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Herein, we report a Rh-catalyzed asymmetric [2+2+2] cycloaddition of ene-yne-yne enediynes to generate enantio-enriched tricyclic cyclohexadienes bearing a quaternary bridgehead carbon. We found that the Rh-Phanephos complex is an appropriate catalyst for the cycloaddition of enediynes bearing an unsubstituted propiolate terminus, whereas Rh-biaryl bisphosphine catalysts, which have been widely used for asymmetric cycloadditions of alkynes and alkenes, are not applicable for the reaction of such enediynes. Several control experiments suggest that the reaction using the Rh-Phanephos complex exclusively proceeds via a rhodacyclopentadiene intermediate, unlike when using a Rh-biaryl bisphosphine complex that can form a rhodacyclopentadiene intermediate as well as a rhodacyclopentene intermediate in a substrate-dependent manner. more...

The palladium‐catalyzed reaction of 4‐iodo‐2‐quinolones with activated alkynes was investigated. Cyclopenta[de ]quinoline‐2(1 H )‐ones and/or phenanthridine‐6(5 H )‐ones were obtained through [3+2] annulation involving aromatic C−H activation or [2+2+2] annulation involving vinylic C−H activation, respectively. Reasonable mechanisms for the formation of these annulation products have been proposed based on density functional theory calculations., ファイル公開：2021-03-27 more...

Difluoromethyl‐substituted allylic phosphates were synthesized from 2‐cycloalkenones through the addition of a (difluoromethyl)phosphonate and subsequent phospha‐Brook rearrangement. The obtained allylic phosphates were converted to the corresponding difluoromethyl‐substituted cycloalkenes using the Cu‐mediated SN2’ reaction of Grignard or organolithium reagents., ファイル公開：2020-08-21 more...

Seed coat cracking after soaking (SCAS) and after cooking (SCAC) are unfavorable traits associated with soybeans for food uses, such as cooked and seasoned beans (nimame) and fermented steamed beans (natto) because they cause an inferior appearance of the products and clogging of the production lines. The variation and causes of SCAS and SCAC among cultivars have not yet been clarified, but if they are determined genetically, genetic modification could be possible. Cultivars showed considerable variations in SCAS and SCAC. Significantly positive seasonal correlations of SCAS (Spearman’s rank correlation coefficient, ρ = 0.518) and of SCAC (ρ = 0.681) were observed among recombinant inbred lines (RILs) derived from the cross between cultivars Nattoshoryu and Hyokeikuro 3. Quantitative trait locus (QTL) analyses and statistical analyses using generalized linear models showed that QTLs for SCAS (qSCAS1, qSCAS2, and qSCAS3) and SCAC (qSCAC1 and qSCAC2) were located on chromosomes 4 (linkage group [LG]: C1), 6... more...

The firmness of whole beans and of separated embryos and testas from 20 soybean cultivars grown in the same field conditions was estimated after 40 min cooking with AACC International Approved Method 56-36.01. There were considerable variations in the firmness of whole beans, embryos, and testas among cultivars. Testas were much firmer than embryos because of their leathery texture and resistance at slots in the shear cell during compression. For soft cultivars, the firmness after 10 min cooking was also measured, and an apparent first-order reaction kinetics model was applied to estimate the initial firmness at 0 min cooking and the softening rate constant from firmness data after 10 and 40 min cooking. The estimated initial firmness at 0 min cooking and softening rate constant of embryos and testas varied widely among seven cultivars, and these two parameters were considered to be controlled by different genetic mechanisms, because no correlation was found between the parameters. The softening ... more...

