Effect of tetracycline on the absorption of sulfanilic acid was examined in the rat. It was found that, in the presence of tetracycline, sulfanilic acid disappeared faster from the small intestinal recirculating solution at pH 8.0. At pH 6.0, however, this absorption enhancement effect of tetracycline was not observed. Blood level analyses of sulfanilic acid were carrid out in the rat using in situ single loop preparation. In the presence of tetracycline, blood level of sulfanilic acid increased at pH 8.0 but not at 6.0 and this result agreed with the one obtained from intestinal recirculation method. Partition ratio (organic solvents/water) and UV spectral data of sulfanilic acid showed the absence of interaction between sulfanilic acid and tetracycline in recirculating solution. Results from tetracycline pretreatment experiments showed that sulfanilic acid disappeared faster from recirculating solution even in the absence of tetracycline. These results suggested that the increased absorption of sulfanilic acid is not due to complex formation with tetracycline in the gut lumen but to the direct effect of tetracycline on the absorptive membrane.
The preoperative identification of adrenal tumor is essential to correct diagnosis and appropriate treatment. Adrenal venography is one of the most useful adjuncts for this purpose, but catheters of various types introduced in the past are not necessarily well configured to catheterize adrenal veins. The catheter newly designed by us made catheterization of the left adrenal vein much easier even for unskilled hands. Our new catheter has been used in 20 of 55 venographical studies which have been carried out in our service. Determination of cortisol concentrations in adrenal venous blood which was performed in 6 cases failed to give any clue to determine the laterality of the existing adrenal tumor.
In a previous paper, we reported the availability of mass spectrometry as a useful technique for the identification of drug metabolites. In the present study, the metabolites of 7-hydroxy-4-methylcoumarin in rat were investigated by mass spectrometric technique as shown in Chart 1. A small amount of the administrated urine was evaporated under reduced pressure and the mass spectrum of the residue was recorded(MS-1). From this spectrum, we estimated the presence of various metabolites by observing the shift of mass numbers in high mass region. The remained urine was added with saturated aqueous solution of basic lead acetate and the precipitate was filtrated. After evaporation of the filtrate under reduced pressure various metabolites in the residue were separated by thin-layer chromatography. The mass spectra of extracts of each spot on the thin-layer chromatography were recorded(MS-3). From these spectra, structures of major metabolites were identified by aid of various physical methods(UV, IR, NMR etc.)and of some chemical techniques. Futhermore, the precipitate. was suspended in 50% aqueous MeOH and treated with H2S gas. The filtrate thus obtained was evaporated under reduced pressure and the mass spectrum of the residue was recorded after silylation(MS-4). From this spectrum, we can confirm the presence of various glucuronides.By using these techniques, four metabolites and their glucuronides of the substrate, 7-hydroxy-4-methylcoumarin, were easily identified(Fig. 10).
The structure of the mass spectral molecular ions of 4-hydroxycoumarins is discussed. From the fact that variation of inlet temperatures did not affect the spectral patterns, the molecular ion is considered not to be an equilibrium mixture of keto and enol forms. In contrast to earlier proposals, the enolic nature of the molecular ion is demonstrated by comparison of the spectra with those of acetylated derivatives and by deuterium-labelling experiments.
Hydrogen atoms lost by dehydration in electron ionization mass spectrometry of methyl esters of abscisic acid and 1′,4′-trans and 1′,4′-cis diolabscisic acids were identified using their deuterated analogs. Analysis of mass spectra of the deuterated analogs showed that, in methyl ester of abscisic acid, the 4-hydrogen atom bonded to a double bond was mainly eliminated with a 1′-hydroxyl group to give a dehydrated ion at m/z 260. This unusual dehydration could be due to a proximity effect between the 1′-hydroxyl group and 4-hydrogen. In methyl esters of 1′,4′-diolabscisic acids, the first dehydration derived from loss of the 4′-hydroxyl group was accompanied with a hydrogen atom of the 1′-hydroxyl group, and the second dehydration derived from 1′-oxygen involved 3′-,4′-,5′-, and 7′-hydrogen atoms, and partially involved the 4-hydrogen atom. This indicated that the structure of the first dehydrated ion of the 1′,4′-diolabscisic acid methyl esters was not 4′-deoxyabscisic acid methyl ester. The migration of the hydroxyl hydrogen atom to another hydroxyl group in the first dehydration has also been demonstrated in dehydration of cis-1,4-cyclohexanediol. Based on these results, we proposed dehydration mechanisms in EI MS of methyl esters of abscisic acid and 1′,4′-diolabscisic acids.
Journal Article Chalcone Tetramers, Lophirachalcone and Alatachalcone, from Lophira alata as Possible Anti-tumor Promoters Get access Akira Murakami, Akira Murakami Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto 606, Japan Search for other works by this author on: Oxford Academic Google Scholar Shizuko Tanaka, Shizuko Tanaka Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto 606, Japan Search for other works by this author on: Oxford Academic Google Scholar Hajime Ohigashi, Hajime Ohigashi Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto 606, Japan Search for other works by this author on: Oxford Academic Google Scholar Mitsuru Hirota, Mitsuru Hirota Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto 606, JapanDepartment of Bioscience and Technology, Faculty of Agriculture, Shinsyu University, Minami-minowa, Kami-ina, Nagano 399–45, Japan Search for other works by this author on: Oxford Academic Google Scholar Ryozo Irie, Ryozo Irie Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto 606, JapanDepartment of Bioscience and Technology, Faculty of Agriculture, Shinsyu University, Minami-minowa, Kami-ina, Nagano 399–45, Japan Search for other works by this author on: Oxford Academic Google Scholar Naohito Takeda, Naohito Takeda Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto 606, JapanFaculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, Japan Search for other works by this author on: Oxford Academic Google Scholar Akira Tatematsu, Akira Tatematsu Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto 606, JapanFaculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, Japan Search for other works by this author on: Oxford Academic Google Scholar Koichi Koshimizu Koichi Koshimizu Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto 606, Japan To whom all correspondence should be addressed Search for other works by this author on: Oxford Academic Google Scholar Bioscience, Biotechnology, and Biochemistry, Volume 56, Issue 5, 1 January 1992, Pages 769–772, https://doi.org/10.1271/bbb.56.769 Published: 01 January 1992 Article history Received: 08 November 1991 Published: 01 January 1992
