Seed production of wild soybean (Glycine soja Sieb. et Zucc.) under favorable, ruderal, and natural growing conditions.

Field trials were conducted in Japan under different growing conditions to better understand seed production of wild soybean (Glycine soja Seib. et Zucc.). The objectives of these trials were to evaluate yield and yield components of wild soybean: (1) across 11 diverse populations grown under favorable conditions to assess seed production potential, (2) under different planting densities (112, 208, 416, and 832 plants/m2) to assess intra-specific competition, and (3) across growing conditions (favorable, ruderal, and natural) to assess the impacts of environmental stress and inter-specific competition. Significant differences in yield and seed number observed among the evaluated wild soybean populations were predominantly due to environmental effects and genetic by environmental interaction. Seed production was impacted by both intra- and inter-specific competition. Wild soybean grown without plant competition had 51-fold and 247-fold higher yield compared to when grown in ruderal and natural environments, respectively. Under favorable growing conditions, wild soybean had substantial yield potential due to the ability to produce a high number of seeds. In nature, yield potential is severely limited because of plant competition and other environmental stressors. The results of this research are useful to inform environmental risk assessment when considering the potential impact of soybean biotechnology traits that increase or protect yield. If such traits were to be inadvertently transferred from imported soybean into wild soybean, this research indicates that the effects would likely have little overall impact on wild soybean seed production.

Consideration of familiarity accumulated in the confined field trials for environmental risk assessment of genetically modified soybean (Glycine max) in Japan.

To date, there have been 160 regulatory approvals for environmental safety in Japan for the major genetically modified (GM) crops, including corn, soybean, canola and cotton. Confined field trials (CFTs) have been conducted in Japan for all single events, which contain various traits. The accumulated information from these previously conducted CFTs, as well as the agronomic field study data from other countries, provides a rich source of information to establish "familiarity" with the crops. This familiarity can be defined as the knowledge gained through experience over time, and used to inform the environmental risk assessments (ERA) of new GM crops in Japan. In this paper, we compiled agronomic data from the CFTs performed in Japan for 11 GM soybean events which obtained food, feed and environmental safety approvals from regulatory agencies in Japan. These CFTs were conducted by multiple developers according to Japan regulations to support the ERA of these GM soybean, covering standard measurement endpoints evaluated across developers in Japan. With this dataset, we demonstrate how familiarity gained from the CFTs of GM soybeans in Japan can be used to inform on the ERA of new GM soybean events. By leveraging this concept of familiarity, we discuss potential enhancements to the ERA process for GM soybean events in Japan.

Likelihood assessment for gene flow of transgenes from imported genetically modified soybean (Glycine max (L.) Merr.) to wild soybean (Glycine soja Seib. et Zucc.) in Japan as a component of environmental risk assessment.

Environmental risk assessment is required for genetically modified (GM) crops before their import into Japan. Annual roadside monitoring along transportation routes from ports to processing facilities for GM soybean (Glycine max (L.) Merr.) have been requested as a condition of import only approval because of lack of information on the likelihood of persistence of imported GM soybean for food, feed and processing and the potential for transfer of transgenes into wild soybean (Glycine soja Seib. et Zucc.) through gene flow under the Japanese environment. The survey of soybean seeds, plants and wild soybean populations were conducted along transportation routes from unloading ports to processing facilities that provided data to help quantify actual exposure. The survey indicated that the opportunities for co-existence and subsequent crossing between wild soybean populations and imported soybean are highly unlikely. Together the survey results and the comprehensive literature review demonstrated low exposure of imported GM soybean used for food, feed and processing in Japan. This evaluation of exposure level is not specific to particular GM soybean event but can apply to any GM soybean traits used for food, feed and processing if their weediness or invasiveness are the same as those of the conventional soybean.

Characterization of Natural and Simulated Herbivory on Wild Soybean (Glycine soja Seib. et Zucc.) for Use in Ecological Risk Assessment of Insect Protected Soybean.

