L-Histidine Conversion to a Urinary Glutamic Acid Derivative in Folic-Deficient Rats

Abstract

Communications to the Editor Vol. 75 and 51% styrene when initiated by typical free radical catalysts such as benzoyl peroxide at 60°; for typical cationic initiators such as SnCh a copolymer containing more than 99% styrene is obtained; for typical anionic initiators the copolymer contains more than 99% methyl methacrylate. Thus, the composition of the copolymer formed from /3-ray initiation indicates that a free radical mechanism is operative.By polymerizing pure styrene at 30°with various concentrations of 2-azobisisobutyronitrile, we have shown that the monoradical line3 at 30°is given by: 1 /D.P. = 2.0 X 10-6 + 69.2 Rp (Rp = rate of polymerization in moles liters-1 sec.-1). For the /3-ray induced polymerization the value of Rp is 4.16 X 10-7 (see Table 1) and the D.P. is 1.07 X 104. This point falls on the monoradical line, which constitutes another proof of the free radical mechanism.The rate of initiation of polymer chains for the /3-ray induced polymerization can be computed from Rp and the slope of the monoradical line.2 It is equal to 2.40 X 10-11 mole liter-1 sec.-1 A similar calculation was made for methyl methacrylate.If the /3-ray induced polymerization, which we have proved to proceed via radicals, occurs homogeneously throughout the medium, and if the energy to produce the initiating radicals be estimated at 50 kcal./mole, we compute that 0.19% of the absorbed radiant energy is effective in producing initiating radicals in the case of styrene and 2.3% of the energy is effective in producing initiating radicals in methyl methacrylate.

Enzymatic Deacetylation of N-Acetylhistamine in Animal Tissues

“…Enzymatic acetylation of biogenic amines has been well documented (1,2,3,5,6,7,36,37). In the present study, enzymatic deacetylation was demonstrated.…”

“…On the other hand, Werle and Palm (4) reported the finding of a small amount of N-acetylhistamine in the nerve of normal cows. Tabor et al (5) showed the in vitro acetylation of histamine in a partially purified pigeon liver preparation that acetylated p-nitroaniline, p-aminobenzoic acid and numerous other amines as well as that of histamine. Mammalian tissues also have been found to contain an en zyme catalyzing the N-acetylation of a number of biogenic amines (6,7).…”

A Method for the Determination of Formiminoglutamic Acid in Urine1

“…This activity is not present, however, in the partially purified preparations described in this paper. 3 Silverman, Gardiner, and Condit (19) utes, and the supernatant solution collected.5 Subsequent steps are carried out at 1 to 30 C. 5 The enzyme purification procedure presented here has been very reproducible, and enzymatic assays have not ordinarily been carried out after each step. If desired, however, the following rapid assay can be used to follow the purification procedure.…”

Urinary Excretion of Formiminoglutamic Acid by Human Subjects after Antifolic Acid Therapy1

“…Previous results (2)(3)(4)(5) have demonstrated that the urinary excretion of this compound is markedly increased in folic acid-deficient rats. Formiminoglutamic acid has also been reported (6,7) in the urine of several patients receiving folic acid antagonists, although the techniques available for these studies were relatively cumbersome and inaccurate.…”