Unusual polyketides from the wood-decay fungus Sistotrema raduloides

1995 ◽  
Vol 73 (12) ◽  
pp. 2119-2125 ◽  
Author(s):  
Albert K. Amegadzie ◽  
William A. Ayer ◽  
Lynne. Sigler
Keyword(s):  
Natural Products ◽  
Absolute Configuration ◽  
Wood Decay ◽  
Fungal Metabolites ◽  
Methyl Carbon ◽  
Decay Fungus ◽  
Insoluble Material ◽  
New Type ◽  
Biosynthetic Studies ◽  
C Nmr

The metabolites of the wood rot decay fungus Sistotremaraduloides (P. Karst) Donk have been investigated and a new type of norpentaketide has been discovered. The compounds sistodiolynne (1), sistolynone (5), and sistopyrone (6) represent new carbon skeletons among natural products. The compounds are very unstable and readily polymerize in the presence of air to give black insoluble material. It has been shown by 13C NMR labelling experiments that they arise from five acetate units, and that a methyl carbon of one of the acetate units is lost during the biosynthesis. The structures were determined by spectroscopy methods, mainly NMR, and the absolute configuration of sistodiolynne was established by circular dichroism methods. Keywords: fungal metabolites, Sistotremaraduloides, norpentaketides, biosynthetic studies, polyacetylenes.

scholarly journals Absolute Configuration Determination by Quantum Mechanical Calculation of Chiroptical Spectra: Basics and Applications to Fungal Metabolites

2018 ◽  
Vol 25 (2) ◽  
pp. 287-320 ◽  
Author(s):  
Stefano Superchi ◽  
Patrizia Scafato ◽  
Marcin Gorecki ◽  
Gennaro Pescitelli
Keyword(s):  
Natural Products ◽  
Circular Dichroism ◽  
Absolute Configuration ◽  
Optical Rotation ◽  
Computational Approach ◽  
Quantum Mechanical ◽  
Fungal Metabolites ◽  
Common Technique ◽  
The Absolute ◽  
Circular Dichroïsm

Background: Quantum mechanical simulations of chiroptical properties, such as electronic circular dichroism (ECD), optical rotation (OR), and vibrational circular dichroism (VCD), have rapidly become very popular to assign the absolute configuration of novel natural products. Objective: We review the application of the ECD/OR/VCD computational methodology to chiral metabolites of fungal origin. First, we summarize the fundamentals of the three spectroscopies; then, we focus on the specific experimental and computational issues allied to the application of their calculations. Methods: We surveyed the entire literature describing the use of ECD/OR/VCD computations for fungal metabolites, and catalogued all papers according to the method employed and to the structural family of compounds. Then, we chose several examples to illustrate the use of the techniques and highlight the practical application of the computational approach. Results: Our literature survey demonstrates that the simulation of ECD/OR/VCD spectra is nowadays widespread and accessible also to non-experts, although a good computational practice is necessary to avoid wrong assignments. ECD is still the most common technique used in the context of fungal metabolites. OR and VCD may be profitably employed when the compound of interest lacks chromophoric groups. Our examples illustrate that the combination of two or more chiroptical methods is strongly advisable in some cases, especially in the presence of high conformational flexibility, where a single technique does not lead to a safe conclusion. Conclusion: The ECD/OR/VCD computational approach is a reliable and versatile method to assign the absolute configuration of fungal metabolites and related natural products.

Total syntheses of spirocyclic PKS-NRPS-based fungal metabolites

2018 ◽  
Vol 54 (50) ◽  
pp. 6750-6758 ◽  
Author(s):  
Deokhee Jo ◽  
Sunkyu Han
Keyword(s):  
Natural Products ◽  
Biological Activities ◽  
Fungal Metabolites ◽  
Comprehensive Description ◽  
Total Syntheses ◽  
Fungal Natural Products ◽  
Biosynthetic Studies

We present the isolations, the biosynthetic studies, the biological activities, and the comprehensive description of all reported total syntheses of spirocyclic PKS-NRPS-based fungal natural products.

