One-step synthesis of biotinyl photoprobes from unprotected carbohydrates

A simple and versatile approach for the preparation of carbohydrate photoprobes has been developed. By a single-step reaction at 37 degrees C, a biotinylated carbene-generating unit was introduced to the reducing end of unprotected carbohydrates. Micromole quantities of N-acetyllactosamine, Lewis X trisaccharide, and sialyl Lewis X tetrasaccharide were easily converted to their biotinylated photoreactive analogues, which enabled the nonradioisotopic chemiluminescent detection of the photolabeled products. Thus, a sequence of lectin photoaffinity labeling, from the probe synthesis to the detection of labeled protein, was readily accomplished within one week. Our strategy may be applicable to any aldehyde-bearing ligand.

Membrane Anchoring and Intervesicle Transfer of a Derivative of the Antibiotic Moenomycin A.

The anchoring of moenomycin A (1) to the bacterial cell cytoplasmic membrane is essential for its biological activity. The first details of the strength of this interaction and the kinetics of the diffusion-mediated intervesicle transfer have been obtained by means of fluorescence spectroscopic methods using a coumarin-labeled moenomycin A derivative.