Tritium-Labeled Compounds VI. Alditols-1-t and Alditols-2-t

Area of Science:

• Carbohydrate Chemistry
• Isotope Labeling
• Organic Synthesis

Background:

• Tritium labeling is crucial for metabolic and mechanistic studies of carbohydrates.
• Accurate synthesis of labeled compounds is essential for quantitative analysis.

Purpose of the Study:

• To synthesize a comprehensive series of 1-tritium-labeled alditols from aldoses and aldonic lactones.
• To prepare and separate 2-tritium-labeled epimeric alditol pairs from ketoses.
• To investigate stereomeric relationships of labeled alditols and their corresponding ketoses.

Main Methods:

• Reduction of aldoses and aldonic lactones using lithium borohydride-t.
• Reduction of ketoses using lithium borohydride-t, followed by separation of epimeric products.
• Isotope-dilution technique for determining yields of epimeric alditols.
• Oxidation with Acetobacter suboxydans to study stereomeric relationships.

Main Results:

• Successfully synthesized 1-tritium-labeled alditols including d-arabinitol-1-t, d-mannitol-1(6)-t, and d-glucitol-1-t.
• Prepared and separated epimeric pairs of 2-tritium-labeled alditols, such as d-mannitol-2(5)-t/d-glucitol-2-t and d-galactitol-2-t/d-talitol-2-t.
• Quantified yields of epimeric alditols derived from ketoses.

Conclusions:

• Established reliable synthetic routes for various tritium-labeled alditols.
• Provided insights into the stereochemistry of alditol synthesis and their precursor ketoses.
• The labeled alditols serve as valuable tools for biochemical and metabolic research.