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Publications - Bioorganic Chemistry

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Books and chapters

Wessjohann, L. A.; Filho, R. A. W. N.; Puentes, A. R.; Morejón, M. C. Macrocycles from Multicomponent Reactions (Eds. Marsault E, Peterson ML). 339-376, (2017) ISBN: 978-1-11909-259-9 DOI: 10.1002/9781119092599.ch14

Macrocyclizations may be performed through two main processes: single‐component reactions and multicomponent reactions (MCRs). This chapter discusses MCRs and details approaches where isonitrile‐based MCRs (IMCRs) were applied to accomplish the macrocyclization of long linear molecules. It also introduces some insights about general aspects, concepts, and classifications of IMCR‐based macrocyclizations. The chapter then focuses on the early development of this method and case studies, where it was applied to the synthesis of rationally designed macrocyclic molecules. It further covers a special topic on the use of multiple IMCR‐based macrocyclizations for synthesizing three‐dimensional structures. In the past, most studies were directed toward understanding the principles of using MCRs in macrocyclizations and to explore the scope of these reactions, especially of the valuable IMCRs. In the future, this will be extended to even more and different MCRs, which in themselves are only at the advent of being explored.
Books and chapters

Wessjohann, L. A.; Kaluđerović, G. N.; Neves Filho, R. A. W.; Morejon, M. C.; Lemanski, G.; Ziegler, T. Further Components Carboxylic Acid and Amine (Ugi Reaction). (Stuttgart [u.a.]: Thieme Verl.). 415-502, (2014) ISBN: Print ISBN: 9783131668813; Online ISBN: 9783132064614 DOI: 10.1055/b-003-125816

Books and chapters

Degenhardt, A.; Wittlake, R.; Seilwind, S.; Liebig, M.; Runge, C.; Hilmer, J.-M.; Krammer, G.; Gohr, A.; Wessjohann, L. Quantification of Important Flavor Compounds in Beef Stocks and Correlation to Sensory Results by “Reverse Metabolomics” (Ferreira, V. & Lopez, R., eds.). 15-19, (2014) ISBN: 978-0-12-398549-1 DOI: 10.1016/B978-0-12-398549-1.00003-9

The meaningful correlation of sensory data with analytical data is one of the most challenging tasks in flavor research. In beef stocks in particular, due to the presence of low levels of aroma-active compounds and the taste contribution of non-volatile molecules to the typical “juiciness” character, the consumer encounters a complex matrix situation. The goal of our study was to carry out a comprehensive analysis of all relevant flavor molecules and the correlation to human sensory data.A technique recently developed at the IPB and termed “reverse metabolomics” was used to link biological activity (i.e., sensory data) with variations in the metabolic profile (i.e., analytical data). We used this methodology for the first time to correlate sensorial attributes and GC-MS, LC-MS, and NMR data in culinary beef stocks.Reverse metabolomics was applied to study the link between sensory and chemical composition in a series of freshly prepared culinary beef stocks. A set of 10 different beef stocks was prepared. The degree of liking of the samples was recorded on a hedonic 1–9 scale. Analysis of the stocks was performed by LC-MS, GC-MS, and NMR. 1H-NMR data directly obtained from the meat stock were very complex.Analysis of this dataset by reverse metabolomics revealed some basic structural elements of the key taste compounds, such as carnosine or anserine. The reverse metabolomics correlation of quantitative data with partiality revealed the importance of a set of compounds. This relevance of these compounds has been confirmed by additional sensory experiments which showed an increase in perceived juiciness.
Books and chapters

Bilova, T.; Greifenhagen, U.; Paudel, G.; Lukasheva, E.; Brauch, D.; Osmolovskaya, N.; Tarakhovskaya, E.; Balcke, G. U.; Tissier, A.; Vogt, T.; Milkowski, C.; Birkemeyer, C.; Wessjohann, L.; Frolov, A. Glycation of Plant Proteins under Environmental Stress — Methodological Approaches, Potential Mechanisms and Biological Role (Shanker, A. K. & Shanker, C., eds.). 295-316, (2016) ISBN: 978-953-51-2250-0 DOI: 10.5772/61860

Environmental stress is one of the major factors reducing crop productivity. Due to the oncoming climate changes, the effects of drought and high light on plants play an increasing role in modern agriculture. These changes are accompanied with a progressing contamination of soils with heavy metals. Independent of their nature, environmental alterations result in development of oxidative stress, i.e. increase of reactive oxygen species (ROS) contents, and metabolic adjustment, i.e. accumulation of soluble primary metabolites (amino acids and sugars). However, a simultaneous increase of ROS and sugar concentrations ultimately results in protein glycation, i.e. non-enzymatic interaction of reducing sugars or their degradation products (α-dicarbonyls) with proteins. The eventually resulting advanced glycation end-products (AGEs) are known to be toxic and pro-inflammatory in mammals. Recently, their presence was unambiguously demonstrated in vivo in stressed Arabidopsis thaliana plants. Currently, information on protein targets, modification sites therein, mediators and mechanisms of plant glycation are being intensively studied. In this chapter, we comprehensively review the methodological approaches for plant glycation research and discuss potential mechanisms of AGE formation under stress conditions. On the basis of these patterns and additional in vitro experiments, the pathways and mechanisms of plant glycation can be proposed.
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