Exopolysaccharides from the Energy Microalga Strain Botryococcus braunii: Purification, Characterization, and Antioxidant Activity.

Botryococcus braunii, a prestigious energy microalga, has recently received widespread attention because it can secrete large amounts of exopolysaccharides (EPS) with potential applications in food, cosmetics, and nutraceuticals. Unfortunately, the insufficiency of research on the bioactivity and structure-activity relationship of B. braunii EPS has impeded the downstream applications. In the present study, alcohol precipitation, deproteinization, and DEAE-cellulose column chromatography were used to extract and purify B. braunii SCS-1905 EPS. It was found that B. braunii SCS-1905 EPS were high-molecular-weight heteropolysaccharides containing uronic acid (7.43-8.83%), protein (2.30-4.04%), and sulfate groups (1.52-1.95%). Additionally, the EPS primarily comprised galactose (52.34-54.12%), glucose (34.60-35.53%), arabinose (9.41-10.32%), and minor amounts of fucose (1.80-1.99%), with the presence of a pyranose ring linked by a ß-configurational glycosidic bond. Notably, the antioxidant activity of crude exopolysaccharides (CEPS) was stronger, and the half maximal inhibitory concentration (IC50) for ABTS and hydroxyl radicals was significantly lower than that of deproteinized exopolysaccharides (DEPS). Overall, this study indicated a potential application of B. braunii SCS-1905 EPS as a natural antioxidant. In summary, B. braunii EPS could be used as a potential feedstock for the production of antioxidant health foods.

Adsorption and desorption characteristics of ginsenosides from Panax ginseng C. A. Meyer on middle-pressure chromatogram isolated gels.

Four types of middle-pressure chromatogram isolated gels are evaluated for adsorption or desorption characteristics of ginsenosides from Panax ginseng. Among them, SP207SS and SP2MGS were selected for dynamic investigations based on their static adsorption or desorption capacity of total ginsenoside. Their adsorption kinetics was better explained by pseudosecond-order model and isotherms were preferably fitted to Langmuir model. Dynamic breakthrough experiments indicated an optimum sample loading speed of 4 bed volume/h for either SP207SS or SP2MGS. Desorption speed was determined to be 2 bed volume/h according to desorption amount of total ginsenoside in their effluents. Eight ginsenosides were identified and quantified by high performance liquid chromatography-triple quadropole-mass spectrometry in total ginsenoside extract and different fractions during stepwise dynamic elution. For SP207SS, 27.62% of loaded ginsenosides was detected in 40% ethanol fraction, while 59.12% of them were found in 60% ethanol fraction. As on SP2MGS, the number went to 53.71 and 44.43%, respectively. Recovery rate of ginsenosides were calculated to 78.65% for SP207SS and 89.53% for SP2MGS, respectively. Intriguingly, content of Rg1 and Re in 40% ethanol fraction from SP207SS became 20.1 and 18.6 times higher than that in total ginsenoside extract by one-step elution, which could be leveraged for the facile enrichment of these two ginsenosides from natural sources.

Flavonoids Extraction from Propolis Attenuates Pathological Cardiac Hypertrophy through PI3K/AKT Signaling Pathway.

Propolis, a traditional medicine, has been widely used for a thousand years as an anti-inflammatory and antioxidant drug. The flavonoid fraction is the main active component of propolis, which possesses a wide range of biological activities, including activities related to heart disease. However, the role of the flavonoids extraction from propolis (FP) in heart disease remains unknown. This study shows that FP could attenuate ISO-induced pathological cardiac hypertrophy (PCH) and heart failure in mice. The effect of the two fetal cardiac genes, atrial natriuretic factor (ANF) and ß-myosin heavy chain (ß-MHC), on PCH was reversed by FP. Echocardiography analysis revealed cardiac ventricular dilation and contractile dysfunction in ISO-treated mice. This finding is consistent with the increased heart weight and cardiac ANF protein levels, massive replacement fibrosis, and myocardial apoptosis. However, pretreatment of mice with FP could attenuate cardiac dysfunction and hypertrophy in vivo. Furthermore, the cardiac protection of FP was suppressed by the pan-PI3K inhibitor wortmannin. FP is a novel cardioprotective agent that can attenuate adverse cardiac dysfunction, hypertrophy, and associated disorder, such as fibrosis. The effects may be closely correlated with PI3K/AKT signaling. FP may be clinically used to inhibit PCH progression and heart failure.

Anti-inflammatory iridoids from the stems of Cistanche deserticola cultured in Tarim Desert.

