The chemistry of Eremophila spp. XVIII. A new class of diterpenes from Eremophila viscida

1983 ◽  
Vol 36 (5) ◽  
pp. 993 ◽  
Author(s):  
EL Ghisalberti ◽  
CH Hocart ◽  
PR Jefferies ◽  
GM Proudfoot ◽  
BW Skelton ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
Crystallographic Analysis ◽  
X Ray ◽  
New Class

Two new diterpenes have been isolated from the resin of E. viscida Endl. Evidence for their structure was obtained from spectroscopic data and from X-ray crystallographic analysis which show them to be members of a new class of diterpenes containing a C 5 extended acorane skeleton.

A New Class of Tricyclic Diterpenes from Eremophila georgei (Myoporaceae)

1997 ◽  
Vol 50 (7) ◽  
pp. 705 ◽  
Author(s):  
Yana M. Syah ◽  
Emilio L. Ghisalberti ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Spectroscopic Data ◽  
Model Compounds ◽  
X Ray ◽  
New Class ◽  
Relative Stereochemistry

The first example of a new class of tricyclic diterpenes together with two new viscidanes have been isolated from a variety ofEremophila georgei. The structures of the viscidane compounds were assigned on the basis of spectroscopic data and comparison with model compounds. The structure and relative stereochemistry of the lactone (2), which represents a new diterpene skeleton, were established by spectroscopic and X-ray crystallographic methods. The derivation of (2) from a viscidane is suggested.

(3E)-5-Hydroxy-3-[5-(hydroxymethyl)furan-2-ylmethylene]-1-benzofuran-2(3H)-one

2007 ◽  
Vol 63 (11) ◽  
pp. o4354-o4354
Author(s):  
Hong-Yan Ma ◽  
Ji Shi ◽  
Chang-Hong Wang ◽  
Zheng-Tao Wang
Keyword(s):  
Hydrogen Bonds ◽  
Spectroscopic Data ◽  
Furan Ring ◽  
Crystallographic Analysis ◽  
Relative Configuration ◽  
X Ray ◽  
H Nmr ◽  
Compound C ◽  
A Chain ◽  
C Nmr

The title compound, C14H10O5, was isolated from Senecio cannabifolius Less var. integrifolius aqueous extract. The structure was elucidated on the basis of spectroscopic data, including MS, 1H NMR and 13C NMR, and the relative configuration was confirmed by X-ray crystallographic analysis. The benzofuran ring is almost coplanar with the furan ring [dihedral angle = 10.47 (15)°]. A chain is formed through supramolecular R 2 2(10) synthons and three-centre hydrogen bonds.

scholarly journals Synthesis, structure, and first reactions of a new class of thiacyclophanes

2017 ◽  
Vol 95 (3) ◽  
pp. 278-285 ◽  
Author(s):  
Arunachalam Kannan ◽  
Henning Hopf ◽  
Ina Dix ◽  
Peter G. Jones ◽  
Ludger Ernst
Keyword(s):  
Spectroscopic Data ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
X Ray ◽  
Flash Vacuum Pyrolysis ◽  
New Class ◽  
Product Mixture ◽  
Vacuum Pyrolysis ◽  
Molecular Bridge ◽  
Meta Isomer

In our effort to prepare [m.n]cyclophanes carrying functional groups in their molecular bridges, the thiacyclophanes 14, 19, 20, and 21 have been prepared by simple routes from the pseudo-gem dibromide 10a and the corresponding bis-thiol 10b. The triply-bridged bis-thia-cyclophanes 14, and 19-21 were characterized by their spectroscopic data as well as by X-ray structural analyses. The meta-isomer 20 was oxidized to the bis-sulfone 23, which on flash vacuum pyrolysis (FVP) yielded a product mixture presumably containing the hydrocarbon 26 with a cleaved molecular bridge. Subjecting 23 to Ramberg-Bäcklund conditions (CCl4, NaOH, phase transfer catalysis) provided the chloride 24 in poor yield (9%), a [2.2]paracyclophane in which the new molecular bridge is fully conjugated.

Rearrangements in the Furan Series. V. Reaction of 2,4-Di-p-methylanilino-cyclopent-2-enone With Maleic Anhydride

1991 ◽  
Vol 44 (11) ◽  
pp. 1533 ◽  
Author(s):  
BR Darcy ◽  
KG Lewis ◽  
PJ Oliver ◽  
MF Mackay
Keyword(s):  
Acetic Acid ◽  
Maleic Anhydride ◽  
Spectroscopic Data ◽  
Crystallographic Analysis ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Furan Series

A yellow product formed in the reaction of 2,4-di-p-methylanilinocyclopent-2-enone with maleic anhydride has been shown by X-ray crystallographic analysis to be (4′-p-methylanilino-1′-p-methylphenyl-2′,5′-dioxo-1′,2′,3′,5′,6′,6′a- hexahydrocyclopenta[b]pyrrol-3′-yl)acetic acid (3) in accord with the spectroscopic data. Monoclinic crystals of (3) belong to the space group P21/n with a 13.399(2), b 8.386(1), c 17.935(3)Ǻ, β 92.06(2)° and Z 4. Full-matrix refinement with 2292 observed data converged at R 0.063.

