Bile conjugation and its effect on in vitro lipolysis of emulsions.

Bile Salts (BS) are responsible for stimulating lipid digestion in our organism. Gut microbiota are responsible for the deconjugation process of primary conjugated to secondary unconjugated BS. We use two structurally distinct BS and characterize the rate of lipolysis as a compound parameter. A static in-vitro digestion model as well as meta-analysis of literature data has been performed to determine the most influential factors affecting the lipid digestion process. The results demonstrate that lipolysis of emulsions using conjugated BS (NaTC, FFA = 60.0 %, CMC in SIF = 5.58 mM, MSR of linoleic acid = 0.21, rate of adsorption = -0.057 mN/m.s) enhances the release of FFA compared to deconjugated BS (NaDC, FFA = 49.5 %, CMC in SIF = 2.49 mM, MSR of linoleic acid = 0.16 rate of adsorption = -0.064 mN/m.s). These results indicate that conjugation plays an important role in controlling the rate of lipolysis in our organism which can be in turn, tuned by the microflora composition of our gut, ultimately controlling the rate of deconjugation of the BS.

A Self-Healing PVA-Linked Phytic Acid Hydrogel-Based Electrolyte for High-Performance Flexible Supercapacitors.

Flexible supercapacitors can be ideal flexible power sources for wearable electronics due to their ultra-high power density and high cycle life. In daily applications, wearable devices will inevitably cause damage or short circuit during bending, stretching, and compression. Therefore, it is necessary to develop proper energy storage devices to meet the requirements of various wearable electronic devices. Herein, Poly(vinyl alcohol) linked various content of phytic acid (PVA-PAx) hydrogels are synthesized with high transparency and high toughness by a one-step freeze-thaw method. The effects of different raw material ratios and agents on the ionic conductivity and mechanical properties of the hydrogel electrolyte are investigated. The PVA-PA21% with 2 M H2SO4 solution (PVA-PA21%-2 M H2SO4) shows a high ionic conductivity of 62.75 mS cm-1. Based on this, flexible supercapacitors fabricated with PVA-PA21%-2 M H2SO4 hydrogel present a high specific capacitance at 1 A g-1 after bending at 90° (64.8 F g-1) and for 30 times (67.3 F g-1), respectively. Moreover, the device shows energy densities of 13.5 Wh kg-1 and 14.0 Wh kg-1 at a power density of 300 W kg-1 after bending at 90° and for 30 times during 10,000 cycles. It provides inspiration for the design and development of electrolytes for related energy electrochemical devices.

Analysis of aromatic acids by nonaqueous capillary electrophoresis with ionic-liquid electrolytes.

The separation of six kinds of aromatic acids by CZE with 1-ethyl-3-methylimidazolium chloride (EMIMCl) and 1-ethyl-3-methylimidazolium hydrogen sulfate (EMIMHSO4 ), two kinds of ionic liquids (ILs) as background electrolytes, and acetonitrile as solvent were investigated. The six kinds of aromatic acids can be separated under positive voltage with low IL concentration with either of the two ILs and separation with EMIMHSO4 is better in consideration of peak shapes and separation efficiency. But the migration order is different when the IL is different. Under negative voltage with high IL concentration, the six analytes can be separated with EMIMCl as background electrolytes and the migration order of the analytes is opposite to those with low concentration of EMIMCl as background electrolyte. The separations are based on the combination effects of heteroconjugation between the anions and cations in the ILs and the analytes, of which the heteroconjugation between the anions in the ILs and the analytes plays a dominant role. The heteroconjugation between the anions of the ILs and analytes is proton sensitive and only a very small amount of proticsolvents added into the electrolyte solution can harm the separation. When EMIMCl concentration is high, the heteroconjugation between the IL anions and the proton in the analytes make the effective mobility of the analytes much higher than the EOF and their migration direction reversed. Finally, the six aromatic acids in water samples were analyzed by nonaqueous CE with low concentration of EMIMHSO4 as background electrolytes with satisfactory results.

Determination of kaempferol and quercetin in Xindakang tablet by ß-cyclodextrin modified micellar electrokinetic capillary chromatography.

