Specific Inhibition by Uracil Derivatives of the Mechanism of Dormancy Release in Light-sensitive Lettuce Seeds

Nature ◽  
1966 ◽  
Vol 211 (5055) ◽  
pp. 1323-1324 ◽  
Author(s):  
HARRY SMITH ◽  
BARRY FRANKLAND
Keyword(s):  
Dormancy Release ◽  
Specific Inhibition ◽  
Uracil Derivatives ◽  
Lettuce Seeds ◽  
Derivatives Of

Preparation of Chloro and Sulfanyl Derivatives of 1-(2-Deoxy-4-C-hydroxymethyl-α-L-threo-Pentofuranosyl)uracil

1997 ◽  
Vol 62 (7) ◽  
pp. 1114-1127 ◽  
Author(s):  
Hubert Hřebabecký ◽  
Jan Balzarini ◽  
Antonín Holý
Keyword(s):  
Nucleophilic Substitution ◽  
Hydrogen Chloride ◽  
Thionyl Chloride ◽  
Sodium Methoxide ◽  
Thioacetic Acid ◽  
Uracil Derivatives ◽  
Derivatives Of ◽  
Hiv 1

3'-Chloro and 3'-acetylsulfanyl derivatives of 1-(2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil were prepared by reaction of 2,3'-anhydro-1-{5'-O-benzoyl-4'-C-[(benzoyloxy)methyl]-2'-deoxy-α-L-erythro-pentofuranosyl}uracil (3) with hydrogen chloride and thioacetic acid, respectively. The reaction with hydrogen chloride gave a mixture of N-1 and N-3 substituted uracil derivatives 12 and 14. Reaction of 1-{3-O-benzoyl-4-C-[(benzoyloxy)methyl]-2-deoxy-α-L-threo-pentofuranosyl}uracil (7) with thionyl chloride and subsequent debenzoylation afforded 1-(4-C-chloromethyl-2-deoxy-β-D-erythro-pentofuranosyl)uracil (19). Nucleophilic substitution with lithium thioacetate, followed by deacylation, converted 1-{3-O-benzoyl-4-C-[(benzoyloxy)methyl]-2-deoxy-5-O-p-toluenesulfonyl-α-L-threo-pentofuranosyl}uracil (9) into 1-(2-deoxy-4-C-sulfanylmethyl-β-D-erythro-pentofuranosyl)uracil (21). The obtained thiols were oxidized with iodine or air to give 1,1'-[disulfandiylbis(2,3-dideoxy-4-hydroxymethyl-α-L-threo-pentofuranose-3,1-diyl]di(pyrimidine-2,4-(1H,3H)-dione) (17) and 1,1'-[disulfandiylbis(2,5-dideoxy-4-hydroxymethyl-α-L-threo-pentofuranose-5,1-diyl]di(pyrimidine-2,4(1H,3H)-dione) (22). Reaction of 1-{3-acetylsulfanyl-5-O-methanesulfonyl-4-C-[(benzoyloxy)methyl]-2,3-dideoxy-α-L-threo-pentofuranosyl)}uracil (24) with methanolic sodium methoxide afforded 1-(3,5-anhydro-2,3-dideoxy-4-C-hydroxymethyl-3-sulfanyl-α-L-threo-pentofuranosyl)uracil (25). The same reagent was used in the preparation of 1-(3,5-anhydro-2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil (26) from 1-{4-C-[(benzoyloxy)methyl]-2-deoxy-5-O-p-toluenesulfonyl-α-L-threo-pentofuranosyl}uracil (8). From the series of 4'-substituted 2'-deoxyuridine derivatives, synthesized in this study, solely the 4'-chloromethyl derivative 19 and the oxetane derivative 26 exhibited an appreciable activity against HIV-1 and HIV-2.

Synthesis, antitumorigenic activity, and electrochemical properties of uracil derivatives of the furan series

1991 ◽  
Vol 27 (12) ◽  
pp. 1358-1364 ◽  
Author(s):  
M. Trushule ◽  
�. Kupche ◽  
I. Augustane ◽  
N. V. Verovskii ◽  
�. Lukevits ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Antitumorigenic Activity ◽  
Furan Series ◽  
Uracil Derivatives ◽  
Derivatives Of

New C4- and C1-derivatives of furo[3,4-c]pyridine-3-ones and related compounds: Evidence for site-specific inhibition of the constitutive proteasome and its immunoisoform

2014 ◽  
Vol 24 (6) ◽  
pp. 1571-1580 ◽  
Author(s):  
Anna Hovhannisyan ◽  
The Hien Pham ◽  
Dominique Bouvier ◽  
Alexander Piroyan ◽  
Laure Dufau ◽  
...  
Keyword(s):  
Specific Inhibition ◽  
Site Specific ◽  
Derivatives Of ◽  
Related Compounds

The novel C-5 aryl, alkenyl, and alkynyl substituted uracil derivatives of l-ascorbic acid: Synthesis, cytostatic, and antiviral activity evaluations

2007 ◽  
Vol 15 (2) ◽  
pp. 749-758 ◽  
Author(s):  
Tatjana Gazivoda ◽  
Silvana Raić-Malić ◽  
Marko Marjanović ◽  
Marijeta Kralj ◽  
Krešimir Pavelić ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Antiviral Activity ◽  
Acid Synthesis ◽  
The Novel ◽  
Uracil Derivatives ◽  
Ascorbic Acid Synthesis ◽  
Derivatives Of

scholarly journals Novel prenyl-linked benzophenone substrate analogues of mycobacterial mannosyltransferases

