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Associated health effects from algal toxin exposure are a growing concern for human and animal health. Algal toxin poisonings may occur from contact with or consumption of water supplies or from ingestion of contaminated animals. The U.S. Federal Government owns or holds in trust about 259 million hectares of land, in addition to the Trust species obligations. We completed the first comprehensive review of potential toxin-producing algal blooms in surface waters on Federal lands and Trust species exposed to algal toxins. Events were sorted into three tiers based on potentially toxic algae abundance or toxin concentration and related effects on animal morbidity and mortality. At least 11.1% of Federal lands are known to have been affected by algal events, but exposure is likely underreported. The occurrence of potential toxin producers and their toxins (Tier 1) have been documented 337 times, health advisory threshold exceedances (Tier 2) were reported 943 times, and 86 events involved animal sickness or death linked to cyanobacteria or marine toxins (Tier 3). Trust species exposed to cyano- or algal toxins included marine mammals, migratory birds, threatened and endangered species, and species of concern. We report numerous data gaps ranging from potential effects on human health from consuming intoxicated animals to the infrequency of measuring and reporting certain toxins. Improvements to field and laboratory methods, more consistent evaluation of toxin exposure, decreased latency on data analysis, delivery and interpretation will be necessary to improve response and management strategies for protecting human and animal health where issues persist. [ABSTRACT FROM AUTHOR]

The interaction between the [alpha]-face of the carbohydrate and the aromatic side chain of the protein is studied in the context of a [beta]-hairpin in aqueous solution, in which the interaction is examined in the absence of other cooperative noncovalent interactions. The studies have shown the importance of carbohydrate-[pi] interactions within biological systems and also their utility as a molecular recognition element in designed systems.

Directed ortho metallation (DOM) processes are used to functionalize the cavity and rim of title cavitand. The preorganization of the host resulted in a considerable reduction in the range of products produced, thus, whereas 69 products are possible from per-functionalization, only 12 were observed when the host was treated with three different alkyllithiums.

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 of the protein. To elucidate this interaction, it 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 and the carbohydrate were 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 their utility as a molecular recognition element in designed systems. [ABSTRACT FROM AUTHOR]

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

The synthesis of three different nanoscale molecular hosts is reported. These cavitands each possess a highly preorganized cavity with an open portal (nearly 1 nm wide), by which guests can enter and egress the cavity. Additionally, these hosts are deep-functionalized with a crown of weakly acidic benzal C-H groups which can form a variety of noncovalent interactions with guest molecules residing within the cavity. Thirty-one guests were examined for their propensity to form complexes with the hosts. Guests that possess halogen atoms were the strongest binders, suggesting the formation of polydentate C-H triplebond X-R hydrogen bonds with the deep crown of benzal hydrogens. Exchange rates between the free and bound states were noted to be dependent on the size of the guest and the solvent used to study complexation. In general, stronger binding and slower exchange were noted for complexations carried out in DMSO with highly complementary guests. The orientation of each guest within the cavity was determined using either EXSY NMR spectroscopy or (1)H NMR shift data. Cumulatively these results showed that the principal factors directing orientation were interactions with the benzal groups and the type of solvent. Van't Hoff analyses of selected complexations were also carried out. As well as revealing that all complexations were entropically unfavorable, these experiments provided support for guest orientation determinations, and gave an estimation that the formation of a C-H triplebond I-R hydrogen bond releases between 1 and 1.5 kcal mol(-1).