Main description:

The metabolic products of micro-organisms can be classified either as compounds of primary metabolic concern or else as secondary metabolites - substances which are apparently non-essential to the producing or- ganism. Fungi have a remarkable capacity to produce such secondary metabolites, e. g. mycotoxins with a diverse array of structural and pharmacological properties (1). The present resurgence of interest in all aspects of mycotoxin research (2, 3) can be related to the impact of the hepatotoxins (aflatoxin, sporidesmin, and phomopsin), nephrotoxins (ochratoxin and citrinin), and dermal toxins (trichothecenes) on human and animal health. Some of the mycotoxins appear to act at the level of the central nervous system. Ergotism, the earliest known mycotoxicosis, that is a disease caused by mycotoxins, was attributed to the contamination of wheat by the parasitic neurotoxin-producing fungus, C/aviceps purpurea. These neuro- toxins elaborated by C. purpurea are collectively called the ergot toxins (4).
The neurotoxin, citreoviridin (1) which causes paralysis in the extremities of laboratory animals, followed sometimes by convulsions and respiratory arrest, has been implicated in acute cardiac beri-beri in Japan (5). Tremoring has not been associated with citreoviridin or the structurally related aurovertins (2) (6) and asteltoxin (3) (7); these compounds are therefore excluded from this review. However, verrucosidin (4) (8), a tremorgenic compound which structurally resembles (1)-(3), will be described later.

Contents:

