Kento Mori

Total Synthesis and Structural Revision of Clavilactone D

A structural revision of clavilactone D, a potent inhibitor of protein tyrosine kinases, was achieved by total syntheses of two newly proposed structures. The syntheses relied on ring-opening/ring-closing metathesis, which transformed a cyclobutenecarboxylate into a γ-butenolide. The syntheses confirmed that the correct structure of clavilactone D has an amino group at C-3 instead of a hydroxy group at C-2 in the originally proposed structure.

Total Synthesis of Clavilactones

Clavilactones A, B, and D are epidermal growth factor receptor tyrosine kinase inhibitors that were isolated from cultures of the fungus Clitocybe clavipes. Here, we report full details of the total synthesis of these clavilactones. A key feature of our synthetic approach is a ring-opening/ring-closing metathesis strategy that allows the concise transformation of a cyclobutenecarboxylate into a γ-butenolide. Coupled with enantioselective Ti/BINOL-catalyzed alkynylation of a multisubstituted benzaldehyde and ring-closing metathesis of a diene-bearing silylene acetal to construct the 10-membered carbocycle, this strategy enabled the total synthesis of the natural enantiomers (+)-clavilactone A and (-)-clavilactone B. In addition, the correct structure of clavilactone D was determined by the synthesis of two newly proposed structures. This research resulted in the asymmetric synthesis of the revised (+)-clavilactone D.

Impingement type micro fluidic device using electro-conjugate fluid

An electro-conjugate fluid (ECF) is a kind of dielectric fluid which produces a strong jet flow (ECF jet) when subjected to high DC voltage. Namely, a pair of electrodes generates nonuniform electric field, which induces the ECF jet. It is known that some kinds of ECF may possibly produce an impingement jet which occurs between electrodes. This study proposes an impingement type micro fluidic device whose power source is integrated by using the ECF. We developed a prototype and confirmed our concept.

Control of a flexible finger using electro-conjugate fluid

An electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a powerful flow when subjected to high DC voltage. It is known that a strong ECF flow is generated under non-uniform electric field, for example, the field with a pair of needle and ring electrodes. The ECF flow could be used as a micro fluid pressure source (an ECF pump) for actuators including an artificial muscle and a flexible finger etc. However, previous studies on ECF soft actuators only focused on confirmation of the driving principle. This means, an improvement of performance of ECF pumps and a control scheme for ECF soft actuators have yet to be studied in detail. Hence, this study improves the performance of the ECF pump, and proposes a novel control system for an ECF flexible finger. The ECF pump developed in this study generates maximum pressure of 92.6 kPa and maximum flow rate of 103.0 ml/min with 200.3 mm3. The flexible finger (φ5 mm × 30 mm), driven by the ECF pump, bends 150 deg with a rise time of 1000 ms. In addition, we construct a master-slave system using the ECF flexible finger and confirm its performance.

Theoretical modeling and corroborative experiments for electro-conjugate fluid flow

An electro-conjugate fluid (ECF) is a kind of dielectric fluid which produces a powerful flow (ECF jet) when subjected to high DC voltage. The ECF jet is a promising micro fluid power source for actuators and sensors including micro motors [4] [5], liquid rate gyroscope [8] [9] etc. However, these applications are developed upon trials and errors because the theory of the ECF flow has yet to be fully established. In this study we introduce the Coulomb force to develop an ECF flow model. Then we hypothesize that the Coulomb force is occurred by two causes; an inherent dominant charge depending on each fluid and a charge injected from a sharp electrode. The hypotheses are proved by the experimental results in this study.