A5021423029- Allelopathy and phytotoxic interactions
- Synthesis and Biological Evaluation
- Weed Control and Herbicide Applications
- Phenothiazines and Benzothiazines Synthesis and Activities
- Chemical synthesis and alkaloids
- Chemical Reaction Mechanisms
- Carbohydrate Chemistry and Synthesis
- X-ray Diffraction in Crystallography
- Synthesis of Organic Compounds
- Analytical Chemistry and Chromatography
- Synthesis and Reactions of Organic Compounds
- Crystallization and Solubility Studies
- Plant biochemistry and biosynthesis
- Synthesis and biological activity
- Molecular spectroscopy and chirality
- Structural and Chemical Analysis of Organic and Inorganic Compounds
- Plant and fungal interactions
- Synthesis of heterocyclic compounds
- Microbial Metabolic Engineering and Bioproduction
- Enzyme Catalysis and Immobilization
- Plant Toxicity and Pharmacological Properties
- Synthesis and Characterization of Heterocyclic Compounds
- Botanical Research and Chemistry
- Chemical Synthesis and Analysis
- Axial and Atropisomeric Chirality Synthesis
Leipzig University
2012-2022
University of Bonn
2021
University of Tübingen
2019
Universität Ulm
2019
Institut für Nichtklassische Chemie
2014
Universidad Andrés Bello
2009
Technical University of Munich
2008
Shanghai Institute of Organic Chemistry
2002
Chinese Academy of Sciences
2002
Friedrich Schiller University Jena
1997-1998
Abstract Benzoxazinoids were identified in the early 1960s as secondary metabolites of grasses that function natural pesticides and exhibit allelopathic properties. are synthesized seedlings stored glucosides (glcs); main aglucone moieties 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA) 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA). The genes DIBOA-glc biosynthesis have previously been isolated enzymatic functions characterized. Here, enzymes for conversion to DIMBOA-glc...
A new, efficient method for the isolation of (2R,3S)-isocitric acid (ICA) from its fermentation solution was developed. It is noteworthy that this based on selective adsorption directly activated carbon, followed by release both ICA and citric means elution with methanol their final separation known methods. Thereby, several disadvantages were overcome: Electrodialysis no longer necessary to remove cations such as Na+ solution. Also, hitherto accompanying dyestuffs not observed method....
The ability of phytopathogenic fungi to overcome the chemical defense barriers their host plants is great importance for fungal pathogenicity. We studied role cyclic hydroxamic acids and related benzoxazolinones in plant interactions with pathogenic fungi. identified species-dependent differences abilities Gaeumannomyces graminis var. tritici, graminis, avenae, Fusarium culmorum detoxify these allelochemicals gramineous plants. G. isolate degraded benzoxazolin-2(3H)-one (BOA)...
Benzoxazinoids, secondary metabolites of several Poaceae, and some benzoxazinoid downstream are bioactive compounds that act as allelochemicals natural pesticides. Since a short lifetime the substances is crucial to avoid long-term environmental effects, total degradation by microorganisms exceptional importance. We performed screening with cultivable (Species names strain numbers: Mycobacterium fortuitum, 7; Bacillus aryabhattai, 34; cereus, 59; megaterium, 21, 48; methylotrophicus, 58;...
No longer just analytical: Previously, (2R,3S)-isocitric acid (1), a component of the citric cycle, had not been available on preparative scale. A new route to this kilogram scale combines biotechnological formation through fermentation from sunflower oil with chemical separation process. In variety transformations into further chiral derivatives, 1 is established as valuable member pool (see scheme). Supporting information for article WWW under...
A convenient four step procedure for the synthesis of 2,4-dihydroxy-2H-1.4-benzoxazin-3(4H)-one (6), a bioactive natural product from Gramineae, is described that avoids disadvantages hitherto existing methods and affords 6 in 60% overall yield.
Incubation of Zea mays cv. Nicco seedlings with 6-methoxybenzoxazolin-2(3H)-one (MBOA) led to a minor detoxification product hitherto only found in Poaceae. This new compound was identified as 1-(2-hydroxy-4-methoxyphenylamino)-1-deoxy-β-glucoside 1,2-carbamate (1) (methoxy glucoside carbamate) and represents an analogue the previously described 1-(2-hydroxyphenylamino)-1-deoxy-β-glucoside (glucoside from benzoxazolin-2(3H)-one (BOA). In Portulaca oleracea var. sativa Gelber treatment BOA...
The major detoxification product in maize roots after 24 h benzoxazolin-2(3H)-one (BOA) exposure was identified as glucoside carbamate resulting from rearrangement of BOA-N-glucoside, but the pathway N-glucosylation, enzymes involved and site synthesis were previously unknown. Assaying whole cell proteins revealed necessity H2O2 Fe2+ ions for production. Peroxidase produced BOA radicals are apparently formed within extraplastic space young root. Radicals seem to be preferred substrate either...
A new two-step synthesis of 6-methoxybenzoxazolin-2(3H)-one, a bioactive natural product from Gramineae, is described. The procedure avoids disadvantages hitherto existing methods and affords the title compound in 75% overall yield 5-methoxy-2-nitrophenol.
A facultative, microbial micro-community colonizing roots of Abutilon theophrasti Medik. supports the plant in detoxifying hydroxylated benzoxazolinones. The root is composed several fungi and bacteria with Actinomucor elegans as a dominant species. yeast Papiliotrema baii bacterium Pantoea ananatis are actively involved detoxification benzoxazolinones by generating H2O2. At surface, laccases, peroxidases polyphenol oxidases cooperate for initiating polymerization reactions, whereby enzyme...
Abstract Solid sodium nitrite in anhydrous propionic acid is an effective system for regioselective nitrosation of the subject compounds. High yields pure 2-nitroso products are obtained rapidly and efficiently. Attack at 4-position becomes competitive if water present medium. The 5-alkoxy (but not 3,5-dialkoxy)-2-nitrosphenols can be easily oxidized with nitric to yield corresponding 2-nitro
Abstract The discrimination of enantiomeric cyclic hemiacetals and methyl acetals derived from hydroxamic acids lactams with the 2 H ‐1,4‐benzoxazin‐3(4 )‐one ‐1,4‐benzothiazin‐3(4 skeleton was investigated using ( S )‐(−)‐phenylethylamine, (−)‐quinine, β‐cyclodextrin and, for first time, (5 R ,11 )‐(+)‐2,8‐dimethyl‐6 ,12 ‐5,11‐ methanodibezo [ b,f ] [1,5]diazocine, a Troeger's base enantiomer, as chiral solvating agents (CSA). Conditions six configurationally stable are reported....
Pantoea ananatis is a bacterium associated with other microorganisms on Abutilon theophrasti Medik. roots. It converts 6-hydroxybenzoxazolin-2(3H)-one (BOA-6-OH), hydroxylated derivative of the allelochemical benzoxazolin-2(3H)-one, into 6-hydroxy-5-nitrobenzo[d]oxazol-2(3H)-one. The compound was identified by NMR and mass spectrometric methods. In vitro synthesis succeeded protein, isolated proteins from root surface or horseradish peroxidase in presence nitrite H2O2. Nitro-BOA-6-OH...