BACKGROUND: Diethyl ether-extractable free lipid (FL), non-polar or neutral lipid (NL), glycolipid (GL) and phospholipid (PL) contents and water-saturated 1-butanol (WSB)-extractable non-starch lipid (NSL)—monogalactosyldiglyceride (MGDG), digalactosyldiglyceride (DGDG) and phosphatidylcholine (PC)—contents in bread wheat (Triticum aestivum L.) grain were evaluated to elucidate the possible influence of the Wx-D1 gene on the lipid composition. RESULTS: Waxy near-isogenic lines with a non-functional Wx-D1d allele showed consistently increased NL, GL and PL contents among FL and MGDG, DGDG and PC contents among NSL compared with non-waxy near-isogenic lines with a functional Wx-D1a allele throughout three growing/harvest seasons. However, the proportion of NL, GL and PL among FL was not influenced by the non-waxy/waxy state of the endosperm. The nearly non-functional Wx-D1f allele influenced the FL and NL contents in a similar manner to the non-functional allele across two seasons, while the partly functional Wx-D1g allele only affected the NL content. CONCLUSION: The Wx-D1 locus has pleiotropic effects on the diethyl ether-extractable FL, NL, GL and PL contents and WSB-extractable MGDG, DGDG and PC contents of bread wheat grain. The non-functional Wx-D1d allele causes an increase in the levels of these lipids. Copyright © 2012 Society of Chemical Industry more...

The introduction of an O-acyl group at the α-position of carbonyl compounds is smoothly achieved using tetrabutylammonium iodide catalyst in the presence of hydrogen peroxide or tert-butyl hydroperoxide. more...

Large A-type endosperm starch granules were isolated from near-isogenic waxy and non-waxy lines and low-amylose mutant lines of bread wheat with a common genetic background. The amylose contents of A-type starch ranged from 2.6% to 23.6%. Amylopectin was isolated by concanavalin A (Con A) precipitation from the isolated starch. The λ max (range: 532-538 nm) and blue values at 680 nm (range: 0.026-0.037) of the iodine-amylopectin complex were not significantly different among the isolated amylopectins, indicating that amylopectins from non-waxy and low-amylose lines did not contain such long chains as amylose or extra-long chains of amylopectin affecting iodine complex properties. Chain-length distribution profiles measured by both high-performance size-exclusion chromatography (HPSEC) and high-performance anion-exchange chromatography (HPAEC) showed that the amylopectin structures of these lines were indistinguishable from each other. Extra-long chains were not detected in the amylopectins by HPSEC measurement. The side-chains measured by HPAEC were classified into four groups according to their degree of polymerization (DP), and the proportion of each group were in the following ranges: DP 6-12, 26.5-27.5%; DP 13-24, 43.6-44.1 %; DP 25-36, 13.6-14.2%, and DP 37-60, 11.0-11.7%. The alleles on the Vlix-D1 locus, i.e., Wx-D1a, Wx-D1d, Wx-D1f, and Wx-D1g, responsible for granule-bound starch synthase (GBSS I) biosynthesis had no influence on the properties of iodine-amylopectin complex and the chain-length distribution profiles of amylopectin. more...

Morphological, physical, and chemical properties of grain and flour of 20 chalky rice mutants were compared with those of a translucent parental cultivar, Koshihikari. Compound starch granules were loosely packed and single starch granules were observed in chalky parts of mutant endosperm. Chalky mutant lines were classified into milky-white and white-core lines based on the degree of endosperm chalkiness. Physical and chemical characteristics also suggest a division of chalky mutant lines into two groups, consistent with the classification made based on morphological characteristics. Milky-white mutant lines showed significantly lower grain weight, decreased starch content, and lower grain hardness than white-core mutants and Koshihikari. Rice flour prepared from milky-white mutants by dry milling showed less starch damage and finer mean particle size than white-core mutants and the parent. These results indicated that a loosely packed structure in chalky endosperm was responsible for fragile gr... more...

Starch and gluten were isolated from 10 wheat cultivars or lines with varied amylose content. The rheological properties of 30% wheat flour gel, starch gel, and the gel of isolated gluten mixed with common starch were determined in dynamic mechanical testing under shear deformation, creep-recovery, and compression tests under uniaxial compression. Variation of wheat samples measured as storage shear modulus (G′), loss shear modulus (G″), and loss tangent (tan δ = G″/G′) was similar between flour and starch gels and correlated significantly between flour and starch gel. The proportion of acetic acid soluble glutenin exhibited a significant relationship with tan δ of gluten-starch mixture gel. The small difference in amylose content strongly affected the rheological parameters of flour gels in creep-recovery measurement. Wheat flour gel with lower amylose content showed higher creep and recovery compliance that corresponded to the trend in starch gel. Compressive force of flour gel at 50 and 95% st... more...

