scholarly journals High field 13C NMR spectroscopic analysis of the triacylglycerols of Jatropha curcas oil

2004 ◽  
Vol 18 (1) ◽  
Author(s):  
E.T. Akintayo ◽  
E.I. Adeyeye ◽  
C.O. Akintayo ◽  
P.O. Oyewusi
Keyword(s):  
Jatropha Curcas ◽  
High Field ◽  
Spectroscopic Analysis ◽  
C Nmr

scholarly journals Multi-Spectroscopic Analysis of Seed Quality and 13C-Stable-Iotopologue Monitoring in Initial Growth Metabolism of Jatropha curcas L.

Metabolites ◽  
2014 ◽  
Vol 4 (4) ◽  
pp. 1018-1033 ◽  
Author(s):  
Takanori Komatsu ◽  
Risa Ohishi ◽  
Amiu Shino ◽  
Kinya Akashi ◽  
Jun Kikuchi
Keyword(s):  
Jatropha Curcas ◽  
Spectroscopic Analysis ◽  
Seed Quality ◽  
Initial Growth ◽  
Jatropha Curcas L ◽  
Growth Metabolism

13C-NMR-Spektroskopie an polycyclischen Aromaten, IIΙ Die 13C-NMR-Spektren von Amino- und Dimethylaminonaphthalinen /13C NMR Spectroscopy of Polycyclic Aromatics, III The 13C NMR Spectra of Amino- and Dimethylaminonaphthalenes

1975 ◽  
Vol 30 (9-10) ◽  
pp. 794-799 ◽  
Author(s):  
Ludger Ernst
Keyword(s):  
13C Nmr ◽  
High Field ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Double Resonance ◽  
Substituent Effects ◽  
13C Nmr Spectroscopy ◽  
Polycyclic Aromatics ◽  
Electrophilic Reagents ◽  
C Nmr

The 13C NMR spectra of twelve amino-, dimethylamino-, diamino-, and bis(dimethylamino)naphthalenes are completely assigned by selective 13C{1H} double resonance and by interpretation of proton-coupled spectra. Strong substituent effects (Δδ) upon chemical shifts are observed and can largely be accounted for by mesomerism. The pronounced high-field shifts of C-6 in the 2-amino- and 2-dimethylaminonaphthalenes coincide with the enhanced reactivity of this position towards electrophilic reagents. In 1-dimethylaminonaphthalene and even more so in 1-dimethylamino-2-methylnaphthalene, conjugation is inhibited for steric reasons and Δδ’s are greatly diminished, thus giving an estimate for the contribution of resonance to substituent-induced shifts in the unhindered compounds. In two 1,8-disubstituted naphthalenes there are large deviations from additivity of substituent effects.

scholarly journals Drypetdimer A: A New Flavone Dimer from Drypetes gerrardii

2011 ◽  
Vol 6 (8) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Margaret Mwihaki Ng'ang'a ◽  
Hidayat Hussain ◽  
Sumesh Chhabra ◽  
Caroline Langat-Thoruwa ◽  
Muhammad Riaz ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
C Nmr

A new flavone dimer, drypetdimer A (1), was isolated from Drypetes gerrardii J. Hutch. The structure of the new compound was elucidated by detailed spectroscopic analysis such as 1H, 13C NMR, COSY, HMQC, HMBC and HREIMS.

scholarly journals Alkaloid and Steroid from the Stem Bark of Jatropha curcas (Euphorbiaceae)

2012 ◽  
Vol 10 (1) ◽  
pp. 9-11
Author(s):  
Dipankar Das Gupta ◽  
Md Enamul Haque ◽  
Md Nahidul Islam ◽  
Shafiqur Rahman ◽  
AKM Mahbub Hasan ◽  
...  
Keyword(s):  
Thin Layer ◽  
13C Nmr ◽  
Jatropha Curcas ◽  
Spectroscopic Analysis ◽  
Ethyl Acetate Extract ◽  
Preparative Thin Layer Chromatography ◽  
Stem Bark ◽  
Published Data ◽  
Layer Chromatography ◽  
Different Parts

