scholarly journals 1H and13C NMR assignments of dihydropipataline, the main of four long-chain 1-(3,4-methylenedioxyphenyl)-alkanes fromPiper darienenceD.C.

2000 ◽  
Vol 14 (4) ◽  
pp. 195-201
Author(s):  
Myriam Meléndez-Rodríguez ◽  
Willy Rendón ◽  
Galia Chávez ◽  
Gerardo Martínez-Guajardo ◽  
Pedro Joseph-Nathan
Keyword(s):  
Nmr Assignment ◽  
Nmr Assignments ◽  
Chemical Shifts ◽  
2D Nmr ◽  
1H And13c Nmr ◽  
Main Compound ◽  
Nmr Techniques ◽  
Nmr Methods ◽  
Nmr Simulation ◽  
C Nmr

Four 1-(3,4-methylenedioxyphenyl)-alkanes having linear ten, eleven, twelve and fourteen carbon atom chains, found in the roots ofPiper darienenceD.C., were separated by HPLC and their structures determined by mass spectrometry and NMR spectroscopy. Conventional 1D NMR methods were used for1H chemical shifts assignment of the main compound dihydropipataline (3) [1-(3,4-methylenedioxyphenyl)‒dodecane]. The13C NMR assignment was carried out using conventional considerations and 2D NMR techniques (HETCOR and FLOCK) in combination with spectral13C NMR simulation andab initioDFT-GIAO NMR calculations.

scholarly journals Alkaloids from Lindera Aggregata

2009 ◽  
Vol 4 (1) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Li-She Gan ◽  
Wei Yao ◽  
Jian-Xia Mo ◽  
Chang-Xin Zhou
Keyword(s):  
Nmr Assignments ◽  
Chemical Shifts ◽  
2D Nmr ◽  
L1210 Cell ◽  
Tumor Cell Lines ◽  
Chemical Methods ◽  
Cytotoxicity Assays ◽  
Weak Activity ◽  
Nmr Techniques ◽  
Sensitive Behavior

Eight alkaloids, including a new compound, (+)-norboldine acetate (1), and seven known ones, (+)-norboldine (2), (+)-boldine (3), (+)-laurotetanine (4), (+)- N-methyllaurotetanine (5), (+)-reticuline (6), (–)-pronuciferine (7), and pallidine (8) were isolated from the roots of Lindera aggregata. The structures of these alkaloids were determined by spectroscopic and chemical methods, especially 2D NMR techniques, which also allowed the first full NMR assignments of alkaloids 2, 4 and 5. Among them, the 1D NMR chemical shifts of (+)-norboldine (2) showed a remarkable environmental sensitive behavior. All the alkaloids were tested in cytotoxicity assays against L1210 and K562 tumor cell lines; only (+)-norboldine (2) showed weak activity against the L1210 cell line.

scholarly journals 1H and13C NMR spectroscopic studies of half-esters from monohydrolysis of dialkyl bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylates

2004 ◽  
Vol 18 (3) ◽  
pp. 469-483
Author(s):  
Yoshikazu Hiraga ◽  
Satomi Niwayama
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
2D Nmr ◽  
Spectroscopic Studies ◽  
Carboxyl Group ◽  
1H And13c Nmr ◽  
Nmr Chemical Shifts ◽  
2D Nmr Spectra ◽  
Spectral Assignment ◽  
C Nmr

The structures of the half-esters from the monohydrolysis of (exo,exo)-, (endo,endo)-, and (endo,exo)-dialkyl bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylates were determined by1H and13C NMR as well as 2D NMR spectra, and the complete spectral assignment has been made. After conversion of one of the carboalkoxy groups to a carboxyl group, different tendencies were observed for the differences in1H and13C NMR chemical shifts between half-esters and the corresponding diesters.

scholarly journals 1H and13C NMR Assignments of Cytotoxic 3S-1,2,3,4-Tetrahydro-β-carboline-3-carboxylic Acid from the Leaves ofCichorium endivia

2012 ◽  
Vol 2012 ◽  
pp. 1-3 ◽  
Author(s):  
Fu-Xin Wang ◽  
An-Jun Deng ◽  
Jin-Feng Wei ◽  
Hai-Lin Qin ◽  
Ai-Ping Wang
Keyword(s):  
Carboxylic Acid ◽  
Nmr Assignments ◽  
Human Cancer ◽  
2D Nmr ◽  
1H And13c Nmr ◽  
Human Cancer Cell Lines ◽  
Complete Assignment ◽  
Isolated Compound ◽  
First Time ◽  
C Nmr

An amino acid, 3S-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid, was isolated for the first time from the leaves ofCichorium endivia. The complete assignment of its1H and13C NMR spectroscopic data was carried out also for the first time based on extensive 1D and 2D NMR experiments. Cytotoxicity of this isolated compound against HCT-8 and HepG2 human cancer cell lines was evaluated for the first time, with moderate activities being found.

