Spectroscopic properties of porphyropsins

摘要: Abstract The difference spectra of porphyropsins bleached at various pH as well in the presence hydroxylamine and sodium borohydride are described, their relationships with absorption discussed. Since bleaching NaBH 4 results formation 3-dehydro N-retinylopsin, an band well-separated from those porphyropsins, obtained this reagent very close to corresponding over a considerable wavelength range. These spectra, together spectrum porphyropsin extract still containing some impurities, used obtain approximation pure porphyropsin. Bleaching also gives which quite spectrum, but more restricted Plotted against wavenumber scale, instead wavelength, (hydroxylamine) ranging λ max 521 543 nm identical shape. we considering only regions unaffected by photoproduct absorption, is applicable well. observations basis for tabulating standard spectrum. Tables arc included enable easy calculation Amax any porphyropsin, given its spectrum: conversely, they may be predict unknown . A different, narrower must case rhodopsins. spectroscopic properties differ rhodopsins respect maxima, extinction coefficients differences found between compounds retinol 3-dehydroretinol series, it concluded that similar features chromophoric structure influence light-absorption both photopigments these substances.