Effect of Magnetic Fields on UV Absorption and Evaporation of Water

We investigated the effects of unipolar magnetic fields (N or S polarity) on the physical properties of deionized water. Long-term experiments revealed significant pole-dependent changes in water absorption in the UV range (180 – 350 nm). In the case of water in open vessels, the order of absorption values was C-N-S. That is, control (C) water absorbed the most, N-pole-influenced water absorbed less, and S pole the least. The differences in absorption between N and S waters were substantial. In the case of closed vessels, the differences in absorption spectra substantially diminished, and the arrangement of the absorption values became C-S-N (highest to lowest). A correlation between UV absorption values and evaporation rates was also found. The relative order of evaporation rates, C-N-S (highest to lowest), was the same as the order of the absorption values, also C-N-S. The differences in UV absorption spectra of the N- and S-treated waters persisted for several months after removing the magnets. Hence, the effects of magnetic fields were long term. The interaction of magnetic fields with water is of interest not only from a physical sciences perspective, but also in the context of the significant applications in medicine and biology.

Simultaneous Preparation of Abundant Flavonol Triglycosides from Tea Leaves

Flavonol glycosides are important components of tea leaves, contributing to the bioactivities as well as bitterness and astringency of tea. However, the standards of many flavonol triglycosides are still not available, which restricts both sensory and bioactivity studies on flavonol glycosides. In the present study, we established a simultaneous preparation method of seven flavonol triglycoside individuals from tea leaves, which consisted of two steps: polyamide column enrichment and preparative HPLC isolation. The structures of seven flavonol triglycoside isolates were identified by mass and UV absorption spectra, four of which were further characterized by nuclear magnetic resonance spectra, namely, quercetin-3-O-glucosyl-rhamnosyl-glucoside, quercetin-3-O-rhamnosyl-rhamnosyl-glucoside, kaempferol-3-O-glucosyl-rhamnosyl-glucoside and kaempferol-O-rhamnosyl-rhamnosyl-glucoside. The purities of all isolated flavonol triglycosides were above 95% based on HPLC, and the production yield of total flavonol glycosides from dry tea was 0.487%. Our study provides a preparation method of flavonol triglycosides from tea leaves, with relatively low cost of time and solvent but high production yield.

Formation of an exceptionally stable ketene during phototransformations of bicyclo[2.2.2]oct-5-en-2-ones having mixed chromophores

Photochemical reactions of bicyclo[2.2.2]oct-5-en-2-ones having mixed chromophores like a 5,6 dibenzoyl moiety and bulky electron-deficient substituents like phenyl or isopropenyl at the bridgehead position were analyzed for the first time in different solvents and upon irradiation with different wavelengths. In all cases, a regioselective photoinduced 1,5-phenyl migration leading to vinyl ketenes from the more congested site of the molecule to the less congested one has been observed. The ketenes were exceptionally stable both in air and solution. Its stability studies in acetonitrile through time-dependent UV absorption spectra revealed that it remained almost unchanged at least for a couple of weeks.

Simulation of UV Absorption Spectra and Relaxation Dynamics of Uracil and Uracil-Water Clusters

Despite many studies, the mechanisms of nonradiative relaxation of uracil in the gas phase and in aqueous solution are still not fully resolved. Here we combine theoretical UV absorption spectroscopy...

Interactions between β-Lactoglobulin and 3,3′-Diindolylmethane in Model System

The compound 3,3′-diindolylmethane (DIM) has a broad spectrum of anticancer activities. However, low stability and bioavailability limit its application. Elucidating interactions between DIM and β-lactoglobulin (β-LG) may be useful for fabricating whey protein-based protecting systems. Interaction with DIM increased the diameter and absolute zeta potential value of β-LG. UV-absorption spectra suggested that there was a complex of DIM and β-LG. β-LG showed enhanced fluorescence intensity by complexing with DIM with a binding constant of 6.7 × 105 M−1. Upon interaction with DIM, β-LG was decreased in secondary structure content of helix and turn while increased in β-sheet and unordered. FT-IR spectra and molecular docking results indicated the roles of hydrophobic interaction and hydrogen bond for the formation of DIM and β-LG nanocomplexes. Data suggested that β-LG may be a good vehicle for making a protein-based DIM protection and delivery system due to the tight binding of DIM to β-LG.

Gas-phase UV absorption spectra and OH-oxidation kinetics of 1H-1,2,3-triazole and pyrazole

In this work, we report the gas phase UV absorption spectra and the kinetics of the OH-oxidation of 1H-1,2,3-triazole and pyrazole.