The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester*

Biochemistry ◽  
1963 ◽  
Vol 2 (5) ◽  
pp. 942-946 ◽  
Author(s):  
Roger L. Peterson ◽  
Konrad W. Hubele ◽  
Carl Niemann
Keyword(s):  
Methyl Ester ◽  
Alkyl Derivatives ◽  
Hydrolysis Of ◽  
Derivatives Of

Synthesis of Some 2'-C-Alkyl Derivatives of 9-(2-Phosphonomethoxyethyl)adenine and Related Compounds

1994 ◽  
Vol 59 (9) ◽  
pp. 2069-2094 ◽  
Author(s):  
Hana Dvořáková ◽  
Antonín Holý ◽  
Ivan Rosenberg
Keyword(s):  
Reaction Pathway ◽  
Sodium Hydride ◽  
Amino Group ◽  
Trimethylsilyl Derivative ◽  
Phosphonic Acids ◽  
Alkyl Derivatives ◽  
Hydrolysis Of ◽  
Trifluoromethyl Derivative ◽  
Derivatives Of ◽  
Related Compounds

To study the effect of β-substitution in 2'-alkyl derivatives of 9-(2-phosphonomethoxyethyl)adenine (Ia) on the antiviral activity or group specificity, these derivatives were synthesized. 9-(2-Hydroxyalkyl)adenines VIII were prepared by alkylation of adenine with suitably substituted oxiranes XIII or 2-hydroxyalkyl p-toluenesulfonates IV and VI. After protection of the adenine amino group by benzoylation (compounds IX) or amidine formation (compounds X), the intermediates were alkylated with diisopropyl p-toluenesulfonyloxymethanephosphonate (XI) in the presence of sodium hydride. After deprotection, the obtained phosphonate diesters XII were converted into phosphonic acids I by transsilylation and hydrolysis. This synthetic scheme was used for the preparation of ethyl (Ie), propyl (If), 2-propyl (Ig), 2-methylpropyl (Ih), cyclopropyl (Ii), cyclohexyl (Ij), benzyl (Ik) and phenyl (Il) derivatives. The 2'-trifluoromethyl derivative XXIIa was prepared analogously from 9-(2-hydroxy-3,3,3-trifluoropropyl)adenine (XXa), obtained by alkylation of adenine sodium salt with 2-hydroxy-3,3,3-trifluoropropyl bromide. 2'-Trimethylsilyl derivative XIXa was obtained by alkylation of adenine with 2-diisopropylphosphonomethoxy-3-(4-toluenesulfonyloxy)propyltrimethylsilane (XVII) followed by transsilylation and hydrolysis of diester XVIIIa. 2,6-Diaminopurine derivatives XVIIId and XXIIb were obtained analogously. 9-(3-Phosphonomethoxybutyl)adenine (XXVIII) and 9-(2-methyl-2-phosphonomethoxypropyl)adenine (XXXV) were prepared from the corresponding hydroxy derivatives XXVIb and XXXII, respectively, by the same reaction pathway as derivatives I.

Behavior of Amiben and Dinoben Derivatives in Arkansas Soils

Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 10-15 ◽  
Author(s):  
R. E. Talbert ◽  
R. L. Runyan ◽  
H. R. Baker
Keyword(s):  
Methyl Ester ◽  
Organic Matter Content ◽  
Matter Content ◽  
Digitaria Sanguinalis ◽  
Culture Studies ◽  
Aluminum Salts ◽  
Dry Soil ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of ◽  
Derivatives Of

The influence of six Arkansas soils on the leaching characteristics of derivatives of 3-amino-2,5-dichlorobenzoic acid (amiben) and 3-nitro-2,5-dichlorobenzoic acid (hereinafter referred to as dinoben) in slotted soil columns was determined using large crabgrass [Digitaria sanguinalis (L.) Scop.] bioassay. The ammonium and aluminum salts of amiben and the sodium salt of dinoben were easily leached and leaching was not noticeably affected by soil type. The ammonium salt of amiben was not adsorbed, while the methyl ester of amiben was adsorbed by these soils. Adsorption was related to the clay and organic matter content of the soil. Methyl and butoxyethyl ester derivatives of amiben and dinoben resisted leaching in these soils and the amide of amiben was intermediate in leaching. The adsorption and leaching behavior of the ester derivatives of these compounds were complicated by their rapid hydrolysis in these soils. The hydrolyzed product behaved identically to the salt derivatives of the compounds in leaching, adsorption, and chromatographic properties. Hydrolysis of the methyl ester was inhibited by soil sterilization, dry soil, and temperatures below 20 C. In non-sterile, warm, moist soil, the half-life of the methyl ester of amiben was 28 hr. Four species of Bacillus were capable of hydrolyzing the methyl ester of amiben in pure culture studies.

scholarly journals Kinetics and mechanism of catalysis by proteolytic enzymes. A comparison of the kinetics of hydrolysis of synthetic substrates by bovine α- and β-trypsin

1974 ◽  
Vol 141 (2) ◽  
pp. 545-554 ◽  
Author(s):  
D. V. Roberts ◽  
D. T. Elmore
Keyword(s):  
Methyl Ester ◽  
Proteolytic Enzymes ◽  
Catalytic Efficiency ◽  
Kinetics And Mechanism ◽  
Molecular Flexibility ◽  
Kinetics Of Hydrolysis ◽  
Mechanism Of Catalysis ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Derivatives Of

