(-)-Armepavine: Gradient-Enhanced 2D NMR Study and X-Ray Crystal Structure Determination

1997 ◽  
Vol 62 (10) ◽  
pp. 1623-1630 ◽  
Author(s):  
Radek Marek ◽  
Jaromír Marek ◽  
Jiří Dostál ◽  
Jiří Slavík
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Structure Determination ◽  
Nmr Assignment ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
Nmr Study ◽  
Benzylisoquinoline Alkaloid

(-)-Armepavine, a benzylisoquinoline alkaloid isolated from Papaver caucasicum, was examined by gradient-enhanced 2D NMR spectroscopy and X-ray diffraction analysis. Unambiguous 1H, 13C, and 15N NMR assignment of the title alkaloid is reported.

scholarly journals A Phenylpropanoid and Biflavonoids from the Needles of Cephalotaxus harringtonia var. harringtonia

2017 ◽  
Vol 12 (11) ◽  
pp. 1934578X1701201 ◽  
Author(s):  
Anju Mendiratta (Nee Chugh) ◽  
Rameshwar Dayal ◽  
John P. Bartley ◽  
Graham Smith
Keyword(s):  
Nmr Spectroscopy ◽  
Oral Dose ◽  
Spectral Data ◽  
2D Nmr ◽  
Hepatoprotective Activity ◽  
X Ray Diffraction ◽  
Soluble Extract ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
First Time

A phenylpropanoid [2-(3-methoxy-4-hydroxyphenyl)-propane-1,3-diol] (1) together with four known biflavonoids namely 7, 4′, 7′″, 4′″-tetra- O-methyl amentoflavone (2); 7, 4′, 7″-tri- O-methyl amentoflavone (3); ginkgetin (4); sequoiaflavone (5) were isolated from the acetone soluble extract of needles of Cephalotaxus harringtonia var. harringtonia. Their structures were elucidated mainly on the basis of interpretation of 1D and 2D NMR spectroscopy and X-ray diffraction studies. The detailed spectral data of phenylpropanoid have been described for the first time. Ginkgetin (4) exhibited significant hepatoprotective activity in rat at 6 mg/kg oral dose level.

New polysubstituted monoterpenic thiazolidinones: synthesis, spectroscopic and crystal structure studies

2018 ◽  
Vol 74 (12) ◽  
pp. 1629-1634 ◽  
Author(s):  
Abdellah N'ait Ousidi ◽  
Moulay Youssef Ait Itto ◽  
Aziz Auhmani ◽  
Abdelkhalek Riahi ◽  
Anthony Robert ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
2D Nmr ◽  
Asymmetric Unit ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
X Ray Crystallography ◽  
Naturally Occurring ◽  
Spectroscopic Analyses ◽  
Graph Set

The synthesis of three new polysubstituted monoterpenic thiazolidin-4-ones, namely (Z)-3-methyl-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C14H21N3OS (2), (2Z,5Z)-5-[(dimethylamino)methylidene]-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C16H24N4OS (3), and (2Z,5Z)-5-[(dimethylamino)methylidene]-3-methyl-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C17H26N4OS (4), is reported, starting from the corresponding thiosemicarbazones obtained from naturally occurring (R)-camphor. All the newly obtained thiazolidin-4-ones have been fully characterized by HRMS and 1H and 13C (1D and 2D) NMR spectroscopy. Two of them, i.e. 2 and 3, were identified by single-crystal X-ray crystallography, confirming the synthetic pathway and the spectroscopic analyses. In 3, there are two roughly identical molecules within the asymmetric unit with the same absolute configuration. These two molecules are linked through N—H...O hydrogen bonds, building an R 2 2(8) graph-set motif.

scholarly journals Guaiane Sesquiterpenoids from Jatropha curcas

2008 ◽  
Vol 3 (10) ◽  
pp. 1934578X0800301
Author(s):  
Xia-Chang Wang ◽  
Shi-Ping Ma ◽  
Jing-Han Liu ◽  
Li-Hong Hu
Keyword(s):  
Nmr Spectroscopy ◽  
Spectral Data ◽  
Jatropha Curcas ◽  
2D Nmr ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
Esi Ms ◽  
Related Compounds

Two new guaiane sesquiterpenoids named jatrophaols A and B (1, 2), along with three known analogues, were isolated from the roots of Jatropha curcas. Their structures were determined by spectroscopic methods, including 1D and 2D NMR spectroscopy, HR-EI-MS, HR-ESI-MS, and X-ray diffraction, as well as by comparison of their spectral data with those of related compounds.

scholarly journals Tautomerisation in 1-(4-Methylphenylazo)naphthalen-2-ol and 2-(4-Methylphenylazo)-4-methylphenol: A Crystallographic and 13C{1H}NMR Study

1999 ◽  
Vol 23 (3) ◽  
pp. 178-179
Author(s):  
Wendy I. Cross ◽  
Kevin R. Flower ◽  
Robin G. Pritchard
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Resonant Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Study ◽  
Acetic Acid Esters ◽  
Acid Esters ◽  
Equivalent Carbon

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

Structure determination of fatty acid ester biofuels via in situ cryocrystallisation and single crystal X-ray diffraction

CrystEngComm ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Siriyara Jagannatha Prathapa ◽  
Cara Slabbert ◽  
Manuel A. Fernandes ◽  
Andreas Lemmerer
Keyword(s):  
Crystal Structure ◽  
Fatty Acid ◽  
Fatty Acid Ester ◽  
Structure Determination ◽  
Homologous Series ◽  
Methyl Esters ◽  
X Ray Diffraction ◽  
X Ray

In situ cryocrystallisation enabled the crystal structure determination of a homologous series of low-melting n-alkyl methyl esters Cn−1H2n+1CO2CH3.

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