ChemInform Abstract: ARYNIC CONDENSATION OF KETONE ENOLATES PART 8, ONE STEP SYNTHESIS OF DIBENZOTRICYCLO(4,2,2,1(2,5))UNDECA-8,10-DIENE-1-OL, STRUCTURE ELUCIDATION BY (13)C AND (1)H NMR

1973 ◽  
Vol 4 (36) ◽  
pp. no-no
Author(s):  
P. CAUBERE ◽  
M. S. MOURAD ◽  
D. CANET
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Farooq Azam ◽  
Bashir Ahmad Chaudhry ◽  
Hira Ijaz ◽  
Muhammad Imran Qadir

Abstract This study evaluates the antioxidant activity of Ranunculus muricatus and isolation and structure elucidation of the active constituents. The aerial parts of the plants were shade dried at room temperature and powdered and extracted with methanol. The free radical scavenging activity was evaluated by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay. The percentage scavenging activity was determined based on the percentage of DPPH radical scavenged. Column chromatography was used in order to isolate the active compounds. Spectral techniques UV, IR, 1H NMR, 13CNMR and HREI-MS were used for the structure elucidation of the isolated compounds. Two isolated compounds, A (caffeoyl-β-d-glucopyranoside) and B (1,3-dihydroxy-2-tetracosanoylamino-4-(E)-nonadecene), exibited a significant antioxidant activity as showed by DPPH radical scavenging method. Percentage inhibition for compound A (at 0.5 mM) was 82.67 ± 0.19 with IC50 of 93.25 ± 0.12 (μM), and for compound B (at 0.5 mM) was 69.23 ± 0.19 with IC50 of 183.34 ± 0.13 (μM). Quercetin was used as standard control. It was conclued from the present study that caffeoyl-β-d-glucopyranoside and 1,3-dihydroxy-2-tetracosanoylamino-4-(E)-nonadecene isolated from methanol extract of aerial parts of Ranunculus muricatus posses antioxidant activity.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Xinxin Li ◽  
Jinku Xu

In this paper, three kinds of ZnS NPs capping different amount of mercaptoethanol (ME) were synthesized, and the effect of capping amount on ZnS NPs was studied, indicating that the capping amount of ME on ZnS surface decreases, while ZnS size increases as the decrease of added capping agent in synthesis process, and ZnS NP capping middle amount of ME (~27.7 wt%) shows a highest apparent refractive index (RI) value. ZnS NPs were composited into polymeric matrices by a simple “one-step” thermocuring method characterized by adding a small amount of functional monomer of glycidyl methacrylate (GMA) and solvent of N,N-dimethylformamide (DMF) The reaction mechanism, studied by 1H NMR spectra, indicates that the epoxy of GMA monomer can be easily opened and chemically grafted on ME-capped ZnS surface under the catalysis of DMF, and then copolymerized with other monomer. By the route, ZnS NPs can be composited into pure poly(N,N-dimethylacrylamide)-type (DMA-type), DMA-type copolymer, and DMA-free matrices to fabricate transparent films, and its RI value can be improved by either optimizing capping amount on ZnS surface or increasing ZnS content in the nanocomposites. The RI value of resulting dried nanocomposites can be improved to 1.764 by compositing 80 wt% ZnS capping middle amount of ME.


1994 ◽  
Vol 49 (9) ◽  
pp. 1297-1304 ◽  
Author(s):  
G. Falsone ◽  
F. Cateni ◽  
E. Vrech ◽  
L. Birkofer ◽  
V. Lucchini ◽  
...  

From the marine brown macroalga Fucus virsoides J. AG. (Fucales, Phaeophyceae), a mixture of triacylglycerols 1 -3, fucosterol 4, a mixture of galactosyldiacylglycerols 5-8 and fucoxanthin 9 have been isolated. Normal phase column flash chromatography was effective for the isolation of the marine compounds. FAB-MS, CI-MS spectrometry, 1H NMR, 13C NMR, 1H-1H COSY and 1H-13C COSY experiments were useful in providing informations for their structure elucidation


1992 ◽  
Vol 47 (10) ◽  
pp. 1444-1458 ◽  
Author(s):  
Roland Ferth ◽  
Andreas Baumann ◽  
Wolfgang Robien ◽  
Brigitte Kopp

From leaves and bulbs of Ornithogalum nutans L. (2 n = 28), seventeen cardenolides were isolated by column chromatography, DCCC and TLC. The structure elucidation was performed by means of 1H NMR, 13C NMR, HH-Cosy, HC-Cosy and FAB-MS studies and identification of the sugar moieties by GLC after acid hydrolysis of the cardenolides. Sugar compounds were identified as digitoxose, 3-acetyl-digitoxose, 2-deoxy-allose, 6-deoxy-allose, rhamnose, xylose and apiose. Glycosides of 7β,15β, 16 α-trihydroxy-uzarigenin, 8β,16 α-dihy-droxy, 15-oxo-uzarigenin, 3 β, 11β-dihydroxy, 12-oxo, 18-nor-5 α-card-13-enolid, 11 α-hydroxygitoxigenin, 12-oxo,8, 14β-epoxy-uzarigenin, 8β-hydroxy, 15-oxo-uzarigenin and 12β-hydroxy-oleandrigenin are described for the first time, the presence of oleandrigenin-glycosides in the genus Ornithogalum was not known until now. Ornithogalum nutans L. shows a different cardenolide pattern from the second European species of the section Myogalum (LINK) PETERM. - Ornithogalum boucheanum (KUNTH) ASCHERS.