A method was proposed to determine kaempferol and quercetin in Hippophae rhamnoides L medicinal preparation xindakang tablet by ß-cyclodextrin modified micellar electrokinetic capillary chromatography. Under the optimized conditions: buffer solution of 20 mmol/L Na(2)B(4)O(7)-KH(2)PO(4) (pH 9.0)-20mmol/L SDS-6mmol/L ß-CD-5%(v/v) MeCN, applied voltage of 16 kV and injection time of 8s, the two analytes were separated well within 10 minutes. The calibration was linear in the 0.02-0.80 and 0.02-0.70 mg/mL range for kaempferol and quercetin, respectively. The reproducibility based on migration time and peak height were 0.47% and1.87% for kaempferol, 0.55% and 2.02% for quercetin. The detection limits based on three times noise were 0.010 mg/mL and 0.008 mg/mL for kaempferol and quercetin, respectively. The developed method was utilized to analyze real samples and running recovery experiments with satisfactory results.

Research on flavonoids contents in Fructus sophorae with capillary zone electrophoresis.

Genistin, genistein, kaempferol, quercetin and rutin, five kinds of flavonoids in Fructus sophorae, have been analyzed by capillary zone electrophoresis with internal standard calibration. Buffer pH and concentration, applied voltage, ß-cyclodextrin and ethanol concentration were optimized and the optimum conditions are: 20 mmol/L borax (pH 9.5) with 8 mmol/L ß-cyclodextrin and 5% (v/v) ethanol and at a voltage of 25 kV. The contents of five flavonoids in Fructus Sophorae grown in different area of Dezhou, Shandong Province of China were determined by the developed method and with satisfactory results. The distributions of the studied flavonoids were also investigated.

Analysis of flavonoids by non-aqueous capillary electrophoresis with 1-ethyl-3-methylimidazolium ionic-liquids as background electrolytes.

The separation of three flavonoids, kaempferol, quercetin and luteolin, by capillary zone electrophoresis with three 1-ethyl-3-methylimidazolium ionic liquids (ILs), namely chloride, hydrogen sulfate and tetrafluoroborate salts, under non-aqueous conditions using acetonitrile as solvent was investigated. Depending on the IL, the three flavonoids can be separated under positive voltage with a low IL concentration and negative voltage with a high IL concentration. The separations are based on heteroconjungation between the IL anions and the analytes. The heteroconjungation between the anions of the ILs and the analytes is proton sensitive and only a very small amount of protic solvents, such as methanol, added into the electrolyte solution can harm the separation, but higher IL concentrations can overcome this higher amount of protic solvents. Using a high concentration of IL in the sample was used to enhance the flavonoid solubility by as much as 10, overcoming the problem of the low solubility during NACE analysis with ACN as the solvent. Finally, kaempferol, quercetin and luteolin in Semen Plantaginis were analysed by nonaqueous capillary electrophoresis with low concentration of the hydrogen sulfate ionic liquid with excellent results.

Analysis of brazilin and protosappanin B in sappan lignum by capillary zone electrophoresis with acid barrage stacking.

A method was developed to determine brazilin and protosappanin B in natural products by CE after acid barrage stacking. The optimum conditions were as follows: a BGE of 20 mM sodium tetraborate (pH 9.2) containing 6% v/v of methanol, hydrodynamic injection (0.5 psi, 65 s) followed by hydrodynamic injection of 150 mM citric acid (pH 2.3; 0.5 psi, 22 s), and separated with +25 kV. Under these conditions, brazilin and protosappanin B were separated with a sample-to-sample time less than 13 min and detection limits of 0.28 µg/mL and 0.15 µg/mL, respectively. The applicability of the developed method was demonstrated by the detection of brazilin and protosappanin in methanol extract of sappan lignum.

Analysis of flavonoids by capillary zone electrophoresis with electrokinetic supercharging.

On-line concentration via Electrokinetic Supercharging (EKS) was used to enhance the sensitivity of the capillary electrophoretic separation of the four flavonoids naringenin, hesperetin, naringin and hesperidin. Separation conditions, including the background electrolyte pH and concentration, the length and choice of terminator and the electrokinetic injection time were optimized. The optimum conditions were: a background electrolyte of 30 mM sodium tetraborate (pH 9.5) containing 5% (v/v) of methanol, electrokinetic injection of the sample (130 s, -10 kV) followed by hydrodynamic injecting of 100 mM 2-(cyclohexylamino)ethanesulfonic acid (CHES) (17 s, 0.5 psi) as terminator, and separation with -20 kV. Under these conditions the four flavonoids could be separated with a sample-to-sample time of 15 min and detection limits from 2.0 to 6.8 ng mL(-1). When compared to a conventional hydrodynamic injection the sensitivity was enhanced between 824 and 1515 times which is 7.6-16 times higher than other CE methods for the on-line concentration of flavonoids. The applicability of the developed method was demonstrated by the detection of the four flavonoids in an aqueous extract of Clematis hexapetala pall.

