TY  - JOUR
A1  - Othman, Abdelmageed M.
A1  - Wollenberger, Ulla
T1  - Amperometric biosensor based on coupling aminated laccase to functionalized carbon nanotubes for phenolics detection
JF  - International journal of biological macromolecules
N2  - A biosensor for phenolic compounds based on a chemically modified laccase from Coriolus hirsula immobilized on functionalized screen-printed carbon electrodes (SPCEs) was achieved. Different enzyme modifications and immobilization strategies were analyzed. The electrochemical response of the immobilized laccase on SPCEs modified with carboxyl functionalized multi-walled carbon nanotubes (COOH-MWCNT) was the highest when laccase was aminated prior to the adsorption onto the working electrode. The developed lactase biosensor sensitivity toward different phenolic compounds was assessed to determine the biosensor response with several phenolic compounds. The highest response was obtained for ABTS with a saturation value of I-max = 27.94 mu A. The electrocatalytic efficiency (I-max/K-m(app)) was the highest for ABTS (5588 mu A mu M-1) followed by syringaldazine (3014 mu A.mu M-1). The sensors were considerably stable, whereby 99.5, 82 and 77% of the catalytic response using catechol as substrate was retained after 4, 8 and 10 successive cycles of reuse respectively, with response time average of 5 s for 12 cycles. No loss of activity was observed after 20 days of storage.
KW  - amperometry
KW  - laccase
KW  - amination
KW  - biosensor
KW  - carbon nanotubes
KW  - phenols
Y1  - 2020
U6  - https://doi.org/10.1016/j.ijbiomac.2020.03.049
SN  - 0141-8130
SN  - 1879-0003
VL  - 153
SP  - 855
EP  - 864
PB  - Elsevier
CY  - New York, NY [u.a.]
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Berger, René
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
T1  - Pd-Catalyzed [2+2+1] coupling of alkynes and arenes phenol diazonium salts as mechanistic trapdoors
JF  - Chemistry - a European journal
N2  - Alkynes and phenol diazonium salts undergo a Pd-catalyzed [2+2+1] cyclization reaction to spiro[4,5]decatetraene-7-ones. This structure was confirmed for one example by X-ray single-crystal structure analysis. The reaction is believed to proceed through oxidative addition of the phenol diazonium cation to Pd(0), subsequent insertion of two alkynes, followed by irreversible spirocyclization.
KW  - alkynes
KW  - diazo compounds
KW  - palladium
KW  - phenols
KW  - spirocycles
Y1  - 2011
U6  - https://doi.org/10.1002/chem.201100609
SN  - 0947-6539
VL  - 17
IS  - 25
SP  - 7032
EP  - 7040
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Riemer, Martin
T1  - Microwave-Promoted Deprenylation: Prenyl Ether as a Thermolabile Phenol Protecting Group
JF  - Synthesis
N2  - para-Substituted aryl prenyl ethers undergo a deprenylation reaction upon microwave irradiation. This offers the opportunity to use a prenyl ether as a thermolabile protecting group in the synthesis of natural products with a chromone structure, which proceeds via a tandem deprenylation/6-endo-cyclization sequence.
KW  - microwave irradiation
KW  - phenols
KW  - chromenes
KW  - protecting groups
KW  - Claisen rearrangement
Y1  - 2016
U6  - https://doi.org/10.1055/s-0035-1561366
SN  - 0039-7881
SN  - 1437-210X
VL  - 48
SP  - 1399
EP  - 1406
PB  - Thieme
CY  - Stuttgart
ER  -