title: Cryoprotection with L- and meso-trehalose: stereochemical implications.
abstract: Two unnatural stereoisomers of alpha,alpha-trehalose (L- and meso-trehalose) were synthesized and evaluated as cryoprotectants in order to determine the functional consequences of relative or absolute stereochemistry on their physicochemical properties. Adherent yeast cell cultures were frozen in 10% solutions of D-, L-, and meso-trehalose for periods of 7-28 days, then evaluated by a MTT viability assay. D- and L-trehalose were equally effective in maintaining high rates of cell survival, thus demonstrating the absence of chiral discrimination at the carbohydrate-lipid interface, whereas meso-trehalose was inferior in cryoprotection efficacy. Differential scanning calorimetry revealed a difference in the glass transition temperatures (Tg) of D- and meso-trehalose of nearly 75 degrees C. This can be attributed to differences in conformational behavior, as portrayed by torsional energy maps for rotation about the glycosidic bonds of D- and meso-trehalose. We conclude that the biostabilizing properties of alpha,alpha-trehalose depend on relative stereochemical factors, but are independent of absolute stereochemical configuration.
authors.affiliation: Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907-2084, USA.
authors.forename: Seung-Kee
authors.initials: SK
authors.lastname: Seo
authors.forename: Michael L
authors.initials: ML
authors.lastname: McClintock
authors.forename: Alexander
authors.initials: A
authors.lastname: Wei
mesh_terms: D002152:Calorimetry, Differential Scanning; D002240:Carbohydrate Sequence; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000737:chemistry* / Q000494:pharmacology; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D015394:Molecular Structure; D044367:Phase Transition; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013696:Temperature; D014199:Trehalose / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D003451:Cryoprotective Agents; D014199:Trehalose