Analysis of phenolic acids by non-aqueous capillary electrophoresis after electrokinetic supercharging.

Electrokinetic supercharging (EKS), a new and powerful on-line preconcentration method for capillary electrophoresis, was utilized in non-aqueous capillary electrophoresis (NACE) to enhance the sensitivity of phenolic acids. The buffer acidity and concentration, leader and terminator length and electrokinetic injection time were optimised, with the optimum conditions being: a background electrolyte of 40 mM Tris-acetic acid (pH 7.9), hydrodynamic injection of 50 mM ammonium chloride (22 s, 0.5 psi) as leader, electrokinetic injection of the sample (180 s, -10 kV), hydrodynamic injection of 20 mM CHES (32 s, 0.5 psi) as terminator, before application of the separation voltage (-25 kV). Under these conditions the sensitivity was enhanced between 1333 and 3440 times when compared to a normal hydrodynamic injection with the sample volume <3% of the capillary volume. Detection limits for the seven phenolic acids were in the range of 0.22-0.51 ng/mL and EKS was found to be 3.6-7.9 times more sensitive than large-volume sample stacking and anion selective exhaustive injection for the same seven phenolic acids.

Fast analysis of phenolic acids by electrokinetic supercharging-nonaqueous capillary electrophoresis.

A method was developed to analyze phenolic acids by nonaqueous CE after online concentration with electrokinetic supercharging. The EOF was reversed using a polyelectrolyte multilayer approach based on the successive adsorption of poly(diallyldimethylamonium chloride) and poly(styrenesulfonate) to reduce the analysis time. The results showed that the coatings were stable during 40 consecutive injections. Four phenolic acids were separated within 8 min using 30 mM ammonium acetate (pH* 8.0). The electrokinetic injection time and terminator length of the electrokinetic supercharging method were optimized to improve the detection sensitivity. Under the optimized conditions (electrokinetic injection of 100 s, -10 kV; terminator of 20 mM 2-(cyclohexylamino) ethanesulfonic acid, 22 s, 0.5 psi), the sensitivity was enhanced from 300- to 440-fold. The detection limits, based on three times noise, were in the range 1.0-2.5 ng/mL.

Poly[[(µ-3,4-dicarboxy-tetra-hydro-furan-2,5-dicarboxyl-ato-κO,O,O:O)(1,10-phenanthroline-κN,N')copper(II)] 0.69-hydrate].

In the crystal structure of the title compound, {[Cu(C(8)H(6)O(9))(C(12)H(8)N(2))]·0.69H(2)O}(n), the Cu(II) atom has a distorted octa-hedral geometry, coordinated by four O atoms from two 3,4-dicarboxy-tetra-hydro-furan-2,5-dicarboxyl-ate ligands and two N atoms from one 1,10-phenanthroline ligand. One of the carboxylate groups bridges the Cu(II) atoms, forming a zigzag chain running along the b axis. The chains are linked by a π-π inter-action between aromatic rings with a centroid-to-centroid distance of 3.567 (1) Å, and by hydrogen bonds between the carboxyl-ate group and the disordered water mol-ecule, forming a three-dimensional network.

Penta-aqua-[5,5'-(m-phenylene)ditetra-zolato-κN]manganese(II) dihydrate.

The title compound, [Mn(C(8)H(4)N(8))(2)(H(2)O)(5)]·2H(2)O, is the fourth transition metal complex containing the 1,3-di(2H-tetra-zol-5-yl)benzene ligand to be structurally characterized. The Mn^II^ cation has a distorted octahedral coordination geometry. The 1,3-di(tetra-zol-5-yl)benzene ligand is planar. All H atoms bonded to O atoms participate in hydrogen bonds, which link the mol-ecules into a framework structure.