A rule to distinguish diastereomeric bianthrones by 1H NMR

Ji, Nai‐Yun; Liang, Xiujuan; Sun, Ranran; Miao, Fang

doi:10.1039/c3ra47055e

Cited by 15 publications

(22 citation statements)

References 33 publications

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“…The anti-conformer configuration is suggested to be neglected relative to two predominant gauche conformers with crossed rings A/B′ (I) and A′/B (II) for the cis H-10/10′ dianthrones or crossed A/A′ (III) and B/B′ (IV) for the trans H-10/10′ dianthrones (Angela et al 2007; Ji et al 2014). The crossed rings A/B′ (I), A′/B (II), A/A′ (III) and B/B′ (IV) shift 1 H NMR peaks form the overlapped parts upfield because of their mutually-shielding effect.…”

Section: Resultsmentioning

confidence: 99%

Polygonumnolides A1–B3, minor dianthrone derivatives from the roots of Polygonum multiflorum Thunb

et al. 2017

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Seven new dianthrone glycosides, named polygonumnolides A1–B3 (1–7), were isolated from the 70 % EtOH extract of the dried roots of Polygonum multiflorum Thunb. using column chromatography and preparative high-performance liquid chromatography. Their structures were determined by 1D and 2D NMR and mass spectroscopy. The isolated compounds were evaluated for their cytotoxic effects against KB tumor cell lines and compounds 1–4 showed moderate cytotoxicity.Electronic supplementary materialThe online version of this article (doi:10.1007/s12272-016-0816-7) contains supplementary material, which is available to authorized users.

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Section: Resultsmentioning

confidence: 99%

Polygonumnolides A1–B3, minor dianthrone derivatives from the roots of Polygonum multiflorum Thunb

et al. 2017

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“…6 Neobulgarones D, E, and F were first isolated as moderately cytotoxic inhibitors of appressorium formation from the fungus Neobulgaria pura, 6 with neobulgarone E subsequently being reported from an endophytic Penicillium species isolated from Limonium tubiflorum. 7 However, elucidating the stereochemistry of bianthrones is challenging due to the occurrence of mesomeric dimers and racemic mixtures, 8 presumably formed through non-enzymatic oxidative coupling reactions. Methods that rely on polarimetric data often lead to erroneous stereochemical assignments and are therefore untenable.…”

mentioning

confidence: 99%

“…Methods that rely on polarimetric data often lead to erroneous stereochemical assignments and are therefore untenable. 8 As such, when originally isolated, the configurations of 1, 2, and 3 were not determined and, unfortunately, 2 was later incorrectly reported to have syn (cis) relative stereochemistry on the basis of polarimetric data. 7 A procedure to unambiguously distinguish between diastereomeric bianthrones based upon detailed analysis of their molecular conformations and the shielding effects observed in their 1 H-NMR spectra was recently reported.…”

mentioning

confidence: 99%

Halogenated Bianthrones From Penicillium roseopurpureum: a Fungal Endophyte of the Marine Alga Petalonia fascia

Morehouse

Flewelling

Johnson

et al. 2020

Natural Product Communications

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An extract of the fungus Penicillium roseopurpureum (KP1-135C) isolated from the marine alga Petalonia fascia showed selective antimicrobial activity against Staphylococcus aureus and Mycobacterium tuberculosis H37Ra. Bioassay-guided fractionation revealed that three halogenated bianthrones, neobulgarone D, neobulgarone E, and neobulgarone F, were responsible for the observed activity of the extract. The stereochemistry of the neobulgarones was unambiguously assigned based on polarimetric data and the analysis of 1H-nuclear magnetic resonance data obtained for the three bianthrones.

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“…The basic question is the mutual arrangement of the two parts of the dianthrone. The results of structural [26][27][28] and theoretical [29] research show that a gauche form is a typical arrangement; however, for dianthrone analogues anti stacking [27] is also possible. Other structural problems are related to unsymmetrically substituted dianthrones and their cis/trans conformation.…”

Section: Scheme 1 Molecular Structures Of Sennidin (A-d)mentioning

confidence: 96%

In Silico Studies on Sennidines—Natural Dianthrones from Senna

Szymański

Majerz

2021

Biology

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The rapid development of technology allows for more accurate research of biological systems with the use of in silico methods. One of the tools is the quantum-chemical method used for determining the structure, properties and interactions of molecules of great pharmacological importance. The accuracy of theoretical models is increasing and can be a real help in biology, chemistry and pharmacy. The aim of the study is to determine the spatial structure and intramolecular interactions of sennidines—natural pharmaceutical substances present in Senna species. Calculations carried out in the gas-phase and in the solvent model, compared with the available experimental data indicate the possibility of sennidines to form conformers. QTAIM and NCI analysis suggests the presence of many intramolecular interactions in the sennidin structure. Taking into account the lowest energy optimized structure, it can be predicted that the sennidin in the gauche conformation will be present in the plant material. The single C-C bond connecting the anthrone moieties is elongated and its reduced Bond Dissociation Energy (BDE) could be the cause of an easy breakdown of the sennidin molecule into monoanthrones. This work contains data on theoretical, vibrational and electron excitation spectra, which can be used in the analysis of experimental samples.

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A rule to distinguish diastereomeric bianthrones by 1H NMR

Cited by 15 publications

References 33 publications

Polygonumnolides A1–B3, minor dianthrone derivatives from the roots of Polygonum multiflorum Thunb

Polygonumnolides A1–B3, minor dianthrone derivatives from the roots of Polygonum multiflorum Thunb

Halogenated Bianthrones From Penicillium roseopurpureum: a Fungal Endophyte of the Marine Alga Petalonia fascia

In Silico Studies on Sennidines—Natural Dianthrones from Senna

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