A higher β-glucosidase-producing strain was isolated and identified as Tolypocladium cylindrosporum syzx4 based on its morphology and internal transcribed spacer（ITS） rDNA gene sequence.The present study is to ferm...A higher β-glucosidase-producing strain was isolated and identified as Tolypocladium cylindrosporum syzx4 based on its morphology and internal transcribed spacer（ITS） rDNA gene sequence.The present study is to ferment,purify and characterize a β-glucosidase from T.cylindrosporum gams.The enzyme was purified to homogeneity by sulfate precipitataion,diethylaminoethyl cellulose anion exchange chromatography and Sephadex G-100 gel filtration with a 9.47-fold increase in specific activity and a recovery of 12.27%.The molecular weight（Mw） of the β-glucosidase was estimated to be 58600 by SDS-PAGE,which is much lower than that of the enzyme from other fungi.The β-glucosidase shows high activity over a wide range of temperature from 35℃ to 70℃ and the optimum pH is approximately 2.4.Then the kinetic parameters Km（0.85 mmol/L） and vmax[85.23 mmol/（L·s）] of the β-glucosidase were studied,respectively with high affinity p-nitrophenyl-β-D-glucopyranoside（p-NPG） as the substrate,inhibition constant Ki（39.5 mmol/L） with the tolerance of glucose.Although β-glucosidases have been purified and characterized from several other sources,T.cylindrosporum β-glucosidase with the unique optimal pH and higher tolerance of glucose distinguished from others makes the β-glucosidase a potential application in simultaneous saccharification and fermentation（SSF）.展开更多
Tetramic acid-containing natural products are attracting significantly increasing attention from biologists and chemists due to their intriguing structures and biological activities.In the present study,two new tetram...Tetramic acid-containing natural products are attracting significantly increasing attention from biologists and chemists due to their intriguing structures and biological activities.In the present study,two new tetramic acid alkaloids tolypyridone I(1)and tolypyridone J(2),together with five known ones(3–7),were isolated from cultures of a marine fungus Tolypocladium cylindrosporum FB06 isolate obtained from a marine sediment in Beaufort sea of North Alaska.Their structures were elucidated using 1D,2D NMR,and HRESIMS.Their configurations were established on the basis of 1H coupling constants,ROESY correlations and DP4 calculations.Compound 2 was isolated as mixtures of rotational isomers with C-3 to C-7 axis between 4-hydroxy-2-pyridone and 1-ethyl-3,5-dimethylcyclohexane,hindering rotation.In our unbiased screening to discover neuroprotective compounds in an in vitro Parkinson’s disease(PD)model,SH-SY5Y dopaminergic cells were treated with isolated compounds followed by treatment with 1-methyl-4-phenylpyridinium(MPP^(+)),a parkinsonian neurotoxin.Among tested compounds,F-14329(7)significantly protected cells from MPP^(+)-induced cytotoxicity.MPP^(+)-mediated cell death is known to be related to the regulation of Bcl-2 family proteins,specifically the down-regulation of anti-apoptotic Bcl-2 and the up-regulation of pro-apoptotic Bax levels.Treatment with 2 mmol/L of MPP^(+)for 24 h significantly reduced Bcl-2 levels compared to control treated with vehicle.However,treatment with F-14329(7)attenuated such reduction.This study demonstrates that tetramic acid-motif compounds could be potential lead compounds for treating PD.展开更多
Cordyceps sinensis(Cs) or Dongchongxiacao in Chinese is a rare and precious medicinal mushroom.In this work,a Tolypocladium sp. fungus named Cs-HK1 was isolated from a natural Cs fruiting body,and its ultraviolet(UV),...Cordyceps sinensis(Cs) or Dongchongxiacao in Chinese is a rare and precious medicinal mushroom.In this work,a Tolypocladium sp. fungus named Cs-HK1 was isolated from a natural Cs fruiting body,and its ultraviolet(UV),infrared(IR) and high-performance liquid chromatography(HPLC) spectra all exhibited high degrees of matching to those of natural Cs,indicating the similarity of chemical composition. A crude polysaccharide(PS) fraction isolated from Cs-HK1 fungal mycelium showed significant antitumor activity,inhibiting melanoma tumor growth in mice. The PS-treated mice showed significantly higher serum interferon-γ(IFN-γ)level and higher proliferation rate of lymphocytes ex vivo than the control animals,suggestive of the immunomodulatory activity of the PS fraction. In cell cultures,the PS fraction caused a significant and dose-dependent inhibitory effect on the proliferation of two cancer cell lines,B16/neu mouse melanoma and MDA-MB-231human breast cancer cells,but not on normal spleen lymphocytes in vitro. Most of these bioactivities of the CsHK1 fungus were comparable to or even greater than those of natural Cs. The results showed that Cs-HK1 fungus may be a functional substitute for the natural Cs in health food and herbal medicine.展开更多
