Improvement of mechanical properties of orodispersible hyaluronic acid film by carboxymethyl cellulose addition.

Orodispersible films (ODF) were prepared with mixtures of hyaluronic acid (HA) and carboxymethyl cellulose (CMC), and the effect of CMC addition on the disintegration and mechanical properties of the composite films were examined. Low molecular weight HA (10 kDa) appeared more acceptable for ODF than high molecular weight HA (800 kDa) because of its rapid disintegration in the oral cavity. The composite films appeared similar to pullulan film with excellent transparency and surface smoothness.

Impact of single and dual modifications on physicochemical properties of japonica and indica rice starches.

The japonica (JR) and indica (IR) rice starches were modified by acetylation, hydroxypropylation, cross-linking, and dual modification (cross-linked acetylation and cross-linked hydroxypropylation) and the effects of single and dual chemical modifications of JR and WR on the physicochemical properties were investigated. The JR had a greater substitution degree of acetyl or hydroxypropyl groups than IR. The dual-modified JR showed broader gelatinization temperature range than corresponding single-modified starches, but narrower it in IR.

Profiling analysis of biogenic amines and their acidic metabolites in mouse brain tissue using gas chromatography-tandem mass spectrometry.

The profiling analysis of biogenic amines, including catecholamines and serotonin, and their metabolites in mouse brain tissue provides an important key to understanding their roles in the body and the possibility of simple and accurate diagnosis of neural diseases. A novel approach in the analysis of biogenic amines and their acidic metabolites in brain tissue using gas chromatography-tandem mass spectrometry (GC-MS/MS) is presented. Biogenic amines and their acidic metabolites in brain tissue were effectively separated using a mixed-cation-exchange solid-phase extraction (MCX-SPE) cartridge with a variation in the composition of the SPE elution solvents.

GC-MS/MS method for the quantification of α-cedrene in rat plasma and its pharmacokinetic application.

α-Cedrene is a pharmacologically active ingredient isolated from the essential oil of cedar. A selective and sensitive GC-MS/MS method was developed for the quantification of α-cedrene in rat plasma for the first time. α-Cedrene was extracted from rat plasma using ethyl acetate at neutral pH.

Comprehensive profiling analysis of bioamines and their acidic metabolites in human urine by gas chromatography/mass spectrometry combined with selective derivatization.

A comprehensive analytical method was developed for the profiling of biogenic amines in human urine using GC/MS in SIM mode. Biogenic amines and their acidic metabolites were converted into their volatile O-trimethylsilyl/N-heptafluorobutyryl (OTMS/-NHFBA) derivatives for GC/MS analysis. Dual hexamethyldisilazane (HMDS)/-N-methyl-bis-heptafluorobutyramide (MBHFBA) derivatizations have been shown to be quite effective, with high derivatization yields and the absence of side products for primary biogenic amines.

One-pot synthesis of 2-pyridones via chemo- and regioselective tandem Blaise reaction of nitriles with propiolates.

The Blaise reaction intermediate, generated in situ from Reformatsky reagent and nitrile, reacted with propiolates in a chemo- and regioselective manner to afford 2-pyridone derivatives in good to excellent yields.

Structural determination of sildenafil and its analogues in dietary supplements by fast-atom bombardment collision-induced dissociation tandem mass spectrometry.

Sildenafil and its analogues, which are used as illegal additives in several dietary supplements, were isolated by liquid-liquid extraction and column chromatography and analyzed by fast-atom bombardment mass spectrometry (FAB-MS). Structures of sildenafil and its derivatives were elucidated by FAB-tandem mass spectrometry (MS/MS) with exact mass measurement in the positive-ion mode. To find structurally diagnostic ions for the sildenafil analogues, authentic sildenafil was preferentially analyzed by high-energy collision-induced dissociation (CID)-MS/MS.

Structural determination of monoacylglycerols extracted from marine sponge by fast atom bombardment tandem mass spectrometry.

Five new monoacylglycerols (MAGs) were isolated from the marine sponge Stelletta sp. by reversed-phase high-performance liquid chromatography and analyzed by positive ion fast atom bombardment mass spectrometry (FAB-MS). FAB mass spectra of these compounds produced abundant sodium-adducted molecules [M+Na]+ from a mixture of 3-nitrobenzyl alcohol and sodium iodide.