Several esters of the α-N-toluene-p-sulphonyl and α-N-benzoyl derivatives of S-(3-aminopropyl)-l-cysteine and the methyl ester of S-(4-aminobutyl)-N-toluene-p-sulphonyl-l-cysteine were synthesized. The kinetics of hydrolysis of these and esters of the α-N-toluene-p-sulphonyl and α-N-benzoyl derivatives of l-arginine, l-lysine, S-(2-aminoethyl)-l-cysteine and esters of γ-guanidino-l-α-toluene-p-sulphonamidobutyric acid and α-N-toluene-p-sulphonyl-l-homoarginine by α- and β-trypsin were compared. On the basis of values of the specificity constants (kcat./Km), the two enzymes display similar catalytic efficiency towards some substrates. In other cases α-trypsin is less efficient than β-trypsin. It is possible that α-trypsin possesses greater molecular flexibility than β-trypsin.

scholarly journals THE BIOCHEMISTRY OF THE USTILAGINALES: III. THE DEGRADATION PRODUCTS AND PROOF OF THE CHEMICAL HETEROGENEITY OF USTILAGIC ACID

1951 ◽  
Vol 29 (5) ◽  
pp. 415-425 ◽  
Author(s):  
R. U. Lemieux
Keyword(s):  
Acetic Acid ◽  
Methyl Ester ◽  
Caprylic Acid ◽  
Degradation Products ◽  
Caproic Acid ◽  
Specific Rotation ◽  
Chemical Heterogeneity ◽  
Hydroxy Acids ◽  
Hydrolysis Of ◽  
Derivatives Of

The D-glucolipid designated as ustilagic acid was shown to be a mixture of partially acylated derivatives of a di-D-glucosyl-dihydroxyhexadecanoic acid. The dihydroxyhexadecanoic acid was named "ustilic acid" and its di-D-glucosyl derivative was termed "glucoustilic acid". Alkaline hydrolysis of ustilagic acid yielded glucoustilic acid, acetic acid, dextro-β-hydroxy-n-caproic acid, dextro-β-hydroxy-n-caprylic acid and a small amount of n-caproic acid. The β-hydroxy-acids were characterized as dextro-β-hydroxy-n-caprohydrazide, m.p. 131–132°C., [α]D + 15.9° (water), and dextro-β-hydroxy-n-caprylhydrazide, m.p. 127–128°C., [α]D + 12° (water). Ustilic acid, m.p. 114–115°C., [α]D − 6.3° (methanol), yielded a methyl ester, m.p. 80−81.8°C, [α]D − 0.2 (chloroform). The methyl ustilate formed a di-phenylurethane derivative, m.p. 76–77°C. The infrared spectra of crystalline and amorphous samples of ustilagic acid are given. The specific rotation of glucoustilic acid, [α]D − 11° (methanol) was that expected of β-D-glucosides and the infrared spectrum of this substance showed a marked resemblance to that of methyl-β-D-glucopyranoside.

Theoretical Study of the Process of Passage of Glycoside Amides through the Cell Membrane of Cancer Cell

2020 ◽  
Vol 20 ◽  
Author(s):  
Vasil Tsanov ◽  
Hristo Tsanov
Keyword(s):  
Cell Membrane ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Quantum Chemical ◽  
Density Functional ◽  
Enzyme Regulation ◽  
Amide Derivatives ◽  
Pass Through ◽  
Hydrolysis Of ◽  
Derivatives Of

Background:: This article concentrates on the processes occurring in the medium around the cancer cell and the transfer of glycoside amides through their cell membrane. They are obtained by modification of natural glycoside-nitriles (cyano-glycosides). Hydrolysis of starting materials in the blood medium and associated volume around physiologically active healthy and cancer cells, based on quantum-chemical semi-empirical methods, is considered. Objective:: Based on the fact that the cancer cell feeds primarily on carbohydrates, it is likely that organisms have adapted to take food containing nitrile glycosides and / or modified forms to counteract "external" bioactive activity. Cancers, for their part, have evolved to create conditions around their cells that eliminate their active apoptotic forms. This is far more appropriate for them than changing their entire enzyme regulation to counteract it. In this way, it protects itself and the gene sets and develops according to its instructions. Methods:: Derived pedestal that closely defines the processes of hydrolysis in the blood, the transfer of a specific molecular hydrolytic form to the cancer cell membrane and with the help of time-dependent density-functional quantum- chemical methods, its passage and the processes of re-hydrolysis within the cell itself, to forms causing chemical apoptosis of the cell - independent of its non-genetic set, which seeks to counteract the process. Results:: Used in oncology it could turn a cancer from a lethal to a chronic disease (such as diabetes). The causative agent and conditions for the development of the disease are not eliminated, but the amount of cancer cells could be kept low for a long time (even a lifetime). Conclusion:: The amide derivatives of nitrile glycosides exhibit anti-cancer activity, the cancer cell probably seeks to displace hydrolysis of these derivatives in a direction that would not pass through its cell membrane and the amide- carboxyl derivatives of nitrile glycosides could deliver extremely toxic compounds within the cancer cell itself and thus block and / or permanently damage its normal physiology.

7-O-Alkyl derivatives of daunomycinone

1984 ◽  
Vol 49 (1) ◽  
pp. 313-319 ◽  
Author(s):  
Věra Přikrylová ◽  
Petr Sedmera ◽  
Josef V. Jizba ◽  
Jindřich Vokoun ◽  
Helena Lipavská ◽  
...  
Keyword(s):  
H Nmr ◽  
Toluenesulfonic Acid ◽  
Alkyl Derivatives ◽  
Derivatives Of

Reaction of daunomycinone (I) with alcohols and p-toluenesulfonic acid produces a mixture (~3 : 1) of its (7S)- and (7R)-O-alkyl derivatives II-IX. According to the 1H NMR evidence, the alicyclic ring exists in the 9H8 conformation in (7R)-O-alkyl derivatives, on the contrary to (7S)-epimers and 7-epi-daunomycinone that adopt the 8H9 conformation.

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