Publications

TitleAbstractYear
Filter
PMID
Filter
new species of aspergillus producing sterigmatocystin.a number of species belonging to the genus aspergillus were evaluated for their toxicity to ducklings and the ability to produce sterigmatocystin. three new species capable of producing sterigmatocystin were found, namely, aspergillus aurantio-brunneus, aspergillus quadrilineatus, and aspergillus ustus. all three were toxic to ducklings. the production of sterigmatocystin by aspergillus rugulosus was confirmed, and the toxicity of aspergillus stellatus and aspergillus multicolor is described.1977406838
the biosynthesis of fungal metabolites. part vi. structures and biosynthesis of some minor metabolites from variant strains of aspergillus variecolor. 19751170194
the biosynthesis of fungal metabolites. part vii. production and biosynthesis of 4,7-dimethoxy-5-methylcoumarin in aspergillus variecolor. 19751170195
bioactive metabolites from a marine-derived strain of the fungus emericella variecolor.from a marine-derived strain of the fungus emericella variecolor, varitriol (1), varioxirane (2), dihydroterrein (3), and varixanthone (4), besides the known mold metabolites ergosterol, terrein, shamixanthone, and tajixanthone hydrate, were identified. the chemical structures of 1-4 were established by means of spectroscopic techniques and some chemical transformations. in the nci's 60-cell panel, varitriol (1) displayed increased potency toward selected renal, cns, and breast cancer cell lines ...200211908979
bioactive metabolites from a marine-derived strain of the fungus emericella variecolor.from a marine-derived strain of the fungus emericella variecolor, varitriol (1), varioxirane (2), dihydroterrein (3), and varixanthone (4), besides the known mold metabolites ergosterol, terrein, shamixanthone, and tajixanthone hydrate, were identified. the chemical structures of 1-4 were established by means of spectroscopic techniques and some chemical transformations. in the nci's 60-cell panel, varitriol (1) displayed increased potency toward selected renal, cns, and breast cancer cell lines ...200211908979
1,6-dihydr-oxy-3-hydroxy-methyl-8-methoxy-anthracene-9,10-dione monohydrate.the title compound, c(16)h(12)o(6)·h(2)o, isolated from the halotolerant fungus aspergillus variecolor b-17, is also known as questinol monohydrate. in the crystal structure, o-h⋯o hydrogen bonds link the mol-ecules, forming a three-dimensional network. π-π stacking inter-actions consolidate the supra-molecular structure [the shortest inter-planar distances are 3.456 (3), 3.366 (4) and 3.382 (4) å].200721200893
8-[(3,3-dimethyl-oxiran-2-yl)methoxy-meth-yl]-11-hydr-oxy-2-isopropenyl-5-methyl-12-oxo-1,2,3,12-tetra-hydro-pyrano[3,2-a]xanthen-1-yl acetate.the title compound, commonly known as 14-methoxy-tajixanthone-25-acetate, c(28)h(30)o(8), was isolated from emericella variecolor. the central xanthone core is approximately planar (r.m.s. deviation = 0.084 å). the dihydro-pyran ring adopts a distorted half-chair conformation. the oxirane plane is oriented at an angle of 63.3 (2)° with respect to the phenol group. an intra-molecular o-h⋯o hydrogen bond forms an s(6) ring. in the crystal, mol-ecules are linked into a two-dimensional network paral ...200921577999
8-[(3,3-dimethyl-oxiran-2-yl)methoxy-meth-yl]-11-hydr-oxy-2-isopropenyl-5-methyl-12-oxo-1,2,3,12-tetra-hydro-pyrano[3,2-a]xanthen-1-yl acetate.the title compound, commonly known as 14-methoxy-tajixanthone-25-acetate, c(28)h(30)o(8), was isolated from emericella variecolor. the central xanthone core is approximately planar (r.m.s. deviation = 0.084 å). the dihydro-pyran ring adopts a distorted half-chair conformation. the oxirane plane is oriented at an angle of 63.3 (2)° with respect to the phenol group. an intra-molecular o-h⋯o hydrogen bond forms an s(6) ring. in the crystal, mol-ecules are linked into a two-dimensional network paral ...200921577999
varioxiranols i-l, new lactones from a sponge-associated emericella variecolor fungus.chemical examination of the sponge-associated fungus emericella variecolor resulted in the isolation of four new lactones namely varioxiranols i-l(1-4)with different scaffolds, together with asteltoxin (5) and asteltoxin b (6). the structure elucidation of new compounds was accomplished by spectroscopic analysis, while the absolute configurations were determined by computed circular dichroism (ecd) and induced cd effects. antitumor activities of these compounds were evaluated against different t ...201526700546
