping, the orientation of trypsinolytic recognition sites on the PADs surface from both fungal isolates was very similar. PADs from both isolates are calcium dependent, with participation of serine and cysteine residues on their catalytic sites. PADs displayed a higher affinity to deiminate the peptidylarginine residues with a feeble affinity to work as ADI. So, PADs from E. dentata and A. nidulans had a relatively similar conformational and kinetic properties. Further molecular modeling analysis are ongoing to explore the role of PADs in citrullination of human proteins in Aspergillosis, that will open a new avenue for unraveling the vague of protein-protein interaction of human A. nidulans pathogen.


Assuntos
Aspergillus nidulans/enzimologia , Emericella/enzimologia , Desiminases de Arginina em Proteínas/química , Desiminases de Arginina em Proteínas/metabolismo , Aspergillus fumigatus/enzimologia , Estabilidade Enzimática , Humanos , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Peptídeos/química , Conformação Proteica , Desiminases de Arginina em Proteínas/isolamento & purificação , Temperatura
7.
J Org Chem ; 84(3): 1534-1541, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30608689

RESUMO

Six new 3,5-demethylorsellinic acid-based meroterpenoids, emeridones A-F (1-6), and eight known analogues (7-14) were isolated from Emericella sp. TJ29. Their structures and absolute configurations were elucidated by comprehensive spectroscopic analyses, single-crystal X-ray diffraction experiments, and electronic circular dichroism calculations. Emeridone A (1) represents the first meroterpenoid featuring a unique rigid 6/6/5/6 tetracyclic carbon ring system with two additional lactone rings. Emeridones B and C (2 and 3) possess a 2,6-dioxabicyclo[2.2.1]heptane and a spiro[bicyclo[3.2.2]nonane-2,1'-cyclohexane] moiety, respectively, and both functionalities were found for the second time in meroterpenoids. These new compounds were evaluated for their cytotoxic activities against five human cancer cells, and compounds 2, 4, and 6 exhibited moderate cytotoxic activities, with IC50 values ranging from 8.19 to 18.80 µM.


Assuntos
Dicroísmo Circular/métodos , Emericella/química , Fenômenos Bioquímicos , Cristalografia por Raios X , Humanos , Concentração Inibidora 50
8.
Nat Prod Res ; 33(14): 2088-2094, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29911443

RESUMO

The marine fungus Emericella sp was isolated from the deep sea sediments. The fungus was identified by its morphology and ITS region. A new emerixanthone E (1) together with four (2-5) known emodin derivatives were isolated from the metabolites of the fungus Emericella SCSIO05240. The structures were elucidated on the basis of NMR spectroscopic analysis and mass spectrometry. The biological properties of those compounds (1-5) were explored for antimicrobial, antifungal and antitumor activity.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Emericella/química , Xantonas/química , Antibacterianos/química , Antifúngicos/química , Antineoplásicos/química , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos/métodos , Emericella/genética , Emericella/isolamento & purificação , Emodina/química , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Água do Mar/microbiologia , Xantonas/isolamento & purificação , Xantonas/farmacologia
9.
Fitoterapia ; 131: 55-58, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30352295

RESUMO

Two novel sesquiterpenoids with an unprecedented tricyclo[4,4,2,1]hendecane scaffold, namely emericellins A (1) and B (2) representing a new skeleton, were isolated from the liquid cultures of an endophytic fungus Emericella sp. XL 029 associated with the leaves of Panax notoginseng. Their structures and relative configurations were characterized by extensive spectroscopic methods. Compounds 1-2 displayed moderate activities against three fungal strains (Verticillium dahliae Kleb, Helminthosporium maydis, and Botryosphaeria dothidea) and three bacterial strains (Bacillus subtilis, Bacillus cereus and Escherichia coli) with MIC values of 25-50 µg/mL.


