On lineγ-Ray emission following 30 MeV/A12C induced reactions on some medium-heavy targets

Preliminary results on residual nuclei production in 30 MeV/A¹²C interaction with medium heavy targets are presented. Gamma-ray spectroscopic techniques were used. Evidence for charge and angular momentum transfer is found.

     

Methotrexate analogs. 7. Synthesis of two higher homologs and a positional isomer of methotrexate diethyl ester as potential antitumor agents

Analogs of methotrexate diethyl ester ( 1 ) were prepared, in which the distances separating the ester functions from each other and from the carboxamide function of the p-aminobenzoate moiety were varied via the use of methylene groups as “spacers”. The diethyl esters 3 and 4 , with D,L-α-aminoadipate and D,L-α-aminopimelate side chains in place of L-glutamate, displayed approximately the same order of activity as compound 1 against bacterial and mammalian cells in culture, and were inhibitors of the enzyme dihydrofolate reductase. When given intraperitoneally to L1210 1eukemic mice at a dose of 120 mg./kg. q3d 1,4,7, compound 4 produced a 67% increase in survival and no evidence of toxicity, whereas methotrexate diethyl ester ( 1 ) gave a 44% increase in survival at a dose of 45 mg./kg. q3d 1,4,7 but was toxic at higher doses. The positional isomer 2 was inactive.     

Novel electrophoresis mechanism based on synchronous alternating drag perturbation

We present a novel means of transporting molecules in solution by applying a zero-time-average alternating motive force to the molecules, and perturbing the molecular drag coefficient synchronously with the applied force, thus causing a net drift in a direction determined by the phase of the alternating drag perturbation relative to the alternating force. We apply an electrophoretic form of the method to transport and concentrate DNA in a gel, such that all molecules migrate on average away from the nearest electrode and toward a central region. Since an electrode does not occupy this central region, this method presents the possibility of transporting and focusing DNA and other charged molecules in regions free from electrodes and the associated electrochemistry.     

Chemical and biological studies on dihydro-s-triazines. XVII. Modifications of the three-component synthesis favoring the formation of 2-guanidino-4-methylquinazoline byproducts

A modified three-component reaction of arylamines, cyanoguanidine, and acetone is described, wherein formation of anomalous guanidinoquinazoline byproducts is greatly enhanced at the expense of the normal dihydro-s-triazines. Four new guanidinoquinazolines and four new dihydro-s-triazines were synthesized via this modification, starting from 2,4-, 2,5-, 3,4-, and 3,5-dimethoxyaniline. The guanidinoquinazoline to dihydro-s-triazine ratio was much higher with 3,4- and 3,5-dimethoxyaniline than with 2,4-dimethoxyaniline. 2,5-Dimethoxyaniline gave an unexpectedly low yield of guanidinoquinazoline, apparently because of steric hindrance. The modified three-component synthesis was also examined in detail with 2-naphthylamine.