varioxiranols i-l, new lactones from a sponge-associated emericella variecolor fungus.chemical examination of the sponge-associated fungus emericella variecolor resulted in the isolation of four new lactones namely varioxiranols i-l(1-4)with different scaffolds, together with asteltoxin (5) and asteltoxin b (6). the structure elucidation of new compounds was accomplished by spectroscopic analysis, while the absolute configurations were determined by computed circular dichroism (ecd) and induced cd effects. antitumor activities of these compounds were evaluated against different t ...201526700546
varioxiranols a-g and 19-o-methyl-22-methoxypre-shamixanthone, pks and hybrid pks-derived metabolites from a sponge-associated emericella variecolor fungus.chemical examination of a sponge (cinachyrella sp.)-associated emericella variecolor fungus resulted in the isolation of seven new polyketide derivatives, namely, varioxiranols a-g (1-7), and a new hybrid pks-isoprenoid metabolite, 19-o-methyl-22-methoxypre-shamixanthone (8), together with nine known analogues. their structures were elucidated on the basis of extensive spectroscopic analyses, including ecd effects, mosher's method, x-ray diffraction, and chemical conversion for the determination ...201526394166
varioxiranols a-g and 19-o-methyl-22-methoxypre-shamixanthone, pks and hybrid pks-derived metabolites from a sponge-associated emericella variecolor fungus.chemical examination of a sponge (cinachyrella sp.)-associated emericella variecolor fungus resulted in the isolation of seven new polyketide derivatives, namely, varioxiranols a-g (1-7), and a new hybrid pks-isoprenoid metabolite, 19-o-methyl-22-methoxypre-shamixanthone (8), together with nine known analogues. their structures were elucidated on the basis of extensive spectroscopic analyses, including ecd effects, mosher's method, x-ray diffraction, and chemical conversion for the determination ...201526394166
molecular basis for stellatic acid biosynthesis: a genome mining approach for discovery of sesterterpene synthases.the search for a new sesterterpene synthase in the genome of emericella variecolor, which reportedly produces diverse sesterterpenoids, is described. one gene product (a chimeric protein with prenyltransferase and terpene cyclase domains) led to the synthesis of a novel tricyclic sesterterpene, stellata-2,6,19-triene (1), from dmapp and ipp, and the hydrocarbon was further transformed into stellatic acid (2) by cytochrome p450 monooxygenase encoded by the gene adjacent to the sesterterpene synth ...201526351860
molecular basis for stellatic acid biosynthesis: a genome mining approach for discovery of sesterterpene synthases.the search for a new sesterterpene synthase in the genome of emericella variecolor, which reportedly produces diverse sesterterpenoids, is described. one gene product (a chimeric protein with prenyltransferase and terpene cyclase domains) led to the synthesis of a novel tricyclic sesterterpene, stellata-2,6,19-triene (1), from dmapp and ipp, and the hydrocarbon was further transformed into stellatic acid (2) by cytochrome p450 monooxygenase encoded by the gene adjacent to the sesterterpene synth ...201526351860
marine-derived fungal sesterterpenes, ophiobolins, inhibit biofilm formation of mycobacterium species.biofilm formation in pathogenic bacteria defends them from antibiotics and the host's immune system. in the course of our search for new inhibitors of biofilm formation in mycobacterium species, we isolated the sesterterpenes ophiobolin k (1), 6-epi-ophiobolin k (2), and 6-epi-ophiobolin g (3) from a culture of marine-derived fungus of emericella variecolor. ophiobolins 1-3 inhibited biofilm formation of mycobacterium smegmatis with mics of 4.1-65 μm, whereas these compounds did not show antimic ...201322684914
marine-derived fungal sesterterpenes, ophiobolins, inhibit biofilm formation of mycobacterium species.biofilm formation in pathogenic bacteria defends them from antibiotics and the host's immune system. in the course of our search for new inhibitors of biofilm formation in mycobacterium species, we isolated the sesterterpenes ophiobolin k (1), 6-epi-ophiobolin k (2), and 6-epi-ophiobolin g (3) from a culture of marine-derived fungus of emericella variecolor. ophiobolins 1-3 inhibited biofilm formation of mycobacterium smegmatis with mics of 4.1-65 μm, whereas these compounds did not show antimic ...201322684914
production and optimization of physicochemical parameters of cellulase using untreated orange waste by newly isolated emericella variecolor ns3.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 ...201728776201
anthraquinone-steroids, evanthrasterol a and b, and a meroterpenoid, emericellic acid, from endophytic fungus, emericella variecolor.two new anthraquinone-steroids, evanthrasterol a and b (1 and 2), and a new meroterpenoid, emericellic acid (3), together with six known compounds (4-9) were isolated from an endophytic fungus, emericella variecolor. their structures were determined by spectroscopic analysis (1d and 2d nmr, hresims and ftir). herein emericellic acid (3) is a new skeleton of meroterpenoid with carboxylic functional group at c-9' and this is the first report on isolation of anthraquinone-steroids from e. variecolo ...201626718087
