TY  - JOUR
A1  - Matic, Aleksandar
A1  - Schlaad, Helmut
T1  - Thiol-ene photofunctionalization of 1,4-polymyrcene
JF  - Polymer international
N2  - 1,4-Polymyrcene was synthesized by anionic polymerization of -myrcene and was subjected to photochemical functionalization with various thiols (i.e. methyl thioglycolate, methyl 3-mercaptopropionate, butyl 3-mercaptopropionate, ethyl 2-mercaptopropionate and 2-methyl-2-propanethiol) using benzophenone/UV light as the radical source. The yield of thiol addition to the trisubstituted double bonds of 1,4-polymyrcene decreased in the order 1 degrees thiol (ca 95%) > 2 degrees thiol (ca 80%) > 3 degrees thiol (<5%), due to the reversibility of the thiol-ene reaction. Remarkably, thiol addition to the side-chain double bonds was 8 - 10 times (1 degrees thiol) or 24 times (2 degrees thiol) faster than to the main-chain double bonds, which can be explained by the different accessibility of the double bonds and steric hindrance. Despite the use of a 10-fold excess of thiol with respect to myrcene units, the thiol-ene addition was accompanied by chain coupling reactions, which in the extreme case of 3 degrees thiol (or in the absence of thiol) resulted in the formation of insoluble crosslinked material. As an example, a methyl-thioglycolate-functionalized 1,4-polymyrcene was saponified/crosslinked to give submicron polyelectrolyte particles in dilute alkaline solution. (c) 2018 Society of Chemical Industry
KW  - polymyrcene
KW  - thiol-ene
KW  - photochemistry
KW  - regioselectivity
Y1  - 2018
U6  - https://doi.org/10.1002/pi.5534
SN  - 0959-8103
SN  - 1097-0126
VL  - 67
IS  - 5
SP  - 500
EP  - 505
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Senf, Deborah
A1  - Ruprecht, Colin
A1  - Kishani, Saina
A1  - Matic, Aleksandar
A1  - Toriz, Guillermo
A1  - Gatenholm, Paul
A1  - Wagberg, Lars
A1  - Pfrengle, Fabian
T1  - Tailormade polysaccharides with defined branching patterns
BT  - Enzymatic polymerization of arabinoxylan oligosaccharides
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - The heterogeneous nature of non-cellulosic polysaccharides, such as arabinoxylan, makes it difficult to correlate molecular structure with macroscopic properties. To study the impact of specific structural features of the polysaccharides on crystallinity or affinity to other cell wall components, collections of polysaccharides with defined repeating units are required. Herein, a chemoenzymatic approach to artificial arabinoxylan polysaccharides with systematically altered branching patterns is described. The polysaccharides were obtained by glycosynthase-catalyzed polymerization of glycosyl fluorides derived from arabinoxylan oligosaccharides. X-ray diffraction and adsorption experiments on cellulosic surfaces revealed that the physicochemical properties of the synthetic polysaccharides strongly depend on the specific nature of their substitution patterns. The artificial polysaccharides allow structure-property relationship studies that are not accessible by other means.
KW  - carbohydrates
KW  - enzymes
KW  - glycosynthases
KW  - structure elucidation
KW  - synthetic methods
Y1  - 2018
U6  - https://doi.org/10.1002/anie.201806871
SN  - 1433-7851
SN  - 1521-3773
VL  - 57
IS  - 37
SP  - 11987
EP  - 11992
PB  - Wiley-VCH
CY  - Weinheim
ER  -