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 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.

scholarly journals Comparative Study of Naphthoquinone Contents of Selected Greek Endemic Boraginaceae Plants - Antimicrobial Activities

2017 ◽  
Vol 12 (2) ◽  
pp. 1934578X1701200
Author(s):  
Teisa Tufa ◽  
Harilaos Damianakos ◽  
Konstantia Graikou ◽  
Ioanna Chinou
Keyword(s):  
Antimicrobial Activity ◽  
Nmr Spectroscopy ◽  
Comparative Study ◽  
Pathogenic Fungi ◽  
2D Nmr ◽  
Antimicrobial Activities ◽  
2D Nmr Spectroscopy ◽  
Chromatographic Separations ◽  
Esi Ms ◽  
Related Compounds

The cyclohexane (Ch) extracts of the roots of five Greek endemic Boraginaceae plants, Onosma kaheirei Teppner, O. graeca Boiss., O. erecta Sibth. & Sm., Alkanna sfikasiana Kit Tan, Vold and Strid and Cynoglossum columnae Ten, were investigated for the presence of alkannin/shikonin-related compounds. All species, s except C. columnae and O. erecta, were found to contain this type of compounds. Seven compounds were obtained after several chromatographic separations from the Ch extracts of the investigated plants: deoxyalkannin (1), 2″-( S)- α-methylbutyrylalkannin (2), isobutyrylalkannin (3), propionylalkannin (4), acetylalkannin (5), β-hydroxyisovalerylalkannin (6), and β,β-dimethylacrylalkannin (7). All structures were identified by 1D 1H-/13C- and 2D NMR spectroscopy, assisted also by ESI-MS. The extracts and the isolated compounds exhibiting an interesting antimicrobial profile when evaluated for their antimicrobial activity against six Gram-positive and -negative bacteria and three human pathogenic fungi.

(-)-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.

A New Norditerpenoid Alkaloid from Delphinium Densiflorum

2009 ◽  
Vol 2009 (5) ◽  
pp. 306-307 ◽  
Author(s):  
Jian-Yun Sun ◽  
Tian-Cheng Li
Keyword(s):  
Nmr Spectroscopy ◽  
2D Nmr ◽  
Spectroscopic Methods ◽  
2D Nmr Spectroscopy ◽  
Esi Ms ◽  
Etoh Extract ◽  
Norditerpenoid Alkaloid ◽  
Whole Plants

A new norditerpenoid alkaloid delphidenine was isolated from the EtOH extract of the whole plants of Delphinium densiflorum. Its structure was established by extensive application of spectroscopic methods, including IR, HR-ESI-MS, 1D and 2D NMR spectroscopy.

scholarly journals Two New 8, 14-seco-pregnane Steroidal Aglycones from Roots of Cynanchum bungei

2016 ◽  
Vol 11 (12) ◽  
pp. 1934578X1601101
Author(s):  
Jia-Wen Zhao ◽  
Feng-Yang Chen ◽  
Li-Juan Gao ◽  
Shi-Fang Xu ◽  
Shu-Juan Hao ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
2D Nmr ◽  
Spectroscopic Methods ◽  
Soluble Extract ◽  
2D Nmr Spectroscopy ◽  
Chemical Evidence

Two new 8, 14-seco skeleton C21 steroidal aglycones, cynanbungeigenin A ( 1 ) and cynanbungeigenin B ( 2 ), were isolated from the hydrolyzed extract of the EtOAc soluble extract of the roots of Cynanchum bungei. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods, including 1D and 2D NMR spectroscopy.

scholarly journals Synthesis and characterization of allyl- and vinyl-substituted 1,2-bis(tetrazolo)ethanes as polymeric precursors

2016 ◽  
Vol 71 (12) ◽  
pp. 1199-1209
Author(s):  
Vera A. Hartdegen ◽  
Maximilian S. Hofmayer ◽  
Konstantin Karaghiosoff ◽  
Thomas M. Klapötke
Keyword(s):  
Allyl Bromide ◽  
2D Nmr ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
Physical Stimuli ◽  
Thermal Stability Of

AbstractOn the basis of 1,2-bis(5-tetrazolo)ethane (BTE) the corresponding twofold vinyl and allyl N-substituted derivatives were synthesized using 1,2-dibromoethane and allyl bromide, respectively. The compounds were obtained as two different constitutional isomers. Both species were analyzed using NMR and IR spectroscopy, elemental analysis, as well as mass spectrometry. In the case of the diallyl bistetrazoles, the two isomers were characterized using 2D NMR spectroscopy. The synthesis of the divinyl compounds gave crystals of the 2,2′-N-substituted isomer, which were analyzed by single-crystal X-ray diffraction. The thermal stability of the compounds was determined using differential scanning calorimetry (DSC) and gave decomposition temperatures around 190°C and 230°C. For the investigation of the inherent energetic potential, sensitivities toward physical stimuli and detonation parameters were determined. The compounds turned out to be insensitive toward friction and impact and possess moderate energetic properties.

Synthesis of the 4-Pyridine Analog of Kostanecki's Triketone. Determination of Constitution and Stereochemistry by 2D-NMR Spectroscopy and X-ray Structural Analysis

1991 ◽  
Vol 1991 (12) ◽  
pp. 1337-1341 ◽  
Author(s):  
Horst Kessler ◽  
Siggi Mronga ◽  
Bernhard Kutscher ◽  
Arndt Müller ◽  
William S. Sheldrick
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
X Ray

Chiral Polymorphic Hydrazine-based Asymmetric Liquid Crystal Trimers with Resorcinol as Linking Group

2021 ◽  
Vol 18 ◽  
Author(s):  
Wan-Sinn Yam ◽  
Yit-Peng Goh ◽  
Foo-Win Yip ◽  
Gurumurthy Hegde
Keyword(s):  
Liquid Crystal ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
2D Nmr Spectroscopy ◽  
Spacer Length ◽  
X Ray ◽  
Phase Sequence ◽  
Molecular Length ◽  
Ft Ir

Introduction: This is the first report on chiral polymorphic hydrazine-based asymmetric liquid crystal trimers, 1-[4'-(4''- (5-Cholesteryloxy)carbonyl)butyloxy]-3-[N-benzylideneoxy-N'-(4'''-decyloxybenzylidene)hydrazine] butyloxybenzenes, and 1-[4'-(4''-(10-cholesteryloxy)carbonyl)nonyloxy]-3-[N-benzylideneoxy-N'-(4'''- decyloxybenzylidene)hydrazine]butyloxybenzenes., in which the hydrazine and cholesterol arms were connected via two flexible methylene spacers (n = 3-12 units and m = 4 or 9, respectively) to the central resorcinol core. Materials and Methods: FT-IR, 1D and 2D NMR spectroscopy, and CHN microanalysis were used to elucidate the structures of the trimers. Differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction were used to study the transitional and phase properties of the trimers, of which they were length and spacer parity dependent. Trimers with short spacer length in the cholesteryl arm, m = 4 showed interesting phase sequence of BP/N*-TGBA*-SmA*. Results and discussion: The TGBA∗ phase was sensitive to spacer length as it was only observed in trimers with short ester linkage. For the long analogues, m = 9, characteristic visible reflection and a much simpler phase sequence with only N* and SmA* phases were seen. Conclusion: The X-ray diffraction measurements revealed that layer periodicities of the SmA* phase were approximately half the estimated all-trans molecular length (d/L ≈ 0.44-0.52), thus suggesting that the molecules are either strongly intercalated or bent.

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