2004 ◽  
Vol 382 (3) ◽  
pp. 905-912 ◽  
Author(s):  
Mark R. GUY ◽  
Petr A. ILLARIONOV ◽  
Sudagar S. GURCHA ◽  
Lynn G. DOVER ◽  
Kevin J. C. GIBSON ◽  
...  
Keyword(s):  
Active Site ◽  
Covalent Modification ◽  
Biosynthetic Pathways ◽  
Specific Inhibition ◽  
Enzyme Active Site ◽  
Substrate Analogues ◽  
Glycosyl Donor ◽  
Derivatives Of ◽  
Polyprenyl Phosphates

PPM (polyprenol monophosphomannose) has been shown to act as a glycosyl donor in the biosynthesis of the Man (mannose)-rich mycobacterial lipoglycans LM (lipomannan) and LAM (lipoarabinomannan). The Mycobacterium tuberculosis PPM synthase (Mt-Ppm1) catalyses the transfer of Man from GDP-Man to polyprenyl phosphates. The resulting PPM then serves as a donor of Man residues leading to the formation of an α(1→6)LM intermediate through a PPM-dependent α(1→6)mannosyltransferase. In the present study, we prepared a series of ten novel prenyl-related photoactivatable probes based on benzophenone with lipophilic spacers replacing several internal isoprene units. These probes were excellent substrates for the recombinant PPM synthase Mt-Ppm1/D2 and, on photoactivation, several inhibited its activity in vitro. The protection of the PPM synthase activity by a ‘natural’ C75 polyprenyl acceptor during phototreatment is consistent with probe-mediated photoinhibition occurring via specific covalent modification of the enzyme active site. In addition, the unique mannosylated derivatives of the photoreactive probes were all donors of Man residues, through a PPM-dependent mycobacterial α(1→6)mannosyltransferase, to a synthetic Manp(1→6)-Manp-O-C10:1 disaccharide acceptor (where Manp stands for mannopyranose). Photoactivation of probe 7 led to striking-specific inhibition of the M. smegmatis α(1→6)mannosyltransferase. The present study represents the first application of photoreactive probes to the study of mycobacterial glycosyltransferases involved in LM and LAM biosynthesis. These preliminary findings suggest that the probes will prove useful in investigating the polyprenyl-dependent steps of the complex biosynthetic pathways to the mycobacterial lipoglycans, aiding in the identification of novel glycosyltransferases.

scholarly journals Quantification of Dormancy—Physiological and Biochemical Approaches

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 907F-908
Author(s):  
Anwar A. Khan
Keyword(s):  
Cellular Level ◽  
Growth Potential ◽  
Gibberellin Biosynthesis ◽  
Dormancy Release ◽  
Physiological Level ◽  
Metabolic Functions ◽  
Lettuce Seeds ◽  
Time Strength ◽  
Biochemical Level ◽  
Physiological And Biochemical

Quantification of seed dormancy has been achieved by measuring physiological, biochemical, and molecular changes accompanying dormancy release, as well as dormancy development. At the physiological level, dormancy is quantified in terms of stratification time, strength of embryo covering structures, embryo growth potential, responsiveness to light, and to temperatures and other changes. At the biochemical level, dormancy has been related to hormone (abscisic acid, gibberellin, etc.) levels, respiratory activity, and other metabolic functions. At the molecular and cellular level, dormancy has been associated with RNA and protein synthesizing ability and with gene expression. Our recent studies with lettuce seeds using gibberellin biosynthesis inhibitors indicate that the amount of gibberellin produced during seed soak may mediate dormancy release and is quantitatively related to the level of dormancy. Examples of quantifiable changes associated with dormancy will be described. Whether a quantifiable change reflects a causal relationship with dormancy release or development, or is a consequence thereof, will be discussed.

New Boron-Nitrogen Analogues of Uracil Derivatives [1]

1989 ◽  
Vol 44 (11) ◽  
pp. 1421-1426 ◽  
Author(s):  
Ludwik Komorowski ◽  
Kurt Niedenzu
Keyword(s):  
Thermal Stability ◽  
Uracil Derivatives ◽  
Derivatives Of ◽  
Boron Nitrogen ◽  
Nitrogen Analogues

The reaction of Ν,N′-dimethylurea with 1,5-dimethyl-2,4-bis-(dimethylamino)-1,5-diaza-2,4-dibora-3-oxacyclohexan-6-one (2) in the melt proceeds with condensation of the urea to yield two major products: the acid 1,3,5-trimethyl-2-hydroxy-1,3,5-triaza-2-boracyclohexa-4,5-dione (la); and a mixture of the methylammonium (4 a) and dimethylammonium salt (4b) of the anion [{CH3N(u-CONCH3)2}2B]-. Analogous products were obtained from the reaction of 2 with Ν,Ν′,N″-triorganylbiurets. The 2-hydroxy derivatives of type 1 form 1:1 molar adducts with amines (3) of variable thermal stability. The anhydride of la was obtained as the bis(dimethylamine) adduct [CH3N(μ-CONCH3)2B]2O · 2 (CH3)2NH (6) from the reaction of [(CH3)2N]2BOB[N(CH3)2]2 with N,N′,N″-trimethylbiuret.

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