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.

The first contribution summarizes current trends in research on medicinal plants in Mexico with emphasis on work carried out at the authors' laboratories. The most relevant phytochemical and pharmacological profiles of a selected group of plants used widely for treating major national health problems are described. The second contribution provides a detailed survey of the so far reported literature data on the capacities of selected oxyprenylated phenylpropanoids and polyketides to trigger receptors, enzymes, and other types of cellular factors for which they exhibit a high degree of affinity and therefore evoke specifice responses. And the third contribution discusses aspects of endophytic actinobacterial biology and chemistry, including biosynthesis and total synthesis of secondary metabolites produced in culture. It also presents perspectives fo the future of microbial biodiscovery, with emphasis on the seondary metabolism of endophytic actinobacteria.

For some 50 years, Professor Asakawa and his group have focused their research on the chemical constituents of bryophytes and have found that these plants contain large numbers of secondary metabolites, such as terpenoids, acetogenins, and aromatic compounds representative of many new skeletons, which exhibit interesting biological activities. Individual terpenoids, when found as constituents of both a bryophyte and a higher plant, tend to occur in different enantiomeric forms. Professor Asakawa has covered the literature on bryophytes in two earlier volumes of "Progress in the Chemistry of Organic Natural Products," namely, Volumes 42 (1982) and 65 (1995). Since the publication of the latter volume, a great deal of new information has appeared on bryophytes. One example is that known sex pheromones of algae have been discovered in two liverworts, indicating that some members of the latter taxonomic group might originate from brown algae. From information provided in this volume, it is suggested that two orders of the Marchantiophyta should be combined.

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The book summarizes important aspects of cheminformatics that are relevant for natural product research. It highlights cheminformatics tools that help to match natural products with their respective biological targets or off-targets, and discusses the potential and limitations of this approach.

The first contribution presents coumarins, the largest group of 1-benzopyran derivatives found in plants. Coumarin chemistry remains one of the major interest areas of phytochemists, especially because of their structural diversity and medicinal properties, along with the wide-ranging bioactivities of these compounds, inclusive of analgesic, anticoagulant anti-HIV, anti-inflammatory, antimicrobial, antineoplastic, antioxidant, and immunomodulatory effects. The second contribution presents a comprehensive survey of the many aspects of PAD biochemistry and physiology. The third contribution gives a comprehensive overview of secondary metabolites from higher fungi, with more than 700 references highlighting the isolation, structure elucidation, biological activities, chemical synthesis, and biosynthesis of pigments, nitrogen-containing compounds, and terpenoids from mushrooms.

The volumes contain contributions on various topics related to the origin, distribution, chemistry, synthesis, biochemistry, function or use of various classes of naturally occurring substances ranging from small molecules to biopolymers. Each contribution is written by a recognized authority in his field and provides a comprehensive and up-to-date review of the topic in question.

The book presents the current state of the art on phytocannnabinoid chemistry and pharmacology and will be of much use to those wishing to understand the current landscape of the exciting and intriguing phytocannabinoid science. The focus is on natural product cannabinoids which have been demonstrated to act at specific receptor targets in the CNS.

Resin glycosides are part of a very extensive family of secondary metabolites known as glycolipids or lipo-oligosaccharides and are constituents of complex resins (glycoresins) (1) unique to the morning glory family, Convolvulaceae (2). These active principles are responsible for the drastic purgative action of all the important Convolvulaceous species used in traditional medicine throughout the world since ancient times. Several commercial purgative crude drugs can be prepared from the roots of different species of Mexican morning glories. Their incorporation as therapeutic agents in Europe is an outstanding example of the assimilation of botanical drugs from the Americas as substitutes for traditional Old World remedies (3). Even though phytochemical investigations on the constituents of these drugs were initiated during the second half of the nineteenth century, the structure of their active ingredients still remains poorly known for some examples of these purgative roots. During the last two decades, the higher resolution c- abilities of modern analytical isolation techniques used in conjunction with pow- ful spectroscopic methods have facilitated the elucidation of the active principles of these relevant herbal products. This chapter describes the ethnobotanical information associated with the p- gative morning glory species and how traditional usages were instrumental in plant selection for chemical studies. The advantages and limitations of available analy- cal techniques for the isolation, puri?cation, and structure characterization of the individual constituents of these complex glycoconjugates are also discussed.