Reichardt’s dye: the NMR story of the solvatochromic betaine dye

2014 ◽  
Vol 92 (2) ◽  
pp. 128-134 ◽  
Author(s):  
Michal Afri ◽  
Hugo E. Gottlieb ◽  
Aryeh A. Frimer
Keyword(s):  
Chemical Shift ◽  
Nmr Assignments ◽  
Chemical Shifts ◽  
Solvent Polarity ◽  
2D Nmr ◽  
Polar Solvents ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Reichardt’S Dye ◽  
C Nmr

Reichardt’s dye, 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)phenolate (1), has a very large negative solvatochromism in the long wavelength absorption in the UV–vis spectrum when going from nonpolar to polar solvents. This shift provides the basis of the important and widely used ET(30) scale of solvent polarity. While many papers have investigated the properties of this dye, only a few describe the 1H and 13C NMR assignments in any detail. We report herein, our detailed analysis of the proton and carbon chemical shift assignments for this molecule based on 1D and 2D NMR measurements, as well as those of the protonated and methoxy derivatives 2 and 3, respectively. Much to our surprise, some of the critical chemical shift values we observed were significantly different from those previously reported. In addition, we discovered a good correlation not only between the solvent polarity and the chemical shifts of carbons C1 and C4 of Reichardt’s dye (1), but also between the concentration of the dye and these chemical shifts.

Flavon- and Flavonolglycosides from Achillea pannonica Scheele

2001 ◽  
Vol 56 (7-8) ◽  
pp. 521-525 ◽  
Author(s):  
Denata Kasaj ◽  
Liselotte Krenn ◽  
Sonja Prinz ◽  
Antje Hüfner ◽  
Shi Shan Yuc ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
2D Nmr ◽  
Flavonoid Glycosides ◽  
Spectroscopic Methods ◽  
Esi Ms ◽  
Aerial Parts ◽  
Nmr Techniques ◽  
Chemotaxonomic Study ◽  
First Time ◽  
C Nmr

The detailed investigation of a methanolic extract of aerial parts of Achillea pannonica SCHEELE. within a chemotaxonomic study led to the isolation of 6 flavonoid glycosides. Besides rutin, apigenin-7-O-glucopyranoside, luteolin-7-O-glucopyranoside, apigenin-7-O-rutinoside and acacetin-7-O-rutinoside, an unusual flavondiglucoside was isolated. Its structure was established by UV, 1HNMR and 13C NMR spectroscopic methods including 2D-NMR techniques and ESI-MS as luteolin-7,4′-O-β-diglucoside. This substance is reported for the first time in the genus Achillea. Chemotaxonomic aspects are discussed briefly

E-Homolupane Derivatives Substituted in Position 17 and 22a. 1H NMR, 13C NMR and IR Spectra

1995 ◽  
Vol 60 (4) ◽  
pp. 619-635 ◽  
Author(s):  
Václav Křeček ◽  
Stanislav Hilgard ◽  
Miloš Buděšínský ◽  
Alois Vystrčil
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Coupling Constants ◽  
Side Chain ◽  
Oxidation Reactions ◽  
H Nmr ◽  
Complete Assignment ◽  
Nmr Techniques ◽  
Intramolecular Association ◽  
C Nmr

A series of derivatives with various oxygen functionalities in positions 17,22a or 19,20 was prepared from diene I and olefin XVI by addition and oxidation reactions. The structure of the obtained compounds was confirmed by 1H NMR, 13C NMR and IR spectroscopy. The kind of intramolecular association of the 17α-hydroxy group was studied in connection with modification of the side chain and substitution in position 22a. Complete assignment of the hydrogen signals and most of the coupling constants was accomplished using a combination of 1D and 2D NMR techniques. The 1H and 13C NMR spectra are discussed.

scholarly journals Flavonoids from Curcuma longa Leaves and their NMR Assignments

2015 ◽  
Vol 10 (1) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Chia-Ling Jiang ◽  
Sheng-Fa Tsai ◽  
Shoei-Sheng Lee
Keyword(s):  
Nmr Assignments ◽  
Soluble Fraction ◽  
Curcuma Longa ◽  
2D Nmr ◽  
Etoh Extract ◽  
Spectroscopic Analyses ◽  
Nmr Data ◽  
The Common ◽  
Reported Data ◽  
C Nmr

Chemical investigation of the n-BuOH-soluble fraction of the EtOH extract of the aerial part of Curcuma longa led to the isolation of 11 flavonol glycosides and one dihydroflavonol glucoside (1) via chromatography over Sephadex LH-20 and Lobar RP-18 columns. Although they are known, the 1H and 13C NMR data recorded in CD3OD rather than the common DMSO- d6 are doubly checked via extensive 2D NMR spectroscopic analyses, leading to some revisions of the reported data, especially for the glycon part.

