jump to searchjump to navigationjump to content

Publications - Bioorganic Chemistry

Sort by: Year Type of publication

Displaying results 1 to 10 of 33.

Books and chapters

Restrepo, S.; Samper, C.; di Palma, F.; Hodson, E.; Torres, M.; Reol, E. M.; Eddi, M.; Wessjohann, L.; Jaramillo, G. P.; et al., .; Colombia hacia una sociedad del conocimiento. Reflexiones y propuestas 1-450, (2020) ISBN: 978-958-5135-12-3

0
Books and chapters

Abbas, G.; Ali, M.; Hamaed, A.; Al-Sibani, M.; Hussain, H.; Al-Harrasi, A.; Azadirachta indica: the medicinal properties of the global problems-solving tree (Ozturk, M. et al., eds.). 305-316, (2020) ISBN: 9780128223703 DOI: 10.1016/B978-0-12-819541-3.00017-7

The Azadirachta indica, which is commonly known as the neem tree, has gained prominence thanks to its wide spectrum of medicinal properties and its great potential to treat various diseases. In 1992 the US National Academy of Sciences recognized the importance of this plant and declared neem as a tree for solving global problems. The A. indica belongs to the family Meliaceae. It is a fast growing tropical evergreen tree indigenous to the Indo-Pakistan subcontinent since antiquity. The A. indica is also known as a wonder tree due to its richness in bioactive components in all parts of the tree such as the leaves, the bark, the flowers, the fruits, the seeds, the roots, and the gum oil and therefore it is highly exploitable. Over the years, a large number of diverse types of chemical constituents belonging to the various classes of compounds such as flavonoids, alkaloids, triterpenoids, steroids, carotenoids, and ketones, as well as phenolic compounds, have been extracted from the neem plant. The ultimate goal is to promote plant-derived products with the least side effects as modern drugs. In the last few decades, apart from the chemical analysis of the neem compounds, many researchers have investigated the potential of natural products as candidate medications for the treatment of various diseases. As a summary, substantial progress has been made in identifying neem-derived bioactive compounds for the development of medications for the treatment of a wide range of diseases. In this chapter, the major bioactive components of A. indica are presented along with their applications for the cure of many life-threatening diseases.
Books and chapters

Osmolovskaya, N.; Shumilina, J.; Bureiko, K.; Chantseva, V.; Bilova, T.; Kuchaeva, L.; Laman, N.; Wessjohann, L. A.; Frolov, A.; Ion Homeostasis Response to Nutrient-Deficiency Stress in Plants (Vikas, B. & Fasullo, M., eds.). 1-23, (2019) ISBN: 978-1-78985-311-7 DOI: 10.5772/intechopen.89398

A crucial feature of plant performance is its strong dependence on the availability of essential mineral nutrients, affecting multiple vital functions. Indeed, mineral-nutrient deficiency is one of the major stress factors affecting plant growth and development. Thereby, nitrogen and potassium represent the most abundant mineral contributors, critical for plant survival. While studying plant responses to nutrient deficiency, one should keep in mind that mineral nutrients, along with their specific metabolic roles, are directly involved in maintaining cell ion homeostasis, which relies on a finely tuned equilibrium between cytosolic and vacuolar ion pools. Therefore, in this chapter we briefly summarize the role of the ion homeostasis system in cell responses to environmental deficiency of nitrate and potassium ions. Special attention is paid to the implementation of plant responses via NO3− and K+ root transport and regulation of ion distribution in cell compartments. These responses are strongly dependent on plant species, as well as severity and duration of nutrient deficiency.
Books and chapters

Wessjohann, L. A.; Bartelt, R.; Brandt, W.; Natural and Nature-Inspired Macrocycles: A Chemoinformatic Overview and Relevant Examples (Marsault, E. & Peterson, M. L., eds.). 77-100, (2017) ISBN: 978-1-11909-259-9 DOI: 10.1002/9781119092599.ch4

This chapter discusses theoretical analyses and experimental studies of biologically and medicinally relevant macrocyclic compounds (MCs). The most important groups of macrocyclic natural products—excluding cyclopeptides—are discussed on the basis of selected examples. A common principle in the biosynthesis of most natural MCs is the primary synthesis of a linear precursor, followed by macrocyclization. Modification of the MC then leads to the final natural product. The chapter also focuses on the aspects of structure‐activity relationships (SAR) of macrocycles derived from chemoinformatic analyses and related theoretical methods. It further reviews the few examples that clearly show how chemoinformatics and modeling techniques, such as docking studies, can contribute essential information for drug design to improve their properties (mostly bioavailability or potency) and help to analyze and understand SAR of MCs. Finally, the chapter explores known aspects of quantitative SAR (QSAR) related to anticancer activities, antibiotics, HIV treatments, and other diseases.
Books and chapters