The three reviews cover the advances in the chemistry and biology of withanolides over the last 16 years, review the chemistry and biology of the rocaglamide-type derivatives and related compounds, with emphasis on their structural diversity, biosynthesis, pharmacological significance and total synthesis, and summarize the extensive chemistry and biology studies on a natural product, which have resulted in a novel therapy approved worldwide.

Lignans, by convention, are a group of natural products that are formed by linking two phenylpropanoid units (C C units) by oxidative coupling. Most importantly, in 6 3 a lignan, two (C C units) are bound through the central carbon of their side chains, 6 3 0 i. e. the 8 and 8 positions (1, 2). The occurrence of C C -dimers, linked at sites other 6 3 0 than the 8-8 positions, is also known and these compounds have been termed neolignans (3, 4). As these two groups of compounds have close structural as well as biosynthetic relationships, they are often associated together and incorporated under the general term "lignan" (5). The diverse structural categorization of true lignans and of a few neolignans is presented in Fig. 1. Through the years, several review articles or books covering different facets of lignans, including their ch- istry (6, 7), biogenesis (8), synthesis (9), and biological activities (10) have been published. Enduring research for the investigation of secondary metabolites of plants has evidenced some compounds that are biogenetically related to true lignans or neolignans but bear some features not discerned in conventional lignans. These compounds or groups of compounds have been termed as "non-conventional lignans", and include coumarinolignans, ?avonolignans, and stilbenolignans. The non-conventional lignans, like the conventional ones, have two C C units linked 6 3 together but have additional structural features to place them also under the category of coumarins, ?avonoids, or stilbenes.

The first contribution describes apolar and polar molecular fossils and, in particular biomarkers, along the lines usually followed in organic chemistry textbooks, and points to their bioprecursors when available. Thus, the apolar compounds are divided in linear and branched alkanes followed by alicyclic compounds and aromatic and heterocyclic molecules, and, in particular, the geoporphyrins. The polar molecular fossils contain as functional groups or constituent units ethers, alcohols, phenols, carbonyl groups, flavonoids, quinones, and acids, or are polymers like kerogen, amber, melanin, proteins, or nucleic acids. The final sections discuss the methodology used and the fundamental processes encountered by the biomolecules described, including diagenesis, catagenesis, and metagenesis. The second contribution covers the distribution of phthalides in nature and the findings in the structural diversity, chemical reactivity, biotransformations, syntheses, and bioactivity of natural and semisynthetic phthalides.

The first contribution reviews the occurrence of xanthine alkaloids in the plant kingdom and the elucidation of the caffeine biosynthesis pathway, providing details of the N-methyltransferases, belonging to the motif B' methyltransferase family which catalyze three steps in the four step pathway leading from xanthosine to caffeine. The second contribution in this book provides a background on the molecule and related compounds and update knowledge on the most recent advances in Iboga alkaloids. The third contribution presents a comprehensive analysis of frequently occurring errors with respect to 13C NMR spectroscopic data and proposes a straightforward protocol to eliminate a high percentage of the most obvious errors.

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.

The first review describes examples of very promising compounds discovered from plants acquired from Africa, Southeast Asia, the Americas, and the Caribbean region with potential anticancer activity. These include plant secondary metabolites of the diphyllin lignan, penta[b]benzofuran, triterpenoid, and tropane alkaloid types. The second review presents 40 more erythrinan alkaloids, which were either new or were missed out in the last major reviews, bringing to a total of 154 known erythrinan alkaloids known to date. The reported pharmacological activities of the new and known alkaloids showed a greater bias towards central nervous system and related activities. Other prominent activities reported were antifeedant or insecticidal, cytotoxicity/anti tumor/anti cancer/estrogenic, antiprotozoal, antiinflammatory, antioxidant, antifungal and antiviral activities.

