Holding of planar chirality of pillar[5]arene by kinetic trapping using host-guest interactions with achiral guest solvents.

We report a solvent-dependent switching and holding of planar chirality of pillar[5]arene with stereogenic carbons at both rims by host-guest complexation with achiral guest solvents. The planar chirality could be held for a given length of time at 25 °C in long linear guest solvents by kinetic trapping through host-guest complexation. The kinetic trapping worked at 25 °C, but not at 60 °C, thus a planar-chiral inversion using kinetic trapping based on host-guest complexation in the long linear solvents was demonstrated.

Progressive Parkinsonism Three Years after Shunt Surgery in a Patient with Idiopathic Normal Pressure Hydrocephalus.

An 86-year-old man, who had undergone a lumboperitoneal shunt for idiopathic normal pressure hydrocephalus (iNPH) implanted 4 years earlier showed progressive parkinsonism for the past year. His clinical symptoms, including resting tremor and rapid eye movement sleep behavior disorder, responsiveness to levodopa, and abnormal findings on 123I-meta-iodobenzylguanidine myocardial scintigraphy and dopamine transporter imaging, indicated that his pathological background of parkinsonism included concomitant synucleinopathy, such as Parkinson's disease or dementia with Lewy bodies, in addition to iNPH. Clinicians should consider the possibility of concomitant proteinopathies and their treatments when clinical symptoms become evident after shunt operations in patients with iNPH.

Alkane-Shape-Selective Vapochromic Behavior Based on Crystal-State Host-Guest Complexation of Pillar[5]arene Containing One Benzoquinone Unit.

Colored crystals of pillar[5]arene containing one benzoquinone unit were found to exhibit alkane-shape-selective vapochromic behavior. Activated pillar[5]arene crystals, prepared by removing solvated methanol from pillar[5]arene crystals, changed color from dark-brown to light-red after exposure to linear alkane vapors; however, no color changes were observed on exposure to branched or cyclic alkanes. Uptake of methanol vapor by the activated crystals induced a different color change, from dark-brown to black. This multi-vapochromism results from the different intermolecular π-stacking interactions between the benzoquinone and 1,4-diethoxybenzene units in the alkane- and methanol-containing crystals. Unlike most known vapochromic materials, these pillar[5]arene-based materials were highly stable; after uptake of n-alkanes or methanol the color of the crystals did not change after storage in air for 3 weeks. This is because the included guests were stabilized in the cavity by multiple CH/π interactions.

Redox-responsive host-guest system using redox-active pillar[5]arene containing one benzoquinone unit.

A pillar[5]arene containing one benzoquinone unit formed a weak host-guest complex with a triazole-substituted 1,4-butylene linker. In contrast, the corresponding reduced pillar[5]arene containing one hydroquinone unit formed a stable host-guest complex with the same guest.

Four new 2-(2-phenylethyl)chromone derivatives from withered wood of Aquilaria sinensis.

Four new chromone derivatives, 5-hydroxy-6-methoxy-2-(2-phenylethyl)chromone (1), 6-hydroxy-2-(2-hydroxy-2-phenylethyl)chromone (2), 8-chloro-2-(2-phenylethyl)-5,6,7-trihydroxy-5,6,7,8-tetrahydrochromone (3), 6,7-dihydroxy-2-(2-phenylethyl)-5,6,7,8-tetrahydrochromone (4) were isolated from the MeOH extract of withered wood of Aquilaria sinensis, together with seven known constituents of agarwood.

Antiproliferative sesquiterpene lactones from the roots of Inula helenium.

The MeOH extract of the roots of Inula helenium showed a high inhibitory activity for cell growth against MK-1, HeLa and B16F10 cell lines. Significant activity was found in the hexane-soluble fraction. From the hexane-soluble fraction, seven sesquiterpenes, namely, one germacrane (4beta,5alpha-epoxy-1(10),11(13)-germacradiene-8,12-olide), one elemane (igalane), and five eudesmanes (alantolactone, isoalantolactone, 11alpha,13-dihydroalantolactone, 11alpha,13-dihydro-isoalantolactone, 5-epoxyalantolactone) were isolated. In vitro antiproliferative activities of the isolates against MK-1, HeLa and B16F10 cells are reported.

Six new 2-(2-phenylethyl)chromones from Agarwood.

Six new chromones, 6-methoxy-2-[2-(3-methoxy-4-hydroxyphenyl)ethyllchromone (2), 6,8-dihydroxy-2-(2-phenylethyl)chromone (3), 6-hydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone (4), 6-hydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone (5), 7-hydroxy-2-(2-phenylethyl)chromone (6), and 6-hydroxy-7-methoxy-2-(2-phenylethyl)chromone (7) were isolated from the ether extract of agarwood in addition to a known compound, 2-(2-phenylethyl)chromone or flidersiachromone (1). Their structures were determined by spectroscopic methods including UV, IR, and NMR spectral data and comparisons with the calculated values using the hydroxyl and methoxyl substituent increments of the chromone ring.