2019 ◽  
Vol 6 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Mohammad Ali Ghasemzadeh ◽  
Mohammad Hossein Abdollahi-Basir ◽  
Zahra Elyasi

Background: This research introduces an effective and green method for the synthesis of polysubstituted 2-pyrrolidinone derivatives as biologically-active heterocyclic compounds using multi- component reactions using Fe3O4@L-arginine as a reusable organocatalyst. Material and Method: The Fe3O4@L-arginine nanoparticles were prepared by a facile one-step approach and the structure elucidation of the magnetic nanocatalyst has been done using various spectroscopy techniques. Results: L-arginine-functionalized magnetite nanoparticles were obtained with particle sizes around 10 nm. Fe3O4@L-arginine exhibited strong catalytic activity to obtain some polysubstituted 2- pyrrolidinone. Conclusion: The considerable advantages of this research are short reaction times, excellent yields, simple workup procedure and reusability of the nanocatalyst which is in good agreement with green chemistry disciplines. The study on the reusability of the Fe3O4@L-arginine nanoparticles showed that the recovered catalyst could be reused six consecutive times.


2005 ◽  
Vol 70 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Stefania Garbacia ◽  
Caroline Hillairet ◽  
Rachid Touzani ◽  
Olivier Lavastre

Eight new substituted bis(pyrazol-1-ylmethyl)amines have been prepared in one step condensation of 1-(hydroxymethyl)-3,5-disubstituted pyrazoles with a series of primary amines. The effect of substituents of divers bulkiness and electron donor/acceptor power that have been introduced to these tridentate molecules is visualised by 1H NMR spectroscopy.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Veikko Uahengo ◽  
Ping Cai ◽  
Likius S. Daniel

A benzotrithiophenes (BTT) based colorimetric sensor (2) was synthesized via a simple one-step reaction process, and its recognition properties towards several biologically important anions and cations were investigated by naked eye observation and spectroscopic methods of UV-vis and 1H NMR analysis in DMSO. The molar addition of anions such as F−, AcO−, and H2PO4- induced a marked red shift of the charge transfer band (Δλ=94 nm, from 440 nm to 534 nm) concomitant with a clearly visible “naked eye” detectable colorimetric activities (from orange to pink). However, the molar addition of H2PO4- did not induce significant spectral changes, compared to F− and AcO−. Furthermore, the molar addition of Hg2+ to 2 resulted in hypochromic shift at 440 nm and the eventual disappearance of a low energy band at 534 nm, concomitant with the colorimetric activities (from orange to yellow). Moreover, both spectral and color changes induced by the addition of anions (F− and AcO−) were all reversible by the molar addition of metal cations of 3d5–10. The reversibility properties triggered the logic operation studies, and, subsequently, the complementary IMP/INH logic functions based on color and spectral switching (ON/OFF) were confirmed. Conclusively, 2 can thus be utilized as a colorimetric molecular switch modulated by AcO−/MII.


2014 ◽  
Vol 69 (11-12) ◽  
pp. 1061-1072 ◽  
Author(s):  
Ulf H. Strasser ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Raphael J. F. Berger ◽  
Norbert W. Mitzela

Abstract 5,11,17,23-Tetrakis(trimethylsilylethynyl)-25,26,27,28-tetra-n-propoxycalix[4]arene (1) was synthesised in two steps starting from 25,26,27,28-tetra-n-propoxycalix[4]arene, and the structure of 1 was determined by X-ray diffraction. Compound 1 was desilylated (K2CO3) to give 5,11,17,23- tetrakis(ethynyl)-25,26,27,28-tetra-n-propoxycalix[4]arene (2), which was tetra-aurated under basic conditions (NaOEt, THF) with a series of phosphane-gold chlorides (o-Tol3PAuCl, Ph3PAuCl, Ph2MePAuCl, PhMe2PAuCl, Me3PAuCl, Cy3PAuCl, t-Bu3PAuCl) to afford in good to excellent yields the tetra-aurated tetraethynylcalix[4]arene species 3-9 in one step [with phosphane ligands o-Tol3P (3), Ph3P (4), Ph2MeP (5), PhMe2P (6), Me3P (7), Cy3P (8), t-Bu3P (9)]. All compounds were characterised by 1H NMR and infrared spectroscopy, mass spectrometry and by elemental analyses, additionally 3, 4, 5, 8 and 9 by 13C{1H}, and 3-6, 8 and 9 by 31P{1H} NMR spectroscopy. The molecular structures of complexes 3 and 9 were determined by X-ray diffraction and show pinched-cone conformations, but neither intra- nor intermolecular attractive aurophilic Au···Au contacts. The acceptor ability of complexes 3 and 9 was investigated by complexation attempts with various phosphane-gold chlorides and xenon gas under pressure, but interactions could not be determined experimentally. The formation of a complex between xenon and gilded calix[4]arene could, however, be predicted for fluorine-substituted species and with very small phosphane ligands (PH3) on the basis of quantum-chemical calculations; the energy of formation is 9:6 kJ mol-1. The crystal structure of Ph2MePAuCl was also determined and shows Au···Au-bonded dimers.


2020 ◽  
Vol 11 (17) ◽  
pp. 4351-4359 ◽  
Author(s):  
Alexander Howarth ◽  
Kristaps Ermanis ◽  
Jonathan M. Goodman

A robust system for automatic processing and assignment of raw 13C and 1H NMR data DP4-AI has been developed and integrated into our computational organic molecule structure elucidation workflow.


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