REACTIONS OF OXODELCOSINE AND INTERRELATION OF DELCOSINE AND DELSOLINE

1960 ◽  
Vol 38 (12) ◽  
pp. 2433-2440 ◽  
Author(s):  
Vinko Skarić ◽  
Léo Marion
Keyword(s):  
Sodium Borohydride ◽  
Membered Ring ◽  
Lead Tetraacetate ◽  
The Other ◽  
Supporting Evidence ◽  
Close Relationship ◽  
Suggested Structure ◽  
Hydrolysis Of

The oxidation of diacetyldelcosine produces a lactam which, after hydrolysis of the acetyl groups, can be oxidized further to a diketo-lactam in which one of the keto groups is in a five- and the other in a six-membered ring. This result leads to an alteration of the previously suggested structure of delcosine. The new structure suggests a close relationship between delcosine and delsoline which is confirmed by the methylation of the former. The reaction is selective and gives rise to a monomethyldelcosine identical in every way with delsoline. Reduction of the diketo-lactam (didehydro-oxodelcosine) with sodium borohydride gives oxodelcosine. Dehydro-oxodelcosine is also described, and its oxidation with lead tetraacetate as well as that of oxodelcosine lead to the formation of keto-products which lend supporting evidence for the structure assigned to delcosine.

FORMATION OF CYCLIC O-2′-HYDROXYETHYLIDENE ACETALS FROM POLYALCOHOLS OF 4-O-LINKED POLYSACCHARIDES

1965 ◽  
Vol 43 (11) ◽  
pp. 2978-2984 ◽  
Author(s):  
P. A. J. Gorin ◽  
J. F. T. Spencer
Keyword(s):  
Acid Hydrolysis ◽  
Sodium Periodate ◽  
Rhodotorula Glutinis ◽  
Membered Ring ◽  
The Other ◽  
Complete Oxidation ◽  
Partial Acid Hydrolysis ◽  
Ring Form ◽  
Hydrolysis Of ◽  
By Products

Partial acid hydrolysis of polyalcohols derived from some 1,4-O-linked polysaccharides gave cyclic O-2′-hydroxyethylidene derivatives as by-products in yields of 6–18%. Polysaccharides containing β-links such as Rhodotorula glutinis mannan and cellulose gave rise to 6-membered ring acetals with lesser amounts of the 5-membered ring form. On the other hand, two α-linked polyalcohols, obtained following partial and complete oxidation of starch with sodium periodate, were converted to 5-membered O-2′-hydroxyethylidene acetals.

scholarly journals RING CONTRACTION DURING THE LEAD TETRAACETATE OXIDATION OF REDUCING SUGARS

1964 ◽  
Vol 42 (11) ◽  
pp. 2365-2374 ◽  
Author(s):  
A. S. Perlin
Keyword(s):  
Reducing Sugars ◽  
Acyl Migration ◽  
Large Change ◽  
High Reactivity ◽  
Membered Ring ◽  
Lead Tetraacetate ◽  
The Other ◽  
Concentration Change ◽  
Pyranose Form ◽  
Cleavage Step

The rate of oxidation of D-glucose by lead tetraacetate in acetic acid is affected little by a large change in concentration of reactants, showing that the glycol cleavage step is not rate-controlling. Oxidation of 3-O-methyl-6-O-trityl-D-glucose yields 3-O-formyl-2-O-methyl-5-O-trityl-D-arabinose; the latter is not derived by production initially of a 4-O-formyl derivative that undergoes acyl migration. It is probable that the oxidation of D-glucose proceeds with conversion of the pyranose sugar into a furanose intermediate. By contrast, D-mannose appears to be oxidized mainly in the pyranose form, as shown by the oxidation patterns of D-mannose-1- and -2-14C and 5-O-methyl-D-mannofuranose, and the effects of concentration change on the reaction of D-mannose and derivatives. The proximity of the ring oxygen atom to the 1,2-diol group may contribute to the unusually high reactivity of D-mannopyranose as compared with other types of monocyclic six-membered ring vic-diols.Intermediate proportions of furanose and pyranose pathways characterize the lead tetraacetate oxidation of the other six aldohexoses. Similarities in the behavior of glucose and idose, gulose and mannose, and allose and talose may originate in steric similarities between these pairs of sugars.

