ABSTRACT
There is growing concern about sensory pollutants affecting ecological communities. Anthropogenically enhanced oxidants [ozone (O3) and nitrate radicals (NO3)] rapidly degrade floral scents, potentially reducing pollinator attraction to flowers. However, the physiological and behavioral impacts on pollinators and plant fitness are unknown. Using a nocturnal flower-moth system, we found that atmospherically relevant concentrations of NO3 eliminate flower visitation by moths, and the reaction of NO3 with a subset of monoterpenes is what reduces the scent's attractiveness. Global atmospheric models of floral scent oxidation reveal that pollinators in certain urban areas may have a reduced ability to perceive and navigate to flowers. These results illustrate the impact of anthropogenic pollutants on an animal's olfactory ability and indicate that such pollutants may be critical regulators of global pollination.
Subject(s)
Environmental Pollutants , Moths , Nitrates , Odorants , Oenothera , Pollination , Reactive Nitrogen Species , Smell , Animals , Flowers/physiology , Moths/physiology , Pheromones , Pollination/physiology , Oenothera/physiology , Manduca/physiology , Environmental PollutionABSTRACT
[structure: see text] We report an initial step toward the development of sulfonamide-based complements for extended peptide strands. A molecule containing one secondary sulfonamide unit and one valine residue linked by a turn-forming segment was found by IR and NMR to exhibit a doubly hydrogen-bonded folding pattern in chloroform.
Subject(s)
Amino Acids/chemistry , Anti-Infective Agents/chemistry , Sulfonamides/chemistry , Hydrogen Bonding , Magnetic Resonance Spectroscopy , Spectrophotometry, InfraredSubject(s)
Biological Products/chemical synthesis , Biological Products/pharmacology , Hydrocarbons, Cyclic , Imines , Animals , Biological Products/chemistry , Dinoflagellida/chemistry , Epoxy Compounds/chemical synthesis , Epoxy Compounds/chemistry , Heterocyclic Compounds, 3-Ring/chemical synthesis , Heterocyclic Compounds, 3-Ring/chemistry , Macrolides , Marine Biology , Marine Toxins/chemical synthesis , Marine Toxins/chemistry , Methods , Porifera/chemistry , Sesquiterpenes/chemical synthesis , Sesquiterpenes/chemistry , Thiazoles/chemical synthesis , Thiazoles/chemistryABSTRACT
[formula: see text] Homooligomers of beta-amino acids (S)-3-pyrrolidine-3-carboxylic acid (PCA) and (S)-nipecotic acid (Nip) were studied by circular dichroism (CD) in methanol. In each series, a profound change in the far-UV CD spectrum was observed from monomer to tetramer, but little change was observed from tetramer to hexamer. A comparable pattern is observed in the CD spectra of short proline oligomers. We conclude that both PCA and Nip oligomers with > or = four residues adopt a characteristic secondary structure.
Subject(s)
Nipecotic Acids/chemistry , Peptides/chemistry , Proline/analogs & derivatives , Pyrrolidines/chemistry , Chromatography, High Pressure Liquid , Circular Dichroism , Proline/chemistry , Protein Structure, Secondary , Spectrophotometry, UltravioletABSTRACT
The use of a simple fluorescent nucleoside analogue in detection of point mutations by hybridization in solution is described. Pyrene is placed at 3' and 5' ends of a pair of oligodeoxynucleotide probes via a phosphoramidite derivative of deoxyribose with this fluorophore attached at the 1' position, replacing a DNA base. Adjacent binding of dual probes containing this fluorophore to a complementary target sequence results in a pronounced spectral change from blue pyrene monomer emission (lambdamax= 381 398 nm) to green-white excimer emission (lambdamax= 490 nm). Optimization of the relative binding positions of the two probes shows that the greatest spectral change occurs when they bind with partial end overlap. In optimum orientation, the monomer emission band for the probes decreases intensity by as much as a factor of seven and the excimer band increases up to 40-fold on binding a complementary target. Application to the detection of a single-base point mutation in solution is described.