基金Supported by the Important Agriculture Program of the Jilin Province Technology Department,China(No.20096013)the Jilin University Basic Science Research Fund,China(No.200903259)+1 种基金the Graduate Innovation Fund of Jilin University,China (No.20101043)the Project of Jilin Fuel Alcohol Company Ltd.,China
文摘A higher β-glucosidase-producing strain was isolated and identified as Tolypocladium cylindrosporum syzx4 based on its morphology and internal transcribed spacer（ITS） rDNA gene sequence.The present study is to ferment,purify and characterize a β-glucosidase from T.cylindrosporum gams.The enzyme was purified to homogeneity by sulfate precipitataion,diethylaminoethyl cellulose anion exchange chromatography and Sephadex G-100 gel filtration with a 9.47-fold increase in specific activity and a recovery of 12.27%.The molecular weight（Mw） of the β-glucosidase was estimated to be 58600 by SDS-PAGE,which is much lower than that of the enzyme from other fungi.The β-glucosidase shows high activity over a wide range of temperature from 35℃ to 70℃ and the optimum pH is approximately 2.4.Then the kinetic parameters Km（0.85 mmol/L） and vmax[85.23 mmol/（L·s）] of the β-glucosidase were studied,respectively with high affinity p-nitrophenyl-β-D-glucopyranoside（p-NPG） as the substrate,inhibition constant Ki（39.5 mmol/L） with the tolerance of glucose.Although β-glucosidases have been purified and characterized from several other sources,T.cylindrosporum β-glucosidase with the unique optimal pH and higher tolerance of glucose distinguished from others makes the β-glucosidase a potential application in simultaneous saccharification and fermentation（SSF）.
基金supported by the New Faculty Startup Fund from Seoul National Universitythe National Research Foundation of Korea(NRF-2021R1A2C1004958,2022R1A4A3022401,and RS-2023-00209597).
文摘Tetramic acid-containing natural products are attracting significantly increasing attention from biologists and chemists due to their intriguing structures and biological activities.In the present study,two new tetramic acid alkaloids tolypyridone I(1)and tolypyridone J(2),together with five known ones(3–7),were isolated from cultures of a marine fungus Tolypocladium cylindrosporum FB06 isolate obtained from a marine sediment in Beaufort sea of North Alaska.Their structures were elucidated using 1D,2D NMR,and HRESIMS.Their configurations were established on the basis of 1H coupling constants,ROESY correlations and DP4 calculations.Compound 2 was isolated as mixtures of rotational isomers with C-3 to C-7 axis between 4-hydroxy-2-pyridone and 1-ethyl-3,5-dimethylcyclohexane,hindering rotation.In our unbiased screening to discover neuroprotective compounds in an in vitro Parkinson’s disease(PD)model,SH-SY5Y dopaminergic cells were treated with isolated compounds followed by treatment with 1-methyl-4-phenylpyridinium(MPP^(+)),a parkinsonian neurotoxin.Among tested compounds,F-14329(7)significantly protected cells from MPP^(+)-induced cytotoxicity.MPP^(+)-mediated cell death is known to be related to the regulation of Bcl-2 family proteins,specifically the down-regulation of anti-apoptotic Bcl-2 and the up-regulation of pro-apoptotic Bax levels.Treatment with 2 mmol/L of MPP^(+)for 24 h significantly reduced Bcl-2 levels compared to control treated with vehicle.However,treatment with F-14329(7)attenuated such reduction.This study demonstrates that tetramic acid-motif compounds could be potential lead compounds for treating PD.
基金financially supported by grantsfrom The Hong Kong Polytechnic UniversityUGC of Hong Kong Government
文摘Cordyceps sinensis(Cs) or Dongchongxiacao in Chinese is a rare and precious medicinal mushroom.In this work,a Tolypocladium sp. fungus named Cs-HK1 was isolated from a natural Cs fruiting body,and its ultraviolet(UV),infrared(IR) and high-performance liquid chromatography(HPLC) spectra all exhibited high degrees of matching to those of natural Cs,indicating the similarity of chemical composition. A crude polysaccharide(PS) fraction isolated from Cs-HK1 fungal mycelium showed significant antitumor activity,inhibiting melanoma tumor growth in mice. The PS-treated mice showed significantly higher serum interferon-γ(IFN-γ)level and higher proliferation rate of lymphocytes ex vivo than the control animals,suggestive of the immunomodulatory activity of the PS fraction. In cell cultures,the PS fraction caused a significant and dose-dependent inhibitory effect on the proliferation of two cancer cell lines,B16/neu mouse melanoma and MDA-MB-231human breast cancer cells,but not on normal spleen lymphocytes in vitro. Most of these bioactivities of the CsHK1 fungus were comparable to or even greater than those of natural Cs. The results showed that Cs-HK1 fungus may be a functional substitute for the natural Cs in health food and herbal medicine.