Tremorgenic Mycotoxins.- 1. Introduction.- 2. The Penitrems, Janthitrems, Lolitrems, Aflatrem, Paxilline, Paspaline, Paspalicine, Paspalinine, and Paspalitrems A and B.- 2.1 The Penitrems.- 2.1.1 Producing Organisms.- 2.1.2 Isolation and Chromatography of the Penitrems.- 2.1.3 Structure of the Penitrems.- 2.1.3.1 General Aspects, Ultraviolet and Infrared Spectroscopy.- 2.1.3.2 Nuclear Magnetic Resonance Spectroscopy.- 2.1.3.3 Mass Spectrometry.- 2.1.3.4 Stereochemistry of the Penitrems: Conformation and Absolute Configuration.- 2.2 The Janthitrems.- 2.2.1 Producing Organisms.- 2.2.2 Isolation and Chromatography of the Janthitrems.- 2.2.3 Structure of the Janthitrems.- 2.2.3.1 General Aspects, Ultraviolet and Infrared Spectroscopy.- 2.2.3.2 Nuclear Magnetic Resonance Spectroscopy.- 2.2.3.3 Stereochemistry of the Janthitrems: The Relative Configuration.- 2.3 The Lolitrems.- 2.3.1 Producing Organisms.- 2.3.2 The Structure of Lolitrems B and C.- 2.3.2.1 The Stereochemistry of Lolitrem B.- 2.4 Aflatrem.- 2.4.1 Producing Organism.- 2.4.2 The Structure of Aflatrem.- 2.5 Paxilline.- 2.5.1 Producing Organism.- 2.5.2 Production and Isolation of Paxilline.- 2.5.3 Structure of Paxilline.- 2.6 Paspaline, Paspalicine, Paspalinine and Paspalitrems A and B.- 2.6.1 Producing Organism.- 2.6.2 Structural Studies.- 2.7 Biosynthesis of the Penitrems, Janthitrems, Lolitrems, Aflatrem, Paxilline, Paspaline, Paspalicine, Paspalinine, and Paspalitrems A and B.- 2.8 Mode of Action of the Penitrem Type of Fungal Neurotoxins.- 3. The Territrems.- 3.1 Producing Organisms.- 3.2 Isolation and Chromatography of the Territrems.- 3.3 Structure of the Territrems.- 4. Verrucosidin.- 4.1 Producing Organism.- 4.2 Structure of Verrucosidin.- 5. Verruculotoxin.- 5.1 Producing Organism.- 5.2 Isolation and Chromatography.- 5.3 Structure of Verruculotoxin.- 5.4 Synthesis.- 6. Tremorgens Containing a 6-Methoxyindole Moiety: The Verruculogens and Fumitremorgins.- 6.1 Producing Organisms.- 6.2 Isolation and Chromatography.- 6.3 Structure of Verruculogen.- 6.4 Structure of the Fumitremorgins.- 6.5 Biosynthesis of the Fumitremorgins and Verruculogen.- 7. The Tryptoquivalines.- 7.1 Producing Organisms.- 7.2 Isolation and Chromatography.- 7.3 Structure of Tryptoquivaline A.- 7.4 Structure of Nortryptoquivalone (Tryptoquivaline B or Tryptoqui val one).- 7.5 Structures of Toxic Metabolites Related to Tryptoquivaline A and Nortryptoquivalone.- 7.6 Structures of Nontoxic Metabolites Related to Tryptoquivaline A and Nortryptoquivalone.- 7.7 Synthesis of the Tryptoquivalines.- 7.7.1 Tryptoquivaline A.- 7.7.2 Tryptoquivaline G.- 7.8 Biosynthesis of the Tryptoquivalines.- References.- Structure of Palytoxin.- I. Introduction.- II. Isolation.- III. Characterization.- IV. Gross Structure Determination.- IV.1 Periodate Oxidation.- a) Degradation Products Implying C(1)-C(16) Segment.- b) Degradation Products Implying C(17)-C(27) and C(65)-C(72) Segments.- c) Degradation Products Implying C(73)-C(87) and C(98)-C(108) Segments.- d) Degradation Products Implying C(28)-C(64) Segment.- e) Degradation Products Implying C (89)-C (96) Segment.- f) Degradation Products Implying C(109)-C(123) Segment.- IV.2 Ozonolysis.- a) Degradation Products Implying C(7)-C(14) Segment.- b) Degradation Products Implying C(15)-C(59) Segment.- c) Degradation Products Implying C(60)-C(84) Segment.- d) Degradation Products Implying C(85)-C(91), C(92)-C(106), and C(107)-C(123) Segments.- V. Stereochemistry.- V.1 Methods Used for Relative Stereochemistry.- a) X-Ray Crystallography.- b) 1XH NMR Spectroscopy.- c) Periodate Oxidation.- d) Borate Complexation.- V.2 Methods Used for Absolute Stereochemistry.- a) X-Ray Crystallography.- b) Circular Dichroic Spectroscopy.- c) Synthesis.- VI. Conclusions.- Acknowledgement.- References.- Sesterterpenes: An Emerging Group of Metabolites from Marine and Terrestrial Organisms.- I. Introduction.- II. Summary of Carbon Skeletons and Structural Variations.- 1. Conventions.- Table 1. Sesterterpene Carbon Skeleton Classes.- Table 2. Modified Sesterterpene Carbon Skeleton Classes.- 2. Carbon Skeletons of "Regular" Sesterterpenes.- 3. Carbon Skeletons of Modified Sesterterpenes.- 4. Heteroatom Substituent Patterns.- III. Biosynthetic and Comparative Biochemical Observations.- 1. Introduction.- Table 3. Relationships Between Sesterterpene Carbon Skeletons and Their.- Organism Sources.- 2. Biogenesis.- 3. Biomimetic Synthesis.- 4. Comparative Biochemistry.- IV. Synthesis and Biological Activity.- 1. Synthesis.- 2. Biological Activity.- Table 4. Summary of Sesterterpenes with Biological Activity.- V. Spectroscopic Analysis.- 1. Introduction.- 2. Acyclic Sesterterpenes.- Table 5. Methyl Chemical Shifts for Tri-Substituted Double Bond Isomers.- 3. Monocarbocyclic Sesterterpenes.- 4. Tri- and Tetracarbocyclic Sesterterpenes.- 5. Pentacarbocyclic Sesterterpenes.- 6. Absolute Stereochemistry.- VI. Physical and Spectroscopic Tables.- 1. Table 6. Summary of Structures and Carbon-13 NMR Chemical Shifts.- 2. Table 7. Physical Properties.- Acknowledgement.- References.- Author Index.