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Biomedical subjects

M J Wanner

Publications and source records attributed to M J Wanner.

5 recordsLinked to original sources
PubMed2004

New (1-deaza)purine derivatives via efficient C-2 nitration of the (1-deaza)purine ring.

Nitration of substituted (1-deaza)purines using a mixture of tetrabutylammonium nitrate (TBAN) and trifluoracetic acid anhydride (TFAA) was applied to prepare nitrosubstituted (1-deaza)purines at low temperature. The nitro group influences the system twofold: 1) it activates other substituents towards nucleophilic aromatic substitution and 2) it can be substituted itself leading to a variety of di-substituted (1-deaza)purines, also via solid phase syntheses. Several of the molecules obtained were studied for their antiprotozoal activity and for interactions with the different human adenosine receptors.

Acetic Anhydrides↗
PubMed2000

2-Nitro analogues of adenosine and 1-deazaadenosine: synthesis and binding studies at the adenosine A1, A2A and A3 receptor subtypes.

The influence of nitro substituents on the properties of adenosine and 1-deazaadenosine was studied. Combination of a nitro group at the 2-position with several N6 substituents such as cyclopentyl and m-iodobenzyl gave a series of analogues with good adenosine receptor affinity, showing directable selectivity for the A1, A2A and A3 adenosine receptor subtypes.

Adenosine↗
PubMed1980

Potential carcinostatics. 4. Synthesis and biological properties of erythro- and threo-beta-fluoroaspartic acid and erythro-beta-fluoroasparagine.

(E)- and (Z)-Di-tert-butyl 2-amino-3-fluoro-2-butene-1,4-dioate [(E)- and (Z)-2] were synthesized in two ways: (a) by elimination of hydrogen fluoride from di-tert-butyl beta,beta-difluoroaspartate under the influence of 1,5-diazabicyclo[4.3.0]non-5-ene and (b) by amination with the ammonium acetate of di-tert-butyl monofluorooxaloacetate (3), obtained via condensation of tert-butyl monofluoroacetate with di-tert-butyl oxalate. Reduction of 2 with sodium cyanoborohydride yielded a mixture of di-tert-butyl monofluoroaspartates in which the erythro isomer constituted the major product. The structure of this isomer (4a) was established by X-ray crystallographic analysis of the corresponding acid 5a. Esterification of 5a to the beta-methyl ester 6, followed by aminolysis, yielded erythro-beta-fluoroasparagine (7). Tests with 5a and 7 in the L-5178Y test system showed that the compounds exhibited toxicity at levels at which no antitumor activity was observed.

Animals↗
PubMed1977

Potential carcinostatics. Synthesis and biological properties of d- and 1-beta,beta-difluoroaspartic acid and beta,beta-difluoroasparagine.

Di-tert-butyl beta,beta-difluorooxaloacetate, prepared by fluorination of di-tert-butyl oxaloacetate with perchloryl fluoride, was converted to di-tert-butyl beta,beta-difluoroaspartate via its O-methyl oxime, followed by reduction. The tert-butyl ester was hydrolyzed to give a mixture of dl-beta,beta-difluoroaspartic acid, which was resolved via its brucine salts. dl-Difluoroaspartic acid was converted into beta,beta-difluoroasparagine by monoesterification and subsequent ammonolysis. Racemic beta,beta-difluoroaspartic acid inhibits aspartate aminotransferase. Cell growth of 3T3-F cells was slightly inhibited by l-beta,beta-difluoraspartic acid while the d enantiomer was without effect in this test system.

Animals↗