Assuntos
Anti-Infecciosos/química , Emericella/química , Panax notoginseng/microbiologia , Sesquiterpenos/química , Anti-Infecciosos/isolamento & purificação , China , Endófitos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Folhas de Planta/microbiologia , Sesquiterpenos/isolamento & purificação
10.
Angew Chem Int Ed Engl ; 57(45): 14752-14757, 2018 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-30187610

RESUMO

The results of quantum chemical calculations on the mechanism of the carbocation cascade of reactions in the biosynthetic pathways leading to the pentacyclic sesterterpenes quiannulatene and sesterfisherol provide reasonable answers to several persistent mechanistic questions in sesterterpene biosynthesis, including: 1) the reaction pathways of the multicyclic ring system construction and skeletal rearrangements, 2) the mechanism of triquinane skeleton formation, which requires more complicated rearrangements than previously proposed, 3) the stereochemistry of the final carbocation intermediate, and 4) the determining factor of biosynthetic selection for either 5/6/4/6/5 or 5/6/5/5/5 pentacyclic skeleton formation. This in-depth mechanistic study on sesterterpene biosynthesis revealed that the shape of the final product and the type of triquinane skeleton formed are regulated by the stereochemistry and conformation of the common starting material, geranylfarnesyl diphosphate (GFPP).


Assuntos
Arabidopsis/metabolismo , Carbono/metabolismo , Emericella/metabolismo , Sesterterpenos/metabolismo , Arabidopsis/química , Vias Biossintéticas , Carbono/química , Ciclização , Emericella/química , Modelos Moleculares , Conformação Molecular , Fosfatos de Poli-Isoprenil/química , Fosfatos de Poli-Isoprenil/metabolismo , Sesquiterpenos/química , Sesquiterpenos/metabolismo , Sesterterpenos/química , Estereoisomerismo , Termodinâmica
11.
Pharm Biol ; 56(1): 357-362, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30266071

RESUMO

CONTEXT: Tanshinone IIA, commercially produced from Salvia miltiorrhiza Bunge (C.Y.Wu) (Labiatae), has various biological benefits. Currently, this compound is mainly extracted from plants. However, because of the long growth cycle and the unstable quality of plants, the market demands can barely be satisfied. OBJECTIVE: The genomic shuffling technology is applied to screen the high-yield tanshinone IIA strain, which could be used to replace the plant S. miltiorrhiza for the production of tanshinone IIA. The change in the production of tanshinone IIA is clarified by comparing it with the original strain. MATERIALS AND METHODS: Tanshinone IIA was extracted from Strains cells, which was prepared through 0.5 mL protoplast samples by using hypertonic solution I from two different strains. Then, it was analyzed by high-performance liquid chromatography at 30 °C and UV 270 nm. Total DNA from the strains was extracted for RAPD amplification and electrophoresis to isolate the product. RESULTS: In this study, a high-yield tanshinone IIA strain F-3.4 was screened and the yield of tanshinone IIA was increased by 387.56 ± 0.02 mg/g, 11.07 times higher than that of the original strain TR21. DISCUSSION: This study shows that the genetic basis of high-yield strains is achieved through genome shuffling, which proves that genome shuffling can shorten the breeding cycle and improve the mutagenesis efficiency in obtaining the strains with good traits and it is a useful method for the molecular breeding of industrial strains.


Assuntos
Abietanos/biossíntese , Embaralhamento de DNA/métodos , Emericella/metabolismo , Endófitos/metabolismo , Salvia miltiorrhiza , Abietanos/genética , Abietanos/isolamento & purificação , Emericella/genética , Endófitos/genética , Mutação/fisiologia
12.
J Am Chem Soc ; 140(30): 9743-9750, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29972643

RESUMO

AndA, an Fe(II)/α-ketoglutarate (αKG)-dependent enzyme, is the key enzyme that constructs the unique and congested bridged-ring system of anditomin (1), by catalyzing consecutive dehydrogenation and isomerization reactions. Although we previously characterized AndA to some extent, the means by which the enzyme facilitates this drastic structural reconstruction have remained elusive. In this study, we have solved three X-ray crystal structures of AndA, in its apo form and in the complexes with Fe(II), αKG, and two substrates. The crystal structures and mutational experiments identified several key amino acid residues important for the catalysis and provided insight into how AndA controls the reaction. Furthermore, computational calculations validated the proposed reaction mechanism for the bridged-ring formation and also revealed the requirement of a series of conformational changes during the transformation.


