Exopolymers which anchor sessile bacteria to metallic surfaces exhibit the capacity to bind copper ions with high affinity. Ionized carboxyl groups on the polymers appear to participate in cupric ion binding. Formation of complexes between the polymers and cupric ions results in the release of protons from the polymer molecule. Attenuated total reflectance Fourier transform infrared spectroscopy showed that polymers composed of acidic polysaccharides promote ionization and deterioration of metallic copper surfaces. X-ray photoelectron spectroscopy studies revealed that the ionic state of the surface-derived copper varied depending on the type of acidic polysaccharide that was in contact with the surface. The results suggest that exopolymers elaborated by adherent bacteria can enhance corrosion of the surfaces with which they are associated.
It has been established that chlorpromazine undergoes photooxidation via its cation radical, yielding chlorpromazine 5-sulfoxide as an ultimate photoproduct. Molecular oxygen has been found indispensable not only for the formation of chlorpromazine cation radical but also for the formation of the sulfoxide from the radical. Oxygen atom in the sulfoxide originates from the atmospheric oxygen and not from water, which was ascertained by both tracer experiment and kinetic analysis. It was concluded that phenazathionium ion is not involved in the reaction. The possibility of singlet oxygen participation in the photooxidation was also ruled out. An intermediate, which is formed from the cation radical, was found as a precursor of the sulfoxide and was tentatively assigned as a peroxyl type radical.
Techniques for coating thin copper films on the surface of cylindrical germanium internal reflection elements are described. These films were then characterized in an aqueous environment. The expected exponential relationship between the depth of penetration of the evanescent wave into water and the thickness of the copper film was verified experimentally. The stability of vacuum-deposited copper coatings was strong enough that the internal reflection element could be exposed to an aqueous solution of a polysaccharide for more than 40 h. The weak adhesion of polysaccharides to copper surfaces was studied spectroscopically.
A series of hindered phenolic 1,3-benzoxathioles (7a-l) were prepared and investigated for biological properties. Many compounds had LPO-lowering, antisuperoxide inhibiting, SRS-A inhibiting, and 5-lipoxygenase inhibiting activities. Among them, 5-hydroxy-4,6,7-trimethyl-2-propyl-1,3-benzoxathiole (7d) and 3-(5-hydroxy-4,6,7-trimethyl-1,3-benzoxathiol-2-yl)propanol (7j) were most potent in SRS-A inhibiting and 5-lipoxygenase inhibiting activities, respectively, and were selected for further development as candidate drugs for the treatment of asthma.
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