A biosurfactant-producing yeast Rhodotorula sp.CC01 utilizing landfill leachate as nitrogen source and its broad degradation spectra of petroleum hydrocarbons.

Biosurfactants (BSs) are known for their remarkable properties, however, their commercial applications are hampered partly by the high production cost. To overcome this issue, a biosurfactant producing strain, Rhodotorula sp.CC01 was isolated using landfill leachate as nitrogen source, while olive oil was determined as the best sole carbon source. The BS produced by Rhodotorula sp.CC01 had oil displacement diameter of 19.90 ± 0.10 cm and could reduce the surface tension of water to 34.77 ± 0.63 mN/m. It was characterized as glycolipids by thin layer chromatography, FTIR spectra, and GC-MS analysis, with the critical micelle concentration of 70 mg/L. Meanwhile, the BS showed stability over a wide range of pH (2-12), salinity (0-100 g/L), and temperature (20-100 °C). During the cultivation process, BS was produced with a maximum rate of 163.33 mg L-1 h-1 and a maximum yield of 1360 mg/L at 50 h. In addition, the removal efficiency of NH4+-N reached 84.2% after 75 h cultivation with a maximum NH4+-N removal rate of 3.92 mg L-1 h-1. Moreover, Rhodotorula sp.CC01 has proven to be of great potential in remediating petroleum hydrocarbons, as revealed by chromogenic assays. Furthermore, genes related to nitrogen metabolism and glycolipid metabolism were found in this strain CC01 after annotating the genome data with KEGG database, such as narB, glycoprotein glucosyltransferase, acetyl-CoA C-acetyltransferase, LRA1, LRA3, and LRA4. The findings of this study prove a cost-effective strategy for the production of BS by yeast through the utilization of landfill leachate.

Effect of Ferrous Ion on Heat-Induced Aroma Deterioration of Green Tea Infusion.

Aroma deterioration is one of the biggest problems in processing tea beverages. The aroma of tea infusion deteriorates fast during heat sterilization and the presence of ferrous ion (Fe2+) aggravates it. The underlying mechanism remains unveiled. In this study, Fe2+ was verified to deteriorate the aroma quality of green tea infusion with heat treatment. Catechins were necessary for Fe2+-mediated aroma deterioration. By enhancing the degradation of catechins, Fe2+ dramatically increased the production of hydrogen peroxide (H2O2). Fe2+ and H2O2 together exacerbated the aroma of green tea infusion with heat treatment. GC-MS analysis revealed that the presence of Fe2+ enhanced the loss of green/grassy volatiles and promoted the formation of new volatiles with diversified aroma characteristics, resulting in a dull scent of green tea infusion. Our results revealed how Fe2+ induced aroma deterioration of green tea infusion with heat treatment and could help guide tea producers in attenuating the aroma deterioration of tea infusion during processing.

Effect of chemical composition of black tea infusion on the color of milky tea.

Milky tea is popular in many countries and its color is an important sensory property. The effects of black tea infusion on the color of milky tea prepared with non-dairy creamer were investigated. The results showed that the redder black tea infusion produced milky tea with more redness, and the color of milky tea was a pleasant pink when the a* value (redness indicator) was in the range of 6.0-7.0. Correlation analysis revealed that the respective theaflavins (TFs), thearubigins (TRs), thearubigins (TBs), (-)-epigallocatechin-3-gallate (EGCG) and chlorogenic acid contents significantly correlated with the a* values of milky tea. A series of complementary experiments were performed to elucidate that TFs and EGCG contributed to the redness of milky tea. The color formation was mainly associated with the binding of phenols to the proteins in the non-dairy creamer. These results contribute to understand the mechanism of color formation in milky tea.

A predictive model for astringency based on in vitro interactions between salivary proteins and (-)-Epigallocatechin gallate.

Astringency is an important quality attribute of green tea infusion, and (-)-Epigallocatechin gallate (EGCG) is the main contributor to astringency. Turbidity was used to predict the intensity of astringency for EGCG. The interactions between the selected proteins and EGCG, and the impacts of temperature, pH, protein structure, and EGCG concentration were studied. Mucin was selected as the protein in study for the prediction of EGCG astringency intensity. A predictive model (R2 = 0.994) was developed based on the relationship between the astringency of EGCG and the turbidity of EGCG/mucin mixtures at pH 5.0 and 37 °C. The fluorescence quenching analyses showed the interactions between EGCG and the selected proteins, which induced the reversible protein molecule conformational changes. The interactions were considered as the main reason that causes the astringency of tea infusions. The results provided a biochemical approach to explore the sensory qualities of green tea.

UHPLC-MS/MS method for the quantification of aloin-A in rat plasma and its application to a pharmacokinetic study.

Aloin-A (also known as barbaloin), the main bioactive anthraquinone-C-glycoside of Aloe species, exhibits various beneficial pharmacological effects. However, the determination and pharmacokinetic study of aloin-A in rat plasma need to be improved and systematically demonstrated. In the present study, a simple, robust and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for rapid quantification of aloin-A in rat plasma was developed. Plasma preparation was conducted by a single step protein precipitation with obtusin serving as an internal standards (IS) followed by separation of the analytes using an Agilent C18 column with a gradient mobile phase comprised of acetonitrile and formic acid aqueous solution. Negative ion electrospray was used and multiple reaction monitoring transitions were m/z 417.1 → 297.0 for aloin-A and m/z 343.1 → 328.1 for IS, respectively. The developed method was validated with linear range of 1-1000 ng/mL. All validation parameters were well within the acceptance criteria based on the guidance of FDA. The validated approach was successfully applied to analyze samples from a pharmacokinetic study in healthy rats following intravenous and oral administration. Aloin-A was found to be quickly absorbed, extensively distributed and rapidly eliminated. The absolute bioavailability of aloin-A was 5.79%.