anthraquinone-steroids, evanthrasterol a and b, and a meroterpenoid, emericellic acid, from endophytic fungus, emericella variecolor.two new anthraquinone-steroids, evanthrasterol a and b (1 and 2), and a new meroterpenoid, emericellic acid (3), together with six known compounds (4-9) were isolated from an endophytic fungus, emericella variecolor. their structures were determined by spectroscopic analysis (1d and 2d nmr, hresims and ftir). herein emericellic acid (3) is a new skeleton of meroterpenoid with carboxylic functional group at c-9' and this is the first report on isolation of anthraquinone-steroids from e. variecolo ...201626718087
cytochrome p450 for citreohybridonol synthesis: oxidative derivatization of the andrastin scaffold.a biosynthetic gene cluster similar to that for andrastin a (1) was discovered in emericella variecolor nbrc 32302. ctr-p450, a cytochrome p450 uniquely present in the cluster, was coexpressed with the andrastin a biosynthetic genes, leading to the production of the antifeedant agent citreohybridonol (4), along with four new andrastin derivatives. the results revealed the unusual multifunctionality of ctr-p450 and indicated that this approach can be applied for further natural product diversific ...201626731665
cytochrome p450 for citreohybridonol synthesis: oxidative derivatization of the andrastin scaffold.a biosynthetic gene cluster similar to that for andrastin a (1) was discovered in emericella variecolor nbrc 32302. ctr-p450, a cytochrome p450 uniquely present in the cluster, was coexpressed with the andrastin a biosynthetic genes, leading to the production of the antifeedant agent citreohybridonol (4), along with four new andrastin derivatives. the results revealed the unusual multifunctionality of ctr-p450 and indicated that this approach can be applied for further natural product diversific ...201626731665
diasteltoxins a-c, asteltoxin-based dimers from a mutant of the sponge-associated emericella variecolor fungus.three novel asteltoxin-bearing dimers namely diasteltoxins a-c (1-3) along with asteltoxin were isolated from a mutated strain of a sponge-derived fungus emericella variecolor xsa-07-2. their structures were determined by extensive spectroscopic analyses including the computed electronic circular dichroism (ecd) data for the configurational assignment. the biogenetic formation of the dimers through [2 + 2] cycloaddition of asteltoxin was postulated. diasteltoxins 1-3 exerted inhibitory effects a ...201627571434
diasteltoxins a-c, asteltoxin-based dimers from a mutant of the sponge-associated emericella variecolor fungus.three novel asteltoxin-bearing dimers namely diasteltoxins a-c (1-3) along with asteltoxin were isolated from a mutated strain of a sponge-derived fungus emericella variecolor xsa-07-2. their structures were determined by extensive spectroscopic analyses including the computed electronic circular dichroism (ecd) data for the configurational assignment. the biogenetic formation of the dimers through [2 + 2] cycloaddition of asteltoxin was postulated. diasteltoxins 1-3 exerted inhibitory effects a ...201627571434
chemogenomics driven discovery of endogenous polyketide anti-infective compounds from endosymbiotic emericella variecolor clb38 and their rna secondary structure analysis.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 int ...201728245269
chemogenomics driven discovery of endogenous polyketide anti-infective compounds from endosymbiotic emericella variecolor clb38 and their rna secondary structure analysis.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 int ...201728245269
an unusual chimeric diterpene synthase from emericella variecolor and its functional conversion into a sesterterpene synthase by domain swapping.di- and sesterterpene synthases produce c20 and c25 isoprenoid scaffolds from geranylgeranyl pyrophosphate (ggpp) and geranylfarnesyl pyrophosphate (gfpp), respectively. by genome mining of the fungus emericella variecolor, we identified a multitasking chimeric terpene synthase, evvs, which has terpene cyclase (tc) and prenyltransferase (pt) domains. heterologous gene expression in aspergillus oryzae led to the isolation of variediene (1), a novel tricyclic diterpene hydrocarbon. intriguingly, i ...201626546087
