Structural revisions of natural products by Computer-Assisted Structure Elucidation (CASE) systems.

@article{Elyashberg2010StructuralRO,
  title={Structural revisions of natural products by Computer-Assisted Structure Elucidation (CASE) systems.},
  author={Mikhail E. Elyashberg and Antony J. Williams and Kirill A. Blinov},
  journal={Natural product reports},
  year={2010},
  volume={27 9},
  pages={
          1296-328
        }
}
Covering: up to the end of 2009 It is shown in this review that the application of an expert system for the purpose of computer-assisted structure elucidation allows the researcher to avoid the production of incorrect structural hypotheses, and also to evaluate the reliability of suggested structures. Many examples of structure revision using CASE methods are given. 

Structure revision of asperjinone using computer-assisted structure elucidation methods.

The elucidated structure of asperjinone, a natural product isolated from thermophilic Aspergillus terreus, was revised using the expert system Structure Elucidator using 180 structures containing the (3,3-dimethyloxiran-2-yl)methyl fragment as a basis for comparison and whose chemical shifts contradict the suggested structure.

The role of computer-assisted structure elucidation (CASE) programs in the structure elucidation of complex natural products.

Four different CASE programs are described with particular emphasis on how they deal with the presence of longer range correlation peaks, and the increasing use of theoretical DFT calculations to determine 3D structures and to predict chemical shifts is discussed.

Computer–Based Structure Elucidation from Spectral Data: The Art of Solving Problems

Here, the authors introduce readers to solving molecular structure elucidation problems using the expert system ACD/Structure Elucidator. They explain in detail the concepts of the Computer-Assisted

Structure Validation of Complex Natural Products: Time to Change the Paradigm. What did Synthesis of Alstofolinine A Prove?

It appears that computational methods for structure elucidation are gradually becoming a better alternative, being faster and more reliable, as found in the case of alstofolinine A.

Computationally-assisted discovery and structure elucidation of natural products

In this review, several examples of recent studies that used computer technology to facilitate the discovery and structure determination of various natural products are provided.

Elucidating ‘undecipherable’ chemical structures using computer‐assisted structure elucidation approaches

It is concluded that it is now impossible to evaluate the capabilities of novel NMR experimental techniques in isolation from expert systems developed for processing fuzzy, incomplete and contradictory information obtained from 2D NMR spectra.

Computational methods for NMR and MS for structure elucidation I: software for basic NMR

The topics of NMR prediction and CASE programs are addressed, and the elucidation of natural peptides is discussed, resulting in a new approach to structure elucidation.

Fundamentals of Structure Elucidator System

It is concluded that to solve real-world problems, Structure Elucidator must be capable of deducing correct structures from a fuzzy, incomplete, and frequently contradictory set of axioms composing the initial information.

Minimizing the risk of deducing wrong natural product structures from NMR data.

The purpose of this tutorial is to point out some of issues, highlight the kinds of errors that have been made and provide specific advice on how to avoid these missteps such that the risk of reporting a wrong structure is minimized.
...

References

SHOWING 1-10 OF 83 REFERENCES

Recent developments in automated structure elucidation of natural products.

Advancements in the field of Computer-Assisted Structure Elucidation of Natural Products achieved in the past five years are discussed and the option to validate the result by an independent procedure, a high quality ab initio quantum mechanical calculation, is discussed.

Applications of a HOUDINI-Based Structure Elucidation System

A comparison of the performance of COCOA-based and HOUDINI-based SESAMI using a set of complex, naturally occurring compounds as a test set of unknowns revealed faster execution times and more efficient processing of ambiguous structural information for the latter.

Application of a new expert system for the structure elucidation of natural products from their 1D and 2D NMR data.

Applications of the latest version of the StrucEluc expert software system, enhanced to use 2D NMR data, to the structure elucidation of 60 recently isolated natural products illustrate that Struc eluc is a powerful and versatile analytical tool for the structure elaboration of natural products.

Applying computer-assisted structure elucidation algorithms for the purpose of structure validation: revisiting the NMR assignments of hexacyclinol.

The application of the ACD/Structure Elucidator expert system is described to help resolve the conflict between two different hypothetical hexacyclinol structures derived by different researchers from the NMR spectra of this complex natural product.

Computer‐assisted structure elucidation of natural products with limited 2D NMR data: application of the StrucEluc system

This paper considers the strategy of the StrucEluc expert system application for structure elucidation of new natural products when there is a lack of connectivity information that is characteristic

Computer assisted structure elucidation of natural products using two-dimensional NMR spectroscopy†

The role of 2D NMR spectroscopy in CASE is discussed and the methods a natural product chemist may apply to elucidate the structure of a complex natural product are highlighted.

Structure Elucidator: A Versatile Expert System for Molecular Structure Elucidation from 1D and 2D NMR Data and Molecular Fragments

The use of fragments has frequently transformed very difficult 2D NMR elucidation challenges into easily solvable tasks and a strategy to utilize molecular fragments has been developed and optimized based on specific challenging examples.

Efficient Application of 2D NMR Correlation Information in Computer-Assisted Structure Elucidation of Complex Natural Products

The rationale and implementation of the newly developed CASE system, CISOC-SES (Computerized Information System for Organic Chemistry-Structure Elucidation System), 2D NMR correlation information, instead of chemical shifts, is fully exploited through some novel approaches.

Are Deterministic Expert Systems for Computer-Assisted Structure Elucidation Obsolete?

The conclusion is that 2D NMR deterministic expert systems are certainly capable of elucidating large structures and can deal with the complexities associated with both poor and contradictory spectral data.
...