In order to determine the chemical constituents of Cistanche deserticola cultured in Tarim desert, a systematically phytochemical investigation was carried out. The constituents were isolated by silica gel, Sephadex LH-20, MCI gel, ODS column chromatography, and semi-preparative HPLC. Their structures were determined on the basis of MS and NMR spectroscopic analyses, by chemical methods, and/or comparison with literature data. The anti-inflammatory activities of the isolates were evaluated for their inhibitory effects on the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 mouse microglial cells. Nine iridoids were isolated and identified as cistadesertoside A (1), cistanin (2), cistachlorin (3), 6-deoxycatalpol (4), gluroside (5), kankanoside A (6), ajugol (7), bartsioside (8), and 8-epi-loganic acid (9). Compound 9 exhibited potent inhibition on the NO production with an IC50 value being 5.2 µmol·L(-1), comparable to the positive control quercetin (4.3 µmol·L(-1)). Compound 1 was a new iridoid, and compounds 5, 6, and 8 were isolated from this species for the first time.

Highly Selective Bioconversion of Ginsenoside Rb1 to Compound K by the Mycelium of Cordyceps sinensis under Optimized Conditions.

Compound K (CK), a highly active and bioavailable derivative obtained from protopanaxadiol ginsenosides, displays a wide variety of pharmacological properties, especially antitumor activity. However, the inadequacy of natural sources limits its application in the pharmaceutical industry. In this study, we firstly discovered that Cordyceps sinensis was a potent biocatalyst for the biotransformation of ginsenoside Rb1 into CK. After a series of investigations on the biotransformation parameters, an optimal composition of the biotransformation culture was found to be lactose, soybean powder and MgSO4 without controlling the pH. Also, an optimum temperature of 30 °C for the biotransformation process was suggested in a range of 25 °C-50 °C. Then, a biotransformation pathway of Rb1→Rd→F2→CK was established using high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). Our results demonstrated that the molar bioconversion rate of Rb1 to CK was more than 82% and the purity of CK produced by C. sinensis under the optimized conditions was more than 91%. In conclusion, the combination of C. sinensis and the optimized conditions is applicable for the industrial preparation of CK for medicinal purposes.

Hydrothermal synthesis, structures, and luminescent properties of zinc(II) and cadmium(II) phosphonates with a 3D framework structure using terephthalate as second linkers.

By introduction of 1,4-benzenedicarboxylic acid as a second organic ligand, two new divalent metal(II) phosphonates with a 3D framework structure, namely, [Zn(HL1)(bdc)(0.5)] (1) and [Cd(1.5)(HL2)(bdc)(0.5)] (2) (H(2)L1 = H(2)O(3)PCH(NH(2))C(6)H(5), H(3)L2 = H(2)O(3)PCH(2)-NC(5)H(9)-COOH, H(2)bdc = HOOCC(6)H(4)COOH), have been synthesized under hydrothermal conditions. The two compounds show three-dimensional (3D) framework structure with infinite two-dimensional (2D) networks pillared by H(2)bdc. For compound 1, the {ZnO(4)} polyhedra are interconnected by phosphonate groups into a 2D layer, and the adjacent layers are further cross-linked via the bdc(2-) anions to generate a three-dimensional framework structure with two types of channel system along the c-axis. A notable feature of compound 1 is the presence of alternate left- and right-handed helical chains in the structure. In compound 2, the inorganic chains, composed of {Cd(1)O(7)}, {Cd(2)O(4)} and {CPO(3)} polyhedra, are linked by HL2(2-) ligands to form a double layer structure in the ab plane, and the adjacent layers are further linked by the bdc(2-) anions to form a 3D framework structure with one-dimensional channel systems along the a-axis. Luminescence properties of compounds 1 and 2 have also been studied.

Hydrothermal synthesis, crystal structures, and luminescent properties of a series of new lanthanide oxalatophosphonates with a layer architecture.

Eleven new lanthanide oxalatophosphonate hybrids with a 2D layered structures, namely, [Ln(H(3)L)(C(2)O(4))]·2H(2)O (Ln = La-Dy, Er and Y, H(4)L = C(6)H(5)CH(2)N(CH(2)PO(3)H(2))(2)), have been synthesized under hydrothermal conditions and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. Compounds 1-11 are isomorphous and they exhibit a 2D framework structure. Two {LnO(8)} polyhedra and four {CPO(3)} tetrahedra are interconnected into a unit via corner-sharing, and the so-built units are bridged by the oxalate anions into a layer. The result of connections in this manner is the formation of a 24-atom window. The thermal stabilities and guest desorption-sorption properties of compounds 1-11 have been investigated. The luminescent properties of compounds 5, 6, 8 and 9 have also been studied.

Orthodontic bonding with self-etching primer and self-adhesive systems.

