In order to study the role of hydrophobicity in bitter peptides, several O-aminoacyl sugars, in which amino acids or peptides were attached to the 2- and 3-position of methyl alpha-D-glucopyranoside, were synthesized and sensory analyses were carried out. It was found that the bitterness increased as the hydrophobicity of compounds increased, implying that the bitterness receptor recognizes the hydrophobicity of bitter peptides. A structure for the bitterness receptor is also discussed.

Novel acrylic monomers bearing a monosaccharide residue were synthesized in reactions of some methyl glycosides with 2-hydroxylethyl acrylate or methacrylate in the presence of heteropoly acid. All of them were highly soluble in water and readily polymerized by radical initiators.

Copolymers having pendant monosaccharide groups were synthesized by copolymerizing 2-(glucosy1oxy)ethyl methacrylate (GEMA, l), with methyl methacrylate (MMA) or styrene (St).The surface characteristics of the copolymer films were investigated by means of contact angle measurements, X-ray photoelectron spectroscopy (XPS), and protein adsorption. The surface free energy of the GEMA/St copolymer films was constant in the range of a GEMA content from 10 mol-To to 60 mol-To. Insertion of GEMA of over 60 mol-To, however, caused an increase of the surface free energy of the copolymer films. The surface composition determined by means of XPS supported the result from surface free energy measurements. There was a significant difference between the GEMA/St and GEMA/MMA copolymer films in the effect of the GEMA content on the surface characteristics of the films. The differences could be explained on the basis of the sequence of monomeric units in each copolymer. Immersing the copolymer films in hot water made the copolymer surface more hydrophilic. This is because each component migrates to the surface or the bulk in order to minimize the surface free energy of the copolymer films. The introduction of GEMA to the copolymer suppressed fibrinogen adsorption onto the copolymer films.

We synthesized a series of non-ionic detergents, alkyl thiomaltosides, and investigated their properties and usefulness. We solubilized membrane proteins of Vibrio parahaemolyticus using the detergents. With octyl thiomaltoside, nonyl thiomaltoside, decyl thiomaltoside, or undecyl thiomaltoside, we observed satisfactory solubilization of the membrane proteins. Alkyl thiomaltosides possessing longer alkyl chains showed better solubilization than ones possessing shorter chains. H(+)-translocating ATPase (F0F1), which is localized in the cytoplasmic membrane (inner membrane), was solubilized with the detergents, and the solubilized enzyme showed much higher specific activity than that solubilized with octyl glucoside or heptyl thioglucoside, other useful non-ionic detergents. 5'-Nucleotidase, which seems to be an outer membrane protein, was also efficiently solubilized with the alkyl thiomaltosides. Membrane proteins of Escherichia coli were also efficiently solubilized with the detergents. Octyl thiomaltoside and nonyl thiomaltoside were removed fairly rapidly on dialysis. Decyl thiomaltoside was removed slowly, and undecyl thiomaltoside and dodecyl thiomaltoside were difficult to remove by dialysis.

Glucosyloxyethyl methacrylate (GEMA) was copolymerized with butyl acrylate (BA) for the preparation of a biomedical pressure‐sensitive adhesive with pendant monosaccharides, for possible use in medical applications. The measurements of 180° peel strength, ball tack, and holding power for the GEMA–BA copolymer films revealed that the film at the GEMA content of 5 mol % has excellent pressure‐sensitive adhesive properties. Protein adsorption onto the GEMA–BA copolymer film hardly occurred due to very low interfacial free energy between its surface and water. Release profiles of vitamin B12 from the GEMA–BA copolymer film suggests that it is useful as a material for a transdermal therapeutic system. © 1995 John Wiley & Sons, Inc.