scholarly journals PARTIAL DEGRADATION OF THE BENZENE RING OF ESTRONE. ISOLATION OF CARBON ATOMS 2 AND 4

1956 ◽  
Vol 223 (2) ◽  
pp. 651-660
Author(s):  
Harold Werbin ◽  
Clayton Holoway
Keyword(s):  
Benzene Ring ◽  
Partial Degradation

Electron Microscopic and Isozyme Study of a Case of Ochronosis

1972 ◽  
Vol 30 ◽  
pp. 88-89
Author(s):  
Jay W. Cha ◽  
Perry J. Melnick
Keyword(s):  
Benzene Ring ◽  
Enzyme System ◽  
Homogentisic Acid ◽  
Degenerative Changes ◽  
Acid Oxidase ◽  
Electron Microscopic ◽  
Tyrosine Metabolism ◽  
Collagenous Tissues

Hereditary ochronosis in very few cases has been examined electron microscopically or histochemically. In this disease homogentisic acid, a normal intermediary of tyrosine metabolism, forms in excessive amounts. This is believed to be due to absence or defective activity of homogentisic acid oxidase, an enzyme system necessary to break the benzene ring and to further break it down to fumaric and acetoacetic acids. Ochronotic pigment, a polymerized form of homogentisic acid, deposits mainly in mesenchymal tissues. There has been a question whether the pigment originates from the collagenous tissues, or deposits passively, where in contrast to melanin it induces degenerative changes.

Pharmacologically potentials of different substituted coumarin derivatives

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Benzene Ring ◽  
Bioactive Compounds ◽  
Biological Activities ◽  
Pharmacological Properties ◽  
Coumarin Derivatives ◽  
Wide Range ◽  
Anti Oxidant ◽  
Anti Inflammatory ◽  
Coumarin Compounds

Coumarin and its derivatives are widely spread in nature. Coumarin goes to agroup as benzopyrones, which consists of a benzene ring connected to a pyronemoiety. Coumarins displayed a broad range of pharmacologically useful profile.Coumarins are considered as a promising group of bioactive compounds thatexhibited a wide range of biological activities like anti-microbial, anti-viral,antiparasitic, anti-helmintic, analgesic, anti-inflammatory, anti-diabetic, anticancer,anti-oxidant, anti-proliferative, anti-convulsant, and antihypertensiveactivities etc. The coumarin compounds have immense interest due to theirdiverse pharmacological properties. In particular, these biological activities makecoumarin compounds more attractive and testing as novel therapeuticcompounds.

Hosoya polynomials of general spiro hexagonal chains

Filomat ◽  
2014 ◽  
Vol 28 (1) ◽  
pp. 211-215 ◽  
Author(s):  
Xianyong Li ◽  
Xiaofan Yang ◽  
Guoping Wang ◽  
Rongwei Hu
Keyword(s):  
Organic Chemistry ◽  
Benzene Ring ◽  
Spiro Compounds

Spiro hexagonal chains are a subclass of spiro compounds which are an important subclass of Cycloalkynes in Organic Chemistry. This paper addresses general spiro hexagonal chains in which every hexagon represents a benzene ring, and establishes the formulae for computing the Hosoya polynomials of general spiro hexagonal chains.

Proximity and conformation effects in 29Si and 13C NMR spectra of di-ortho substituted trimethylsiloxybenzenes

1990 ◽  
Vol 55 (8) ◽  
pp. 2027-2032 ◽  
Author(s):  
Jan Schraml ◽  
Robert Brežný ◽  
Jan Čermák
Keyword(s):  
Benzene Ring ◽  
13C Nmr ◽  
Proximity Effect ◽  
Nmr Spectra ◽  
Methoxy Group ◽  
Chemical Shifts ◽  
Proximity Effects ◽  
13C Nmr Spectra ◽  
Methoxy Groups ◽  
C Nmr

29Si and 13C NMR spectra of five 4-substituted 2,6-dimethoxytrimethylsiloxybenzenes were studied with the aim to elucidate the nature of the deshielding proximity effects observed in the spectra of ortho substituted trimethylsiloxybenzenes. The sensitivity of 29Si chemical shifts to para substitution is in the studied compounds essentially the same as in mono ortho methoxytrimethylsiloxybenzenes. The deshielding proximity effect of the ìsecondî methoxy group is somewhat smaller than that of the ìfirstî group. The present results indicate that the two methoxy groups assume coplanar conformations with the benzene ring and are turned away from the trimethylsiloxy group which is not in the benzene plane. It is argued that in mono ortho methoxytrimethylsiloxybenzenes the two substituent groups adopt the same conformations as in the compounds studied here.