A METHOD FOR THE IDENTIFICATION OF THE MONO-O-METHYLGLUCOSES

1953 ◽  
Vol 31 (9) ◽  
pp. 814-820 ◽  
Author(s):  
R. U. Lemieux ◽  
H. F. Bauer
Keyword(s):  
Paper Chromatography ◽  
Sodium Borohydride ◽  
Alkaline Hydrolysis ◽  
Periodate Oxidation ◽  
Methyl Cellulose ◽  
Water Soluble ◽  
The Other ◽  
Potential Value ◽  
Hydrolysis Of

Periodate oxidation of any one mono-O-methylglucopyranose and alkaline hydrolysis of the product yields a substance which can be positively distinguished by paper chromatography from the products formed under the same conditions from the other mono-O-methylglucopyranoses. Thus, the components of a mixture of the mono-O-methylglucopyranoses can be readily identified. The method appears useful for the identification of di-O-methylglucoses. Reduction with sodium borohydride prior to periodate oxidation renders the method useful for the identification of tri-O-methylglucoses. The potential value of the method, which can be used on a microscale, is illustrated by an application to the characterization of the O-methylglucoses derived from a water-soluble O-methyl-cellulose

A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

2015 ◽  
Vol 12 (1) ◽  
pp. 3910-3918 ◽  
Author(s):  
Dr Remon M Zaki ◽  
Prof Adel M. Kamal El-Dean ◽  
Dr Nermin A Marzouk ◽  
Prof Jehan A Micky ◽  
Mrs Rasha H Ahmed
Keyword(s):  
Biological Activity ◽  
Carbonyl Compounds ◽  
Mass Spectra ◽  
The Other ◽  
Pyridine Derivatives ◽  
Facile Synthesis ◽  
High Biological Activity ◽  
Basic Hydrolysis ◽  
Pyridine Carboxylate ◽  
Hydrolysis Of

 Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f  which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

Albrecht Durer and the 16TH Century Melancholy

2020 ◽  
Vol 2 ◽  
pp. 37-49
Author(s):  
Marcel Henrique Rodrigues
Keyword(s):  
Religious Culture ◽  
The Other ◽  
16Th Century ◽  
Other Hand ◽  
Close Relationship ◽  
The One ◽  
Deep Sense

Little has been discussed in academia about the close relationship between the Renaissance of the 16th century and melancholy humor, and esoteric elements arising mainly from Florentine Neoplatonism. The link between melancholy and esotericism becomes very clear when we analyze the gravure “Melencolia I” by Albrecht Dürer (1471-1528), composed of a significant number of symbols that refer to an esoteric religious culture that then emerged. Renaissance melancholy gained several nuances. On the one hand, it was considered a sin, a despicable mood characteristic of witches; on the other hand, a deep sense of inspiration typical of men of “genius”. This ambivalence also occurred in the firmament, as the melancholic people were guided by the dark planet Saturn, according to astrological belief. We also have the cultural scenario of the 16th century, especially in Dürer's Germany, which contributed to strengthening the melancholy issues.

Epodes

1972 ◽  
Vol 6 ◽  
pp. 6-14
Keyword(s):  
Social Status ◽  
Lyric Poetry ◽  
The Other ◽  
Similar Attitude ◽  
Other Hand ◽  
Close Relationship