Insect-protected soybean (Glycine max (L.) Merr.) was developed to protect against foliage feeding by certain Lepidopteran insects. The assessment of potential consequences of transgene introgression from soybean to wild soybean (Glycine soja Seib. et Zucc.) is required as one aspect of the environmental risk assessment (ERA) in Japan. A potential hazard of insect-protected soybean may be hypothesized as transfer of a trait by gene flow to wild soybean and subsequent reduction in foliage feeding by Lepidopteran insects that result in increased weediness of wild soybean in Japan. To assess this potential hazard two studies were conducted. A three-year survey of wild soybean populations in Japan was conducted to establish basic information on foliage damage caused by different herbivores. When assessed across all populations and years within each prefecture, the total foliage from different herbivores was ≤ 30%, with the lowest levels of defoliation (< 2%) caused by Lepidopteran insects. A separate experiment using five levels of simulated defoliation (0%, 10%, 25%, 50% and 100%) was conducted to assess the impact on pod and seed production and time to maturity of wild soybean. The results indicated that there was no decrease in wild soybean plants pod or seed number or time to maturity at defoliation rates up to 50%. The results from these experiments indicate that wild soybean is not limited by lepidopteran feeding and has an ability to compensate for defoliation levels observed in nature. Therefore, the potential hazard to wild soybean from the importation of insect-protected soybean for food and feed into Japan is negligible.

Isocyanurates with planar chirality: design, optical resolution, and isomerization.

Designs and syntheses of isocyanurates (1-3) are described on the basis of a novel concept that two enantiotopic faces of C(s) -symmetric, prochiral planar molecules are differentiated with a location of groups at the top or bottom of the planar skeleton using a rigid linker. Such isocyanurates are atropisomeric. The planar-chiral structures of 1 and 2(anti) (anti-conformer of 2) were confirmed by single-crystal X-ray analyses, and the space groups were P1 (for 1) and P2(1)/c (for 2(anti)), resulting that the crystals were racemates. Optical resolutions of 1-3 were successfully accomplished by using chiral high-performance liquid chromatography technique in combination with circular dichroism, absorption, and nuclear magnetic resonance spectroscopies and mass spectrometry. Furthermore, the rotational barriers (ΔG(‡)s) related to isomerizations of 1-3 were estimated to be 27.2 (for 1 at 50 °C), 27.6 (for 2(anti) at 50 °C), and 40.6 (for 3(syn) at 150 °C) kcal/mol. The ΔG(‡)s of 2 and 3 were higher than that of 1 and, in particular, that of 3 was highest among them. This result indicates that an introduction of bulky substituents and an intramolecular bridging are effective for inhibitions of the isomerizations.

Planar-chiral metal complexes comprised of square-planar metal and achiral tetradentate ligands: design, optical resolution, and thermodynamics.

Planar-chiral palladium complexes {[[N,N'-[1,4-butanediylbis(oxy-7,1-naphthalenediyl)]bis(2-pyridinecarboxamidato)](2-)-κN(1),κN(1)',κN(2),κN(2)']palladium (PdL(4)) and [[2,2'-[1,4-butanediylbis[[(oxy-7,1-naphthalenediyl)imino]methyl]]dipyrrolato](2-)-κN(1),κN(1)',κN(2),κN(2)']palladium (PdL(5))} were synthesized from achiral tetradentate ligands N,N'-[1,4-butanediylbis(oxy-7,1-naphthalenediyl)]bis(2-pyridinecarboxamide) (H(2)L(4)) and N,N'-bis[(1H-pyrrol-2-yl)methylidene]-7,7'-(1,4-butanediyldioxy)bis(1-naphthalenamine) (H(2)L(5)) bearing two dissymmetric bidentate units at both ends and a Pd(II) ion, respectively. The palladium complexes were crystallized in the monoclinic space group P2(1)/n with the unit cell parameters a = 16.5464(6) Å, b = 11.3534(4) Å, c = 17.6697(7) Å, ß = 115.5300(10)°, and Z = 4 for PdL(4) and a = 17.2271(8) Å, b = 10.1016(5) Å, c = 17.9361(9) Å, ß = 105.6310(10)°, and Z = 4 for PdL(5). The planar-chiral structures of PdL(4) and PdL(5) were confirmed by single-crystal X-ray analyses, resulting in the fact that the crystals were racemic mixtures. The racemic mixtures were successfully resolved by using chiral high-performance liquid-chromatography techniques. Racemizations of the complexes were found to be drastically dependent on the arrangement of the charged or uncharged metal-binding N atoms of the ligands.

Chirality induction in metal-induced achiral polythiophene aggregates assisted by optically active amines and polythiophene.

A regioregular achiral polythiophene bearing oxazoline pendant groups formed a unique optically active metal-induced supramolecular aggregate upon complexation with chiral amines or in the presence of a chiral polythiophene in a good solvent for the polymers, thus showing an induced circular dichroism.