This volume begins with a short history of malaria and follows with a summary of its biology. It then traces the fascinating history of the discovery of quinine for malaria treatment, and then describes quinine's biosynthesis, its mechanism of action, and its clinical use, concluding with a discussion of synthetic antimalarial agents based on quinine's structure. It also covers the discovery of artemisinin and its development as the source of the most effective current antimalarial drug, including summaries of its synthesis and biosynthesis, its mechanism of action, and its clinical use and resistance. A short discussion of other clinically used antimalarial natural products leads to a detailed treatment of additional natural products with significant antiplasmodial activity, classified by compound type. Although the search for new antimalarial natural products from Nature's combinatorial library is challenging, it is very likely to yield new antimalarial drugs. This book thus ends by identifying ten natural products with development potential as clinical antimalarial agents.

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.

The first chapter describes the oldest method of communication between living systems in Nature, the chemical language. Plants, due to their lack of mobility, have developed the most sophisticated way of chemical communication. Despite that many examples involve this chemical communication process - allelopathy, there is still a lack of information about specific allelochemicals released into the environment, their purpose, as well as in-depth studies on the chemistry underground. These findings are critical to gain a better understanding of the role of these compounds and open up a wide range of possibilities and applications, especially in agriculture and phytomedicine. The most relevant aspects regarding the chemical language of plants, namely, kind of allelochemicals have been investigated, as well as their releasing mechanisms and their purpose, are described in this chapter. The second chapter is focused on the natural products obtained from Hypericum L., a genus of the family Hypericaceae within the dicotyledones. Hypericum has been valued for its important biological and chemical properties and its use in the treatment of depression and as an antibacterial has been well documented in primary literature and ethnobotanical reports. The present contribution gives a comprehensive summary of the chemical constituents and biological effects of this genus. A comprehensive account of the chemical constituents including phloroglucinol derivatives, xanthones, dianthrones, and flavonoids is included. These compounds show a diverse range of biological activities that include antimicrobial, cytotoxic, antidepressant-like, and antinociceptive effects. The third chapter addresses microtubule stabilizers, which are a mainstay in the treatment of many solid cancers and are often used in combination with molecularly targeted anticancer agents and immunotherapeutics. The taccalonolides are a unique class of such microtubule stabilizers isolated from plants of Tacca species that circumvent clinically relevant mechanisms of drug resistance. Although initial reports suggested that the microtubule stabilizing activity of the taccalonolides is independent of direct tubulin binding, additional studies have found that potent C-22,23 epoxidated taccalonolides covalently bind the Aspartate 226 residue of -tubulin and that this interaction is critical for their microtubule stabilizing activity. Some taccalonolides have demonstrated in vivo antitumor efficacy in drug-resistant tumor models with exquisite potency and long-lasting antitumor efficacy as a result of their irreversible target engagement. The recent identification of a site on the taccalonolide scaffold that is amenable to modification has provided evidence of the specificity of the taccalonolide-tubulin interaction and the opportunity to further optimize the targeted delivery of the taccalonolides to further improve their anticancer efficacy and potential for clinical development.

This book describes current understandings and recent progress into a varied group of natural products. In the first chapter the role that total synthesis may play in revising the structures proposed for decanolides, which are ten-membered lactones found primarily in fungi, frogs, and termites is presented. The following chapter presents the development of the intriguing plant-derived sesquiterpene lactone, thapsigargin, a potent inhibitor of the enzyme, SERCA (sarco-endoplasmic Ca2+ ATPase), which has potential as a lead compound to treat cancer. The third chapter covers the potential of various plant phenolic compounds for treating the tropical and sub-tropical infectious disease, leishmaniasis. In addition the volume presents recent advances related to the plant alkaloid, cryptolepine, which is of particular interest as a lead for the treatment of malaria, trypanosomiasis, and cancer.

