Mattie S M Timmer

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To date, the structures of the glycolipids from Lactobacillus plantarum, a commonly used beneficial probiotic, have not been conclusively assigned. Herein, we report for the first time, the full characterisation of the four principal glycolipids of the L. plantarum cell wall using sugar, linkage and FAME analysis, as well as ESI-MS/MS and 1D- and 2D-NMR(More)
A variety of 6,7-substituted-5,8-quinolinequinones were synthesised and assessed for their anti-tumour and anti-inflammatory activities, and their ability to inhibit the growth of Mycobacterium bovis BCG. In particular, the introduction of a sulfur group at the 7-position of the quinolinequinone led to the discovery of two compounds,(More)
A protecting group free synthesis of 2,3-cis substituted hydroxypyrrolidines is reported. Two novel reaction methodologies allow for the stereoselective formation of cyclic carbamates from olefinic amines, and the formation of primary amines via a Vasella/reductive amination reaction, both performed in aqueous media.
A series of N,N-bis(glycityl)amines with promising anti-cancer activity were prepared via the reductive amination of pentoses and hexoses, and subsequently screened for their ability to selectively inhibit the growth of cancerous versus non-cancerous cells. For the first time, we show that this class of compounds possesses anti-proliferative activity, and,(More)
The study of protein-carbohydrate interactions is one central theme of glycomics research. The challenges encountered when investigating these interactions have resulted in an approach that studies saccharides through the enzymes that process them. Proteins and their function are often probed by manipulating the genes that encode them. Efforts in(More)
Glycolipids play an important role in many biological processes and to this end, synthetic chemists have developed a variety of new techniques and "chemical tools" that allow for the study of glycolipids in vitro and in vivo. The types of probes prepared include fluorescent, radio-labelled, biotinylated and photoreactive ones, as well as others based on(More)
The synthesis of a number of N-glycosyl-N-alkyl-methoxyamine bifunctional linkers is described. The linkers contain an N-methoxyamine functional group for conjugation to carbohydrates and a terminal group, such as an amine, azide, thiol, or carboxylic acid, for conjugation to the probe of choice. The strategy for the linker synthesis is rapid (3-4 steps)(More)
Herein, we report on a highly efficient synthesis of a crystalline protected Lewis(X) trisaccharide that was converted to Lewis(X) following global deprotection. The trisaccharide was prepared in a highly convergent synthesis (seven steps, longest linear sequence) and in a 38% overall yield using a strategy that involved the regioselective glycosylation of(More)
A new reverse turn, replacing one of the native type II' beta-turns in the cyclic peptide antibiotic gramicidin S, induced by a furanoid sugar amino acid is revealed. The C3-hydroxyl function plays a pivotal role by acting as a H-bond acceptor, consequently flipping the amide bond between residues i and i + 1, as was established by NMR and X-ray(More)
A practical gram-scale and high-yielding synthesis of the antimicrobial peptide gramicidin S is presented. An Fmoc-based solid-phase peptide synthesis protocol is employed for the generation of the linear decapeptide precursor, which is cyclized in solution to afford the target compound. The versatility of our method is demonstrated by the construction of(More)