an unusual chimeric diterpene synthase from emericella variecolor and its functional conversion into a sesterterpene synthase by domain swapping.di- and sesterterpene synthases produce c20 and c25 isoprenoid scaffolds from geranylgeranyl pyrophosphate (ggpp) and geranylfarnesyl pyrophosphate (gfpp), respectively. by genome mining of the fungus emericella variecolor, we identified a multitasking chimeric terpene synthase, evvs, which has terpene cyclase (tc) and prenyltransferase (pt) domains. heterologous gene expression in aspergillus oryzae led to the isolation of variediene (1), a novel tricyclic diterpene hydrocarbon. intriguingly, i ...201626546087
astellifadiene: structure determination by nmr spectroscopy and crystalline sponge method, and elucidation of its biosynthesis.genome mining of a terpene synthase gene from emericella variecolor nbrc 32302 and its functional expression in aspergillus oryzae led to the production of the new sesterterpene hydrocarbon, astellifadiene (1), having a 6-8-6-5-fused ring system. the structure of 1 was initially investigated by extensive nmr analyses, and was further confirmed by the crystalline sponge method, which established the absolute structure of 1 and demonstrated the usefulness of the method in the structure determinati ...201627038368
astellifadiene: structure determination by nmr spectroscopy and crystalline sponge method, and elucidation of its biosynthesis.genome mining of a terpene synthase gene from emericella variecolor nbrc 32302 and its functional expression in aspergillus oryzae led to the production of the new sesterterpene hydrocarbon, astellifadiene (1), having a 6-8-6-5-fused ring system. the structure of 1 was initially investigated by extensive nmr analyses, and was further confirmed by the crystalline sponge method, which established the absolute structure of 1 and demonstrated the usefulness of the method in the structure determinati ...201627038368
2-hydroxydiplopterol, a new cytotoxic pentacyclic triterpenoid from the halotolerant fungus aspergillus variecolor b-17.a new hopane type pentacyclic triterpenoid, 2-hydroxydiplopterol (1) has been isolated from the metabolites produced by the halotolerant fungal strain aspergillus variecolor b-17. the structure of 1 was determined by spectroscopic methods and single crystal x-ray diffraction analysis. 2-hydroxydiplopterol (1) exhibited cytotoxicity against k562 cells with an ic50 value of 22 microm.200919784575
three novel, structurally unique spirocyclic alkaloids from the halotolerant b-17 fungal strain of aspergillus variecolor.during our search for novel antitumor lead compounds from microorganisms living under extreme conditions, three novel alkaloids, variecolortides a-c (1-3), were isolated from the mycelia of the halotolerant fungal strain aspergillus variecolor b-17. the new compounds were found to share an unprecedented 'spiro-anthronopyranoid diketopiperazine' structure, with a stable hemiaminal function, as corroborated by in-depth nmr-spectroscopic and mass-spectrometric analyses, as well as by a single-cryst ...200718081101
two new cytotoxic quinone type compounds from the halotolerant fungus aspergillus variecolor.two new quinone type compounds, variecolorquinones a (1) and b (2) together with eleven known related compounds 3 approximately 13 have been isolated from the metabolites produced by the halotolerant fungal strain aspergillus variecolor b-17. the structures of 1 and 2 were determined by spectroscopic methods. 1 exhibited selective cytotoxicity against a-549 cells with the ic50 values of 3.0 microm. 2 showed cytotoxicity against hl60 and p388 cells with the ic50 values of 1.3 and 3.7 microm, resp ...200717965475
isoechinulin-type alkaloids, variecolorins a-l, from halotolerant aspergillus variecolor.twelve new compounds, variecolorins a-l ( 1- 12), together with eleven known analogues ( 13- 23) were isolated from the broth of a halotolerant fungus, aspergillus variecolor. the structures of compounds 1- 12 were determined by chemical and spectroscopic methods. compounds 1- 11, 13- 15, and 20- 23 exhibited weak radical scavenging activity against dpph, with ic 50 values from 43 to 103 microm. the new compounds 1- 12 all were essentially nontoxic against the p388, hl-60, bel-7402, and a-549 ce ...200717896816
synthesis of some novel heterocyclic compounds derived from diflunisal hydrazide as potential anti-infective and anti-inflammatory agents.three novel series of 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylic acid derivatives namely 4-substituted-1,2,4-triazoline-3-thiones (4a-g); 2-substituted-1,3,4-thiadiazoles (5a-g) and 2-substituted-1,3,4-oxadiazoles (6a-g) have been synthesized. twenty-one of the newly synthesized compounds were tested against various bacteria, fungi, yeast species and virus. in addition, we have replaced the carboxylic acid group of diflunisal with heterocycles and the anti-inflammatory activity of heterocycle ...200717418454
