Protein-carbohydrate interactions play an important role in many biologically important processes. The recognition is mediated by a number of noncovalent interactions including an interaction between the α-face of the carbohydrate and the aromatic side chain. To this end, this interaction has been studied in the context of a β-hairpin in aqueous solution, in which the interaction can be investigated in the absence of other cooperative noncovalent interactions. In this β-hairpin system both the aromatic side chain as well as the carbohydrate was varied in an effort to gain greater insight into the driving force and magnitude of the carbohydrate-π interaction. The magnitude of the interaction was found to vary from -0.5 to -0.8 kcal/mol, depending on the nature of the aromatic ring and the carbohydrate. Replacement of the aromatic ring with an aliphatic group resulted in a decrease in interaction energy to -0.1 kcal/mol, providing evidence for the contribution of CH-π interactions to the driving force. These findings demonstrate the significance of carbohydrate-π interactions within biological systems and also demonstrate its utility as a molecular recognition element in designed systems

A carbohydrate-pi interaction contributes -0.8 kcal mol(-1) to the stabilization of a beta-hairpin peptide.

Over the past five years, an important development in the area of self-assembling containers has been the increase in interest in those containers that function in aqueous solution. This progress is a reflection of a similar trend within supramolecular chemistry in general, and is driven in part by the need to address issues and challenges within the biological sciences, as well as a desire to develop new strategies for greener chemistries carried out in water. It is also an opportunity to learn more about fundamental topics such as the hydrophobic effect. In this critical review we discuss progress in aqueous-based self-assembling container molecules since 2005 (177 references).

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Sonochemical degradation of aqueous polycyclic aromatic hydrocarbons (PAHs) results in a first-order loss of the PAHs (k = 0.010-0.027 s-1). When sonication occurred in the presence of other organic compounds, the degradation rate constant was reduced quite dramatically. This reduction is believed to come about through scavenging of radicals by the matrix chemical. When oxygen was bubbled into the PAH solution before sonication, the degradation rate constant was elevated. Nitrogen purging resulted in decreased rate constants. These results indicate that oxygen was an important precursor in the degradation of the PAHs. Organic compounds, including humic acid, benzoic acid, and sodium dodecyl sulfate, decreased PAH degradation rate constants by scavenging oxygen derived reactive transients.