Progress in the Chemistry of Organic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins...

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 8000 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...

The Natural Herbal Products industry uses botanicals or herbs as raw materials for production of herbal products or dietary supplements. Recently, the demand for natural herbal products has increased tremendously and this has led to adulteration and to counterfeit herbal products. The present chapter deals with currently used molecular methods from "simple" single genomic regions to high-throughput whole genome or transcriptome sequencing methods used in the identification of botanicals.

In the world trade of medicinal plants, the naming of plants is fundamental to understanding which species are acceptable for therapeutic use. There are a variety of nomenclatural systems that are used, inclusive of common names, Latinized binomials, Galenic or pharmaceutical names, and pharmacopeial definitions. Latinized binomials are the primary system used for naming wild plants, but these alone do not adequately define medicinal plant parts. Each system has its specific applications, advantages, and disadvantages...

The widespread utility of herbal products has been rising considerably worldwide, including both developed and developing countries, leading to the rapid growth of their availability in the United States and globally. This substantial increase in consumption of herbal products has witnessed the emergence of adverse effects upon oral administration of certain of these products, and thus has raised safety concerns. The adverse effects caused by the consumption of certain botanical medicines occur primarily as a result of the poor quality of plant raw materials or the finished products, which inherently may affect safety and/or efficacy...

Based on their current wide bioavailability, botanical dietary supplements have become an important component of the United States healthcare system, although most of these products have limited scientific evidence for their use. The most recent American Botanical Council Market Report estimated for 2020 a 17.3% increase in sales of these products when compared to 2019, for a total sales volume of $11,261 billion. The use of botanical dietary supplements products in the United States is guided by the Dietary Supplement Health and Education Act (DSHEA) from 1994, enacted by the U...

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. This contribution covers recent reports of total syntheses involving as a key step a photocatalytic reaction. Among the selected examples, the photocatalytic processes proceed in a highly chemo-, regio-, and stereoselective manner, thereby allowing the rapid access to structurally complex architectures under light-driven conditions...

This book describes a unique class of secondary metabolites, the mono- and dimeric naphthylisoquinoline alkaloids. They occur in lianas of the paleotropical Ancistrocladaceae and Dioncophyllaceae families, exclusively. Their unprecedented structures include stereogenic centers and rotationally hindered, and thus likewise stereogenic, axes. Extended recent investigations on six Ancistrocladus species from Asia, as reported in this review, shed light on their fascinating phytochemical productivity, with over 100 such intriguing natural products...

No abstract text is available yet for this article.

Medicinal plants of the genus Walsura (family Meliaceae) are native to tropical zones of a number of Asian countries, and have been used in systems of folk medicine. Several original research articles on Walsura species are available, but an overview highlighting the phytochemical and biological aspects of the compounds isolated to date is so far absent. Since the 1970s, phytochemical investigations on the genus Walsura have been undertaken, and more than 220 compounds from ten species have been identified...

The North American newt genera Taricha and Notophthalmus (order Caudata) are well known for the combination of potent toxicity, aposematic coloration, and striking defense postures that protects these animals from predation. This suite of traits is centered around the neurotoxin tetrodotoxin, which causes paralysis and death in metazoans by disrupting the initiation and propagation of electrical signals in the nerves and muscles. Tetrodotoxin defends newts from predation across multiple life history stages and its role in generating arms-race coevolution between Taricha newts and garter snake (genus Thamnophis) predators is well studied...

The phytochemistry of the fragrant infected heartwood of Aquilaria and Gyrinops species, agarwood (oud), is critically reviewed, highlighting the use of this remarkable natural raw material in perfumery. The chemistry of the two main groups of constituents of agarwood (sesquiterpenoids and chromones) is discussed, focusing particularly on the former structural type. The identities of the main key odorants of agarwood essential oil and of the smoke produced by heating the wood of agarwood are also discussed.

Pyrogallols (1,2,3-trihydroxybenzenes) are abundant in Nature, easily oxidized, and are central precursors to important natural products. The rich chemistry of their oxidized derivatives, the hydroxy-o-quinones, has been studied for over a century and still attracts the interest of the scientific community. Only in the last ten years have critical insights of pyrogallol chemistry from the mid-twentieth century been applied to modern natural product synthesis. Historical studies of pyrogallol chemistry, including [5+2], [4+2], and formal [5+5] cycloadditions are discussed here and reactivity guidelines established...

Natural products have made a crucial and unique contribution to human health, and this is especially true in the case of malaria, where the natural products quinine and artemisinin and their derivatives and analogues, have saved millions of lives. The need for new drugs to treat malaria is still urgent, since the most dangerous malaria parasite, Plasmodium falciparum, has become resistant to quinine and most of its derivatives and is becoming resistant to artemisinin and its derivatives. This volume begins with a short history of malaria and follows this with a summary of its biology...

The combination of traditional knowledge of medicinal plants with scientific rationale has yielded positive results in recent years. Bioactive compounds isolated from herbaceous plants have long been used as drugs that benefit human health, as well as providing useful compounds for drug development lead compound optimization. This chapter aims to provide a systematic overview of the structural types of Desmos secondary metabolites, along with their biological potential. Various chromatographic and spectroscopic methods have been utilized for isolating, purifying, and elucidating the structures of compounds from Desmos species...

Herbaceous annual plants of the genus Xanthium are widely distributed throughout the world and have been employed medicinally for millennia. This contribution aims to provide a systematic overview of the diverse structural classes of Xanthium secondary metabolites, as well as their pharmacological potential. On searching in various reference databases with a combination of three keywords "Xanthium", "Phytochemistry", and "Pharmacology", relevant publications have been obtained subsequently. From the 1950s to the present, phytochemical investigations have focused mainly on 15 Xanthium species, from which 300 compounds have been isolated and structurally resolved, primarily using NMR spectroscopic methodology...

This chapter covers a sesquiterpene quinone, commonly named perezone. This molecule is documented as the first secondary metabolite isolated in crystalline form in the New World in 1852. An introduction, with its structure, the IUPAC nomenclature, and the most recent physical and spectroscopic characterizations are firstly described initially. Alongside this, a timeline and scheme with summarized information of the history of this molecule is given including the "Códice Badiano de la Cruz, 1552, highlighting the year of its isolation culminating with information up to 2005...

The interdisciplinary field of Chemical Ecology in Brazil is currently composed of groups that emerged through the pioneering studies of Keith Spalding Brown Jr. and José Tércio Barbosa Ferreira. Following Keith Brown 's steps, José Roberto Trigo continued investigating the role of plant natural products in mediating the association among insects and their host plants, mainly in the Order Lepidoptera. The role of pyrrolizidine alkaloids in those associations was investigated extensively by Brown and Trigo, and most of what is currently known on this subject is based on their studies...

The term "marine biodiscovery" has been recently been adopted to describe the area of marine natural products dedicated to the search of new drugs. Several maritime countries such as Australia, New Zealand, South Korea, and Japan as well as some European countries have invested significantly in this area of research over the last 50 years. In the late 2000s, research in this field has received significant interest and support in Ireland for exploring new marine bioresources from the nutrient-rich waters of the Northeastern Atlantic Ocean...

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