scholarly journals Chemical and metabolic properties of adenosine diphosphate ribose derivatives of nuclear proteins.

1975 ◽  
Vol 147 (3) ◽  
pp. 523-529 ◽  
Author(s):  
J A Smith ◽  
L A Stocken
Keyword(s):  
Adenosine Diphosphate ◽  
S Phase ◽  
The Other ◽  
Hydroxyl Group ◽  
Small Peptide ◽  
Histone 3 ◽  
Liver Nuclei ◽  
Metabolic Properties ◽  
Derivatives Of ◽  
Covalently Bound

1. ADP-ribose is found in rat liver nuclei covalently bound to histone F1, to a non-histone protein, and to a small peptide. 2. A single unit of ADP-ribose, covalently bound to phosphoserine, was isolated from an enzymic hydrolysate of histone F1. ADP-ribose-bearing peptides were isolated from a tryptic digest of the histone. 3. It is proposed that the 1′-hydroxyl group of ADP-ribose is linked to the phosphate group of phosphoserine in histone F1. 4. The incorporation of 32P into ADP-ribose on histone F1 a parallels the DNA content through the cell cycle. An increased incorporation of the nucleotide into the other derivatives is observed during S phase. 5. It is suggested that the ADP-ribose derivative of histone F1 has a role in maintaining the G0 state and that one or both of the other derivatives is concerned with control of DNA synthesis.

Partial hydrolysis of acyl 1,6-anhydro-β-D-glucopyranose

1984 ◽  
Vol 49 (8) ◽  
pp. 1780-1787 ◽  
Author(s):  
Štefan Kučár ◽  
Juraj Zámocký ◽  
Juraj Zemek ◽  
Dušan Anderle ◽  
Mária Matulová
Keyword(s):  
Acid Hydrolysis ◽  
Hydrazine Hydrate ◽  
Hydrogen Chloride ◽  
Ester Group ◽  
The Other ◽  
Hydroxyl Group ◽  
Partial Hydrolysis ◽  
Substantial Influence ◽  
Hydrolysis Of ◽  
Derivatives Of

Partial hydrolysis of per-O-acetyl- and per-O-benzoyl derivatives of 1,6-anhydro-β-D-glucopyranose with methanolic hydrogen chloride and hydrazine hydrate was investigated. The acyl group at C(3) is of substantial influence on the course of hydrolysis. The esterified hydroxyl group at C(3) was found to be most stable on acid hydrolysis with methanolic hydrogen chloride when compared with that at C(2), or C(4); on the other hand, this ester group is the most labile upon hydrolysis with hydrazine hydrate. Selectivity of the respective ester groups towards hydrolysis made it possible to prepare all variations of acetyl and benzoyl derivatives of 1,6-anhydro-β-D-glucopyranose.

scholarly journals Antioxidant activity of some coumarins / Antioxidačná activita niektorých kumarínov

2015 ◽  
Vol 62 (s9) ◽  
pp. 41-45 ◽  
Author(s):  
F. Šeršeň ◽  
M. Lácová
Keyword(s):  
Antioxidant Activity ◽  
Acetic Acid ◽  
Superoxide Anion ◽  
The Other ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Coumarin Derivatives ◽  
Antioxidant Effectiveness ◽  
Derivatives Of ◽  
Superoxide Anion Radicals

AbstractNineteen derivatives of coumarin were tested on the scavenging of 2,2-diphenyl-1-picrylhydrazyl, hydroxyl and superoxide anion radicals. It was found that antioxidant activity exhibits only such coumarins that contain hydroxyl groups. The derivatives without hydroxyl group showed very low antioxidant effectiveness or they were ineffective. On the other hand, the greatest antioxidant effectiveness was exhibited by coumarin derivatives that contained hydroxyl groups in 6 or 8 position, whereas the effectiveness of derivatives with one hydroxyl group in 4, 5 or 7 position was very low. Based on scavenging of the above-mentioned radicals, it was found that the most effective scavengers were 7,8-dihydroxy-4-methylcoumarin (i.e. compound that contains two hydroxyl groups in 7 and 8 positions), (7,8-dihydroxy-2-oxo-2H-chromen-4-yl)acetic acid (this compound contains in addition to two hydroxyl groups in 7 and 8 positions also one hydroxyl group in the acidic residue), esculetin (6,7-dihydroxycoumarin) and 6,7-dihydroxy-4-methylcoumarin.

