Several types of imidazolium salt ionic liquids were prepared derived from poly(oxyethylene)alkyl sulfate and used as an additive or coating material for lipase-catalyzed transesterification in an organic solvent. A remarkably increased enantioselectivity was obtained when the salt was added at 3-10 mol % versus substrate in the Burkholderia cepacia lipase (lipase PS-C)-catalyzed transesterification of 1-phenylethanol by using vinyl acetate in diisopropyl ether or a hexane solvent system. In particular, a remarkable acceleration was accomplished by the ionic liquid coating with lipase PS in an iPr(2)O solvent system while maintaining excellent enantioselectivity; it reached approximately 500- to 1000-fold acceleration for some substrates with excellent enantioselectivity. A similar acceleration was also observed for IL 1-coated Candida rugosa lipase. MALDI-TOF mass spectrometry experiments of the ionic-liquid-coated lipase PS suggest that ionic liquid binds with lipase protein.

The excitation, emission spectra, and decay curves of the emission intensity of thulium atoms implanted in liquid and solid helium were observed in the presence and absence of an external magnetic field. The observed narrow line ͑width ϳ0.1 nm͒ of the excitation spectrum at 590.60 nm is assigned as a zero-phonon transition from the electronic ground state 4 f 13 ( 2 F 7/2 o )6s 2 , which indicates that the transition between the inner shells is weakly perturbed by surrounding helium atoms. The pressure dependence of the emission wavelength suggests that the symmetry of helium atoms distributed around a thulium atom in the solid phase is similar to that in the liquid phase. The emission intensity was stable and large in the solid phase since thulium atoms were trapped at a density of 10 10 -10 11 atoms/cm 3 . The lifetime of the excited state was measured to be 7.09Ϯ0.04 s, which was longer than that of the 4 f 12 ( 3 H 6 )5d 5/2 6s 2 (6,5/2) 7/2 state of free thulium atoms. The excited state is expected to be a mixed state of the 4 f 12 5d6s 2 and 4 f 13 6s6p configurations. The metastable state 4 f 13 ( 2 F 5/2 o )6s 2 is populated by a radiative transition from this excited state and relaxes to the ground state through a magnetic dipole transition. The lifetime of the metastable state of a neutral thulium atom was measured to be 75Ϯ3 ms.

Lignans are a group of plant phenolic compounds with various biological activities, including antitumor and antioxidant properties. O-Methylation is a critical step in biosynthesis of these compounds. However, little is known about the O-methyltransferase (OMT) enzymes that catalyze lignan O-methylation. We discovered a highly regioselective OMT activity in safflower (Carthamus tinctorius) seeds that catalyzed the methylation of matairesinol, a dibenzylbutyrolactone lignan, into 4′-O-methylmatairesinol (arctigenin) but not 4-O-methylmatairesinol (isoarctigenin). By examining such OMT activity in correlation with OMT transcript abundances during seed development, we cloned a few putative OMT cDNAs and produced their recombinant proteins in Escherichia coli. Among them, one protein exhibited O-methylation activity for matairesinol with the regioselectivity identical to that of the plant protein, and was named C. tinctorius matairesinol OMT (CtMROMT). CtMROMT did not show any detectable OMT activities towards phenylpropanoid monomers under the reaction conditions tested, while it methylated flavonoid apigenin efficiently into 4′-O-methylapigenin (acacetin). However, quantitative real-time polymerase chain reaction analysis demonstrated that expression of the CtMROMT gene was synchronized with the CtMROMT activity profile and arctigenin accumulation in the plant. These results demonstrated that CtMROMT is a novel plant OMT for lignan methylation.

An excessive glucagon secretion to intravenous arginine infusion was found in obese hyperinsulinaemic patients with glucose intolerance. This study was designed to determine whether the glucagon hyperresponsiveness to arginine in these patients would improve by insulin infused at a high enough dose to overcome insulin resistance. By infusing high dose insulin during arginine infusion, the previously exaggerated glucagon response to arginine could be normalized. To normalize the abnormal glucagon response, insulin doses of 4.2 +/- 0.7 and 3.8 +/- 0.5 IU were required during arginine infusion in obese hyperinsulinaemic patients with impaired glucose tolerance and Type 2 (non-insulin-dependent) diabetes mellitus, respectively. This achieved plasma peak insulin levels 3 to 4 times higher than those observed in non-obese healthy subjects. Furthermore, we clarified whether or not the effect of normalizing insulin action and/or glycaemic excursions contributed to normalizing the exaggerated glucagon response to arginine in these patients. Blood glucose was clamped while high dose insulin was infused at the same levels as observed during the arginine infusion test with no insulin infusion. As a result, normalization of the exaggerated plasma glucagon response was achieved, whether hyperglycaemia existed or not. These results clearly demonstrate that, similar to non-obese hypoinsulinaemic Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) diabetic patients, the exaggerated Alpha-cell response to arginine infusion in obese hyperinsulinaemic patients with glucose intolerance is secondary to the reduction of insulin action on the pancreatic Alpha cell, and that the expression of insulin action plays an important part in normalizing these abnormalities.