https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Chemistry has its origins as a quantitative science in the careful weighing of products and reactants by Lavoisier and his followers beginning some 200 years ago. Ever since then, the constantly evolving gravimetric balance has been a faithful servant of the laboratory chemist and has played a major role in developing the analytical methods that are the foundation of contemporary chemical science. Perhaps the ultimate stage in the evolution of that balance is represented by the modern mass spectrometer. It is able to determine with high precision the masses of individual atoms and molecules by transforming them into ions and measuring the response of their trajectories in vacuo to various combinations of electric and magnetic fields. Clearly, the sine qua non of such mass determination is the transformation of analyte atoms and molecules from their initial state in a sample to ions in vacuo ready for ”weighing.” Over the years, ingenious investigators have produced a variety of methods for achieving this transformation. One of them, electrospray ( E S ) ionization, has recently shown itself capable of producing intact ions, with multiple charges, from remarkably large, complex, and fragile parent species. Our assignment here is to review what has thus far been learned about this still uncommon technique and what it seems able to offer practitioners of mass spectrometric analysis. Our approach will be to set forth the present state of the ES ionization art in terms of a sort of menu of its procedures, processes, performance, and promise. Until very recently we have been almost the only group that has worked with ES ionization since the pioneering efforts of Malcolm Dole (1) some 20 years ago. Consequently, this review is more tutorial than most. Moreover, it may seem like a cook book that is overly preoccupied with the authors’ own culinary adventures. The reasoil is that many of the dishes to be described were first tried out in our own kitchen. Therefore, we earnestly urge the reader to remember what every gourmet knows: the piquancy of any dish on a bill of fare is due much less to its ingredients than to the skill of the chef whc. prepares it.

Electrospray ionization–principles and practice

Brassinosteroids (BRs) are growth-promoting natural products found at low levels in pollen, seeds, and young vegetative tissues throughout the plant kingdom. Detailed studies of BR biosynthesis and metabolism, coupled with the recent identification of BR-insensitive and BR-deficient mutants, has greatly expanded our view of steroids as signals controlling plant growth and development. This review examines the microchemical and molecular genetic analyses that have provided convincing evidence for an essential role of BRs in diverse developmental programs, including cell expansion, vascular differentiation, etiolation, and reproductive development. Recent advances relevant to the molecular mechanisms of BR-regulated gene expression and BR signal transduction are also discussed.

BRASSINOSTEROIDS: Essential Regulators of Plant Growth and Development

http://hwhuang.rice.edu/pdfs/Yang2001.pdf

Barrel-Stave Model or Toroidal Model? A Case Study on Melittin Pores

Drug discovery from marine natural products has enjoyed a renaissance in the past few years. Ziconotide (Prialt; Elan Pharmaceuticals), a peptide originally discovered in a tropical cone snail, was the first marine-derived compound to be approved in the United States in December 2004 for the treatment of pain. Then, in October 2007, trabectedin (Yondelis; PharmaMar) became the first marine anticancer drug to be approved in the European Union. Here, we review the history of drug discovery from marine natural products, and by describing selected examples, we examine the factors that contribute to new discoveries and the difficulties associated with translating marine-derived compounds into clinical trials. Providing an outlook into the future, we also examine the advances that may further expand the promise of drugs from the sea.

Drug development from marine natural products

Extracts of Brassica napus L. (rape) pollen (family, Cruciferae) have been reported to produce a novel growth-promoting effect when applied to young pinto bean plants1,2. Fractions that are active in the bean second-internode assay3 give rise to both increased cell elongation and cell division4. The validity of these early reports has been questioned because biological activity was not correlated with any one pure compound5. Subsequently, we showed that isolation of the growth promoter was complicated by the presence of chromatographically similar, inactive components that were identified as 6-D-glucopyranosyl esters of long-chain fatty acids6. We now report the isolation, structure determination and biological activity of this new plant growth promoter, named (22R, 23R, 24S)-2α-3α,22,23-tetrahydroxy-24-methyl-6,7-s-5α-cholestano-6,7-lactone or brassinolide (Fig. 1).

Brassinolide, a plant growth-promoting steroid isolated from Brassica napus pollen

Structures of the didemnins, antiviral and cytotoxic depsipeptides from a Caribbean tunicate

Structures of two cockroach neuropeptides assigned by fast atom bombardment mass spectrometry.

High resolution and field desorption mass spectrometry studies and revised structures of alamethicins I and II

An enzyme extracted from marine red algae, Bonnemaisonia hamifera, is capable of incorporating bromine into a number of organic substrates in the pH range 5 to 8. At pH 7.3, incubation of partially purified preparations of bromoperoxidase with hydrogen peroxide, bromide ion, and 3-oxooctanoic acid leads to the formation of three volatile brominated hydrocarbons: dibromomethane, bromoform, and 1-pentyl bromide. The presence of significant quantities of halometabolites including volatile halohydrocarbons in marine organisms, ocean waters, and the upper atmosphere may result from peroxidase-catalyzed halogenation reactions.

https://science.sciencemag.org/content/sci/202/4372/1094.full.pdf

J. Carter Cook

Papers

Brassinolide, a plant growth-promoting steroid isolated from Brassica napus pollen

Structures of the didemnins, antiviral and cytotoxic depsipeptides from a Caribbean tunicate

Structures of two cockroach neuropeptides assigned by fast atom bombardment mass spectrometry.

High resolution and field desorption mass spectrometry studies and revised structures of alamethicins I and II

Halohydrocarbon Synthesis by Bromoperoxidase