Space-Group Revision for 4-Formylphenylboronic Acid

The space group of the title compound, C7H7BO3, previously reported to be P, is properly Cc. There is no disorder of the formyl group or in the H atoms of the B(OH)2 group. Molecules lie on approximate twofold axes and are related by approximate centers, which relate all but the formyl O atom and boronic acid H atoms. The B-O distances are 1.363 (2) and 1.370 (2) Å

Mild colorimetric detection of sialic acid

As part of a broader program focusing on the detection of colorless biomolecules in the visible region, a simple and mild procedure for the visual detection of the most abundant sialic acid at room temperature and neutral pH is reported. The role of the interaction of the sialic acid amide with boron in a readily synthesized boronic acid-based receptor is an important feature of the signaling mechanism. Selectivity of reaction can be tuned by the judicious choice of solvents. This study embodies a departure from many of the author\u27s earlier efforts in sugar solutions that are not heated, affording relatively more selective and milder detection

Visual Detection of Cysteine and Homocysteine

The determination of cysteine and homocysteine levels is of great current interest for the monitoring of desease states. A new colorimetric method for the simultaneous detection of L-cysteine and L-homocysteine has been developed. A fluorescein derivative reacts with the above amino acids, producing their respective thiazolidines resulting in color changes. Interference from other amino acids and proteins is minimal. Copyright © 2004 American Chemical Society

Chromophore formation in resorcinarene solutions and the visual detection of mono- and oligosaccharides

The colorimetric properties of resorcinarene solutions had not been investigated since Baeyer\u27s initial synthesis. We recently reported that solutions containing resorcinarene macrocycles develop color upon heating or standing. In the presence of saccharides, these solutions exhibit significant color changes which are easily seen. We herein present strong evidence that the solution color is due to macrocycle ring opening and oxidation. The optical responses to saccharides are due to complexation of the sugar with the acyclic chromophores. We apply these mechanistic insights toward the challenging problem of the visual detection of neutral oligosaccharides by simple chromogens. In addition, we also report the first single-crystal X-ray crystal structure determination of a rarely observed diamond resorcinarene stereoisomer