• Food Science and Biotechnology
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• 제15권4호
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• pp.555-558
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• 2006

The chemical reduction of Pseudomonas syringae subsp. phaseolicola alginates produces neutral polymers of D-mannose and L-gulose in source specific ratios. L-Gulose was highly sensitive to degradation by 1N HCl at $100^{\circ}C$. As hydrolysis time increased, gulose recovery decreased to 22% after 4 hr, whereas 98% of the D-mannose was recovered under the same conditions. Thin layer chromatography showed the formation of a second product upon L-gulose acid hydrolysis. This new product had a rate of flow (Rf) value of 0.58, identical to that of 1,6 anhydro-${\beta}$-D-mannopyranose and very close to that of 1,6 anhydro-${\beta}$-D-glucopyranose (Rf=0.60). Because of the difference in acid sensitivity between L-gulose and D-mannose, normal acid hydrolytic techniques applied to reduced alginates produces erroneous mannuronic acid (M): guluronic acid (G) ratio's unless one accounts for the differential rates of destruction of each sugar.

• 약학회지
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• 제37권6호
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• pp.591-597
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• 1993

Two new 6-azauracil dioxolane nucleosides which are related to Dioxolane T and expected to have anti-HIV activity were asymmetrically synthesized. The key intermediate 8 have been synthesized in ten steps from D-mannose and condensed with 6-azauracil to give 13 and 14 after desilylation, respectively.