Solvent-induced chirality inversion involving supramolecular helix transformation and color-tunable fluorescence of a C(6)-symmetric hexakis(phenylethynyl)benzene derivative.

A C(6)-symmetric disk-like molecule, a hexakis(phenylethynyl)benzene derivative bearing chiral alanine parts, L-1, exhibited a solvent-induced supramolecular helix-sense inversion involving conformational changes followed by destruction of the supramolecular helical column. This phenomenon has been found by investigating the supramolecular assembly state of L-1 in mixed solvents of various chloroform (CHCl(3))/n-hexane (Hx) ratios. L-1 forms a stable helical columnar assembly via multiple noncovalent bonding interactions in nonpolar Hx, while the molecules in relatively polar CHCl(3) are in a molecularly dispersed state.

Stable supramolecular helical structure of C6-symmetric hydrogen-bonded hexakis(phenylethynyl)benzene derivatives with amino acid pendant groups and their unique fluorescence properties.

A highly stable supramolecular helical structure was formed by the self-assembly of novel C6-symmetric hydrogen-bonded discotic molecules, hexakis(phenylethynyl)benzene derivatives with chiral alanine parts, and exhibited orange excimer emission with a large Stokes shift.

A murine model of enterohemorrhagic Escherichia coli O157:H7 infection to assess immunopotentiating activity of drugs on mucosal immunity: effect of drugs.

An enterohemorrhagic Escherichia coli (EHEC) O157 oral infection murine model was established to examine the potentiating activity of drugs on mucosal immune responses. Groups of ICR mice inoculated intragastrically with 10(11) CFU/kg EHEC O157 showed chronic intestinal infection with the pathogen that persisted over 3 weeks and resulted in the synthesis of relatively high levels of antigen specific fecal IgA antibody. Intraperitoneal administration of 80 NU/kg Neurotropin, an immunopotentiator, augmented the antigen specific mucosal immune responses to EHEC O157.