Molecular rotation has attracted much attention with respect to the development of artificial molecular motors, in an attempt to mimic the intelligent and useful functions of biological molecular motors. Random motion of molecular rotators--for example the 180 degree flip-flop motion of a rotatory unit--causes a rotation of the local structure. Here, we show that such motion is controllable using an external electric field and demonstrate how such molecular rotators can be used as polarization rotation units in ferroelectric molecules. In particular, m-fluoroanilinium forms a hydrogen-bonding assembly with dibenzo[18]crown-6, which was introduced as the counter cation of [Ni(dmit)(2)](-) anions (dmit(2-) = 2-thioxo-1,3-dithiole-4,5-dithiolate). The supramolecular rotator of m-fluoroanilinium exhibited dipole rotation by the application of an electric field, and the crystal showed a ferroelectric transition at 348 K. These findings will open up new strategies for ferroelectric molecules where a chemically designed dipole unit enables control of the nature of the ferroelectric transition temperature.

The intestinal microbiome produces short-chain fatty acids (SCFAs) from dietary fiber and has specific effects on other organs. During endurance exercise, fatty acids, glucose, and amino acids are major energy substrates. However, little is known about the role of SCFAs during exercise. To investigate this, mice were administered either multiple antibiotics or a low microbiome-accessible carbohydrate (LMC) diet, before endurance testing on a treadmill. Two-week antibiotic treatment significantly reduced endurance capacity versus the untreated group. In the cecum acetate, propionate, and butyrate became almost undetectable in the antibiotic-treated group, plasma SCFA concentrations were lower, and the microbiome was disrupted. Similarly, 6-wk LMC treatment significantly reduced exercise capacity, and fecal and plasma SCFA concentrations. Continuous acetate but not saline infusion in antibiotic-treated mice restored their exercise capacity ( P < 0.05), suggesting that plasma acetate may be an important energy substrate during endurance exercise. In addition, running time was significantly improved in LMC-fed mice by fecal microbiome transplantation from others fed a high microbiome-accessible carbohydrate diet and administered a single portion of fermentable fiber ( P < 0.05). In conclusion, the microbiome can contribute to endurance exercise by producing SCFAs. Our findings provide new insight into the effects of the microbiome on systemic metabolism.

A simple and rapid analytical method for strigolactones, germination stimulants for the root parasitic weeds witchweed (Striga spp.) and broomrape (Orobanche spp.), has been developed using high-performance liquid chromatography connected to tandem mass spectrometry (LC/MS/MS). The natural strigolactones (strigol, sorgolactone, orobanchol, and alectrol) were clearly separated and identified by LC/MS/MS. As low as 0.1 pg/microL of strigol and 0.5 pg/microL of sorgolactone could be quantified, whereas 1 pg/microL was needed for the quantification of orobanchol (S/N > 10). Using this method, it was found that red clover produces orobanchol and alectrol but not strigol. The roots of red clover seedlings were found to produce 13, 70, 58, and 65 pg of orobanchol/plant 1, 2, 3, and 4 weeks after germination, respectively.