New compounds of the nitroimidazole series have been synthesized as radiosensitizers which selectively sensitize hypoxic cells to the lethal effect of radiation. The reaction of 2,4(5)-dinitroimidazole (2) with chloroethanol or hydrochloric acid yielded 4(5)-nitro-5(4)-chloroimidazole (3), which upon reaction with ethylene oxide yielded the 4-nitro-5-chloroimidazole-1-ethanol (6). Reaction of 2 with ethylene oxide resulted in a mixture of two compounds, the 2,4-dinitroimidazole-1-ethanol (4) and 2,3-dihydro-5-nitroimidazo[2,1-b]oxazole (5). The structure of the new heterocyclic compound 5 was confirmed by 1H NMR, mass spectrum, and X-ray crystallography. These agents were tested for their ability to sensitize hypoxic Escherichia coli cells to killing by ionizing radiation. Compound 4 was found to be the most active agent of this series of compounds.

In a previous study (Candy, D. J. (1967), Biochem. J. 103, 666) a locust fat body extract was shown to convert myo-to scyZZo-inositol in a reaction involving NADT. The same enzyme preparation reduced scyllomyo-inosose (2,4,6/ 3,5-pentahydroxycyclohexanone) to .scyZZo-inositol, however, with NADPH. This difference in cofactor requirements suggested the presence of more than one enzyme and led us to the study of these systems in the American cockroach, Periplaneta americana L. Dialyzed fat body homogenates were the enzyme source. Analysis of the products of the enzyme reactions was by gas chromatography and by gas chromatography-mass spectrometry of the trimethylsilyl ethers. An inositol: NAD+ epimerase (pH optimum 7.5-8.0) was found which was capable of carrrying out the following inositol conversions: epi-> myo-[scyllo-+ chiro-+ neo-]. The system epimerizes both (d)-and (L)cZiZra-inositol but not mucoinositol. The degree to which the epimerase operates on the t From the Departments of Psychiatry and Biological Chemistry,

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