Photolysis of 2-azi-2-deoxy-d-arabino-hexitol and analogous hexitols; the ineffectiveness of certain carbohydrate diazirines as photoaffinity labels
✍ Scribed by Jochen Lehmann; Stefan Petry
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 773 KB
- Volume
- 239
- Category
- Article
- ISSN
- 0008-6215
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✦ Synopsis
ABSTRACI
Three diazirines 2-axi-2-deoxy-o-urabino-hexitol (41, its l-deoxy analogue (S), and 3-axi-3,6-dideoxy-r_-xylo-hexitol (9) were synthesised and their products of photolysis analysed by TLC. Diazirine 4 gave exclusively 2deoxy-o-arubirw-hexose (121, 5 gave predominantly 1,2-dideoxy-D-erythro-3-hexulose (10) and 1-deoxy-o-glucitO1 (ll), and 9 did not yield any main product. Carrying out the irradiation of 4 in D,O gave selectively (2S@koxy-oarubzizo-@*H)hexose (12a). The results indicate that photolysis of a diaxirine flanked by a hydroxymethyl group, as in compound 4, leads to a rapid and stereoselective intramolecular reaction of the intermediate. This may be an explanation of why compound 4 is ineffective as a photoaffinity reagent for mannitol permease (o-mannitol-specific enzyme II) of the E. coli phosphotransferase system for which it is a substrate. A secondary hydroxymethylene group has a less pronounced effect and still allows some reaction with the medium.