Starch structural mutants showing abnormal endosperm characteristics have been used for investigating the effects of the mutation on structure and physicochemical properties of starches. Inbred lines of barley cultivars 'Shikoku Hadaka 97' and 'Glacier AC38' were used to investigate the impact of amo1 and waxy genes on starch properties. The amo1 type starch had high apparent amylose content and low starch content. The amo1+waxy type starch contained very little amylose. The content of long chains of amylopectin as detected with high-performance size-exclusion chromatography (HPSEC) was decreased, and that of amylopectin chains with the degree of polymerization (DP) of 12-36 was increased in amo1 and amo1 +waxy type starches. The amo1 and amo1 + waxy type starches exhibited high gelatinization temperatures and low gelatinization enthalpies. more...

Wheat lines with modified amylose content were produced by controlling the null alleles of three homoeologous Wx loci, Wx-A1, Wx-B1 and Wx-D1 and those with triple-null Wx alleles were found to yield waxy, amylose-free starch. In this study, the new near-isogenic lines developed by the recurrent backcross method between cv. Kanto 107 and the waxy mutant lines, K107Wx1 or K107Wx2, were cultivated and the physicochemical characteristics of their starches were investigated. The apparent amylose contents of the waxy near-isogenic lines were 1.6 - 3.8%, whereas those of the non-waxy near-isogenic lines were 23.2 - 25.4%. The waxy lines had higher gelatinization temperature and enthalpy than the non-waxy lines and no peak of amylose-lipid complex as determined by DSC. The X-ray diffraction patterns from both waxy and non-waxy near-isogenic lines corresponded to A-type crystallization, like their parent lines. The starches isolated from the waxy lines had lower pasting onset and peak temperatures, higher peak viscosities and breakdown and lower final viscosity than those of the non-waxy lines in the Viscoamylograph. The starch of non-waxy near-isogenic lines had lower peak and final viscosities and higher breakdown than did the recurrent parent line, cv. Kanto 107. The characteristics of the new wheat starches were well understood and classified, which will contribute to the wide application of these starches in food processing. more...

Wheat lines with reduced amylose content were recently produced by single and double mutation from a low-amylose line, Kanto 107. They are appropriate for clarifying the influence of amylose content on starch gel properties because of their similar genetic background. When measured using the concanavalin A method (ConA), the total amylose content of isolated starches from Kanto 107 and three mutants (K107Afpp4, Tanikei A6599-4, K107Wx2) was 24.8, 18.5, 7.1, and 1.7%, respectively. Results of differential scanning calorimetry (DSC) showed that the difference in amylose content strongly affected gelatinization conclusion temperature and enthalpy. We prepared 30 and 40% starch gels and measured their dynamic shear viscoelasticity using a rheometer with parallel plate geometry. Compressive and creep-recovery tests were conducted under uniaxial compression. The storage shear modulus correlated highly with the amylose content of starch in 30 and 40% starch gels. The creep-recovery test showed a clear d... more...

The baseline variation data on the chain-length distribution profiles of endosperm starch were acquired for use as a criterion for variation among bread wheat (Triticum aestivum L.) cultivars/lines. A total of 126 starch samples isolated from closely related species belonging to the Triticum-Aegilops group, i.e., five Triticum and 22 Aegilops species, were examined. Their side-chains were debranched by isoamylase and chain-length distribution profiles were determined by high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). An averaged chain-length distribution profile calculated from all data indicated that the most abundant side-chain had a degree of polymerization (DP) of 11 and its proportion based on relative peak area was 7.5%. The side-chains were classified into four groups, and the average proportions of each group were as follows; DP 6-12, 28.5% (range 26.3-30.9%); DP 13-24, 48.6% (46.2-50.8%); DP 25-36, 13.7% (12.8-15.2%) and DP ≥37, 8.9% (7.2-10.6%). The chain-length distribution profiles of Triticum and Aegilops species were essentially similar and no peculiar profile was observed. The range of the variation in the proportion of side-chain groups, however, was comparable to the difference between waxy and non-waxy bread wheat starches and among starches from wheat grown at different temperatures; this would affect the gelatinization and retrogradation properties of starch. more...