Horace was writing hisEpodes1at the same time as he was writingSatires. The nameEpodesis derived from the metrical term ό ἐπῳδός (і.е. στίχος) which signifies the second and shorter line of a couplet, but Horace himself referred to them asiambi(soEpod. 14. 7,Epist. i. 19. 23). The collection is titledLiber Epodonin the MSS. and the title was used by grammarians of the fourth and fifth centuries. Butiambigives a better idea of their basic inspiration. Horace says of them(Epist. i. 19. 21-5):So he claims(a)originality,(b)Archilochus as a model,(c)that he was the first Roman to use Archilochus as a model, and(d)that he discarded the vicious personal invective of Archilochus. The judgement disregards Catullus, who had writteniambibefore Horace, but whose similarity to Archilochus did not extend far beyond metre and invective. There is a consistency in Horace’s poetic career: he began by recreating the poetry of Archilochus in hisEpodes, and his later—and greatest— work was the recreation in hisOdesof the lyric poetry of poets like Sappho, Alcaeus, and Pindar. There is a similarly close relationship between theSatiresand theEpistles;and, furthermore, all of his writing uses an autobiographical technique. There is another sort of consistency too, for basicallyEpodesandSatiresexpress a similar attitude of mind: anger, contempt, and amusement are the fundamental emotions (though he often transcends these emotions in both works), and a plausible case can be made out for regarding this as a sign of a young man of low social status, unsure of himself and his talent, and already finding ways of expressing a personality that were not too self-revealing. TheOdesandEpistles, on the other hand, express a more meditative, more philosophical, more humane attitude, yet ultimately no more self-revealing.

Dreams of Truck Drivers: A Test of the Continuity Hypothesis of Dreaming

2005 ◽  
Vol 25 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Michael Schredl ◽  
Arthur Funkhouser ◽  
Nicole Arn
Keyword(s):  
Empirical Studies ◽  
Truck Drivers ◽  
The Other ◽  
Continuity Hypothesis ◽  
Future Studies ◽  
Daytime Activity ◽  
Close Relationship ◽  
The One ◽  
Dream Emotions ◽  
The Relationship

Empirical studies largely support the continuity hypothesis of dreaming. The present study investigated the frequency and emotional tone of dreams of truck drivers. On the one hand, the findings of the present study partly support the continuity regarding the time spent with driving/being in the truck and driving dreams and, on the other hand, a close relationship was found between daytime mood (feelings of stress, job satisfaction) and dream emotions, i.e., different dream characteristics were affected by different aspects of daytime activity. The results, thus, indicate that it is necessary to define very clearly how this continuity is to be conceptualized. The approach of formulating a mathematical model (cf. [1]) should be adopted in future studies in order to specify the factors and their magnitude in the relationship between waking and dreaming.

THE ALDOBIOURONIC ACIDS OF HEMICELLULOSE B OF OAT HULLS

1956 ◽  
Vol 34 (3) ◽  
pp. 338-344 ◽  
Author(s):  
E. L. Falconer ◽  
G. A. Adams
Keyword(s):  
Glucuronic Acid ◽  
The Other ◽  
Partial Hydrolysis ◽  
Oat Hulls ◽  
Hydrolysis Of

Partial hydrolysis of hemicellulose B from oat hulls yielded two aldobiouronic acids, which were identified as 2-O-(4-O-methyl-α-D-glucopyruronosyl)-D-xylose and 2-O-(α-D-glucopyruronosyl)-D-xylose respectively. In addition, two aldotriouronic acids were isolated, one yielding on hydrolysis xylose and 4-O-methyl-glucuronic acid, and the other, xylose, galactose, and glucurone.

scholarly journals Comparative Study of Ag Nanostructures: Molecular Simulations, Electrochemical Behavior, and Antibacterial Effect

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Álvaro de Jesús Ruíz-Baltazar ◽  
Simón Yobanny Reyes-López ◽  
D. Larrañaga ◽  
R. Pérez
Keyword(s):  
Cyclic Voltammetry ◽  
Ethylene Glycol ◽  
Comparative Study ◽  
Sodium Borohydride ◽  
Electrochemical Behavior ◽  
Antibacterial Effect ◽  
Chemical Reduction ◽  
Molecular Simulations ◽  
The Other ◽  
E Coli

Nanoparticles of Ag with different sizes and structures were obtained and studied. Two methods for reductions of Ag ions were employed, chemical reduction by sodium borohydride and ethylene glycol. Cuboctahedral and icosahedral structures were obtained. Molecular simulations were carried out in order to evaluate the reactivity of both structures. On the other hand, the electrochemical activity and antibacterial effect (E. coli) of the cuboctahedral and icosahedral structures were measured experimentally. The results obtained by molecular simulation, cyclic voltammetry, and antibacterial effect were compared and discussed in this work.

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