Synthesis of a New Glycoconjugate with Di- ᴅ -Psicose Anhydride Structure.

Demand for healthy diets has led researchers to explore new saccharide as sucrose alternatives. ᴅ -Psicose, the C-3 epimer of ᴅ -fructose, has a similar sweetness intensity to sucrose but contributes fewer calories. This study proposes a disaccharide with a stable structure derived from ᴅ -psicose. The compound with a spiro-tricyclic core was generated at 32% conversion via caramelization of ᴅ -psicose under acidic anhydrous conditions. The compound was identified by high-resolution mass spectrometry and multi-dimensional nuclear magnetic resonance (NMR). The molecular formula was established as C 12 H 20 O 10 from the molecular weight of m / z 324.1055. Twelve signals were observed by the 13 C NMR spectrum. This compound, denoted di- ᴅ -psicose anhydride (DPA), exhibited a lower water solubility (40 g/L) and higher thermal stability (peak temperature = 194.7 °C) than that of ᴅ -psicose (peak temperature = 126.5 °C). The quantitatively evaluated metal ion scavenging ability of DPA was the best in magnesium (average 98.6 ± 1.1%). This synthesis methodology can provide disaccharides with high stability-reducing heavy metals.