The plant Jatropha curcas grows well in different parts of Bangladesh and used in many medicinal purposes locally. The alkaloid atherospermidine and a steroid stigmasterol were isolated from the ethyl acetate extract of the stem bark of J. curcas by a combination of column and preparative thin-layer chromatography over silica gel. The structures of these compounds were determined by spectroscopic analysis (UV, IR, 1H NMR and 13C NMR) and by comparison with published data. This is the first report of isolation of the alkaloid atherospermidine from this plant. DOI: http://dx.doi.org/10.3329/dujps.v10i1.10009 DUJPS 2011; 10(1): 9-11

On the chemistry and high field nuclear magnetic resonance spectroscopy of rapamycin

1980 ◽  
Vol 58 (6) ◽  
pp. 579-590 ◽  
Author(s):  
John A. Findlay ◽  
Lajos Radics
Keyword(s):  
High Field ◽  
Nmr Spectra ◽  
Resonance Spectroscopy ◽  
X Ray ◽  
Conformational Isomers ◽  
H Nmr ◽  
Neutral Compounds ◽  
Complete Assignment ◽  
Hydrolysis Of ◽  
C Nmr

Base catalysed hydrolysis of rapamycin (C51H79NO13) affords six neutral compounds identified by chemical and spectroscopic means as 2a, 3b, 3d, 5, 2,4-dimethylphenol, and L(−)-piperidine-2-carboxylic acid 6, and whose generation has been plausibly rationalized. These findings as well as detailed analyses of 13C nmr and 1H nmr spectra provide independent corroboration of the X-ray derived rapamycin crystal structure 1. Structurally homogeneous in the solid state, rapamycin is found to occur in solutions as a mixture of two conformational isomers (approximately 4:1). Through nearly complete assignment of the high field 1H (400 MHz) and 13C (100.6 MHz) nmr spectra, the isomerism is shown to be associated with trans–cis rotation of an amidic bond within the 31-membered macrolide ring. The predominant form corresponds to the conformer portrayed by X-ray analysis.

New Lignans from Jatropha curcas Linn.

2012 ◽  
Vol 67 (2) ◽  
pp. 176-180 ◽  
Author(s):  
Jun Ju Xu ◽  
Ning Hua Tana
Keyword(s):  
Jatropha Curcas ◽  
Spectroscopic Analysis ◽  
Aerial Parts

Four new lignans, curcasinlignan A (1), curcasinlignan B (2), curcasinlignan C (3), and curcasinlignan D (4), together with eight known compounds, (±)-rel-(2α,3β )-7-Omethylcedrusin (5), (±)-7R∗,8S∗-5-methoxydihydrodehydroconiferyl alcohol (6), dehydrodiisoeugeno1 (7), (threo)-1-(4-hydroxy-3-methoxyphenyl)-2-(4-formyl-2-methoxy-phenoxy)-propane- 1,3-diol (8), (±)-machilin D (9), (+)-pinoresinol (10), 5ʹ-methoxypropacin (11), and hemidesmin-2 (12), were isolated from the aerial parts of Jatropha curcas. Their structures were established on the basis of extensive spectroscopic analysis.

scholarly journals The Effects of Various Acid Catalyst on the Esterification of Jatropha Curcas Oil based Trimethylolpropane Ester as Biolubricant Base Stock

2011 ◽  
Vol 8 (s1) ◽  
pp. S33-S40 ◽  
Author(s):  
Noor Hafizah Arbain ◽  
Jumat Salimon
Keyword(s):  
Perchloric Acid ◽  
Jatropha Curcas ◽  
Pour Point ◽  
Viscosity Index ◽  
Acid Catalyst ◽  
Ester Group ◽  
Molar Ratio ◽  
H Nmr ◽  
Time Of Reaction ◽  
C Nmr

Biolubricant production of trimethylolpropane ester (ET) was conducted via esterification of fatty acid (FA) ofJatropha curcasoil with trimethylolpropane (TMP). The condition for this reaction was as follows: temperature was 150°C, time of reaction was 3 hours, molar ratio of FA: TMP was 4:1 and 2% wt/wt concentrated catalyst (based on weight of FA). Different catalyst was used in this reaction such as perchloric acid, sulfuric acid,p-toluenesulfonic acid, hydrochloric acid and nitric acid. The composition of ET was determined by Gas Chromatography (GC-FID). The ester group was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) and the structure was confirmed by proton and carbon Nuclear Magnetic Resonance (1H-NMR and13C-NMR) spectra. 70% of ET was successfully synthesized using perchloric acid in this research. The pour point of the product was observed as low as –23°C, flash point is >300°C and viscosity index is 150.

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.

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