Synthesis and antimicrobial testing of 2-amino-6-hydroxymethyl-4-(3H)pyrido[3,2-d]pyrimidinone

Synthesis of 2-amino-6-hydroxymethyl-4-(3H)pyrido[3,2-d]pyrimidinone ( 5 ) from 2-amino-6-methyl-4-(3H)-pyrido[3,2-d]pyrimidinone ( 2 ) was accomplished by selenium dioxide oxidation of 2 to the aldehyde 4 followed by sodium borohydride reduction. Compound 2 was available in four steps from 5-aminouracil or in two steps from 5-nitroisocytosine ( 3a ). Catalytic reduction of 4 or 5 gave a mixture of 2-amino-6-methyl-5,6,7,8-tetrahydro-4-(3H)pyrido[3,2-d]pyrimidinone ( 6a ) and the 6-hydroxymethyl compound 6b . These compounds showed only weak inhibitory activity in the coupled reactions catalyzed by 7,8-dihydro-6-hydroxymethylpterin pyrophosphokinase and 7,8-dihydropteroate synthetase from E. Coli. No significant antibacterial activity was observed.     

Stereoselective Synthesis of HIV-1 Protease Inhibitor, DMP 323

DMP 323, a potent HIV-1 protease inhibitor, has been synthesized by an efficient stereoselective process, amenable to large scale preparations. The core C(2) symmetric diol was synthesized by a stereoselective pinacol coupling of CBZ protected D-phenylalanine. Judicious selection of protecting groups allowed cyclic urea formation under mild conditions, enhanced the ease of bis-alkylation, and led to intermediates which were easily purified without chromatography. Additionally, a one-pot, high yield process was developed to prepare the alkylating agent, 4-[(triphenylmethoxy)methyl]benzyl chloride from 1,4-benzenedimethanol.     

IMPROVED QUANTITATION OF DNA-PROTEIN CROSSLINKING CAUSED BY 405-nm MONOCHROMATIC NEAR-UV RADIATION IN HUMAN CELLS

An improved alkaline elution analysis has been used to estimate the yield of DNA-protein crosslinks induced in human P3 cells by monochromatic 405-nm near-ultraviolet radiation. Crosslinks are induced linearly over the fluence range studied, at a rate of 1.22 crosslinks per 10¹⁰ daltons per MJ m^-2± 0.066 (one standard error of the slope, N = 37). This rate is equivalent to 1360 crosslinks per cell genome per lethal event.     

Physiologisch-chemische Notizen

Ohne Zusammenfassung(Aus dem pharmaceutischen Institut der Universität.)     

Untersuchung von Butter

Ohne Zusammenfassung     

Capillaranalyse

Zusammenfassung Die Art des Papiers kann den Ausfall der Capillaranalyse von Farbstoffgemischen usw. erheblich beeinflussen. Man kann aus den Bildern oft Schlüsse ziehen auf die Eigenschaften des Papiers. Einfluß auf den Ausfall der Capillaranalyse haben auch der Gehalt der aufsteigenden Flüssigkeiten an Alkohol, Schutzkolloiden, ihr p_H-Wert usw.Ein abgeändertes Verfabren besteht darin, einen Tropfen der Farbstofflösung auf Papier eintrocknen und dann reines Wasser oder andere Lösemittel hochsteigen zu lassen. Diese Begrenzung der Menge des capillar Aufsteigenden schafft eine ähnliche Wirkung wie die Entwicklung in der Chromatographie. Genügt das Auseinanderziehen der einzelnen Farbbänder noch nicht, so kann man nachträglich senkrecht dazu nochmals eine Flüssigkeit hochsteigen lassen.     

Generation of a dynamic combinatorial library using sialic acid aldolase and in situ screening against wheat germ agglutinin

This paper describes the generation of a dynamic combinatorial library of sialic acid analogues using sialic acid aldolase. Addition of wheat germ agglutinin to the equilibrating libraries results in selective amplification of one or more members.