Detailed structural study of β-artemether: Density functional theory (DFT) calculations of Infrared, Raman spectroscopy, and vibrational circular dichroism

Although demonstrated in 1975, vibrational circular dichroism (VCD) finally started to popularize during this century as a reliable tool to determine the absolute configuration (AC) of organic molecules. This research field continues to be a very dynamic one, in particular for the study of natural products which are a unlimited source of chiral molecules. It therefore turns of interest to summarize the accomplishments published in recent years and to comment on some eventual difficulties that emerged in rare cases to complete the AC determination task. Therefore the aim of this review is to update VCD results for the AC assignment of natural products published from 2015 to 2019, a period in which VCD was reported in some 126 publications involving almost 300 molecules. They are organized according the type of studied metabolite allowing an easily search. The molecules correspond to 28 monoterpenes concerning 17 papers, to 42 sesquiterpenes in 14 papers, to 51 diterpenes in 19 publications, to 5 other terpenoids in three papers, to 48 aromatic molecules in 15 reports, to 20 polyketides in 10 publications, to 27 miscellaneous formulas also in 10 papers, and to 76 nitrogen containing compounds, which include alkaloids and their synthetic analogs, in 38 articles. The landscape of reviewed molecules is quite wide as it goes from simple monoterpenes, like borneol or camphor, to very relevant biological molecules like the alkaloid cocaine or tadalafil samples to distinguish genuine and counterfeit Cialis®. In addition, 5 natural products and a simple derivative published outside the reviewed period, were used to illustrate some aspects of density functional theory calculations.

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“…The consistency of VCD spectra with calculations at the B3WP91/6-311G+ (2d,p) and B3LYP/6-311G+(2d,p) levels confirmed the AC. 48…”

Section: Resultsmentioning

confidence: 99%

“…The consistency of VCD spectra with calculations at the B3WP91/6-311G+ (2d,p) and B3LYP/6-311G+(2d,p) levels confirmed the AC. 48 Diterpenoids. The formulas of the 51 diterpenoids included in this subsection can be seen in Figures 18-30.…”

Section: Monoterpenoids the Formulas Of The 28 Monoterpenoids Includmentioning

confidence: 99%

Vibrational Circular Dichroism Absolute Configuration of Natural Products From 2015 to 2019

Río

Joseph‐Nathan

2021

Natural Product Communications

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“…Experimental gas phase IR spectrum data of the title compound were obtained from NIST Chemistry WebBook (Linstrom and Mallard, 2001) website. Due to overestimation problems of DFT calculations, calculated IR wavenumbers were scaled with two scale factor; 0.989 for lower than 1600 cm -1 and 0.954 for higher than 1600 cm -1 as in Wangs' study (Wang et al, 2015). Experimental and calculated monomeric and dimeric IR spectra which were obtained in gas phase were given in Figure 6.…”

Section: Infrared Spectroscopy Analysismentioning

confidence: 99%

Infrared and NMR Spectral Analyses and Computational Studies of 2-amino-3-methylbenzoic acid

Yıldırım¹

2018

Bilge International Journal of Science and Technology Research

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Detailed infrared spectrum in gas phase, NMR spectra analyses and theoretical studies of 2-amino-3-methylbenzoic acid were performed with DFT/B3LYP/6-311G+(2d,p) level of method in Gaussian 09W. Ground state molecular geometries of monomeric and dimeric structures were calculated in vacuum and compared to the experimental XRD results. Potential energy surface graphics of the proton transfer and torsional tautomerism process were obtained. Also, HOMA aromaticity chancing graphics were drowned in mentioned process. The IR band assignments and the decompositions of potential energy for each band were done using theoretical calculations. 1 H and 13 C NMR chemical shifts analyses were performed by using GIAO NMR calculations with SCRF solvent model.

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Structural, spectroscopic, and theoretical investigations of (E)–methyl–3–(3,5–di–tert–butyl–2–hydroxybenzylideneamino)–4–methylbenzoate

Alpaslan

Gökçe

Macit

et al. 2021

J Chinese Chemical Soc

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A novel Schiff base ((E)–methyl–3–(3,5–di–tert–butyl–2–hydroxybenzylideneamino)–4–methylbenzoate (MDM), C24H31NO3) at phenol–imine form with the OH⋯N intra–molecular hydrogen bond was synthesized. Its structural and spectroscopic characterizations were performed by using experimental (single crystal X–ray diffraction, Fourier transform infrared [FT–IR], NMR chemical shift, and UV–vis spectroscopies) and theoretical (DFT/B3LYP/6‐311+G[2d,p] computational level) methods. X–ray diffraction investigation shows that the MDM crystallized in phenol–imine form with OH⋯N intra–molecular hydrogen bond. Detailed investigations of the presence and nature of the inter–molecular contacts within solid state crystal packing form of MDM were examined by Hirshfeld surface analysis. The intra–molecular electronic transitions in the compound were investigated and determined by UV–vis electronic absorption wavelengths and FMOs analyses. The structural, vibrational, and NMR chemical shift analyses of azomethine (CHN) and phenolic hydroxyl (OH) groups in MDM supported its phenol–imine structural formation.

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Detailed structural study of β-artemether: Density functional theory (DFT) calculations of Infrared, Raman spectroscopy, and vibrational circular dichroism

Cited by 12 publications

References 17 publications

Vibrational Circular Dichroism Absolute Configuration of Natural Products From 2015 to 2019

Vibrational Circular Dichroism Absolute Configuration of Natural Products From 2015 to 2019

Infrared and NMR Spectral Analyses and Computational Studies of 2-amino-3-methylbenzoic acid

Structural, spectroscopic, and theoretical investigations of (E)–methyl–3–(3,5–di–tert–butyl–2–hydroxybenzylideneamino)–4–methylbenzoate

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