Assembly and Folding of Twisted Baskets in Organic Solvents.

A synthetic method for obtaining enantiopure and twisted baskets of type (P)-3 is described. These chiral cavitands were found to fold quinoline gates, at the rim of their twisted platform, in acetonitrile and give molecular capsules that assemble into large unilamellar vesicles. In a less polar dichloromethane, however, cup-shaped (P)-3 packed into vesicles but with the quinoline gates in an unfolded orientation.

Assessment of RNA carrier function in peptide amphiphiles derived from the HIV fusion peptide.

A small library of amphiphilic peptides has been evaluated for duplex RNA carrier function into A549 cells. We studied peptides in which a C-terminal 7-residue cationic domain is attached to a neutral/hydrophobic 23-residue domain that is based on the viral fusion peptide of HIV. We also examined peptides in which the cationic charge was evenly distributed throughout the peptide.

Twisted baskets.

A preparative procedure for obtaining a pair of twisted molecular baskets, each comprising a chiral framework with either right ((P)-1syn) or left ((M)-1syn) sense of twist and six ester groups at the rim has been developed and optimized. The racemic (P/M)-1syn can be obtained in three synthetic steps from accessible starting materials. The resolution of (P/M)-1syn is accomplished by its transesterification with (1R,2S,5R)-(-)-menthol in the presence of a Ti(IV) catalyst to give diastereomeric 8(P) and 8(M).

Discrete assembly of synthetic peptide-DNA triplex structures from polyvalent melamine-thymine bifacial recognition.

We have designed a 21-residue α-peptide that simultaneously recognizes two decadeoxyoligothymidine (dT(10)) tracts to form triplexes with a peptide-DNA strand ratio of 1:2. The synthetic peptide side chain displays 10 melamine rings, which provide a bifacial thymine-recognition interface along the length of the 21-residue peptide. Recognition is selective for thymine over other nucleobases and drives the formation of ternary peptide·[dT(10)](2) complexes as well as heterodimeric peptide·[dT(10)C(10)T(10)] hairpin structures with triplex stems.