Pseudo-Natural Products, Some Artefacts Formed during the Isolation of Terpenoids

Hanson, James R.

doi:10.3184/174751917x15021050367558

Cited by 9 publications

(7 citation statements)

References 61 publications

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“…Although few, there has been some reports on natural occurring triterpenoidal acetonides from plants [ 17 – 19 ]. Despite the fact that 1 is considered unusual being an acyclic acetonide ketal, it is assumed to be an artifact derived from phytolaccagenic acid 3 β - O -myristate ( 1a ) during the chromatographic process, in which acetone was used as solvent [ 20 , 21 ]. The proposed mechanism in the formation of 1 from 1a involves firstly a nucleophilic attack of the C-23 hydroxyl to a protonated acetone molecule, followed by an intramolecular nucleophilic substitution at the fatty acid carbonyl at C-3 (Fig.…”

Section: Resultsmentioning

confidence: 99%

Artificial Triterpenoid Fatty Acid Ester Isolated From the Leaves of Phytolacca icosandra L

Galarraga

Mavares

Urdaneta

et al. 2020

Nat. Prod. Bioprospect.

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The methanol extract form the leaves of Phytolacca icosandra L., afforded the unprecedented artificial triterpenoid fatty acid ester 1 derived from the new natural triterpenoid phytolaccagenic acid 3-O-myristate (1a), along with the three known triterpenoids serjanic, acinosolic and phytolaccagenic acid (2-4). Their structures were stablished by HR-EI-MS, 1D and 2D NMR techniques. The possible mechanistic formation of 1 is proposed, and the in vitro toxicity of all compounds was assessed using the brine shrimp lethality assay (BSLA).

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Section: Resultsmentioning

confidence: 99%

Artificial Triterpenoid Fatty Acid Ester Isolated From the Leaves of Phytolacca icosandra L

Galarraga

Mavares

Urdaneta

et al. 2020

Nat. Prod. Bioprospect.

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“…They vary from simple esterification, solvolysis and oxidation to highly complex chemical rearrangements. Artifact formation of various terpenoids was reviewed by Hanson (2017) . Dehydration, rearrangements, and oxidation, among others, cause formation of artifacts from all kinds of terpenes.…”

Section: Solvents For Extraction and Chromatographymentioning

confidence: 99%

Trivialities in metabolomics: Artifacts in extraction and analysis

Verpoorte

Kim

Choi

2022

Front. Mol. Biosci.

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The aim of this review is to show the risks of artifact formation in metabolomics analyses. Metabolomics has developed in a major tool in system biology approaches to unravel the metabolic networks that are the basis of life. Presently TLC, LC-MS, GC-MS, MS-MS and nuclear magnetic resonance are applied to analyze the metabolome of all kind of biomaterials. These analytical methods require robust preanalytical protocols to extract the small molecules from the biomatrix. The quality of the metabolomics analyses depends on protocols for collecting and processing of the biomaterial, including the methods for drying, grinding and extraction. Also the final preparation of the samples for instrumental analysis is crucial for highly reproducible analyses. The risks of artifact formation in these steps are reviewed from the point of view of the commonly used solvents. Examples of various artifacts formed through chemical reactions between solvents or contaminations with functional groups in the analytes are discussed. These reactions involve, for example, the formation of esters, trans-esterifications, hemiacetal and acetal formation, N-oxidations, and the formation of carbinolamines. It concerns chemical reactions with hydroxyl-, aldehyde-, keto-, carboxyl-, ester-, and amine functional groups. In the analytical steps, artifacts in LC may come from the stationary phase or reactions of the eluent with analytes. Differences between the solvent of the injected sample and the LC-mobile phase may cause distortions of the retention of analytes. In all analytical methods, poorly soluble compounds will be in all samples at saturation level, thus hiding a potential marker function. Finally a full identification of compounds remains a major hurdle in metabolomics, it requires a full set of spectral data, including methods for confirming the absolute stereochemistry. The putative identifications found in supplemental data of many studies, unfortunately, often become “truly” identified compounds in papers citing these results. Proper validation of the protocols for preanalytical and analytical procedures is essential for reproducible analyses in metabolomics.

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“…One of the main problems encountered during their manipulation and study is linked to their chemical instability; this has a significant impact both on their initial detection/identification and on the accuracy of their analytical characterization. Many natural biomolecules and metabolites are highly reactive compounds; consequently, they can potentially lead to artifacts’ formation during their isolation, purification and characterization [ 1 ]. In his review [ 1 ], Hanson reported a list of the main mechanisms often resulting in artifacts, which include dehydration [ 2 ], rearrangement [ 3 ] and oxidation reactions [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

“…Many natural biomolecules and metabolites are highly reactive compounds; consequently, they can potentially lead to artifacts’ formation during their isolation, purification and characterization [ 1 ]. In his review [ 1 ], Hanson reported a list of the main mechanisms often resulting in artifacts, which include dehydration [ 2 ], rearrangement [ 3 ] and oxidation reactions [ 4 ]. In addition, once in contact with organic solvents, NPs may be subjected to chemical transformations which can alter their odorous, appearance, and even biological properties [ 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

“…Most of these processes are related to thermal factors; therefore, the composition of essential oils obtained via supercritical carbon oxide extraction is often reported to be different from those obtained using the traditional method of steam distillation [ 7 , 8 ]. Hanson [ 1 ] also summarizes the formation of artefacts due to the solvent used during compound isolation. As an example, in the case of Scutelaria discolor , the used of EtOH will lead to the formation of an acetal [ 9 ].…”

Section: Introductionmentioning

confidence: 99%

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Caution: Chemical Instability of Natural Biomolecules During Routine Analysis

et al. 2020

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Natural products (NPs) constitute a significant source of active biomolecules widely used in medicine, pharmacology and cosmetics. However, NPs structural characterization has the drawback of their chemical instability during the extraction steps and their likely transformation during the analytical protocol. In particular, tamariscol and conocephalenol are two compounds largely used in the cosmetic industry for their odorant properties. Thus, in the present study, we focused on the evolution of these two metabolites (extracted from Frullania tamarisci and Conocephalum conicum, respectively), as followed by NMR. Interestingly, we found that, once dissolved in deuterated chloroform, these two tertiary alcohols are both subjected to transformation processes, leading to degradation compounds with altered structures. Accordingly, these detected degradation compounds have been fully characterized by NMR and the experimental findings were supported by computational chemistry data.

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Pseudo-Natural Products, Some Artefacts Formed during the Isolation of Terpenoids

Abstract: The formation of artefacts during the isolation, purification and characterisation of terpenoids is reviewed.

Cited by 9 publications

References 61 publications

Artificial Triterpenoid Fatty Acid Ester Isolated From the Leaves of Phytolacca icosandra L

Artificial Triterpenoid Fatty Acid Ester Isolated From the Leaves of Phytolacca icosandra L

Trivialities in metabolomics: Artifacts in extraction and analysis

Caution: Chemical Instability of Natural Biomolecules During Routine Analysis

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