Fuzhuanins A and B: The B-ring Fission Lactones of Flavan-3-ols from Fuzhuan Brick-Tea

2013 ◽  
Vol 61 (28) ◽  
pp. 6982-6990 ◽  
Author(s):  
Zhen-Mei Luo ◽  
Hai-Xia Du ◽  
Li-Xiang Li ◽  
Mao-Qiang An ◽  
Zheng-Zhu Zhang ◽  
...  
Keyword(s):  
Ring Fission

ChemInform Abstract: Eliminative Ring Fission of 1,2,4-Trioxan-5-ones. A New Approach to α-Keto Acids.

ChemInform ◽  
1987 ◽  
Vol 18 (17) ◽  
Author(s):  
C. W. JEFFORD ◽  
J.-C. ROSSIER ◽  
J. BOUKOUVALAS
Keyword(s):  
New Approach ◽  
Ring Fission ◽  
Keto Acids

scholarly journals Feature-Based Molecular Networking Analysis of the Metabolites Produced by in vitro Solid-State Fermentation Reveals Pathways for the Bioconversion of Epigallocatechin Gallate

2020 ◽  
Author(s):  
Hao-Fen Xie ◽  
Ya-Shuai Kong ◽  
Ru-Ze Li ◽  
Hong Zhang ◽  
Lu-Lu Liu ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Fermentation ◽  
Epigallocatechin Gallate ◽  
Oxidation Products ◽  
Molecular Networking ◽  
Hygrothermal Effect ◽  
Ring Fission ◽  
Feature Based ◽  
Ring Oxidation

Flavan-3-ol B-ring fission derivatives (FBRFDs) are secondary metabolites that contribute to the unique properties of fermented dark teas. However, the FBRFD precursors and biochemistry are unclear. Fungal strains cultured from Fuzhuan brick tea (FBT) were incubated in an in vitro solid-state fermentation system containing β-cyclodextrin-embedded epigallocatechin gallate (EGCG), a potential precursor of FBRFDs. The produced metabolites were analyzed through a combination of targeted chromatographic isolation, non-targeted spectroscopic identification, and Feature-based Molecular Networking (FBMN) in the Global Natural Products Social Molecular Networking (GNPS) platform. Dihydromyricetin was identified for the first time, indicating that fungi possess a flavan-3-ol C-ring oxidation pathway. EGCG was verified as the precursor of dihydromyricetin and FBRFDs such as teadenol A and fuzhuanin A. The conversion was driven by the fungi rather than a hygrothermal effect. Isolates from Pezizomycotina showed much stronger abilities to convert EGCG to the B-/C-ring oxidation products than those from Saccharomycotina or Basidiomycota.

Changes of major tea polyphenols and production of four new B-ring fission metabolites of catechins from post-fermented Jing-Wei Fu brick tea

2015 ◽  
Vol 170 ◽  
pp. 110-117 ◽  
Author(s):  
Yun-Fei Zhu ◽  
Jing-Jing Chen ◽  
Xiao-Ming Ji ◽  
Xin Hu ◽  
Tie-Jun Ling ◽  
...  
Keyword(s):  
Tea Polyphenols ◽  
Ring Fission

DEGRADATION STUDIES WITH 14C-FENOXAPROP IN PRAIRIE SOILS

1990 ◽  
Vol 70 (3) ◽  
pp. 343-350 ◽  
Author(s):  
A. E. SMITH ◽  
A. J. AUBIN
Keyword(s):  
Soil Microbial Biomass ◽  
Field Capacity ◽  
First Order ◽  
Soil Microbial ◽  
Prairie Soils ◽  
First Order Kinetics ◽  
Ring Fission ◽  
Capacity Degradation ◽  
Soil Temperatures ◽  
Moisture Conditions

The persistence of 14C-fenoxaprop acid, the major degradation product of the herbicide 14C-fenoxaprop-ethyl, was studied at different controlled temperature and moisture conditions in three Saskatchewan soils. At 85% of field capacity, degradation approximated to first-order kinetics at soil temperatures of 10, 20, and 30 °C, with half-life values ranging from 42 to 5 d. In a clay at 20 °C, there was no effect of moisture, between 50% and 100% field capacity, on the rate of 14C-fenoxaprop acid breakdown. There was no loss of radioactivity after 65-d in air dry soils. In all soils incubated at 85% field capacity and 20 °C with 14C-fenoxaprop-ethyl, uniformly labeled in the chlorophenyl ring, there was evolution of 14CO2 indicating ring fission. Over a 56-d incubation period, 10–15% of the applied radioactivity was released from the treated soils as 14CO2. Extraction with ammoniated acetonitrile recovered 14–19% of the original radioactivity; between 3 and 5% of the initial 14C was incorporated into soil microbial biomass; and 17–25% into the fulvic acid, 7–12% into the humic acid, and 30–34% into the humin soil fractions. Key words: Herbicide, biomass, fenoxaprop-ethyl, fenoxaprop, persistence

Eliminative ring fission of 4-acyl-2,3-dihydro-4H-1,4-benzothiazines

1983 ◽  
Vol 48 (22) ◽  
pp. 4082-4087 ◽  
Author(s):  
F. Babudri ◽  
S. Florio ◽  
G. Indelicati ◽  
G. Trapani
Keyword(s):  
Ring Fission

The regiochemistry of cyclopropylcarbinylstannane ring fission

1994 ◽  
Vol 35 (10) ◽  
pp. 1609-1612 ◽  
Author(s):  
Andrew J Lucke ◽  
David J Young
Keyword(s):  
Ring Fission

The photolytic preparation of cyclopentadienyl and phenyl nitrene from benzene derivatives

1968 ◽  
Vol 303 (1473) ◽  
pp. 139-156 ◽  
Keyword(s):  
Flash Photolysis ◽  
Phenyl Isocyanate ◽  
Benzene Derivatives ◽  
Substituted Benzenes ◽  
Fission Process ◽  
Ring Fission

The flash photolysis of phenols, anilines, nitrobenzenes and some other benzene derivatives results in a novel ring fission process and the production of cyclopentadienyl radicals. The spectra of cyclopentadienyl, and its derivatives obtained from doubly substituted benzenes, have been recorded and analysed in part. A spectrum attributed to phenyl nitrene has been observed after flash photolysis of ortho chloro aniline, ortho bromo aniline and phenyl isocyanate.

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