Pigments of Fungi. LVII. Structure and X-Ray Crystallographic Analysis of Dermocanarin 10, a New Naphthalene - Dihydroanthracenone Dimer from an Australian Dermocybe Toadstool

1999 ◽  
Vol 52 (9) ◽  
pp. 881 ◽  
Author(s):  
Melvyn Gill ◽  
Petra M. Millar ◽  
Evelin Raudies ◽  
Somphone Phonh-Axa ◽  
Jonathan M. White ◽  
...  
Keyword(s):  
Single Crystal ◽  
Structure Analysis ◽  
Spectroscopic Data ◽  
Crystallographic Analysis ◽  
Fungal Metabolite ◽  
X Ray ◽  
Absolute Stereochemistry

The structure and absolute stereochemistry of the fungal metabolite dermocanarin 10 (2), which differs from all previous members of the dermocanarin group by virtue of the connectivity between the anthraquinone and dimethoxynaphthol rings, is deduced from spectroscopic data and confirmed by a single-crystal X-ray structure analysis.

Synthesis of steroidal [4,6-b,c]-benzothiazepines, a new class of aromatase inhibitor

1995 ◽  
Vol 73 (12) ◽  
pp. 2185-2189 ◽  
Author(s):  
Herbert L. Holland ◽  
Sudalaiyandi Kumaresan ◽  
Gingipalli Lakshmaiah
Keyword(s):  
Aromatase Inhibitor ◽  
Michael Addition ◽  
Competitive Inhibitor ◽  
Crystallographic Analysis ◽  
X Ray ◽  
New Class ◽  
Acidic Conditions

Several steroidal [4,6-b,c]benzothiazepines have been prepared via base-catalyzed Michael addition of 2-aminothiophenol to 3β,17β-diacetoxyandrost-4-en-6-one. The product of this reaction has the 4β,5α stereochemistry, but cyclizes to a benzothiazepine with the steroidal 4β,5β configuration, confirmed by X-ray crystallographic analysis. 2-Aminothiophenol reacts with 3β,17β-diacetoxyandrost-4-en-6-one under acidic conditions to give a steroidal 6-spiro-benzothiazole. An androst-4-ene-3,17-dione-based [4,6]benzothiazepine has been shown to be a moderate competitive inhibitor of the human placental aromatase enzyme with IC50 = 42.3 µM. Keywords: steroid, aromatase, benzothiazepine.

scholarly journals New Cytotoxic Steroid Produced by the Soil-Derived Fungus Aspergillus flavus JDW-1

2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1985037 ◽  
Author(s):  
Wenqiang Guo ◽  
Wenjie Liu ◽  
Feng Xiao ◽  
Miaomiao Zhang ◽  
Longqiang Li ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Spectroscopic Data ◽  
Inhibitory Concentration ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Crystallographic Analysis ◽  
Scavenging Activity ◽  
X Ray ◽  
Hct 116 ◽  
Absolute Stereochemistry

One new steroid 1, together with seven known compounds 2 to 8, were discovered in the extract of a soil-derived fungus Aspergillus flavus JDW-1. The structure, including the absolute stereochemistry of new compound 1, was established by interpretation of extensive nuclear magnetic resonance spectroscopic data and further confirmed by X-ray crystallographic analysis. The cytotoxicity of 1 against the A-549, Hela, HCT-116, MGC-803, and HO-8910 cell lines was evaluated, which showed cytotoxicity with the half-maximal inhibitory concentration (IC50) values as 5.00 to 22.38 μM. Compounds 2 to 8 exhibited moderate radical scavenging activity against DPPH with IC50 values ranging from 4.7 to 28.5 μM.

2-Hydroxyindole Compounds. Alkylation of 3-Acetyl-1-benzyl-2-hydroxy-5-,ethoxyindole Under Basic Conditions

1992 ◽  
Vol 45 (12) ◽  
pp. 1953 ◽  
Author(s):  
HM Hugel ◽  
RJ Greenwood ◽  
MF Mackay
Keyword(s):  
Least Squares ◽  
Molecular Mechanics ◽  
Spectroscopic Data ◽  
Minimum Energy ◽  
Benzyl Bromide ◽  
Crystallographic Analysis ◽  
Energy Structure ◽  
Space Group ◽  
X Ray

Alkylation of 3-acetyl-1-benzyl-2-hydroxy-5-methoxyindole with benzyl bromide in the presence of base resulted in isolation of the C- alkylated product which has been shown by X-ray crystallographic analysis to be 3-acetyl-1,3-dibenzyl-5-methoxy-1,3-dihydro-2H-indol-2-one (5c) in accord with the spectroscopic data. Triclinic crystals of (5c) belong to the space group P1 with a 10.649(3), b 13.736(3), c 14.555(2) Ǻ, α: 86-73(2), β 85.98(2), γ 78-01(2)° and Z 4. Least-squares refinement with 1996 observed data converged at R 0.061. Molecular mechanics was used to calculate the minimum-energy structure of (5c) which is compared with the X-ray results.

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

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