A novel anthracene-based fluorescent colorimetric sensor for the simple naked-eye diagnosis of methylmalonic aciduria

A novel molecular sensor using anthracene bearing two amidopyridines emits blue fluorescence in the presence of succinic acid and green fluorescence in the presence of malonic acid, and its fluorescence intensity increased upon binding. Using this molecular sensor, we succeeded in detecting the difference of one carbon atom between succinic acid and malonic acid with the naked-eye. Furthermore, when methylmalonic acid was dissolved in urine to provide a model system for methylmalonic aciduria, the fluorescence changed from blue to green, and methylmalonic acid was successfully detected with the naked-eye.     

Lithium-cation and proton affinities of sulfoxides and sulfones: A fourier transform ion cyclotron resonance study

The kinetic method was used for the quantitative determination of lithium-cation affinities by Fourier transform ion cyclotron resonance. This method was applied to a series of XYSO and XYSO₂ compounds. Proton basicities of the SO and SO₂ compounds were also determined. When comparison is made between Li⁺ basicities and proton basicities, a linear regression encompassing XYSO and XYSO₂ families suggests that Li⁺ may be bonded in a similar way to the SO and SO₂ moieties, that is, to only one oxygen on the latter. PM3 calculations support this hypothesis.     

Determination of the antifungal agent voriconazole in human plasma using a simple column-switching high-performance liquid chromatography and its application to a pharmacokinetic study

A simple column-switching high performance liquid chromatographic (HPLC) method that does not require any complicated pretreatment has been developed to determine voriconazole in human plasma samples. An internal standard (IS) and borate buffer (pH 9.0) were added to plasma samples, which were then injected directly into the column-switching HPLC system using MAYI-ODS as a pre-column. The calibration curve for voriconazole showed good linearity in the range of 0.2-10 mug/ml in human plasma. The mean RSD (%) value of intra-day (n=6) and inter-day (n=5) precision were less than 5.4% and 8.2%, respectively. This system could make more than three hundred successive, accurate measurements when a washing step with ammonium acetate solution was added. This method was successfully applied to measure the therapeutic voriconazole level in patients' plasma, and was used in a study of voriconazole pharmacokinetics after oral administration.     

Synthesis of molecular‐weight‐controlled polyfluorene with boronate at one end

We investigated the synthesis of polyfluorene with a pinacol boronate (PinB) moiety at one end and with controlled molecular weight by means of Suzuki–Miyaura coupling polymerization of pinacol (7‐bromo‐9,9‐dioctyl‐9H‐fluoren‐2‐yl)boronate ( 1 ) with a palladium(0) precatalyst in the presence of pinacol 4‐trifluoromethylphenylboronate ( 2 ) as a chain terminator and CsF/18‐crown‐6 as a base. When we used AmPhos Pd G2, which has a propensity for intramolecular catalyst transfer on a π‐electron face, polyfluorene with the PinB moiety at one end and PhCF₃ (derived from 2 ) at the other end was obtained, and the molecular weight increased in proportion to the feed ratio of [ 1 ]₀/[catalyst]₀, though the molecular weight distribution was broad. Since the molecular weight also linearly increased with respect to the conversion of 1 until the middle stage of polymerization, the polymerization appears to involve chain‐growth polymerization through intramolecular catalyst transfer from the Pd catalyst inserted into the C? Br bond of 1 . The broad molecular weight distribution might be mainly due to slow initiation and slow termination with 2 , rather than polymer–polymer coupling. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2498–2504     

PM3 semiempirical calculations of lithium-cation and proton affinities for XYZPO and XYSO2 compounds

Proton affinities (PAs) of a series of phosphorous compounds bearing the phosphoryl function have been calculated using AM1 and PM3, as well as lithium-cation affinities (LCAs) using the recent PM3 lithium parametrization. Sulfonyl derivatives PAs and LCAs have been also calculated using PM3. The Li⁺ cation can be bonded in a “chelate” form with the two oxygens of the sulfonyl group. Nevertheless, the “linear” adduct, with the lithium-oxygen bond collinear with one of the SO bonds, is more stable. This is confirmed by ab initio calculations on Me₂SO₂ Li⁺ adducts. © 1996 John Wiley & Sons, Inc.