scholarly journals Adenosine diphosphate ribosylated histones

1977 ◽  
Vol 161 (3) ◽  
pp. 583-592 ◽  
Author(s):  
M G Ord ◽  
L A Stocken
Keyword(s):  
Acid Hydrolysis ◽  
Rat Liver ◽  
Leucine Aminopeptidase ◽  
Adenosine Diphosphate ◽  
Histone Proteins ◽  
Rat Liver Nuclei ◽  
Histone 3 ◽  
Liver Nuclei ◽  
Serine Phosphate

When rat liver nuclei were incubated with [adenine-3H]NAD, besides histone 1, histone 2A and especially histone 2B accepted 3H radioactivity. 3H radioactivity was also found on the non-histone proteins and on the small amounts of histones 1 and 3 released into the supernatant during incubation. [14C]Adenine uptake in vivo by liver and thymus nuclei showed radioactivity in histones 1 and 3. After digestion with Pronase and leucine aminopeptidase 14C- or 32P-labelled histone 3 released a serine phosphate-containing nucleotide, which on acid hydrolysis yielded ADP-ribose and serine phosphate. Serine phosphate was also found in the material from the nucleotide peaks from histones 2A and 2B. ADP-ribosylated histones 1 and 3 were more easily released from nuclei than their unmodified forms and showed higher [32P]Pi and [3H]lysine uptakes in vivo [Ord & Stocken (1975) FEBS Meet. Proc. 34, 113-125].

scholarly journals Stereoselective syntheses of 3-aminocyclooctanetriols and halocyclooctanetriols

2020 ◽  
Author(s):  
Emine Salamci ◽  
Yunus Zozik
Keyword(s):  
The Other ◽  
Hydroxyl Group ◽  
Efficient Synthesis ◽  
Azide Group ◽  
Methanol Treatment ◽  
Stereoselective Syntheses ◽  
Hydrolysis Of ◽  
Derivatives Of

The efficient synthesis of two new stereoisomeric 3-aminocyclooctanetriols and new halocyclitol derivatives of them starting from cis,cis-1,3-cyclooctadiene are reported. Reduction of cyclooctene endoperoxide, obtained by photooxygenation of cis,cis-1,3-cyclooctadiene, with zinc yielded a cyclooctene diol followed by acetylation of the hydroxyl group, which gave dioldiacetate by OsO4/NMO oxidation. The cyclooctane dioldiacetate prepared was converted to the corresponding cyclic sulphate via the formation of a cyclic sulphite in the presence of catalytic RuO4. Reaction of this cyclic sulphate with a nucleophilic azide followed by the reduction of the azide group provided the target, 3-aminocyclooctanetriol. The second key compound, bromotriol, was prepared by epoxidation of the cyclooctene diol with m-chloroperbenzoic acid followed by hydrolysis with HBr(g) in methanol. Treatment of bromotriol with NaN3 and the reduction of the azide group yielded the other 3-aminocyclooctanetriol desired. Hydrolysis of the epoxides with HCl(g) in methanol gave stereospecifically new chlorocyclooctanetriols.

scholarly journals The effect of substrate concentration and pH on the enzymic sulphation of l-tyrosyl derivatives

1970 ◽  
Vol 116 (5) ◽  
pp. 805-810 ◽  
Author(s):  
P. Mattock ◽  
D. J. Barford ◽  
J. M. Basford ◽  
J. G. Jones
Keyword(s):  
Methyl Ester ◽  
Enzyme Preparation ◽  
The Other ◽  
Hydroxyl Group ◽  
Amino Group ◽  
Group 4 ◽  
Km Value ◽  
Rapid Equilibrium ◽  
Kinetics Of ◽  
Derivatives Of

