Secondary metabolites of fungi from marine habitats.

Many fungi, lichens, and bacteria produce xanthones (derivatives of 9H-xanthen-9-one, “xanthone” from the Greek “xanthos”, for “yellow”) as secondary metabolites. Xanthones are typically polysubstituted and occur as either fully aromatized, dihydro-, tetrahydro-, or, more rarely, hexahydro-derivatives. This family of compounds appeals to medicinal chemists because of their pronounced biological activity within a notably broad spectrum of disease states, a result of their interaction with a correspondingly diverse range of target biomolecules. This has led to the description of xanthones as “privileged structures”.(1) Historically, the total synthesis of the natural products has mostly been limited to fully aromatized targets. Syntheses of the more challenging partially saturated xanthones have less frequently been reported, although the development in recent times of novel and reliable methods for the construction of the (polysubstituted) unsaturated xanthone core holds promise for future endeavors. In particular, the fascinating structural and biological properties of xanthone dimers and heterodimers may excite the synthetic or natural product chemist.

Xanthones from Fungi, Lichens, and Bacteria: The Natural Products and Their Synthesis

Classification of Aspergillus, Penicillium, Talaromyces and related genera (Eurotiales): An overview of families, genera, subgenera, sections, series and species

Xanthones from fungi, lichens, and bacteria : the natural products and their synthesis

An oxidative Prins-pinacol tandem process mediated by a hypervalent iodine reagent has been developed. This oxidative version of the famous tandem process fits within the concept of “aromatic ring umpolung” and allows the stereoselective transformation of simple phenols into highly elaborated spirocyclic dienone cores containing several quaternary carbon centers. The scope and the limitations of this process, including the study of its stereoselectivity, are described in this article. As a direct application of this stereoselective process, we describe the formal synthesis of (−)-platensimycin, an important antibiotic agent.

Oxidative Prins-pinacol tandem process mediated by a hypervalent iodine reagent: scope, limitations, and applications.

Structure of a novel phospholipase C inhibitor, vinaxanthone (Ro 09-1450), produced by penicillium vinaceum

A novel phospholipase C inhibitor, hispidospermidin, was discovered from a fungal culture broth. The producing fungus, NR 7127, formed abundant pycnidia on banana leaf agar under near UV light. The ostiolate pycnidia were dark colored with a short beak possessing numerous protruding setae. The conidiogeneous cells were phialidic. The conidia were hyaline, 1 septate, smooth and spindle-shaped. From these distinctive characteristics, this strain was identified as Chaetosphaeronema hispidulum (Cda) Moesz of the Coelomycetes. Hispidospermidin was produced in a 50-liter jar fermentor containing 2% glucose, 2% potato starch, 2% Toast soya, 0.5% yeast extract, 0.25% NaCl, 0.0005% ZnSO4.7H2O, 0.0005% CuSO4.5H2O, 0.0005% MnSO4.4H2O, 0.32% CaCO3, and 0.3% Nissan disfoam CA-115. Fermentation was conducted at 27 degrees C at an aeration rate of 30 liters/minute and agitated at 500 rpm for 95 hours. Maximum production yield of hispidospermidin was observed after 72 hours. Hispidospermidin inhibited rat brain phospholipase C at 16 microM of IC50. This is the first recorded discovery of a secondary metabolite from the genus Chaetosphaeronema.

HISPIDOSPERMIDIN, A NOVEL PHOSPHOLIPASE C INHIBITOR PRODUCED BY Chaetosphaeronema hispidulum (Cda) Moesz NR 7127

Hispidospermidin (1) is a novel phospholipase C inhibitor produced by Chaetosphaeronema hispidulum (Cda) Moesz NR 7127. Its structure (C 25 H 47 N 3 O) has been elucidated as a cage compound with a trimethylspermidine side chain based on various NMR studies, including 1 H- 1 H COSY, 13 C- 1 H COSY, HOHAHA, HMBC, COLOC and long range JC-H resolved 2D spectroscopy. The absolute configuration of 1 has been elucidated by modified MOSHER's method on the (R)- and (S)-MTPA amides of a derivative of 1

Hispidospermidin, a novel phospholipase C inhibitor produced by Chaetosphaeronema hispidulum (Cda) Moesz NR 7127. II. Isolation, characterization and structural elucidation.

Hispidospermidin, a Novel Phospholipase C Inhibitor Produced by Chaetosphaeronema hispidulum (Cda) Moesz NR 7127. Part 2. Isolation, Characterization and Structural Elucidation.

The compound represented by the formula, is obtained from cultures of Chaetosphaeronema hispidulum. The compound is an inhibitor of phospholipase C.

Akiko Sakai

Papers

Structure of a novel phospholipase C inhibitor, vinaxanthone (Ro 09-1450), produced by penicillium vinaceum

HISPIDOSPERMIDIN, A NOVEL PHOSPHOLIPASE C INHIBITOR PRODUCED BY Chaetosphaeronema hispidulum (Cda) Moesz NR 7127

Hispidospermidin, a novel phospholipase C inhibitor produced by Chaetosphaeronema hispidulum (Cda) Moesz NR 7127. II. Isolation, characterization and structural elucidation.

Hispidospermidin, a Novel Phospholipase C Inhibitor Produced by Chaetosphaeronema hispidulum (Cda) Moesz NR 7127. Part 2. Isolation, Characterization and Structural Elucidation.

Hispidospermidin and pharmaceutical compositions.