Verena M. Dirsch – författare

This volume describes several highly diverse subjects: Chapter 1 explores marine biodiscovery of the North-eastern Atlantic off the coast of Ireland as a model for best practice in research. The second chapter investigates Brazilian Chemical Ecology and examples of insect-plant communication studies that are mediated by natural products demonstrate the beautiful interconnectedness of species in a biome. Our third chapter comprises the advances in the science of the sesquiterpene quinone, perezone, which in 1852 was the first natural product isolated in crystalline form in the New World. The last two chapters are from a Vietnamese group and the first of these follows the phytochemistry, pharmacology, and ethnomedical uses of the genus Xanthium, which produces interesting sulfur and nitrogen containing natural products. Finally, the genus Desmos is discussed, where an overview of its constituent natural products and their in vitro pharmacological potential is described.

This volume consists of four chapters that cover a structurally diverse range of naturally occurring compounds. Chapter 1 delves into the chemistry of pyrogallols and their oxidized products, the hydroxy-o-quinones, including their role in cycloaddition reactions in the chemical synthesis of several fungal metabolites. Chapter 2 provides an in-depth description of the constituents of agarwood essential oil and smoke samples that are used in the perfumery industry, with an emphasis on the sesquiterpenoid and chromones constituents so far known. Chapter 3 discusses the defensive chemical ecology of two North American newt species that both produce tetrodotoxin, a well-known neurotoxin that causes paralysis and death in metazoans by disrupting electrical signals in the nerves and muscles. Chapter 4 discusses the limonoids and triterpenoids from the genus Walsura of the plant family Meliaceae, of which a number of species are utilized in several southeastern Asian countries in systems of folk medicine.

This book describes a unique class of secondary metabolites, the mono- and dimeric-naphthylisoquinoline alkaloids. They exclusively occur in lianas of the palaeotropical Ancistrocladaceae and Dioncophyllaceae plant families. Their unprecedented structures include stereogenic centers and rotationally hindered, and therefore stereogenic, axes. Extended recent investigations on six Ancistrocladus species from Asia, as reported in this contribution, shed light on their fascinating phytochemical productivity, with over 100 intriguing natural products. This high chemodiversity arises from a similarly unique biosynthesis from acetate-malonate units, following a novel polyketidic pathway to plant-derived isoquinoline alkaloids. Some of the compounds show most promising anti-parasitic activities. Additionally, strategies for the regio- and stereoselective total synthesis of the alkaloids, including the directed construction of the chiral axis, are also presented.

 This book presents recent reports of total syntheses involving a photocatalytic reaction as a key step in the methodology. Modern photocatalysis has proven its generality for the development and functionalization of native functionalities. To date, the field has found broad applications in diverse research areas, including the total synthesis of natural products. Among the selected examples presented in this book, it highlights how the photocatalytic process proceeds in a highly chemo-, regio-, and stereoselective manner, thereby allowing the rapid access to structurally complex architectures under light-driven conditions.

The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number — from fewer than 25 in 1968 — to approximately 8,000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented.  In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.

This volume highlights some recent developments on plants used widely as botanical dietary supplements and herbal medicines, especially in terms of knowledge of the chemical types and diverse biological activities of their constituents, as well as laboratory approaches for their quality control and taxonomic identification. In the first chapter, the biologically active secondary metabolites are described of selected botanicals that have a wide current use in the United States, with recent information provided also on their in vitro and in vivo biological activities. The second chapter constitutes an updated survey of the different chromatographic, spectroscopic, and metabolomics techniques that can be utilized for the quality control of botanical products. The penultimate chapter covers different nomenclatural systems that are of use for the taxonomic identification of source plants used in botanical products. Finally, deoxyribonucleic acid molecular barcoding techniques for the identification for plants used as dietary supplements are covered.

This book deals with neurotrophins (NGF, BDNF, NT3, NT4), which can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons. This makes neurotrophins potential therapeutic agents for the treatment of neurodegenerative disorders. However, these proteins have so far been ineffective in clinical trials mostly because they cannot pass the blood-brain barrier owing to their high-molecular weights. Consequently, small molecules that mimic neurotrophins and stimulate the synthesis of endogenous neurotrophins or enhance their neurotrophic actions are expected to be promising alternatives. Small-molecule natural products, which have been used in dietary functional foods or in traditional medicine over the course of human history, have potential to be developed as new therapeutic agents against neurodegenerative conditions such as Alzheimer’s disease. In this book, the authors introduce a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection and focus on the chemistry and biology of several neurotrophic natural products.

This volume presents three chapters discussing a range of topics. Chapter 1 deals with the development of efficient methods for compound dereplication that have been critical in the re-emergence of research on natural products as a source of new drug leads. It describes the main methods of dereplication, which rely on the combined use of large natural product databases and spectral libraries, alongside the information obtained from chromatographic, UV-Vis, MS, and NMR spectroscopic analyses of the samples of interest. Chapter 2 describes 989 plant natural products and their ecological functions in plant-herbivore, plant-microorganism, and plant-plant interactions. These compounds include alkaloids, phenols, terpenoids, and other structural types. The information presented should  provide the basis for in-depth research on these plant natural products and their natural functions, and also for their further development and utilization. Chapter 3 focuses on lichens, with each constituting a symbiotic association composed of a primary mycobiont and one or more photobionts living mutualistically. Covered are lichens and their bionts, taxonomic identification, and their chemical constituents as exemplified by what is found in lichen biomes, especially those endemic to North America. Extraction and isolation procedures, as well as updates on dereplication methods using mass spectrometric GNPS and NMR spectroscopic spin network fingerprint procedures, and marker-based techniques to identify lichens are discussed. The isolation and structure elucidation of secondary metabolites of an endolichenic Penicillium species that produces bioactive compounds is described in detail.