Phomalone, an antifungal metabolite of Phoma etheridgei

1994 ◽  
Vol 72 (11) ◽  
pp. 2326-2332 ◽  
Author(s):  
William A. Ayer ◽  
Luis Diego Jimenez
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Carbon Skeleton ◽  
Chemical Transformations ◽  
Decay Fungus ◽  
Liquid Cultures ◽  
Antifungal Metabolite ◽  
Physical Methods ◽  
C Nmr

The metabolites produced by liquid cultures of Phoma etheridgei, a new fungus isolated from black galls of aspen, have been examined. This fungus is antagonistic to the aspen decay fungus Phellinus tremulae. The compound responsible for this antagonism has been isolated and its structure elucidated. Phomalone (1) is a previously undescribed natural product that possesses the same carbon skeleton as the Phoma pigmentivora metabolite LL-D253α. The structure was determined by physical methods, mainly 1H and 13C NMR. INAPT experiments played an important role. Some chemical transformations of phomalone (1) are described and it is shown by 13C-labelling experiments to be derived from six acetate units. Phomalone is active against Phellinus tremulae. Compounds 4, 6, 7, and 8 are also new natural products produced by P. etheridgei.

The synthesis and stereochemistry of the ternary cobalt(III) complex with a stereospecific ligand derived from (S)-leucine

1986 ◽  
Vol 51 (2) ◽  
pp. 318-326 ◽  
Author(s):  
Milan Strašák ◽  
Pavol Novomeský
Keyword(s):  
Ir Spectroscopy ◽  
Aqueous Medium ◽  
Absorption Spectroscopy ◽  
Absolute Configuration ◽  
Nmr Spectra ◽  
Methyl Groups ◽  
Electron Absorption Spectroscopy ◽  
Electron Absorption ◽  
C Nmr

A new stereospecific ligand, ethylenediamine-N,N'-di(S)-α-isocapronic acid, was synthesized by condensation of (S)-leucine with 1,2-dibromoethane in alkaline aqueous medium. It follows from the 1H and 13C NMR spectra that the terminal methyl groups are chemically and magnetically nonequivalent. Of the four theoretically possible isomers of the ternary cobalt (III) complex with ethylenediamine, separation on catex yielded only one, whose absolute configuration was determined by a combination of 1H and 13C NMR, electron absorption spectroscopy and CD and IR spectroscopy.

Synthesis and characteristics of ethylenediamine-N,N'-di-S-α-isovalerate and isomers of its cobalt(III) complexes

1982 ◽  
Vol 47 (1) ◽  
pp. 210-216 ◽  
Author(s):  
Milan Strašák ◽  
František Bachratý ◽  
Jaroslav Majer
Keyword(s):  
Amino Acids ◽  
Absolute Configuration ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Chemical Parameters ◽  
Methyl Group ◽  
Nmr Data ◽  
Physico Chemical ◽  
Natural Amino Acids ◽  
C Nmr

The synthesis and physico-chemical parameters are described of a new complexone based on natural amino acids, viz. ethylenediamine-N,N'-di-S-α-isovalerate (SS-EDDIV). 1H- and 13C-NMR data revealed that the methyl group in the substance are not equivalent. The isomers of the cobalt(III) complex with the asymmetric tetradentate SS-EDDIV ligand were prepared and separated; their characteristics are given. The absolute configuration of two of the five theoretically feasible isomers was determined based on their electronic absorption spectra and circular dichroism data.

Absolute Configuration of Highly Flexible Natural Products by the Solid-State ECD/TDDFT Method: Ximaolides and Sinulaparvalides

2012 ◽  
Vol 2012 (34) ◽  
pp. 6722-6728 ◽  
Author(s):  
Tibor Kurtán ◽  
Rui Jia ◽  
Yan Li ◽  
Gennaro Pescitelli ◽  
Yue-Wei Guo
Keyword(s):  
Natural Products ◽  
Solid State ◽  
Absolute Configuration ◽  
Tddft Method
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