Biosynthesis of Lactones From Diols Mediated by an Artificial Flavin

Abstract Background: Lactones are important compounds in the field of medicine, material and chemical industry. One of the promising accesses to these flexible scaffolds is NAD(P)+-dependent alcohol dehydrogenases-catalyzed oxidative lactonization of diols, which relies on the construction of an efficient NAD(P)+ regeneration system. Results: In this study, a novel system combining horse liver alcohol dehydrogenase (HLADH) with the synthetic bridged flavin cofactor was established for biosynthesis of lactones. The reaction conditions of this system were optimized and a variety of lactones including chiral lactones were efficiently obtained from various diols. Compared to the previously reported NAD(P)+-regeneration systems, this system showed better regeneration efficiency and product yield. A two-phase system was further applied to solve the problem of product inhibition, and 80% yield was obtained at the condition of 300 mM substrate.Conclusions: This study provides an efficient method to synthesis of lactones from diols under mild conditions. We believe this system will be a promising alternative to promote the synthesis of other valuable compounds.

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Biosynthesis of lactones from diols mediated by an artificial flavin

Bioresources and Bioprocessing ◽

10.1186/s40643-021-00450-x ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Xiaowang Zhang ◽

Zhuotao Tan ◽

Chaojian Li ◽

Siyu Qi ◽

Mengjiao Xu ◽

...

Keyword(s):

Product Yield ◽

Product Inhibition ◽

Phase System ◽

Regeneration System ◽

Two Phase ◽

Promising Alternative ◽

Liver Alcohol Dehydrogenase ◽

Horse Liver ◽

Valuable Compounds ◽

Chiral Lactones

Abstract Background Lactones are important compounds in the field of medicine, material and chemical industry. One of the promising accesses to these flexible scaffolds is NAD(P)+-dependent alcohol dehydrogenases-catalyzed oxidative lactonization of diols, which relies on the construction of an efficient NAD(P)+ regeneration system. Results In this study, a novel system combining horse liver alcohol dehydrogenase (HLADH) with the synthetic bridged flavin cofactor was established for biosynthesis of lactones. The reaction conditions of this system were optimized and a variety of lactones including chiral lactones were efficiently obtained from various diols. Compared to the previously reported NAD(P)+-regeneration systems, this system showed better regeneration efficiency and product yield. A two-phase system was further applied to solve the problem of product inhibition, and 80% yield was obtained at the condition of 300 mM substrate. Conclusions This study provides an efficient method to synthesis of lactones from diols under mild conditions. We believe this system will be a promising alternative to promote the synthesis of other valuable compounds. Graphic abstract

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The interphase distribution of light REE Ce(III) and La(III) in system based on PEG-1500 – NaNO3 – H2O with the quaternary ammonium base addition

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1212/1/012023 ◽

2022 ◽

Vol 1212 (1) ◽

pp. 012023

Author(s):

A V Levina ◽

A Ya Fedorov ◽

M I Fedorova

Keyword(s):

Organic Solvents ◽

Quaternary Ammonium ◽

Water Solution ◽

Distribution Coefficients ◽

Water Soluble ◽

Process Time ◽

Phase System ◽

Two Phase ◽

Quaternary Ammonium Base ◽

Promising Alternative

Abstract The problem of e-waste processing and recovery of valuable metals from such waste for the second use is attracting more and more scientists’ attention. Liquid extraction as one of hydrometallurgy steps is a traditional method for the metal recovery. However, application of solvent extraction is not meet the green chemistry principles due to organic solvents. Aqueous two-phase systems based on water-soluble polymers are promising alternative for hazardous organic solvents. In this work the dependencies of Ce(III) and La(III) distribution coefficients from process time and the initial quaternary ammonium base concentration have been achieved. Also, based on the Ce(III) and La(III) extraction isotherms it has been shown that the metals initial concentrations are highly affects the distribution coefficients of studied metals. The possibility of aqueous two-phase system application as a solvent for quaternary ammonium salt for light REE (Ce(III) and La(III)) extraction from water solution has been shown.

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Inhibition by ethanol, acetaldehyde and trifluoroethanol of reactions catalysed by yeast and horse liver alcohol dehydrogenases

Biochemical Journal ◽

10.1042/bj1710613 ◽

1978 ◽

Vol 171 (3) ◽

pp. 613-627 ◽

Cited By ~ 17

Author(s):

C J Dickenson ◽

F M Dickinson

Keyword(s):

Alcohol Dehydrogenase ◽

Dissociation Constant ◽

Maximum Rate ◽

Alternative Pathway ◽

Product Inhibition ◽

Experimental Conditions ◽

Alcohol Dehydrogenases ◽

Yeast Alcohol Dehydrogenase ◽

Liver Alcohol Dehydrogenase ◽

Horse Liver

1. Produced inhibition by ethanol of the acetaldehyde-NADH reaction, catalysed by the alcohol dehydrogenases from yeast and horse liver, was studied at 25 degrees C and pH 6-9. 2. The results with yeast alcohol dehydrogenase are generally consistent with the preferred-pathway mechanism proposed previously [Dickenson & Dickinson (1975) Biochem. J. 147, 303-311]. The observed hyperbolic inhibition by ethanol of the maximum rate of acetaldehyde reduction confirms the existence of the alternative pathway involving an enzyme-ethanol complex. 3. The maximum rate of acetaldehyde reduction with horse liver alcohol dehydrogenase is also subject to hyperbolic inhibition by ethanol. 4. The measured inhibition constants for ethanol provide some of the information required in the determination of the dissociation constant for ethanol from the active ternary complex. 5. Product inhibition by acetaldehyde of the ethanol-NAD+ reaction with yeast alcohol dehydrogenase was examined briefly. The results are consistent with the proposed mechanism. However, the nature of the inhibition of the maximum rate cannot be determined within the accessible range of experimental conditions. 6. Inhibition of yeast alcohol dehydrogenase by trifluoroethanol was studied at 25 degrees C and pH 6-10. The inhibition was competitive with respect to ethanol in the ethanol-NAD+ reaction. Estimates were made of the dissociation constant for trifluoroethanol from the enzyme-NAD+-trifluoroethanol complex in the range pH6-10.

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