Detection of creatinine by a designed receptor.

An artificial receptor has been designed to bind creatinine with a color change (chromogenic response) caused by proton transfer from one end of the receptor to the other. The receptor was synthesized and found to extract creatinine from water into chlorocarbon solvents. The color change in the organic layer is specific for creatinine relative to other organic solutes, and it is selective for creatinine relative to sodium, potassium, and ammonium ions. The chromogenic mechanism is revealed by x-ray crystal structures of creatinine, the free receptor, and the complex, showing "induced fit" binding resulting from electronic complementarity between host and guest.

Scent organ development in creatonotos moths: regulation by pyrrolizidine alkaloids.

7-Hydroxy-6,7-dihydro-5H-pyrolizine-1-carboxaldehyde is the major volatile component of the scent organs in males of two species of Creatonotos (Lepidoptera, Arctiidae). The biosynthesis of this presumed pheromone depends on the presence of pyrrolizidine alkaloids in plants that are ingested by the larvae. In addition, these secondary plant substances control the morphogenesis of the scent organs. This morphogenetic effect of an alkaloid has not been observed previously.

Marine spatial planning makes room for offshore aquaculture in crowded coastal waters.

Marine spatial planning (MSP) seeks to reduce conflicts and environmental impacts, and promote sustainable use of marine ecosystems. Existing MSP approaches have successfully determined how to achieve target levels of ocean area for particular uses while minimizing costs and impacts, but they do not provide a framework that derives analytical solutions in order to co-ordinate siting of multiple uses while balancing the effects of planning on each sector in the system. We develop such a framework for guiding offshore aquaculture (bivalve, finfish, and kelp farming) development in relation to existing sectors and environmental concerns (wild-capture fisheries, viewshed quality, benthic pollution, and disease spread) in California, USA. We identify > 250,000 MSP solutions that generate significant seafood supply and billions of dollars in revenue with minimal impacts (often < 1%) on existing sectors and the environment. We filter solutions to identify candidate locations for high-value, low-impact aquaculture development. Finally, we confirm the expectation of substantial value of our framework over conventional planning focused on maximizing individual objectives.

Carriers and channels: current progress and future prospects.

Recent advances in the understanding of biological transport and in the design of artificial transport systems have resulted from the structural elucidation of the K+ ion channel and from synthesis of artificial receptors for cations and anions, as well as neutral and zwitterionic organic molecules. Sensors, gated carriers, and self-assembling capsules and nanotubes are all important offsprings of current efforts to mimic natural transport across biomembranes.

Self-assembly of a double-helical complex of sodium.

Spontaneous self-organization of helical and multiple-helical molecular structures occurs on several levels in living organisms. Key examples are alpha-helical polypeptides, double-helical nucleic acids and helical protein structures, including F-actin, microtubules and the protein sheath of the tobacco mosaic virus. Although the self-assembly of double-helical transition-metal complexes bears some resemblance to the molecular organization of double-stranded DNA, selection between monohelical, double-helical and triple-helical structures is determined largely by the size and geometrical preference of the tightly bound metal. Here we present an example of double-helical assembly induced by the weaker and non-directional interactions of an alkali-metal ion with an organic ligand that is pre-organized into a coil. We have characterized the resulting complex by two-dimensional NMR and fast-atom-bombardment mass spectrometry. These results provide a step toward the creation of molecular tubes or ion channels consisting of intertwined coils.

Pheromones of two arctiid moths (Creatonotos transiens andC. gangis) : Chiral components from both sexes and achiral female components.

The two major components of the female sex pheromones of twoCreatonotos species have been identified as an achiral C21 triene, (Z,Z,Z)-3,6,9-heneicosatriene, and a chiral epoxide, (Z,Z)-2(2,5-octadienyl)-3-undecyloxirane. The ratios of these components in the two species fall into nonoverlapping ranges. Two additional achiral minor components, (Z,Z)-6,9-heneicosadiene and (Z,Z,Z)-3,6,9-tricosatriene, were also identified in the female sex gland extracts. The male pheromone of both species consists of hydroxydanaidal, a chiral dihydropyrrolizine derived from pyrrolizidine alkaloids in the larval diet.Creatonotos transiens was found to convert dietary heliotrine into (R)-(-)-hydroxydanaidal, with inversion at the single asymmetric carbon atom. The possible biological and biosynthetic significance of the chiral pheromone components are discussed, and they are compared with known examples of chiral lepidopteran pheromones.