Assuntos
Dioxigenases/metabolismo , Compostos Heterocíclicos de Anel em Ponte/metabolismo , Enzimas Multifuncionais/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Catálise , Domínio Catalítico/genética , Cristalografia por Raios X , Teoria da Densidade Funcional , Dioxigenases/química , Dioxigenases/genética , Dioxigenases/isolamento & purificação , Emericella/enzimologia , Compostos Heterocíclicos de Anel em Ponte/química , Ácidos Cetoglutáricos/química , Ácidos Cetoglutáricos/metabolismo , Modelos Químicos , Enzimas Multifuncionais/química , Enzimas Multifuncionais/genética , Enzimas Multifuncionais/isolamento & purificação , Mutação , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/isolamento & purificação , Penicillium/enzimologia , Ligação Proteica
13.
PLoS One ; 13(6): e0196796, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29912872

RESUMO

This work describes the production of lipases from endophytic fungi: Vermisporium-like, Emericella nidulans, Dichotomophtora portulacae and D. boerhaaviae and the biological activity against the dermatophyte fungi Malassezia sp and Microsporum canis and the parasite Leishmania amazonensis. All fungal enzymes extract showed lipolysis action in the media that contains long carbon chain lipids. The proteomic analysis of lipases exhibits several molecules mostly ranging in size from 220 to 20 kDa, with clear differences in protein profile's yield. All fungal enzymes were competent to eliminate promastigote forms of Leishmania amazonensis at 5 mg.mL-1. The antileishmanial activity of lipases from Vermisporium-like, E. nidulans, D. portulacae and D. boerhaaviae in amastigote forms, promoted the reduction in viability of 78.88, 39.65, 63.17 and 98.13%, with selectivity index of 19.56, 30.68, 18.09 and 20.99. In relation to antifungal activity, Dichothomophtora enzymes demonstrate best action with MFC of 14.65 µg.mL-1 against Malassezia sp and Microsporum canis, respectively. These results allow us to infer that lipases from entophytic fungi displays activity against dermatophyte fungi (Malassezia sp. and Microsporum canis) as well as Leishmania.


Assuntos
Antifúngicos , Antiprotozoários , Arthrodermataceae/crescimento & desenvolvimento , Misturas Complexas , Emericella , Proteínas Fúngicas , Leishmania/crescimento & desenvolvimento , Lipase , Animais , Antifúngicos/química , Antifúngicos/farmacologia , Antiprotozoários/química , Antiprotozoários/farmacologia , Misturas Complexas/química , Misturas Complexas/farmacologia , Emericella/química , Emericella/enzimologia , Proteínas Fúngicas/química , Proteínas Fúngicas/farmacologia , Lipase/química , Lipase/farmacologia , Camundongos , Camundongos Endogâmicos BALB C
14.
Nat Prod Res ; 32(22): 2625-2631, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28927292

RESUMO

Two new alkylated furan derivatives, 5-(undeca-3',5',7'-trien-1'-yl)furan-2-ol (1) and 5-(undeca-3',5',7'-trien-1'-yl)furan-2-carbonate (2), were isolated from the crude extract of the plant endophytic fungus Emericella sp. XL029 associated with the leaves of Panax notoginseng. The anti-agricultural pathogenic fungal assay indicated that compound 1 displayed significant activity against all tested fungi with minimum inhibitory concentrations (MIC) values from 25 to 3.1 µg/mL, while compound 2 displayed activity against all tested fungi except for Rhizoctonia solani and Fusarium oxysporum with MIC values from 50 to 12.5 µg/mL. Furthermore, compounds 1-2 also exhibited significant inhibitory activity against eight of thirteen tested bacteria with MIC values ranging from 50 to 6.3 µg/mL.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Emericella/química , Furanos/farmacologia , Panax notoginseng/microbiologia , Antibacterianos/isolamento & purificação , Antifúngicos/isolamento & purificação , Bactérias/efeitos dos fármacos , Furanos/isolamento & purificação , Fusarium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Folhas de Planta/microbiologia , Rhizoctonia/efeitos dos fármacos
15.
Zhongguo Zhong Yao Za Zhi ; 42(17): 3374-3378, 2017 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-29192449

RESUMO

We have carried out the investigation on a sponge-derived fungus,which was identified as Emericella variecolor from the south sea of China. Two new chemical constituents,(+)-2-acetyl-dihydroterrein (1) and (+)-3-acetyl-dihydroterrein (2),with four known compounds,anditomin (3),andilesin A (4),andilesin C (5) and andilesin B (6),were isolated from this fungus by column chromatography over silica gel, Sephadex LH-20, and ODS. The structures of 1 and 2 were elucidated by spectroscopic methods including NMR,HR-ESI-MS,and CD.