XXI.—The Synthesis of Some Methyl- and Dimethylfluoranthenes

1972 ◽  
Vol 69 (4) ◽  
pp. 281-286
Author(s):  
H. F. Andrew ◽  
Neil Campbell ◽  
E. M. Swan ◽  
N. H. Wilson
Keyword(s):  
Benzene Ring ◽  
Propionic Acid ◽  
Hydrofluoric Acid ◽  
Phenyl Ring ◽  
Ring Closure ◽  
Methyl Group ◽  
Image Position

3-Methylfluorene-9-propionic acid (1) with hydrofluoric acid undergoes ring-closure on the substituted ring to give 1,2,3,10b-tetrahydro-5-methylfluoranthen-3-one (II).Wolff-Kishner reduction of the ketone yielded l,2,3,10b-tetrahydro-5-methylfluoranthene which on dehydrogenation gave 2-methylfluoranthene (III, R=H) identical with a sample prepared according to the method of Tucker (1952) and differing from 8-methylfluoranthene. This proved that ring-closure of (I) had occurred as expected on the methyl-bearing benzene ring. In this instance ring-closure occurs in the position meta to the methyl group and is reminiscent of the similar ring-closure of 2-phenyl-2-p-tolylpropionic acid to give 6-methyl-3-phenylindanone (Pfeiffer and Roos 1941). It thus provided a further example of the limitations of von Braun's statement that Friedel-Crafts ring-closure occurs much less readily at the position meta to a methyl group than on a phenyl ring (von Braun, Manz and Reinsch 1928).

scholarly journals The formation of a hatching line in the serosal cuticle confers multifaceted adaptive functions on the eggshell of a cicada

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Minoru Moriyama ◽  
Kouji Yasuyama ◽  
Hideharu Numata
Keyword(s):  
Protective Role ◽  
Terminal Phase ◽  
Embryonic Diapause ◽  
Insect Eggs ◽  
Ridge Structure ◽  
Conflicting Demands ◽  
Partial Degradation ◽  
Egg Period ◽  
Eggshell Structure

AbstractInsect eggshells must meet various demands of developing embryos. These demands sometimes conflict with each other; therefore, there are tradeoffs between eggshell properties, such as robustness and permeability. To meet these conflicting demands, particular eggshell structures have evolved in diverse insect species. Here, we report a rare eggshell structure found in the eggshell of a cicada, Cryptotympana facialis. This species has a prolonged egg period with embryonic diapause and a trait of humidity-inducible hatching, which would impose severe demands on the eggshell. We found that in eggs of this species, unlike many other insect eggs, a dedicated cleavage site, known as a hatching line, was formed not in the chorion but in the serosal cuticle. The hatching line was composed of a fine furrow accompanied by ridges on both sides. This furrow-ridge structure formed in the terminal phase of embryogenesis through the partial degradation of an initially thick and nearly flat cuticle layer. We showed that the permeability of the eggshell was low in the diapause stage, when the cuticle was thick, and increased with degradation of the serosal cuticle. We also demonstrated that the force required to cleave the eggshell was reduced after the formation of the hatching line. These results suggest that the establishment of the hatching line on the serosal cuticle enables flexible modification of eggshell properties during embryogenesis, and we predict that it is an adaptation to maximize the protective role of the shell during the long egg period while reducing the barrier to emerging nymphs at the time of hatching.

scholarly journals Structural and Magnetic Properties of Potassium-Doped 2,3-DiMethylnaphthalene

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 608
Author(s):  
Xiao-Lin Wu ◽  
Ren-Shu Wang ◽  
Hui Yang ◽  
Jie Zhang ◽  
Ming-An Fu ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Organic Molecules ◽  
Magnetic Measurements ◽  
Ring Structure ◽  
Molar Ratio ◽  
First Principles Calculations ◽  
Paramagnetic Behavior ◽  
Polycyclic Aromatic ◽  
Metal Doped ◽  
Derivatives Of

The development of potential magnetic materials in metal-doped polycyclic aromatic hydrocarbons has been a research hotspot in recent years. Here we have successfully synthesized stable potassium-doped 2,3-dimethylnaphthalene samples. The combination of first-principles calculations and XRD results identifies that doping of potassium into 2,3-dimethylnaphthalene forms a monoclinic structure with a molar ratio of 1:2 between potassium and molecule. The red shifts in the Raman spectra indicate that potassium 4s electrons are transferred to the organic molecules. The magnetic measurements show that the doped materials exhibit a temperature-independent magnetization in the temperature region of 1.8–300 K, which is consistent with the Pauli paramagnetic behavior. This is distinct from the diamagnetism of pristine material. Compared to the previous focus on benzene ring structure, our study of aromatic hydrocarbon derivatives of benzene ring opens a new route for the development of this field.

scholarly journals Disila- and digermabenzenes

2021 ◽  
Author(s):  
Takahiro Sasamori
Keyword(s):  
Benzene Ring

Reactions of isolable disilynes and digermynes with alkynes can result in the formation of the corresponding disila- (DSBs) and digermabenzenes (DGBs), wherein two carbon atoms of the benzene ring are replaced by silicon or germanium atoms.

scholarly journals N-(3-Chloro-4-ethoxy-1-methyl-1H-indazol-5-yl)-4-methoxybenzenesulfonamide

2014 ◽  
Vol 70 (6) ◽  
pp. o679-o679 ◽  
Author(s):  
Hakima Chicha ◽  
El Mostapha Rakib ◽  
Abdellah Hannioui ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Ring System ◽  
Dihedral Angles ◽  
Ethoxy Group ◽  
Π Interactions ◽  
Compound C ◽  
The Mean

The indazole ring system of the title compound, C17H18ClN3O4S, is almost planar (r.m.s. deviation = 0.0113 Å) and forms dihedral angles of 32.22 (8) and 57.5 (3)° with the benzene ring and the mean plane through the 4-ethoxy group, respectively. In the crystal, molecules are connected by pairs of N—H...O hydrogen bonds into inversion dimers, which are further linked by π–π interactions between the diazole rings [intercentroid distance = 3.4946 (11) Å], forming chains parallel to [101].

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