The purpose of this study was to compare the tensile bond strengths of orthodontic brackets bonded to enamel using conventional multi-step adhesive, self-etching primer (SEP), which combines etching and priming into a single step, and self-adhesive systems, which combine etchant, primer, and adhesive. Metal brackets were bonded to 90 extracted human premolars according to three experimental protocols: group 1, conventional multi-step adhesive system; group 2, SEP; and group 3, self-adhesive system. All specimens were debonded using an Instron universal machine and failures between the tooth surface and bracket base were observed by scanning electron microscopy (SEM). The bracket bases were then analysed by mapping of energy-dispersive X-ray (EDX) spectrometry to calculate the distributive percentages of enamel or resin. The bond strength, percentage distribution, and calcium on the debonded interface were determined and analysed by one-way analysis of variance, and means were ranked by a Tukey interval, calculated at the 95 per cent confidence level. Group 1 produced the greatest bond strength, followed by groups 2 and 3. Group 3 showed the highest debonded interface between resin and enamel or within the resin itself, followed by groups 2 and 1. Groups 1 and 2 displayed significantly more debond failures at the interface between the bracket and the resin than group 3. More calcium particles were observed on the bracket base after debonding in group 3 than in groups 2 and 1. The simplified bonding procedures caused an undesirable decrease in tensile bond strength.

Bond strength of orthodontic light-cured resin-modified glass ionomer cement.

The purpose of this study was to compare the bond strengths and debonded interfaces achieved with light-cured resin-modified glass ionomer cement (RMGIC) and conventional light-cured composite resin. In addition, the effects of acid etching and water contamination were examined. One hundred human premolars were randomly divided into five equal groups. The mini Dyna-lock upper premolar bracket was selected for testing. The first four groups were treated with light-cured RMGIC with or without 15 per cent phosphoric acid-etching treatment and with or without water contamination preceding bracket bonding. The control samples were treated with the conventional light-cured Transbond composite resin under acid etching and without water contamination. Subsequently, the brackets were debonded by tensile force using an Instron machine. The modified adhesive remnant index (ARI) scores were assigned to the bracket base of the debonded interfaces using a scanning electron microscope. The bond strength and modified ARI scores were determined and analysed statistically by one-way analysis of variance and chi-square test. Under all four conditions, the bond strength of the light-cure RMGIC was equal to or higher than that of the conventional composite resin. The highest bond strength was achieved when using RMGIC with acid etching but without water contamination. The modified ARI scores were 2 for Fuji Ortho LC and 3 for Transbond. No enamel detachment was found in any group. Fifteen per cent phosphoric acid etching without moistening the enamel of Fuji Ortho LC provided the more favourable bond strength. Enamel surfaces, with or without water contamination and with or without acid etching, had the same or a greater bond strength than Transbond.

Bond strength of various bracket base designs.

To determine the influence of various bracket base designs on bond strength and debond interface, 6 types of metal interlock brackets of different sizes and with different base designs were evaluated. The bracket base types and mesh sizes tested were as follows: retention groove base (Dynalock, Unitek, Monrovia, Calif), circular concave base (Accuarch appliance Formula-R, Tomy, Tokyo, Japan), double mesh with 5.1 x 10(-2) mm2 mesh size (Ultratrimm, Dentaurum, Ispringen, Germany), double mesh, 3.1 x 10(-2) mm2 (Minidiagonali Roth, Leone, Florence, Italy), double mesh, 3.1 x 10(-2) mm2 (Tip-edge Rx-I, TP Orthodontics, LaPorte Ind), and double mesh, 2.9 x 10(-2) mm2 (Mini Diamond, Ormco, Glendora, Calif). The Unitek bracket is cast in 1 piece; the other brackets are welded together. Brackets were bonded to human teeth and then debonded on a testing machine. The debond interface was recorded and analyzed with scanning electron microscopy and energy-dispersive x-ray spectrometry, and the distribution of interfaces was determined. The ranking of bond strength of individual bases (kg/base) from highest to lowest was Tomy, Dentaurum, Unitek, Leone, TP Orthodontics, and Ormco. The ranking of bonding strength per area squared MPa from highest to lowest was Tomy, Dentaurum, Leone, Unitek, TP Orthodontics, and Ormco. Debond in interfaces occurred between the bracket and resin, within the resin, or between the resin and enamel. The most debonded interfaces were between the bracket and resin and between the resin and enamel. The Tomy bracket, with its circular concave base, produced greater bond strength than did the mesh-based brackets; among the mesh-based brackets, Dentaurum, with the larger mesh size, produced greater bond strength than the brackets with smaller mesh sizes. The Unitek bracket, with its 1-piece cast base with retention grooves, ranked in the midrange of bond strength.