Synthesis and optical resolution of a Cu(I) double-stranded helicate with ketimine-bridged tris(bipyridine) ligands.

A tetranuclear Cu(I) double-stranded helicate was synthesized from ketimine-bridged tris(bipyridine) ligands and Cu(I) ions, and the racemate was successfully resolved by diastereomeric salt formation using an optically pure phosphate anion followed by anion exchange with NaPF(6) without racemization.

Double helix formation of poly(m-phenylene)s bearing achiral oligo(ethylene oxide) pendants and transformation into an excess of one-handed single helix through cholate binding in water.

A water-soluble poly(m-phenylene) bearing an achiral oligo(ethylene oxide) chain at the 5-position was synthesized by the Ni(0)-mediated homo-coupling polycondensation of a 3,5-dibromophenol monomer. The poly(m-phenylene) adopted a single helical conformation in protic media and self-assembled into a double helix in water through aromatic interaction, while it took a random-coil conformation in chloroform. Upon the addition of sodium cholate in water, the double helical poly(m-phenylene) was transformed into single strands, which bound the cholate molecules to form an excess of one-handed single helix.

Double helix formation of oligoresorcinols in water: thermodynamic and kinetic aspects.

We previously reported that the oligoresorcinols formed double-stranded helices in neutral water through interstrand aromatic interactions. In the present study, we synthesized a new series of oligomers from the 2mer to the 15mer to explore the thermodynamics, kinetics, and mechanism of the double helix formation of the oligoresorcinols in water. The double helix formation was dependent on the chain length of the oligomers and significantly affected by solvent, pH, salt, and temperature. The free energy change (-DeltaG) for the double helix formation linearly increased with the chain length from the 4mer to the 11mer (DeltaDeltaG = -0.94 kcal mol(-1) unit(-1)), whereas it did not change for the oligomers longer than the 11mer. The van't Hoff analysis of the 9mer revealed that the double helix formation was an enthalpically driven process (DeltaH = -27 +/- 1.5 kcal mol(-1) and DeltaS = -70 +/- 5 cal mol(-1) K(-1)), which was consistent with the upfield shifts in the (1)H NMR spectra and the hypochromicity of the absorption spectra as a result of the interstrand aromatic interactions in water. Furthermore, the kinetic analysis of the chain exchange reaction between the double helices of the optically active and optically inactive 11mers revealed a small DeltaS(double dagger), suggesting that the chain exchange proceeds not via the dissociation-association pathway, but via the direct exchange pathway.

Helicity induction on water-soluble oligoresorcinols in alkaline water and their application to chirality sensing.

Oligoresorcinol oligomers were found to adopt a single-stranded helical conformation in alkaline water through intramolecular hydrogen bonds, of which a helix-sense bias was induced by the addition of water-soluble chiral compounds, such as ammonium salts, amines and alcohols.

Double helical oligoresorcinols specifically recognize oligosaccharides via heteroduplex formation through noncovalent interactions in water.

We report on the oligosaccharide recognition through noncovalent interactions in water based on a unique supramolecular homoduplex-to-heteroduplex transformation of the oligoresorcinol nonamer as a fully artificial receptor. The oligoresorcinol forms a double helix in water, which unravels and entwines upon complexation with specific oligosaccharides with a particular chain length and glucosidic linkage pattern, thus generating the heteroduplex with an excess one-handed helical conformation that can be readily monitored and further quantified by absorption, circular dichroism, and NMR spectroscopies.

Supramolecular control of unwinding and rewinding of a double helix of oligoresorcinol using cyclodextrin/adamantane system.

The double helix of the oligoresorcinol nonamer formed in water was unwound by beta-cyclodextrin (beta-CD), and the resulting single strands of the nonamer threaded the beta-CD to form a twisted [3]-pseudorotaxane with a controlled helicity. Upon the addition of an adamantane, the single strand of the oligoresorcinol nonamer was expelled out of the beta-CD wheels, thus regenerating the double helix. This supramolecularly controlled, reversible unwinding and rewinding of the double helix is unique and can be readily monitored by spectroscopic techniques.

Oligoresorcinols fold into double helices in water.

We report the first double helices with a controlled helicity in water based on oligoresorcinols as a new, simplest water-soluble structural motif. The molecular strands of the oligoresorcinols self-assemble into double helices with the aid of aromatic interactions in water as characterized by 1H NMR and absorption spectroscopies together with the X-ray crystallographic study of the pentamer. The double helix formation is sensitive to the chain length, solvent composition, and temperature. Moreover, a bias in the screw sense of the double helices was achieved by covalently attaching chiral substituents to both ends of the molecular strands.