MWL fraction with a high concentration of lignin-carbohydrate linkages: Isolation and 2D NMR spectroscopic analysis

Holzforschung ◽  
2007 ◽  
Vol 61 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mikhail Yu. Balakshin ◽  
Ewellyn A. Capanema ◽  
Hou-min Chang
Keyword(s):  
Loblolly Pine ◽  
Spectroscopic Analysis ◽  
Direct Detection ◽  
2D Nmr ◽  
Side Chain ◽  
High Concentration ◽  
Hmbc Correlation ◽  
Nmr Techniques ◽  
C Nmr ◽  
Hmbc Technique

Abstract A preparation enriched in lignin-carbohydrate fragments (LCC-AcOH) was isolated in the course of purification of loblolly pine crude milled wood lignin (MWL). The preparation contained approximately equal amounts of lignin and carbohydrates, with high amounts of arabinose and galactose compared to their levels in wood. LCC-AcOH was investigated by 2D 1H-13C (HMQC and HMBC) correlation NMR techniques and quantitative 13C NMR. The HMQC spectra allowed direct detection of phenyl glycoside, ester and benzyl ether lignin-carbohydrates linkages in high amounts. The assignment of these structures was supported by the HMBC technique. It is noteworthy that in the ester lignin-carbohydrate linkages, a uronic acid residue was attached not to the benzylic position of lignin, as commonly believed, but to the γ-position of the side chain.

scholarly journals Oleanane-type Triterpene Glycosides from Glycyrrhiza Uralensis

2007 ◽  
Vol 2 (3) ◽  
pp. 1934578X0700200 ◽  
Author(s):  
Jinwei Li-Yang ◽  
Jun-ichiro Nakajima ◽  
Nobuhito Kimura ◽  
Kazuki Saito ◽  
Shujiro Seo
Keyword(s):  
Natural Products ◽  
Spectroscopic Data ◽  
2D Nmr ◽  
Mass Spectrometric ◽  
Triterpene Glycosides ◽  
Glycyrrhiza Uralensis ◽  
Nmr Data ◽  
Nmr Methods ◽  
First Time ◽  
C Nmr

Chemical investigation of the roots of Glycyrrhiza uralensis resulted in the isolation of six oleanane-type triterpene glycosides (1 – 6), including one new saponin (1) and two (2 and 3) obtained as natural products for the first time. The new licorice saponin (1) was identified as 22β–acetoxylglycyrrhizin from [α]D, mass spectrometric, and UV, IR, and NMR spectroscopic data.. Full assignments of 1H and 13C-NMR data for compounds 2, 3, 4, 5 and 6 were made for the first time according to 2D NMR methods.

Synthesis and characterization of a series of 4-methyl-1-[2-aryl-1-diazenyl]-1,4-diazepanes and 1,4-di-[2-aryl-1-diazenyl]-1,4-diazepanes

2004 ◽  
Vol 82 (12) ◽  
pp. 1725-1735 ◽  
Author(s):  
Shasta Lee Moser ◽  
Keith Vaughan
Keyword(s):  
Nmr Assignments ◽  
Diazonium Salt ◽  
Variable Temperature ◽  
2D Nmr ◽  
Diazonium Salts ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Compounds ◽  
C Nmr

1-Methylhomopiperazine was coupled with a series of diazonium salts to afford the 4-methyl-1-[2-aryl-1-diazenyl]-1,4-diazepanes (6), a new series of triazenes. These compounds are, in the main, stable crystalline solids (some of the series are stable oils), and they have been characterized by 1H and 13C NMR spectroscopy, IR spectroscopy, and mass spectrometry. NMR assignments were determined by 2D NMR and variable-temperature NMR experiments and by comparison with model compounds. A second series of new compounds, namely, 1,4-di-[2-aryl-1-diazenyl]-1,4-diazepanes (5), were prepared by coupling unsubstituted homopiperazine (1,4-diazepane) with 2 molar equivalents of the diazonium salt and were similarly characterized. The crystal and molecular structure of the parent member of this bis-triazene series (5, X = H) has been determined by single-crystal X-ray diffraction analysis.Key words: triazene, bis-triazene, diazenyl, bis-diazenyl, diazonium salt, NMR, diazepane.

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