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After extraction from whole cells, and purification by gel filtration, the chemical composition and molecular mass estimation of the cell-wall phosphopeptidomannan (PPM) showed no significant difference respectively between flocculent, weakly, very weakly and non-flocculent Kluyveromyces lactis yeast strains. However, when PPMs were tested as ligands of a lectin, extracted from the flocculent strain, the PPM isolated from the flocculent and weakly flocculent strain were recognized to a higher degree than those isolated from the non and very weakly flocculent strains. Acetolysis of PPM extracted from the four strains produced five oligosaccharide fractions corresponding to mono-, di-, tri-, penta-and hexa-saccharides. The flocculent strain was characterised by a high content of di-and penta-saccharides. The 1H NMR analysis of the oligosaccharides demonstrated that the flocculent strain contained equivalent levels of the two mannobioses: Man(alpha 1--2)Man and Man(alpha 1--3)Man and of the two mannotrioses Man(alpha 1--2)Man(alpha 1--2)Man and Man(alpha 1--3)Man(alpha 1--2)Man. In contrast, the non-flocculent and the very weakly flocculent strains contained a single type of mannobiose Man(alpha 1--2)Man and one type of mannotriose Man(alpha 1--2)Man(alpha 1--2)Man.

This paper reports a chemico-enzymatic synthesis of beta-CD derivatives. The recognition properties of these derivatives were tested using flocculating yeast and isolated lectins. It was observed that the substitution of beta-cyclodextrins with galactose end arms induces the better recognition by a cell-linked galactose-specific lectin. The physicochemical effects of the beta-CD derivatives on membranes were estimated using red blood cells and the effects on the viability of yeast and human rectal tumor cells were appreciated by measuring the mitochondrial deshydrogenase activity. The substitutions of the beta-CD ring by sugar antennae decrease the negative physicochemical effects of the beta-CD, ie their hemolytic properties. However, these substitutions induce significant modifications of the biological properties of the molecules, particularly the cytotoxicity and the growth of eukaryotic cells.

Six potential carriers incorporating one or more thio-D-galactosyl residue(s) linked to β-cyclodextrin as complexing tool, were synthesized and evaluated in vitro for their specific recognition towards a cell wall galactose specific lectin (KbCWL). The inhibition of yeast flocculation by the compounds 5–10 was compared to reference compounds as, p-nitrophenyl-galactose or disaccharides containing an α or β-galactose non reducing terminal unit. Among the tested molecules, the heptakis galactosyl-CD derivatives were found the most efficient compounds.