Chiral stimuli-responsive gels: helicity induction in poly(phenylacetylene) gels bearing a carboxyl group with chiral amines.

Poly(phenylacetylene) gels (gel-1-H and gel-2-H) bearing a carboxy pendant were synthesized either by the copolymerization of (4-carboxyphenyl)acetylene (gel-1-H) with a bis(phenylacetylene) derivative as the cross-linking reagent using a rhodium complex ([Rh(cod)(2)]BF(4): cod = 1,5-cyclooctadiene) as the catalyst or by the cross-linking of poly[(4-carboxyphenyl)acetylene] with diamines (gel-2-H). The obtained gels were found to swell in DMSO and exhibited an induced circular dichroism (ICD) in the long absorption region of the main chain in the presence of optically active amines. These results indicate that a predominantly one-handed helix can be induced in the polymer network of the gels through chiral acid-base interactions. The swelling properties and the Cotton effect intensities of the gels depend on the cross-linking ratio and the chiral amines. Gel-1-Na and gel-2-Na prepared from gel-1-H and gel-2-H, respectively, also significantly swelled in water and showed ICDs characteristic of chiral amino alcohols and free amino acids in water.

Metal-induced supramolecualr chirality in an optically active polythiophene aggregate.

Chiral polythiophenes (PTs), in sharp contrast to other optically active polymers, exhibit optical activity in the pi-pi* transition region which is derived from the chirality of the main chain when they self-assemble to form a supramolecular pi-stacked aggregate with intermolecular interactions in a poor solvent or in a film. We now report that the regioregular, optically active PT poly[(R)-3-[4-(4-ethyl-2-oxazolin-2-yl)phenyl]thiophene] (poly-1) exhibits unique split-type induced circular dichroism (ICD) in the pi-pi* transition region of the main chain upon complexation with various metal salts such as trifluoromethanesulfonates of copper(I), copper(II), silver(I), and zinc(II), and iron(II) perchlorate in chloroform, which is a good solvent for poly-1. The appearance of ICD and slight changes in the UV/Vis spectra (no color change), except for the zinc salts, indicated that the chirality may not be induced by chiral pi-stacked aggregates of poly-1, but by the chirality of the main chain, for example, a predominantly one-handed helical structure induced by intermolecular coordination of the oxazoline groups to metal ions. The sign of the Cotton effect depends on the metal salt; most metal salts induced ICDs with similar Cotton-effect patterns, while zinc salts caused an inversion of the signs of the Cotton effect of poly-1 accompanied by a gradual red shift in the absorption of up to 125 nm. The changes in the conformation and the size of the poly-1 aggregates induced by different metal salts were also investigated by (1)H NMR titrations, static light scattering (SLS), atomic force microscopy (AFM), and membrane filtration. On the basis of these results, we propose a possible model for the chiral supramolecular aggregates of poly-1 with metal salts.

Electron-induced switching of the supramolecular chirality of optically active polythiophene aggregates.

A chiral regioregular polythiophene (PT), poly[3-[4-((R)-4-ethyl-2-oxazolin-2-yl)phenyl]thiophene] (poly-1), forms chiral aggregates which exhibit a unique induced circular dichroism (ICD) in the pi-pi transition region derived from the supramolecular chirality in the presence of various poor solvents or metal salts in chloroform. We report here that the chirality of such supramolecular aggregates can be switched ("on" and "off") through electron transfer. We have found that upon the addition of copper(II) trifluoromethanesulfonate [Cu(OTf)(2)] to the chiral aggregates of poly-1 in a chloroform-acetonitrile mixture, the ICD disappears because of the oxidative doping of the poly-1 main chain, while a further addition of amines such as triethylenetetramine (TETA) induces undoping of the poly-1 which results in the reappearance of the ICDs. Therefore, the supramolecular chirality of the poly-1 assemblies was reversibly controlled by the addition or removal of an electron from the poly-1 main chain. This may be the first example of a reversible supramolecular chirality switch on chiral PT aggregates. We investigated the mechanism of the chirality switch through the doping and undoping process on the polymer main chain by means of absorption and CD spectroscopies, ESR, cyclic voltammetry, X-ray diffraction, and AFM measurements.