scholarly journals Production of Hydroxy Acids: Selective Double Oxidation of Diols by Flavoprotein Alcohol Oxidase

2020 ◽  
Vol 132 (12) ◽  
pp. 4899-4902 ◽  
Author(s):  
Caterina Martin ◽  
Milos Trajkovic ◽  
Marco W. Fraaije
Keyword(s):  
Alcohol Oxidase ◽  
Hydroxy Acids ◽  
Double Oxidation

scholarly journals Production of Hydroxy Acids: Selective Double Oxidation of Diols by Flavoprotein Alcohol Oxidase

2020 ◽  
Vol 59 (12) ◽  
pp. 4869-4872 ◽  
Author(s):  
Caterina Martin ◽  
Milos Trajkovic ◽  
Marco W. Fraaije
Keyword(s):  
Alcohol Oxidase ◽  
Hydroxy Acids ◽  
Double Oxidation

Synthesis and Reactivity of Precolibactin 886

2019 ◽  
Author(s):  
Seth Herzon ◽  
Alan R. Healy ◽  
kevin wernke ◽  
Chung Sub Kim ◽  
Nicholas Lees ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Gene Cluster ◽  
Amino Alcohol ◽  
Biomimetic Synthesis ◽  
Cross Linking ◽  
E Coli ◽  
Hplc Purification ◽  
Structural Assignment ◽  
Biosynthetic Precursor ◽  
Double Oxidation

<div>The clb gene cluster encodes the biosynthesis of metabolites known as precolibactins and colibactins. The clb pathway is found in gut commensal E. coli, and clb metabolites are thought to initiate colorectal cancer via DNA cross-linking. Precolibactin 886 (1) is one of the most complex isolated clb metabolites; it contains a 15-atom macrocycle and an unusual 5-hydroxy-3-oxazoline ring. Here we report confirmation of the structural assignment via a biomimetic synthesis of precolibactin 886 (1) proceeding through the amino alcohol 9. Double oxidation of 9 afforded the unstable α-ketoimine 2 which underwent macrocyclization to precolibactin 886 (1) upon HPLC purification (3% from 9). Studies of the putative precolibactin 886 (1) biosynthetic precursor 2, the model α-ketoimine 25, and the α-dicarbonyl 26 revealed that these compounds are susceptible to nucleophilic rupture of the C36–C37 bond. Moreover, cleavage of 2 produces other known clb metabolites or biosynthetic intermediates. This unexpected reactivity explains the difficulties in isolating full clb metabolites and accounts for the structure of a recently identified colibactin–adenine adduct. The colibactin peptidase ClbP deacylates synthetic precolibactin 886 (1) to form a non-genotoxic pyridone, suggesting precolibactin 886 (1) lies off-path of the major biosynthetic route.</div>

Effectiveness of a cosmetic device containing a combination of alpha‐ and beta‐hydroxy acids, urea and thuja for the treatment of seborrheic keratoses

2021 ◽  
Author(s):  
Elena Campione ◽  
Terenzio Cosio ◽  
Monia Di Prete ◽  
Arianna Piccolo ◽  
Caterina Lanna ◽  
...  
Keyword(s):  
Hydroxy Acids ◽  
Seborrheic Keratoses

scholarly journals Controlled Ring-Opening Polymerization of O-Carboxyanhydrides to Synthesize Functionalized Poly(α-Hydroxy Acids)

2021 ◽  
Vol 03 (01) ◽  
pp. 041-050
Author(s):  
Xiaoqian Wang ◽  
Ai Lin Chin ◽  
Rong Tong
Keyword(s):  
Biomedical Engineering ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Catalyst ◽  
Hydroxy Acids ◽  
Controlled Polymerization ◽  
Biodegradable Polyesters ◽  
Recent Advances

Poly(α-hydroxy acids), as a family of biodegradable polyesters, are valuable materials due to their broad applications in packaging, agriculture, and biomedical engineering. Herein we highlight and explore recent advances of catalysts in controlled ring-opening polymerization of O-carboxyanhydrides towards functionalized poly(α-hydroxy acids), especially metal catalyst-mediated controlled polymerization. Limitations of current polymerization strategies of O-carboxyanhydrides are discussed.

The reaction of carboxylic acids with epoxides using lithium naphthalenide

1974 ◽  
Vol 27 (10) ◽  
pp. 2205 ◽  
Author(s):  
T Fujita ◽  
S Watanabe ◽  
K Suga
Keyword(s):  
Carboxylic Acids ◽  
Good Yield ◽  
Hydroxy Acids

Lithium naphthalenide reacts with carboxylic acids in the presence of diethylamine to give the α-anions of lithium carboxylates. Reaction of these anions with various epoxides gives the corresponding y-hydroxy acids in good yield. The γ-hydroxy acids easily cyclize to give γ-butyrolactones.

scholarly journals Positive Selection of Novel Peroxisome Biogenesis-Defective Mutants of the Yeast Pichia pastoris

Genetics ◽  
1999 ◽  
Vol 151 (4) ◽  
pp. 1379-1391
Author(s):  
Monique A Johnson ◽  
Hans R Waterham ◽  
Galyna P Ksheminska ◽  
Liubov R Fayura ◽  
Joan Lin Cereghino ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Allyl Alcohol ◽  
Alcohol Oxidase ◽  
Methylotrophic Yeast ◽  
Direct Selection ◽  
Toxic Exposure ◽  
Peroxisome Biogenesis ◽  
Yeast Pichia Pastoris ◽  
Methylotrophic Yeast Pichia Pastoris ◽  
Selection Of

Abstract We have developed two novel schemes for the direct selection of peroxisome-biogenesis-defective (pex) mutants of the methylotrophic yeast Pichia pastoris. Both schemes take advantage of our observation that methanol-induced pex mutants contain little or no alcohol oxidase (AOX) activity. AOX is a peroxisomal matrix enzyme that catalyzes the first step in the methanol-utilization pathway. One scheme utilizes allyl alcohol, a compound that is not toxic to cells but is oxidized by AOX to acrolein, a compound that is toxic. Exposure of mutagenized populations of AOX-induced cells to allyl alcohol selectively kills AOX-containing cells. However, pex mutants without AOX are able to grow. The second scheme utilizes a P. pastoris strain that is defective in formaldehyde dehydrogenase (FLD), a methanol pathway enzyme required to metabolize formaldehyde, the product of AOX. AOX-induced cells of fld1 strains are sensitive to methanol because of the accumulation of formaldehyde. However, fld1 pex mutants, with little active AOX, do not efficiently oxidize methanol to formaldehyde and therefore are not sensitive to methanol. Using these selections, new pex mutant alleles in previously identified PEX genes have been isolated along with mutants in three previously unidentified PEX groups.

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