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To increase the productivity of crops and ensure their stable production, a growth method based on the physiological information of plants is necessary. Therefore, in recent years, methods for direct measurement of such information are in demand. In this study, we propose a novel microsensor device for quantitative and minimally invasive measurement of moisture storage in plant shoots. The moisture-storage sensor device comprises a moisture-content sensor for measuring moisture storage, as well as an electrical-conductivity sensor and a resistance temperature detector for compensation of the moisture-content value. We fabricated the device on needle-shaped minimally invasive Si probes by using a micro-electromechanical system. We demonstrated the feasibility of the minimally invasive manner of the device in measuring the moisture storage (measurement range of approximately 40%–100%) in plant shoots.

A 1,3-iodo-amination with iodine reagent that involved the Csp2-Csp3 dual functionalization of 2-methyl indoles was developed to provide 2-aminomethyl-3-iodo-indole derivatives. The iodo-amination proceeded via a 1,4-transfer of an imide group through the formation of an indolyl(phenyl)iodonium imide using PhI(OAc)2, followed by an iodination using DIH or a double iodination of indole using excess DIH.

In this study, in order to monitor plant biological information, we proposed a phloem sap extraction–storage device based on microelectromechanical systems technology and an extraction–collection module. The proposed phloem sap extraction–storage device has an electric conductivity microprobe sensor for distinguishing the location of phloem and xylem vascular bundles within the plant, as well as a phloem sap extraction structure on the same microprobe. A reservoir structure for storing phloem sap is connected to this microprobe. A prototype of this device-equipped module was fabricated. Furthermore, we confirmed the utility of the proposed device and module through liquid chromatographic component analysis of the main photosynthetic products (sucrose, glucose, and fructose), thus demonstrating the utility of the proposed module.

To increase the productivity of crops, growth methods based on direct monitoring of physiological information in plants is required. In this study, we proposed a novel micro sensor device for simultaneously measuring moisture and nutrient substance dynamics in plant xylems. A nutrient substance dynamics sensor comprises an electrical conductivity (EC) sensor for measuring nutrient substance concentration and a resistance temperature detector (RTD) for temperature compensation of the EC value. To obtain a high-performance EC sensor, we fabricated a three-dimensional (3D) electrode on a needle-shaped Si probe based on micro-electromechanical system technology. We succeeded in fabricating an EC sensor equipped with a 3D electrode (cell constant of approximately 1200 m-1) and an RTD and demonstrated the feasibility of measuring the nutrient substance dynamics in plants.

A 1,3-iodo-amination with iodine reagent that involved the Csp2-Csp3 dual functionalization of 2-methyl indoles was developed to provide 2-aminomethyl-3-iodo-indole derivatives. The iodo-amination proceeded via a 1,4-transfer of an imide group through the formation of an indolyl(phenyl)iodonium imide using PhI(OAc)2, followed by an iodination using DIH or a double iodination of indole using excess DIH.

Hypervalent iodine(III) compounds containing iodine-nitrogen bonds are very attractive amination reagents in organic synthesis. Heteroaromatic (aryl)iodonium imides containing a iodine-nitrogen bond and a hypervalent iodine(III) atom were prepared from heteroarenes, bis(sulfon)imides and (diacetoxyiodo)arenes under mild conditions. These compounds were stable under air and in organic solvents, and could be easily purified by precipitation. X-ray crystal structure analysis indicated that the structure of N-pivaloyl indolyl(phenyl)iodonium bis(tosyl)imides and N-pivaloyl indolyl(2-butoxyphenyl)iodonium bis(tosyl)imides was a dimer with a T-shaped geometry at the iodine atom linked to an indole group and a bis(tosyl)imide by a monomer unit. Moreover, the use of substituted iodoarenes facilitated the purification of some of the heteroaromatic (aryl)iodonium imides.

In the development of therapeutic approaches for central nervous system diseases, a significant obstacle is efficient drug delivery across the blood-brain barrier owing to its low permeability. Various nanocarriers have been developed for brain-targeted drug delivery by modification with specific ligands. We have previously developed polyethylene glycol-modified liposomes (Bubble liposomes [BLs]) that entrap ultrasound (US) contrast gas and can serve as both plasmid DNA or small interfering RNA carriers and US contrast agents. In this study, we attempted to prepare brain-targeting BLs modified with Angiopep-2 (Ang2) peptide (Ang2-BLs). Ang2 is expected to be a useful ligand for the efficient delivery of nanocarriers to the brain. We showed that Ang2-BLs interacted specifically with brain endothelial cells via low-density lipoprotein receptor-related protein-1. We also confirmed that Ang2-BLs could entrap US contrast gas and had US imaging ability as well as unmodified BLs. Furthermore, we demonstrated that Ang2-BLs accumulated in brain tissue after intravascular injection. These results suggested that Ang2-BLs may be a useful tool for brain-targeted delivery and US imaging via systemic administration.

A regioselective Csp2–H dual functionalization of indoles, which underlies bromo-amination via the 1,3-migration of imide groups on indolyl(phenyl)iodonium imides as novel imide-combined hypervalent iodines(III), has been developed to provide 2-bis(sulfonyl)amino-3-bromo-indoles under the metal-free conditions.

A regioselective C(sp(2))-H dual functionalization of indoles, which underlies bromo-amination via the 1,3-migration of imide groups on indolyl(phenyl)iodonium imides as novel imide-combined hypervalent iodines(III), has been developed to provide 2-bis(sulfonyl)amino-3-bromo-indoles under the metal-free conditions.

A Hofmann-type rearrangement of cyclic imides (I), (V), (VII), (X) and (XIII) via the oxidation of an alkali metal bromide is reported.

The Hofmann-type rearrangement of aromatic and aliphatic imides using KBr as the catalyst proceeded to provide aromatic and aliphatic amino acid derivatives. We have also developed a new synthetic route to gabapentin with this method.

The title reaction allows a new and mild access to various amino acid and anthranilic acid derivatives.

The Hofmann-type rearrangement of aromatic and aliphatic imides using a hypervalent iodine(III) reagent generated in situ from PhI, m-CPBA, and TsOH·H(2)O proceeded in the presence of a base in alcohol to provide anthranilic acid derivatives and amino acid derivatives in high yields, respectively. This reaction proceeds through a tandem reaction via alcoholysis followed by a Hofmann rearrangement promoted by the formation of an imide-λ(3)-iodane intermediate.

まだ研究されていないアルカリ異性化高度不飽和酸エステル自動酸化中の重合体について探究し,その重合機構解明に資した。イカ油より95%純度のドコサヘキサエン酸メチルを製取し,これをアルカリ異性化して共役化し,このメチルエステルを散光日光中35℃において乾燥空気を90時間吹きこんで自動酸化し,過酸化物価(m.eq/kg)1.37×103のものを製取した。これをn-ヘキサン-ジエチルエーテル混合溶剤で抽出し,10個の抽出区分に分離し,四量体相当物質までを取得した。各試料につき紫外および赤外吸収スペクトルを測った。この自動酸化試料には,前報の非共役高度不飽和酸エステル自動酸化試料の場合に比し少量の-OOH基があり,一般に共役トリエンおよびそれ以上の共役ポリエンは存在せず,αβ-不飽和カルボニル基が存在し,酸素を含む環の存在があろう。α-メチレン基,二重結合を消費し,トランス-トランス共役ジエンを増大する機構で重合が行なわれ,単量体はC-O結合により重合する。