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Fluorescence and transient absorption spectra of zinc-porphyrin (ZnP)–viologen linked compounds with various methylene groups indicate that intramolecular electron-transfer from the singlet or triplet excited state of ZnP to viologen occurred and a biradical was generated in the ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) at various temperatures (283–343 K). The decay rate constants of the biradical decreased in 0–0.2∼0.5 T and became constant in 0.2∼0.5–1 T. Unique effects of temperature and methylene chain length on electron-transfer and magnetic field effects were observed and are probably due to the properties of the ionic liquid as compared with benzonitrile.

We disclosed a novel series of G-protein coupled receptor 119 (GPR119) agonists based on a bicyclic amine scaffold. Through the optimization of hit compound 1, we discovered that the basic nitrogen atom of bicyclic amine played an important role in GPR119 agonist activity expression and that an indanone in various bicyclic rings was suitable in this series of compounds. The indanone derivative 2 showed the effect of plasma glucose control in oGTT and scGTT in the rodent model.

Clinical evidence demonstrates altered glutamatergic neurotransmission in patients suffering from obsessive–compulsive disorder (OCD). We examined the effects of glutamate-related drugs on marble-burying behavior, which is an animal model of OCD. The uncompetitive N-methyl- d -aspartate (NMDA) antagonists memantine (10 mg/kg, i.p.) and amantadine (30 mg/kg, i.p.) significantly inhibited marble-burying behavior without affecting locomotor activity in mice. Similarly, the uncompetitive NMDA receptor antagonist 5R,10S-(+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine hydrogen maleate (MK-801, 0.3 mg/kg, i.p.) inhibited marble-burying behavior. However, MK-801 at the same dose markedly increased locomotor activity. By contrast, the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor antagonist 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide (NBQX) and the glutamate release inhibitor riluzole showed no effect on marble-burying behavior and significant suppression of locomotor activity. MK-801 (0.3 mg/kg, i.p.) and memantine (10 mg/kg, i.p.) significantly disrupted prepulse inhibition as an operational measure of sensorimotor gating. By contrast, amantadine (30 mg/kg, i.p.) did not affect prepulse inhibition. These findings suggest that amantadine could be a useful drug for the treatment of OCD.

Magnetic field effects (MFEs) on photoelectrochemical reactions of three porphyrin–viologen linked compounds with various methylene groups [ZnP(n)V (n=4,6,8)] were examined in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) as an ionic liquid using a two-electrode cell. Stable anodic photocurrents are produced by irradiating ZnP(n)V (n=4,6,8) in [BMIM][BF4] with visible light, and the MFEs on photocurrents were clearly observed in ZnP(n)V (n=4,6,8). The MFEs on photocurrents increase with magnetic field for lower magnetic fields (B ≤200 mT) and are constant for higher magnetic fields (B > 200 mT). The magnitude of the MFEs in ZnP(n)V (n=6,8) are larger than that in ZnP(4)V. The MFEs can be explained by radical pair mechanism. The magnitude of the MFEs is larger than those in electrodes modified with ZnP(n)V (n=4,6,8) as Langmuir–Blodgett films. The results are most likely attributable to the properties of [BMIM][BF4] and the mechanism of photoelectrochemical reaction.

Magnetic field effects (MFEs) on photoelectrochemical reaction of a porphyrin-viologen linked compound with six methylene group (ZnP(n)V(n = 6)) were examined in an ionic liquid ([BMIM][BF4 ]) using two-electrode cell. A stable anodic photocurrent is produced by irradiating ZnP(6)V in [BMIM][BF4 ] with visible light, and the photocurrent clearly increased in the presence of a magnetic field. The MFEs are explained by radical pair mechanism. The magnitude of the MFEs is larger than those in electrodes modified with ZnP(n)V(n = 4,6,8) as Langmuir-Blodgett films. The results are most likely ascribed to the properties of [BMIM][BF 4 ].