Wessjohann, L. A.; Filho, R. A. W. N.; Puentes, A. R.; Morejón, M. C.; Macrocycles from Multicomponent Reactions (Marsault, E. & Peterson, M. L., eds.). 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

Moumbock, A. F. A.; Simoben, C. V.; Wessjohann, L.; Sippl, W.; Günther, S.; Ntie‐Kang, F.; Computational Studies and Biosynthesis of Natural Products with Promising Anticancer Properties (Badria, F. A., ed.). 257-285, (2017) ISBN: 978-953-51-3314-8 DOI: 10.5772/67650

We present an overview of computational approaches for the prediction of metabolic pathways by which plants biosynthesise compounds, with a focus on selected very promising anticancer secondary metabolites from floral sources. We also provide an overview of databases for the retrieval of useful genomic data, discussing the strengths and limitations of selected prediction software and the main computational tools (and methods), which could be employed for the investigation of the uncharted routes towards the biosynthesis of some of the identified anticancer metabolites from plant sources, eventually using specific examples to address some knowledge gaps when using these approaches.
Books and chapters

Wessjohann, L.; Bauer, A.-K.; Dippe, M.; Ley, J.; Geißler, T.; Biocatalytic Synthesis of Natural Products by O-Methyltransferases (Hilterhaus, L., et al., eds.). 121-146, (2016) ISBN: 9783527677122 DOI: 10.1002/9783527677122.ch7

O‐Methylation is a crucial step to introduce specific target binding properties as well as physicochemical changes in bioactive natural products, such as aroma compounds or CNS‐active alkaloids. The corresponding O‐methyltransferases, especially those acting on catechol groups to produce vanilloid or isovanilloid moieties, are well behaved enzymes, suitable for scale‐up and heterologous expression in standard production organisms. The chapter lists the currently known applications. It focuses on examples where O‐methyltransferases are applied in the production of bioactive (natural) compounds in vitro and in vivo, with an emphasis on O‐methylated phenylpropanoids with flavonoids, and alkaloids including morphine relatives.The major drawback for large scale application lies in the availability or regeneration of the cofactor S‐adenosylmethionine (SAM). Its biotechnological production and in situ generation therefore is discussed in detail. Furthermore upstream bottlenecks like regioselective enzymatic hydroxylation to form substrates for O‐methylation, or downstream oxidation to form methylene dioxy groups, are shortly discussed.
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) 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.
Books and chapters

Wessjohann, L. A.; Neves Filho, R. A. W.; Puentes, A. R.; Morejon, M. C.; Macrocycles from Multicomponent Reactions (Zhu, J., et al., eds.). 231-264, (2015) ISBN: 9783527678174 DOI: 10.1002/9783527678174.ch09

This chapter focuses on approaches where IMCRs were used in the macrocyclization step itself. In contrast to the conventional approach, IMCR‐based protocols not only mediate the ring‐closing step, but also allow for the incorporation of one or more components as diversity elements into the final product, in an atom‐economical way without additional activation required. However, multicomponent reactions (MCRs) are very suited for the straightforward synthesis of macrocycles endowed with a high level of diversity. The first part concentrates on IMCR‐based macrocyclizations involving a single bifunctional building block (e.g., peptides), followed by those including two bifunctional or trifunctional building blocks. Finally, it discusses the sequential IMCR‐based macrocyclization approaches.
Books and chapters

Wessjohann, L.; Dippe, M.; Tengg, M.; Gruber-Khadjawi, M.; Methyltransferases in Biocatalysis (Riva, S. & Fessner, W. D., eds.). 393-426, (2014) ISBN: 9783527682492 DOI: 10.1002/9783527682492.ch18

The methyl group is one of the most widespread functionalities and decorates more than 67% of the top‐selling drugs of 2011.Although significant advances in synthetic chemistry have been achieved allowing the direct methylation, the need for environmentally benign alternatives is growing. As methylation is one of the most common chemical modifications in living cells, a variety of enzymes catalyzing the introduction of methyl groups has been evolved by nature. The enzymes are called methyltransferases (MTs) and are cofactor‐dependent. S‐adenosyl‐L‐methionine (SAM) is by far the most predominant natural source of methyl groups. Since MTs are involved in many cellular processes, their acceptor substrates are diverse, ranging from large biopolymers to small molecules.Their broad substrate spectrum would allow the use of MTs as catalysts for a wide range of biocatalytic methylation and as shown recently for also other alkylation reactions. The technological exploitation is under intensive investigation. As long as an effective recycling system for SAM is lacking, predominantly in vivo applications (cascade reactions using synthetic biology approaches) will emerge.
  • Die Leibniz-Gemeinschaft
  • Digitalization in agriculture
  • Universität Halle
IPB Mainnav Search