1. The kinetics of the enzymic transfer of sulphate from adenosine 3′-phosphate 5′[35S]-sulphatophosphate to derivatives of l-tyrosine were investigated with a partially purified enzyme preparation from rat liver. 2. At pH7.5 and 37°C the Km values for l-tyrosine methyl ester and adenosine 3′-phosphate 5′[35S]-sulphatophosphate are 0.3mm and 8nm respectively. The Km value for either substrate is independent of the concentration of the other. The available data are consistent with the sulphation reaction proceeding according to a rapid-equilibrium random Bi Bi mechanism. 3. From the effect of pH on the Km and Vmax. values for l-tyrosine methyl ester, tyramine and N-acetyl-l-tyrosine ethyl ester it is concluded that the enzyme is specific for substrate molecules with a free and unprotonated amino group and an un-ionized hydroxyl group. 4. The only ionizing group that can be positively attributed to the enzyme appears to influence the binding of adenosine 3′-phosphate 5′[35S]-sulphatophosphate and has an apparent pK value of approx. 9.5. It is suggested that this group may be an essential thiol. 5. The enzyme is inhibited by iodoacetamide at pH7.5 and 30°C and this inhibition is prevented by the presence of adenosine 3′-phosphate 5′[35S]-sulphatophosphate but not by l-tyrosine methyl ester.

Energy Approximation

2017 ◽  
Author(s):  
Philip Isett
Keyword(s):  
Main Lemma ◽  
The Other ◽  
Coarse Scale ◽  
Continuous Solutions ◽  
Material Derivative ◽  
Energy Variation ◽  
Energy Approximation ◽  
The Difference ◽  
Derivatives Of

This chapter presents the equations and calculations for energy approximation. It establishes the estimates (261) and (262) of the Main Lemma (10.1) for continuous solutions; these estimates state that we are able to accurately prescribe the energy that the correction adds to the solution, as well as bound the difference between the time derivatives of these two quantities. The chapter also introduces the proposition for prescribing energy, followed by the relevant computations. Each integral contributing to the other term can be estimated. Another proposition for estimating control over the rate of energy variation is given. Finally, the coarse scale material derivative is considered.

Inductive effect in EI-mass spectra of some 5,6-dihalogenides and 5,6-halohydrins of 5α-cholestan-3β-ol and 3β-acetoxy-5α-cholestane

1982 ◽  
Vol 47 (11) ◽  
pp. 2946-2960 ◽  
Author(s):  
Antonín Trka ◽  
Alexander Kasal
Keyword(s):  
Mass Spectra ◽  
Inductive Effect ◽  
Molecular Ions ◽  
Hydroxyl Group ◽  
Halogen Atoms ◽  
Derivatives Of

Partial EI-mass spectra of 3β-hydroxy- and 3β-acetoxy-5α-cholestanes substituted in positions 5α-, 6β- or 5α,6β- with a hydroxyl group or halogen atoms (fluorine, chlorine, bromine) are presented. The molecular ions of 5α,6β-disubstituted derivatives of 3β-hydroxy-5α-cholestane (or of its 3-acetate) are considerably more stable than the corresponding monosubstituted derivatives if at least one of the pair of the vicinal substituents is chlorine or fluorine. This increase in stability, most striking in 5α- and 6β-fluoro compounds, is explained by the inductive effect.

scholarly journals Amide-Type Substrates in the Synthesis of N-Protected 1-Aminomethylphosphonium Salts

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 552
Author(s):  
Dominika Kozicka ◽  
Paulina Zieleźny ◽  
Karol Erfurt ◽  
Jakub Adamek
Keyword(s):  
Reaction Times ◽  
The Other ◽  
Hydroxyl Group ◽  
Other Hand ◽  
Step Procedure ◽  
Higher Temperature ◽  
Short Time ◽  
Work Up

Herein we describe the development and optimization of a two-step procedure for the synthesis of N-protected 1-aminomethylphosphonium salts from imides, amides, carbamates, or lactams. Our “step-by-step” methodology involves the transformation of amide-type substrates to the corresponding hydroxymethyl derivatives, followed by the substitution of the hydroxyl group with a phosphonium moiety. The first step of the described synthesis was conducted based on well-known protocols for hydroxymethylation with formaldehyde or paraformaldehyde. In turn, the second (substitution) stage required optimization studies. In general, reactions of amide, carbamate, and lactam derivatives occurred at a temperature of 70 °C in a relatively short time (1 h). On the other hand, N-hydroxymethylimides reacted with triarylphosphonium salts at a much higher temperature (135 °C) and over longer reaction times (as much as 30 h). However, the proposed strategy is very efficient, especially when NaBr is used as a catalyst. Moreover, a simple work-up procedure involving only crystallization afforded good to excellent yields (up to 99%).

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