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Sodium orthophenylphenate (SOPP) has been used extensively for >40 years to control postharvest diseases of citrus fruits. Studies of the metabolism of [(14)C]SOPP have identified orthophenylphenol (OPP) as the major metabolite with phenylhydroquinone (PHQ) as a minor metabolite. The whole-fruit tolerance in the United States for OPP is 10 ppm. This study was conducted to quantify terminal OPP and PHQ residues in whole Navel oranges, grapefruit, and lemons following SOPP applications at maximum application rates and following commercial application and fruit storage practices. OPP and PHQ residues also were determined in products processed from treated Navel oranges. OPP residues in lemons, Navel oranges, and grapefruit treated with SOPP using foamer wash and shipping wax applications remained below the 10 ppm tolerance, and PHQ residues were all < or =0.439 ppm. PHQ residues in whole fruit increased with time in commercial storage. OPP residues in all Navel orange matrices except oil remained relatively stable with time in commercial storage; residues in oil declined substantially while in storage.

We have synthesized as potential imaging agents for human breast tumors a series of hexestrol analogues bearing the halogens fluorine, chlorine, bromine, and iodine at the terminus of the hexane chain. The binding affinity of these compounds for the estrogen receptor from uterine tissues forms a monotonically decreasing series, starting at 129% of that of estradiol for the fluoro analogue and decreasing to 60% for the iodo analogue. Such a modest decrease in binding affinity is thought to reflect the preference of the receptor for lipophilic groups and for substituents of moderate steric size at this site, parameters which change in opposite directions in the halogen sequence going from fluorine to iodine. Three estrogenic bis(trifluoromethyl)diphenylethylenes, prepared by DuPont, also showed substantial binding affinities for the estrogen receptor. In terms of ease of radiolabeling and high receptor binding selectivity, the compound that appears to be the most promising candidate for a breast tumor imaging agent in these series is the chain terminal fluorohexestrol.

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