Mutants of the strain producing natamycin, Streptomyces gilvosporeus, were obtained after space-flight mutation. With respect to the sand spores and slant spores, the mutation ratios were up to 67.6% and 78.3% and the...Mutants of the strain producing natamycin, Streptomyces gilvosporeus, were obtained after space-flight mutation. With respect to the sand spores and slant spores, the mutation ratios were up to 67.6% and 78.3% and the survival ratio was 43.1% and 3.0%, respectively. An improved mutant producing natamycin, S. gilvosporeus LK-45, was screened, which showed natamycin productivity of 1420mg·L^-1. A mutant resistant to 2-deoxy glucose, S.gilvosporeus LK-119, was further obtained using a＇rational screening procedure. The natamycin productivity of 1940mg·L^-1 was achieved when glucose was used as the carbon source.展开更多
The growth mechanism of spectinomycin dihydrochloride crystal in pure water and acetone-water mixture at different temperatures has been studied by induction period measurement. The induction period was measured visua...The growth mechanism of spectinomycin dihydrochloride crystal in pure water and acetone-water mixture at different temperatures has been studied by induction period measurement. The induction period was measured visually. The solid-liquid interfacial tension was determined on the basis of classical homogenous nucleation theory and the surface entropy factor was calculated. It was shown that the interfacial tension and surface entropy factor increased with the increase of acetone concentration and the decrease of temperature. It was demonstrated that the growth mechanism of spectinomycin dihydrochloride crystal was controlled by birth and spread growth in pure water or in acetone-water mixture at high temperatures and turned from birth and spread growth to spiral growth with the increase of acetone concentration in acetone-water mixture at low temperatures.展开更多
The title compound 1 was prepared from 1-bromonaphthalene and cyclobutanone in 11 steps, and its structure was determined by single-crystal X-ray diffraction for its monohydrate. The title compound 1 crystallizes as i...The title compound 1 was prepared from 1-bromonaphthalene and cyclobutanone in 11 steps, and its structure was determined by single-crystal X-ray diffraction for its monohydrate. The title compound 1 crystallizes as its monohydrate（C19H18BrN3O2S·H2O, Mr = 450.35） in triclinic, space group P1 with a = 8.195（3）, b = 8.703（3）, c = 14.610（4） A, α = 90.290（4）, β = 93.764（9）, γ = 116.435（10）°, V = 930.3（5）A^3, Z = 2, Dc = 1.608 g/cm^3, F（000） = 460, μ = 2.347 mm^-1, the final R = 0.0314 and wR = 0.0746 for 3368 observed reflections（I 〉 2σ（I））. The cyclobutane ring adopts a puckered conformation. The crystal lattice is stabilized by three intermolecular hydrogen bonds involving the existing water molecule. 1 was a highly active urate transporter 1（URAT1） inhibitor as it was 14-fold more active in in vitro human URAT1 inhibitory assay versus positive control lesinurad（IC50 = 0.51 μM for 1 vs. 7.18 μM for lesinurad against human URAT1）. The single-crystal structure for the monohydrate of 1 reported herein represents the first unambiguous structural determination of a novel flexible molecular scaffold we discovered earlier that was very promising for the design of highly active URAT1 inhibitors.展开更多
Edible mushroom polysaccharides,as one of the main biological activities of mushrooms,have anti-tumour,anti-inflammatory,antioxidant,immune regulation and other functions.Especially because of its anti-tumour and immu...Edible mushroom polysaccharides,as one of the main biological activities of mushrooms,have anti-tumour,anti-inflammatory,antioxidant,immune regulation and other functions.Especially because of its anti-tumour and immunomodulatory activity,it has been used in the clinical treatment of various diseases.Recent studies have focused on mushroom polysaccharides'functional properties,which may be related to their chemical structures.This review aims to clarify the biological activity of edible mushroom polysaccharides and their medicinal potential in human health and to reveal the relationship between chemical structure and the biological activity of edible mushroom polysaccharides.展开更多
文摘Mutants of the strain producing natamycin, Streptomyces gilvosporeus, were obtained after space-flight mutation. With respect to the sand spores and slant spores, the mutation ratios were up to 67.6% and 78.3% and the survival ratio was 43.1% and 3.0%, respectively. An improved mutant producing natamycin, S. gilvosporeus LK-45, was screened, which showed natamycin productivity of 1420mg·L^-1. A mutant resistant to 2-deoxy glucose, S.gilvosporeus LK-119, was further obtained using a＇rational screening procedure. The natamycin productivity of 1940mg·L^-1 was achieved when glucose was used as the carbon source.
文摘The growth mechanism of spectinomycin dihydrochloride crystal in pure water and acetone-water mixture at different temperatures has been studied by induction period measurement. The induction period was measured visually. The solid-liquid interfacial tension was determined on the basis of classical homogenous nucleation theory and the surface entropy factor was calculated. It was shown that the interfacial tension and surface entropy factor increased with the increase of acetone concentration and the decrease of temperature. It was demonstrated that the growth mechanism of spectinomycin dihydrochloride crystal was controlled by birth and spread growth in pure water or in acetone-water mixture at high temperatures and turned from birth and spread growth to spiral growth with the increase of acetone concentration in acetone-water mixture at low temperatures.
基金Supported by the Key Projects of Tianjin Science and Technology Support Plan(16YFZCSY00910)Tianjin Natural Science Foundation(12JCYBJC18800 and 13JCQNJC13700)Shandong Natural Science Foundation(ZR2015BM028)
文摘The title compound 1 was prepared from 1-bromonaphthalene and cyclobutanone in 11 steps, and its structure was determined by single-crystal X-ray diffraction for its monohydrate. The title compound 1 crystallizes as its monohydrate（C19H18BrN3O2S·H2O, Mr = 450.35） in triclinic, space group P1 with a = 8.195（3）, b = 8.703（3）, c = 14.610（4） A, α = 90.290（4）, β = 93.764（9）, γ = 116.435（10）°, V = 930.3（5）A^3, Z = 2, Dc = 1.608 g/cm^3, F（000） = 460, μ = 2.347 mm^-1, the final R = 0.0314 and wR = 0.0746 for 3368 observed reflections（I 〉 2σ（I））. The cyclobutane ring adopts a puckered conformation. The crystal lattice is stabilized by three intermolecular hydrogen bonds involving the existing water molecule. 1 was a highly active urate transporter 1（URAT1） inhibitor as it was 14-fold more active in in vitro human URAT1 inhibitory assay versus positive control lesinurad（IC50 = 0.51 μM for 1 vs. 7.18 μM for lesinurad against human URAT1）. The single-crystal structure for the monohydrate of 1 reported herein represents the first unambiguous structural determination of a novel flexible molecular scaffold we discovered earlier that was very promising for the design of highly active URAT1 inhibitors.
基金We gratefully acknowledge financial support from the Taishan Industry Leading Talents Project(tscy20200221)the Key Research and Develop Program of Shandong Province(2020CXGC010601).
文摘Edible mushroom polysaccharides,as one of the main biological activities of mushrooms,have anti-tumour,anti-inflammatory,antioxidant,immune regulation and other functions.Especially because of its anti-tumour and immunomodulatory activity,it has been used in the clinical treatment of various diseases.Recent studies have focused on mushroom polysaccharides'functional properties,which may be related to their chemical structures.This review aims to clarify the biological activity of edible mushroom polysaccharides and their medicinal potential in human health and to reveal the relationship between chemical structure and the biological activity of edible mushroom polysaccharides.