Assuntos
Álcoois Benzílicos/análise , Emericella/química , Fungos/química , Poríferos/microbiologia , Animais , China , Oceanos e Mares
16.
PLoS One ; 12(9): e0184223, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28880897

RESUMO

Agricultural management methods, such as cultivation or fallowing, have led to significant changes in soil fertility and hence, crop yield. Such changes may have stemmed from changes in soil microbial communities and associated biogeochemical processes. This phenomenon is particularly true in organic-poor soil in the Loess Plateau of China. In this study, we examined three existing soil management regimes as part of a 10-year field experiment and evaluated their effects on fungal and bacterial community structures by performing high-throughput 454 pyrosequencing. These management regimes were (i) fertilized winter wheat (Triticum aestivum L.) (FW), (ii) continuous natural fallow with weeds but without crop grown (NF), and (iii) continuous bare fallow without weeds or crop grown (BF). After 10 years, soil organic carbon (SOC), microbial biomass carbon (MBC), and available potassium (K) concentrations were highest in NF. Soil N behaved differently, with BF obtaining the highest nitrate nitrogen (N). Meanwhile, slight differences in total N (TN) were observed among FW, NF, and BF. Available phosphorus (P) was highest and available K was lowest in FW. Microbial communities were dominated by Ascomycota (59.1% of fungal sequences), and Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria (75.7% of bacterial sequences) in FW, NF and BF at the phylum level. Soil management regimes did not affect the fungal and bacterial richness and diversity but significantly modified their community compositions. Compared with FW, the abundances of Ascomycota (fungi phylum) and Alternaria, Gibberella, and Emericella (fungi genus) were increased by NF, whereas the values of Chaetomium, Humicola, and Cryptococcus (fungi genus) were decreased by BF. The abundances of Verrucomicrobia (bacteria phylum), and Steroidobacter (bacteria genus) were increased by NF, and Bacteroides (bacteria genus) was increased by BF. Canonical correspondence analysis showed that SOC, available P, and TN might be the key factors in community formation. Therefore, the decadal absence of plants (BF) affected soil fertility by increased available K and nitrate N, whileas natural fallow (NF) affected soil fertility by increased SOC, available K, and MBC, and they all changed fungal and bacterial community compositions.


Assuntos
Microbiologia do Solo , Solo/classificação , Triticum , Alternaria/isolamento & purificação , Ascomicetos/isolamento & purificação , Biomassa , Carbono , Chaetomium/isolamento & purificação , China , Cryptococcus/isolamento & purificação , Emericella/isolamento & purificação , Gibberella/isolamento & purificação , Nitrogênio/análise , Potássio/análise
17.
J Nat Prod ; 80(9): 2399-2405, 2017 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-28901763

RESUMO

Bioassay-guided isolation of metabolites from cultures of the plant-derived fungus Emericella sp. TJ29 yielded three new terpene-polyketide hybrid meroterpenoids, emervaridones A-C (1-3), two new polyketides, varioxiranediols A and B (5 and 6), and three known analogues (4, 7, and 8). The structures and absolute configurations of these new compounds were elucidated by spectroscopic analyses, single-crystal X-ray diffraction, Mo2(OAc)4-induced electronic circular dichroism (ECD) data, and ECD calculations. To date, only one compound (4) bearing the emervaridone-type carbocyclic skeleton has been reported. The structures of emervaridones A-C (1-3) are new members of this type of natural product, and 1 features the first example of an α-directional H-7' in this structural category. Compounds 1 and 5 were active against five drug-resistant microbial pathogens [methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-producing E. coli), Pseudomonas aeruginosa, and Klebsiella pneumoniae] with minimum inhibitory concentration (MIC) values in the micrograms per milliliter range. Notably, the inhibitory effect of emervaridone A (1) against ESBL-producing E. coli was comparable to that of the clinically used antibiotic amikacin, with an MIC value of 2 µg/mL. Compounds 1 and 5, both with low toxicities to mammalian cells, were bacteriostatic and bactericidal, respectively. Importantly, these two compounds may provide novel chemical scaffolds for the discovery of antibacterial agents for drug-resistant microbial pathogens.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Policetídeos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Terpenos/isolamento & purificação , Terpenos/farmacologia , beta-Lactamases/química , Antibacterianos/química , Bioensaio , Emericella , Testes de Sensibilidade Microbiana , Estrutura Molecular , Policetídeos/química , Terpenos/química , beta-Lactamases/metabolismo
18.
Appl Biochem Biotechnol ; 183(2): 601-612, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28776201