This book describes current understandings and recent progress in four areas: in the first one, the cytochalasans, a group of fungal derived natural products characterized by a perhydro-isoindolone core fused with a macrocyclic ring are shown to exhibit high structural diversity and a broad spectrum of bioactivities. The second one is dedicated to a description of bioactive compounds from the medicinal plants of Myanmar, the third one is dedicated to new structure elucidation techniques in the field of sesquiterpenes. The last one discusses the endogenous natural products that are produced by human cells including endogenous amines, steroids, and fatty acid derived natural products. The co-metabolism and natural product production of the human microbiome is also described including tryptophan, bile acids, choline, and cysteine.

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.

The first chapter in volume 111 summarizes research on the sesterterpenoids, which are known as a relatively small group of natural products. However, they express a variety of simple to complicated chemical structures. This chapter focuses on the chemical structures of sesterterpenoids and how their structures are synthesized in Nature. The second chapter is devoted to marine-derived fungi, which play an important role in the search for structurally unique secondary metabolites, some of which show promising pharmacological activities that make them useful leads for drug discovery. Marine natural product research in China in general has made enormous progress in the last two decades as described in this chapter on fungal metabolites. This contribution covers 613 new natural products reported from 2001 to 2017 from marine-derived fungi obtained from algae, sponges, corals, and other marine organisms from Chinese waters.

The first contribution reviews the occurrence of xanthine alkaloids in the plant kingdom and the elucidation of the caffeine biosynthesis pathway, providing details of the N-methyltransferases, belonging to the motif B' methyltransferase family which catalyze three steps in the four step pathway leading from xanthosine to caffeine. The second contribution in this book provides a background on the molecule and related compounds and update knowledge on the most recent advances in Iboga alkaloids. The third contribution presents a comprehensive analysis of frequently occurring errors with respect to 13C NMR spectroscopic data and proposes a straightforward protocol to eliminate a high percentage of the most obvious errors.

The first contribution describes apolar and polar molecular fossils and, in particular biomarkers, along the lines usually followed in organic chemistry textbooks, and points to their bioprecursors when available. Thus, the apolar compounds are divided in linear and branched alkanes followed by alicyclic compounds and aromatic and heterocyclic molecules, and, in particular, the geoporphyrins. The polar molecular fossils contain as functional groups or constituent units ethers, alcohols, phenols, carbonyl groups, flavonoids, quinones, and acids, or are polymers like kerogen, amber, melanin, proteins, or nucleic acids. The final sections discuss the methodology used and the fundamental processes encountered by the biomolecules described, including diagenesis, catagenesis, and metagenesis. The second contribution covers the distribution of phthalides in nature and the findings in the structural diversity, chemical reactivity, biotransformations, syntheses, and bioactivity of natural and semisynthetic phthalides.

The book presents the current state of the art on phytocannnabinoid chemistry and pharmacology and will be of much use to those wishing to understand the current landscape of the exciting and intriguing phytocannabinoid science. The focus is on natural product cannabinoids which have been demonstrated to act at specific receptor targets in the CNS.

The first contribution presents coumarins, the largest group of 1-benzopyran derivatives found in plants. Coumarin chemistry remains one of the major interest areas of phytochemists, especially because of their structural diversity and medicinal properties, along with the wide-ranging bioactivities of these compounds, inclusive of analgesic, anticoagulant anti-HIV, anti-inflammatory, antimicrobial, antineoplastic, antioxidant, and immunomodulatory effects. The second contribution presents a comprehensive survey of the many aspects of PAD biochemistry and physiology. The third contribution gives a comprehensive overview of secondary metabolites from higher fungi, with more than 700 references highlighting the isolation, structure elucidation, biological activities, chemical synthesis, and biosynthesis of pigments, nitrogen-containing compounds, and terpenoids from mushrooms.