Stereochemical course of pheromone biosynthesis in the arctiid moth, Creatonotos transiens.

The biosynthetic conversion of a pyrrolizidine alkaloid (heliotrine, IV) to a male moth pheromone (hydroxydanaidal, III) is found to proceed with inversion of configuration at the remaining asymmetric center (C-7).

Sex pheromones of two Asian moths (Creatonotos transiens, C. gangis; Lepidoptera--Arctiidae): behavior, morphology, chemistry and electrophysiology.

Two sympatric species of Asian arctiid moths (Creatonotos spp.) use a sequential, dual luring and mating system. After sunset males pneumatically expand their coremata from a cavity between the abdominal sternites 7 and 8 and release their pheromone. They attract other males and thus, scent-emitting male groups may develop. About 30 min later females are attracted to the calling males. Upon contact with a female the male's corema deflates and mating follows. After 1-2 h the male calling subsides and now the remaining virgin females continue to emit their pheromone bouquet from internal, tubular glands located in the dorsal part of the abdomen, rostrad from tergite 8/9. This attracts males and further matings occur.- The coremata are huge, pneumatically eversible organs composed of two pairs of tubes, up to 37 mm long, each covered by ca. 3000 scent hairs (scales). There is a giant epidermal (trichogen) gland cell at the base of each hair. One large corema may contain up to 0.5 mg of the pheromone, hydroxydanaidal. The internal, tubular female glands are antler shaped; their air-filled lumen is ventilated by abdominal pumping. The major components of the female attractant are (Z,Z,Z)-3,6,9-heneicosatriene and (Z,Z)-2 (2,5-octadienyl)-3-undecyloxirane with different ratios in the two species. One of the minor components, common to both species, is (Z,Z,Z)-3,6,9-tricosatriene. Only the male antennae possess specialized receptor cells for the female attractants; other antennal cells of both sexes respond to the male pheromone.

Unrecognized Legionnaires' disease as a cause of fatal illness.

Lungs from 224 patients, obtained at autopsy, were examined for Legionella pneumophila by fluorescent antibody (FA) staining. Of 121 patients who died with pneumonia, L pneumophila was present in eight cases (6.6%). (Two of the eight patients exhibited no important respiratory symptoms or fever, although pneumonia contributed considerably to their deaths. Preexisting underlying disease was present in all cases. Legionnaires' disease (LD), endemic in the central Ohio area, may cause up to 3.6% of the nosocomial pneumonias at the study site. Application of the local incidence of LD to the number of annual adult deaths in the United States indicates that many LD-associated deaths may occur each year. The study shows the importance of using the FA and Dieterle stains during routine pathological examination of lung tissue, especially from compromised hosts in endemic areas.

A hydrogen-bonding receptor that binds cationic monosaccharides with high affinity in methanol.

A dicarboxylate host (1) binds cationic monosaccharides such as D-glucosamine HCl (2), D-galactosamine-HCl (3), and D-mannosamine-HCl (4) with high affinity (K1 = 8.0 x 10(4)-2.0 x 10(5) M(-1)) in methanol. In circular dichroism (CD) spectroscopy a positive exciton-coupling band was observed near 290 nm; this indicates that the saccharides are recognized by multiple point interactions. Since the corresponding neutral monosaccharides are not significantly bound, one may conclude that complex formation is primarily due to the electrostatic interaction between NH3+ in the guest and one carboxylate in the host and secondarily due to hydrogen-bonding interactions of OH groups with the other carboxylate and/or nitrogen bases. Molar ratio plots and Job plots indicate that host 1 and cationic monosaccharide guests form CD-active, pseudo-cyclic 1:1 complexes at low guest concentration followed by the formation of CD-silent, acyclic 1:2 1-saccharide complexes at high guest concentration. The possible binding modes are discussed in detail on the basis of molecular mechanics calculations and chemical shift changes in 1H NMR spectra. The results of competition experiments with several cationic reference compounds bearing fewer OH groups than 2-4 are consistent with the proposed binding model. Thus, the present study is a rare example of saccharide recognition in a protic solvent, where in general, hydrogen-bonding interactions are rarely useful because of strong solvation energy. These are apparently the strongest saccharide complexes involving noncovalent interactions between host and guest. We believe that the findings are significant as a milestone toward development of new saccharide recognition systems ultimately useful in aqueous solution.