RESUMO

Cellulase enzymes have versatile industrial applications. This study was directed towards the isolation, production, and characterization of cellulase enzyme system. Among the five isolated fungal cultures, Emericella variecolor NS3 showed maximum cellulase production using untreated orange peel waste as substrate using solid-state fermentation (SSF). Maximum enzyme production of 31 IU/gds (per gram of dry substrate) was noticed at 6.0 g concentration of orange peel. Further, 50 °C was recorded as the optimum temperature for cellulase activity and the thermal stability for 240 min was observed at this temperature. In addition, the crude enzyme was stable at pH 5.0 and held its complete relative activity in presence of Mn2+ and Fe3+. This study explored the production of crude enzyme system using biological waste with future potential for research and industrial applications.


Assuntos
Celulase/biossíntese , Citrus sinensis/química , Emericella/crescimento & desenvolvimento , Frutas/química , Proteínas Fúngicas/biossíntese , Estabilidade Enzimática , Temperatura Alta , Concentração de Íons de Hidrogênio
19.
PLoS One ; 12(2): e0172848, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28245269

RESUMO

In the postgenomic era, a new strategy for chemical dereplication of polyketide anti-infective drugs requires novel genomics and chromatographic strategies. An endosymbiotic fungal strain CLB38 was isolated from the root tissue of Combretum latifolium Blume (Combretaceae) which was collected from the Western Ghats of India. The isolate CLB38 was then identified as Emericella variecolor by its characteristic stellate ascospores culture morphology and molecular analysis of ITS nuclear rDNA and intervening 5.8S rRNA gene sequence. ITS2 RNA secondary structure modeling clearly distinguished fungal endosymbiont E. variecolor CLB38 with other lifestyles in the same monophyletic clade. Ethyl acetate fraction of CLB38 explored a broad spectrum of antimicrobial activity against multidrug resistant pathogens. Biosynthetic PKS type-I gene and chromatographic approach afford two polyketide antimicrobial compounds which identified as evariquinone and isoindolones derivative emerimidine A. MIC of purified compounds against test microorganisms ranged between 3.12 µg/ml and 12.5 µg/ml. This research highlights the utility of E. variecolor CLB38 as an anticipate source for anti-infective polyketide metabolites evariquinone and emerimidine A to combat multidrug resistant microorganisms. Here we demonstrates a chemogenomics strategy via the feasibility of PKS type-I gene and chromatographic approach as a proficient method for the rapid prediction and discovery of new polyketides compounds from fungal endosymbionts.


Assuntos
Combretaceae/microbiologia , Emericella/química , Emericella/fisiologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , DNA Ribossômico/genética , Emericella/genética , Isoindóis/química , Isoindóis/farmacologia , Testes de Sensibilidade Microbiana , Policetídeos/química , Policetídeos/farmacologia , RNA Fúngico/genética , Simbiose
20.
Org Lett ; 18(18): 4670-3, 2016 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-27588428

RESUMO

Six isoindolone containing meroterpenoids, emericellolides A-C (1-3) and emeriphenolicins E-G (4-6), were isolated from a plant endophytic fungus Emericella nidulans HDN12-249. Emericellolides A-C (1-3) feature the unprecedented macrolide skeleton composed of an unusual l-glutamate fragment, an isoindolone unit, and a sesquiterpene moiety, while structures of emeriphenolicins E-G (4-6) with two farnesyl groups attached to one isoindolone unit are rare in isoindolone-derived meroterpenoids. These structures including the absolute configurations were established on the basis of MS, NMR, Mo2(AcO)4-induced ECD, Marfey's method, and chemical conversion. Compound 4 exhibited cytotoxicity against HeLa cells with IC50 value of 4.77 µM.


Assuntos
Antineoplásicos/farmacologia , Emericella/química , Indóis/farmacologia , Isoindóis/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Indóis/química , Indóis/isolamento & purificação , Isoindóis/química , Estrutura Molecular , Relação Estrutura-Atividade
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