The effects of amylose content and other starch properties on concentrated starch gel properties were evaluated using 10 wheat cultivars with different amylose content. Starches were isolated from grains of two waxy and eight nonwaxy wheat lines. The amylose content of waxy wheat lines was 1.4–1.7% and that of nonwaxy lines was 18.5–28.6%. Starch gels were prepared from a concentrated starch suspension (30 and 40%). Gelatinized starch was cooled and stored at 5°C for 1, 8, 16, 24, and 48 hr. The rheological properties of starch gels were studied by measuring dynamic viscoelasticity with parallel plate geometry. The low-amylose starch showed a significantly lower storage shear modulus (G′) than starches with higher amylose content during storage. Waxy starch gel had a higher frequency dependence of G′ and properties clearly different from nonwaxy starches. In 40% starch gels, the starch with lower amylose showed a faster increase in G′ during 48 hr of storage, and waxy starch showed an extremely s... more...

Mixed starches with an amylose content of 5, 10, 18, 20, 23, and 25% were prepared by blending starches isolated from waxy and non-waxy wheat at different ratios. The dynamic viscoelasticity of mixed 30% and 40% starch gels was measured using a rheometer with parallel plate geometry. The change in storage shear modulus (G') over time at 5 °C was measured, and the rate constant of G' development was estimated. As the proportion of waxy starch in the mixture increased, starch gels showed lower G' and higher frequency dependence during 48 h storage at 5 °C. Since the amylopectin of waxy starch granules was solubilized more easily in hot water than that of non-waxy starch granules, mixed starch containing more waxy starch was more highly solubilized and formed weaker gels. G' of 30% and 40% starch gels increased steadily during 48 h. 30% starch gel of waxy, non-waxy and mixed starches showed a slow increase in G'. For 40% starch gels, mixed starch containing more waxy starch showed rapidly developed G' and had a higher rate constant of starch retrogradation. Waxy starch greatly influenced the rheological properties of mixed starch gels and its proportion in the mixture played a major role in starch gel properties. more...

Endosperm starch isolated from an amylose-free waxy mutant hull-less barley line, Shikoku Hadaka 97, had an amylose content of 0.3% and higher swelling power than ordinary waxy barley cultivars/lines with amylose contents of 2.2-6.5%. A highly significant correlation was observed between amylose content and swelling power among waxy barley starches. No clear differences were detected in the chain-length distribution profiles or thermal properties between the amylose-free starch and ordinary waxy starch. The chain-length distribution profile of waxy barley starch was slightly different from that of normal barley starch. Gelatinization temperatures and gelatinization enthalpy of waxy barley starch were higher than those of normal barley starch. Significant correlations were observed between amylose content and thermal properties of starch samples analyzed. Waxy barley starch stained with a concentrated iodine-potassium iodide solution showed a ghost-like appearance. more...

Waxy wheat lines were cultivated. The surface of the grains at 6 days after anthesis was wrinkled, and the diameter of the starch granules in the endosperm was rather small, however, afterwards the grains became smooth and the diameter of the starch granules in the endosperm was increased until 37 days after anthesis. Staining of the developing starch granules with a solution of 1.5 M Kl and 0.4 M I 2 showed that the granules of all starches changed to a ghost-like appearance, which consisted of two parts with different colors; a red-brown central part and a slightly pinkish surrounding part. However, the area of the slightly pinkish surrounding part in the whole ghost-like granule was small in the endosperm of wrinkled grains and gradually increased after the surface of the grain became smooth. Waxy barley, rice, maize, proso millet and foxtail millet starch also changed to ghost-like structure in a solution of 1.5 M Kl and 0.4 M I 2 , showing the internal structure of each granules. However, the ghost-like granules of these waxy starches showed only a simple single structure. more...

