In order to better formulate an artificial shrimp diet, the protein composition of shrimp was assessed and the essential amino acids determined. Penaeus aztecus were treated to remove lipids, carbohydrates and other interfering substances, and the protein was hydrolyzed to its constituent amino acids. The amino acids were then quantitatively analyzed by gasliquid chromatography as their trimethylsilyl derivatives. The essential amino acids were then determined. Shrimp were injected with 14C-labeled glucose and analyses performed to determine which amino acids then exhibited radioactivity, i.e., were synthesized from the labeled glucose. Those amino acids which were not manufactured from the glucose were categorized as "essential".

No abstract

Biological reduction of 3,5-dinitro-o-toluamide results in the formation of amino-nitro-otoluamide. The isomer isolated from tissue homogenates was identified by chemical and physical tests as the 3-amino-5-nitro-o-toluamide. The isomer which is generally obtained by the chemical reduction of 3,5-dinitro-o-toluamide is the 5-amino-3-nitro-otoluamide.

approximately 3.3 p.p.m. was bound. After a 24-hour withdrawal period, the radioactivity remaining in the liver tissue was apparently all bound compound.Similar results were obtained with muscle tissue using a scintillation counting technique which permitted detection of lower concentrations of radioactivity (5). The majority of the extractable material appeared to disappear very rapidly so that within 24 hours the majority of it had disappeared from the tissue (1.4 to 0.2 p.p.m.). The nonextractable activity decreased slightly (0.3 to 0.1 p.p.m.) during the first 24 hours and then remained more or less constant during the remaining portion of the observation period.Although the acetone extraction does not preparing the carboxyl-labeled 3,5-dinitro-o-toluamide-C14 used in these studies.

before diazotizing and coupling. With method 3, this is not necessary.Detection methods 5, 6, 7, and 8 are used to locate specific compounds on the basis of the color produced (Table I).Of approximately 100 solvent systems tested, only those listed in Table II appeared to give satisfactory separation of the various compounds studied.Solvent systems A, C, and D give satisfactory separation of the dinitro compounds by using color tests 5, 6, or 7.