cytotoxic activity of four xanthones from emericella variecolor, an endophytic fungus isolated from croton oblongifolius.four xanthones were isolated from mycelia of emericella variecolor, an endophytic fungus isolated from the leaves of croton oblongifolius. their structures were elucidated by spectroscopic analysis to be shamixanthone, 14-methoxytajixanthone-25-acetate, tajixanthone methanoate, and tajixanthone hydrate. all compounds were tested for cytotoxic activity against various human tumor cell lines including gastric carcinoma, colon carcinoma, breast carcinoma, human hepatocarcinoma, and lung carcinoma. ...200616526278
cytotoxic activity of four xanthones from emericella variecolor, an endophytic fungus isolated from croton oblongifolius.four xanthones were isolated from mycelia of emericella variecolor, an endophytic fungus isolated from the leaves of croton oblongifolius. their structures were elucidated by spectroscopic analysis to be shamixanthone, 14-methoxytajixanthone-25-acetate, tajixanthone methanoate, and tajixanthone hydrate. all compounds were tested for cytotoxic activity against various human tumor cell lines including gastric carcinoma, colon carcinoma, breast carcinoma, human hepatocarcinoma, and lung carcinoma. ...200616526278
inhibition of mitochondrial respiration by asteltoxin, a respiratory toxin from emericella variecolor.asteltoxin, a respiratory toxin from emericella variecolor, was examined for an inhibitory effect on mitochondrial function. asteltoxin strongly inhibited state 3 respiration, which was released by an uncoupling agent, 2,4-dinitrophenol (dnp), indicating that the action site of asteltoxin is localized in the energy transfer system of mitochondria. asteltoxin strongly depressed mg2+-atpase activity in mitochondria and only slightly affected na+, k+-activated atpase in microsomes at the concentrat ...19853000028
inhibition of mitochondrial respiration by asteltoxin, a respiratory toxin from emericella variecolor.asteltoxin, a respiratory toxin from emericella variecolor, was examined for an inhibitory effect on mitochondrial function. asteltoxin strongly inhibited state 3 respiration, which was released by an uncoupling agent, 2,4-dinitrophenol (dnp), indicating that the action site of asteltoxin is localized in the energy transfer system of mitochondria. asteltoxin strongly depressed mg2+-atpase activity in mitochondria and only slightly affected na+, k+-activated atpase in microsomes at the concentrat ...19853000028
the biosynthesis of fungal metabolites. part v. structure of variecoxanthones a, b, and c, metabolites of aspergillus variecolor; conversion of variecoxanthone a into (plus or minus)-de-c-prenylepishamixanthone. 19751170193
evariquinone, isoemericellin, and stromemycin from a sponge derived strain of the fungus emericella variecolor.from a strain of the fungus emericella variecolor derived from the marine sponge haliclona valliculata, two new natural products, evariquinone and isoemericellin, were isolated after hplc-uv, -ms, and -nmr studies of the extract and their structures were elucidated by mass spectrometry and nmr experiments. evariquinone showed antiproliferative activity towards kb and nci-h460 cells at a concentration of 3.16 microg/ml. furthermore, the fungus was found to produce the known metabolites stromemyci ...200312770594
evariquinone, isoemericellin, and stromemycin from a sponge derived strain of the fungus emericella variecolor.from a strain of the fungus emericella variecolor derived from the marine sponge haliclona valliculata, two new natural products, evariquinone and isoemericellin, were isolated after hplc-uv, -ms, and -nmr studies of the extract and their structures were elucidated by mass spectrometry and nmr experiments. evariquinone showed antiproliferative activity towards kb and nci-h460 cells at a concentration of 3.16 microg/ml. furthermore, the fungus was found to produce the known metabolites stromemyci ...200312770594
[study on metabolites from a sponge-derived fungus].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 inclu ...201729192449
complete biosynthetic pathway of anditomin: nature's sophisticated synthetic route to a complex fungal meroterpenoid.anditomin and its precursors, andilesins, are fungal meroterpenoids isolated from aspergillus variecolor and have unique, highly oxygenated chemical structures with a complex bridged-ring system. previous isotope-feeding studies revealed their origins as 3,5-dimethylorsellinic acid and farnesyl pyrophosphate and suggested the possible involvement of a diels-alder reaction to afford the congested bicyclo[2.2.2]octane core structure of andilesins. here we report the first identification of the bio ...201425216349
Displaying items 1 - 43 of 43