Wheat starch granules were separated from waxy wheat flour by the acetic acid (pH 3.5) fractionation technique. Waxy wheat starch samples were stained red-brown using KI/I2 solution. Subsequently, the concentration of the KI/I2 solution was increased to >2.5% KI and 1.0% I2. Then the appearance of the waxy wheat starch granules quickly became ghostlike. The internal structure of the ghost could be observed. This structure consisted of two parts with different colors: a red-brown central part and a slightly pinkish surrounding part. Sonication of the ghost at 20 kHz for 20 sec separated the central part from the surrounding part. Each of the separated parts were subjected to gel-filtration chromatography, and their chromatography profiles indicated only amylopectin and no amylose. The central and surrounding parts had molecular weights of 54.3 × 105 and 23.8 × 106 from Berry plots, respectively. more...

We studied the effect of amylose content on the gelatinization, retrogradation, and pasting properties of starch using wheat starches differing in amylose content. Starches were isolated from waxy and nonwaxy wheat and reciprocal F1 seeds by crossing waxy and nonwaxy wheat. Mixing waxy and nonwaxy wheat starch produced a mixed starch with the same amylose content as F1 seeds for comparison. The amylose content of F1 seeds ranged between waxy and nonwaxy wheat. Nonwaxy-waxy wheat had a higher amylose content than waxy-nonwaxy wheat. Endothermic enthalpy and final gelatinization temperature measured by differential scanning calorimetry correlated negatively with amylose content. Gelatinization onset and peak temperature clearly differed between F1 and mixed starches with the same amylose content as F1 starches. Enthalpy for melting recrystallized starches correlated negatively with amylose content. Rapid Visco Analyser measurement showed that F1 starches had a higher peak viscosity than waxy and no... more...

Two waxy endosperm mutant lines, K107Wx1 and K107Wx2, derived from a bread wheat cultivar, Kanto 107, had a lower flour yield in test milling and a lower peak temperature in flour pasting measurement than their parent. Starch content in the kernel of waxy mutants was low, while fat and (13),(14)-β-D-glucan content was high compared with cv Kanto 107, but protein content was similar for all of them. Waxy mutants had less α-amylase activity than their non-waxy parent, and had lower peak viscosity of flour paste in the pasting medium of water. A pasting test in silver nitrate solution increased peak viscosity in both waxy and non-waxy flours. The viscosity of waxy flour paste rapidly increased above 60°C, while that of non-waxy flour paste increased gradually at 60–80°C. The difference in pasting behaviour was attributed to the presence of amylose in starch granules. © 1999 Society of Chemical Industry more...

This novel and highly effective method gives access to the compounds (II) and (IV) with high enantioselectivities.

The introduction of an O-acyl group at the α-position of carbonyl compounds is smoothly achieved using tetrabutylammonium iodide catalyst in the presence of hydrogen peroxide or tert-butyl hydroperoxide. more...

A chiral catalyst for the enantioselective Kita oxidative spirolactonization of naphthol derivatives (I) is developed.

Asymmetric oxidative cyclization of ketophenols (I) proceeds smoothly in the presence of an in situ generated chiral quaternary ammonium hypoiodite to afford 2-acyldihydrobenzofuran derivatives (II) in up to 92% optical purity. more...

The hypervalent iodine-catalyzed oxylactonization of ketocarboxylic acids to ketolactones was achieved in the presence of iodobenzene (10 mol %), p-toluenesulfonic acid monohydrate (20 mol %) and meta-chloroperbenzoic acid as a stoichiometric co-oxidant. more...

Glutinous (waxy) rice cake is a popular New Year food in Japan. Economic incentives exist for rice cake producers to adulterate the products and mislabel them. Stable carbon isotope ratios (13C/12C) in rice cake products were determined by mass spectrometry to detect such adulteration. Since the 13C/12C ratios in rice (δ13C value of ca - 25 ppt, parts per thousand are different from those of corn (maize) starch (ca −9 ppt), the presence of added waxy corn (maize) starch in rice cake could be detected. more...