The reaction of 4-hydrazino-8-(trifluoromethyl)quinoline (2) with ethoxymethylenecyanoacetate afforded ethyl 5-amino-1-[8-(trifluoromethyl)quinolin-4-yl]-1H-pyrazole-4-carboxylate (3) and that with ethoxymethylenemalononitrile afforded 5-amino-1-[8-(trifluoromethyl)quinolin-4-yl]-1H-pyrazole-4-carbonitrile (5). Compounds 3 and 5 were hydrolyzed to get 5-amino-1-[8-(trifluoromethyl)quinolin-4-yl...

Pyrano[2,3-c]pyrazoles are obtained via mixing ethyl acetoacetate, hydrazine hydrate, aldehydes or ketones and malononitrile in the absence of solvent. These same products were also obtained by reacting arylidenemalononitriles 3 with 3-methyl-2-pyrazolin-5-ones. NOE difference experiments confirmed that these products exist solely in the 2H form. Similar treatments of 3-amino-2-pyrazolin-5-one ...

There are two main forces that affect usage of synonymous codons: directional mutational pressure and selection. The effectiveness of protein translation is usually considered as the main selectional factor. However, biased codon usage can also be a byproduct of a general selection at the amino acid level interacting with nucleotide replacements. To evaluate the validity and strength of such an...

silica-bonded n-propyldiethylenetriamine sulfamic acid (spdtsa) is employed as a recyclable heterogeneous solid acid catalyst for the synthesis of benzopyrano[2,3-d]pyrimidines  through one-pot condensation reaction of salicylaldehydes, malononitrile and secondary amines  at room temperature under solvent-free conditions. spdtsa showed much the same efficiency when used in consecutive reaction ...

The rate of multiplication of a population of cultured human lung fibroblasts is determined by the level of common nutrients and serum factors in the medium. By application of the principles of Henri--Michaelis--Menten kinetic analysis to cell growth in vitro, the relationship between the level of a macromolecular fraction of serum that contains growth factors and the concentration of individua...

DNA preparations from seven bacterial species and from the E. coli phage T4 can, after denaturation with alkali, be separated chromatographically into two distinct components (L and H) through intermittent gradient elution from methylated albumin kieselguhr columns. The direct chemical analysis of the L and H fractions isolated from DNA specimens of the AT type shows them to exhibit a high degr...

Gale & Folkes (1953a, b) showed that there is an inorease in the nucleic acid content of washed suspensions of Staphylococcus aureus (Micrococcu4s pyogenes var. aureus) when these are incubated in the presence of glucose, purines, pyrimidines and a mixture of all those amino acids necessary for protein synthesis. Omission of an essential amino acid resulted in cessation of nucleic acid synthesi...

All metazoan cells in culture require either arginine or citrulline for growth (1, 2). The importance of arginine is emphasized by the fact that it is rapidly depleted from the medium in many primary and established cell strains (3). The L-929 fibroblasts maintained in this laboratory and shown to harbor a pleuropneumonia-like infection also demonstrate a.n elevated requirement for this amino a...

Oxazolo[5,4-d]pyrimidines can be considered as 9-oxa-purine analogs of naturally occurring nucleic acid bases. Interest in this ring system has increased due to recent reports of biologically active derivatives. In particular, 5-aminooxazolo[5,4-d]pyrimidine-7(6H)-ones (9-oxa-guanines) have been shown to inhibit ricin. The preparation of a series of 2-substituted 5-aminooxazolo[5,4-d]pyrimidin-...

The chemical changes occurring during embryonic development have been studied by several workers (l-3). In the hen’s egg there is very little nucleic acid present, whereas a considerable synthesis of both desoxypentose nucleic acid (DNA) and ribose nucleic acid (RNA) occurs in the embryo (4-6). Recently, methods for the determination of purines and pyrimidines in small amounts of tissue have be...