Baicalin alleviates hyperglycemia-induced endothelial impairment 1 via Nrf2.

Baicalin is the major component found in Scutellaria baicalensis root, a widely used herb in traditional Chinese medicine, which exhibits strong anti-inflammatory, anti-viral and anti-tumor activities. The present work was devoted to elucidate the molecular and cellular mechanisms underlying the protective effects of Baicalin against diabetes-induced oxidative damage, inflammation and endothelial dysfunction. Diabetic mice, induced by streptozotocin (STZ), were treated with intraperitoneal Baicalin injections. Human umbilical vein endothelial cells (HUVECs) were cultured either in normal glucose (NG, 5.5 mM) or high glucose (HG, 33 mM) medium in the presence or absence of Baicalin for 72 h. We observed an obvious inhibition of hyperglycemia-triggered oxidative damage and inflammation in HUVECs and diabetic aortal vasculature by Baicalin, along with restoration of hyperglycemia-impaired nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway activity. However, the protective effects of Baicalin almost completely abolished in HUVECs transduced with shRNA against Nrf2, but not with nonsense shRNA. Mechanistic studies demonstrated that HG decreased Akt and GSK3B phosphorylation, restrained nuclear export of Fyn and nuclear localization of Nrf2, blunted Nrf2 downstream target genes, and subsequently induced oxidative stress in HUVECs. However, those destructive cascade, were well prevented by Baicalin in HUVECs. Furthermore, LY294002 and ML385 (inhibitor of PI3K and Nrf2) attenuated Baicalin mediated Nrf2 activation and the ability of facilitates angiogenesis in vivo and ex vivo. Taken together, the endothelial protective effect of Baicalin under hyperglycemia condition could be partly attributed to its role in downregulating reactive oxygen species (ROS) and inflammation via the Akt/GSK3B/Fyn-mediated Nrf2 activation.

Effect of the type of brewing water on the chemical composition, sensory quality and antioxidant capacity of Chinese teas.

The physicochemical characteristics, sensory quality, and antioxidant activity of tea infusions prepared with purified water (PW), mineral water (MW), mountain spring water (MSW), and tap water (TW) from Hangzhou were investigated. The results showed that the taste quality, catechin concentration, and antioxidant capacity of green, oolong, and black tea infusions prepared using MW and TW were significantly lower than those prepared using PW. Extraction of catechins and caffeine was reduced with high-conductivity water, while high pH influenced the stability of catechins. PW and MSW were more suitable for brewing green and oolong teas, while MSW, with low pH and moderate ion concentration, was the most suitable water for brewing black tea. Lowering the pH of mineral water partially improved the taste quality and increased the concentration of catechins in the infusions. These results aid selection of the most appropriate water for brewing Chinese teas.

[Sodium Selenite Regulates Growth and Uptake of Se,As and Heavy Metals of Trillium tschonoskii].

Objective: To study the influence of different concentrations of selenium on the growth and absorbing of Se,Cd,Pb,Hg and As in Trillium tschonoskii. Methods: Trillium tschonoskii was treated with different concentrations of exogenous selenium, arsenic and heavy metals,and then the mass growth, leaf area,root number and other indicators reflecting its growth rule were calculated. Atomic fluorescence method was used to measure the absorption contents of Se,Cd,Pb,Hg and As. Results: The relative mass growth,leaf area and root number of Trillium tschonoskii increased at first and then decreased with the increasing of exogenous selenium concentrations. When the concentration of selenium was 25 mg / kg,the relative mass growth,leaf area and root number of Trillium tschonoskii reached a maximum. When selenium concentrations was over than 30 mg / kg,it inhibited the growth and development of Trillium tschonoskii. Trillium tschonoskii absorbing Cd,Pb,Hg and As had a regular of first decreasing then increasing and last decreasing. It reached the lowest when selenium concentrations at the range of 10 ~ 15 mg / kg. . Conclusion: Selenium had both stimulating effect and inhibiting effect on the growth and development of Trillium tschonoskii. Different selenium concentrations have different effects in absorbing Cd,Pb,Hg and As of Trillium tschonoskii

Sediments in concentrated green tea during low-temperature storage.

The formation and the main chemical components of sediments, including reversible tea sediments (RTS) and irreversible tea sediments (IRS), in concentrated green tea during low-temperature storage were studied. RTS was mainly formed in the first 10 days, and IRS was mainly formed between 20 and 40 days of storage. The RTS were the primary sediment, contributing more than 90% of the total sediment. The RTS comprised of polyphenols, total sugar, caffeine, flavones and proteins, while the IRS mainly comprised of oxalates of Ca, Mg, Ga and Mn. The total mineral content in the IRS (17.1%) was much higher than that in the RTS (2.6%) after 80 days of storage. The Ca, Mg, Mn and Ga contents in IRS were over 1.0% (w/w) each. About 75% of the IRS was soluble in 0.1 M aqueous HCl, with the oxalate accounting for 68%. Minerals and oxalic acid were the crucial factors in the IRS formation.

Irreversible sediment formation in green tea infusions.

The formation of irreversible tea sediment (IRS) and its chemical components in green tea infusions were investigated. The results showed that the amounts of IRS in the green tea infusions from various tea cultivars ranged from 0.10 to 1.47 mg/mL. The amount of IRS was influenced remarkably by the chemical components in the green tea infusion. Principal component analysis and regression analysis indicated that gallated catechins, Mn, Ca, caffeine, Na, and (-)-gallocatechin gallate (GCG) were the principal components. IRS (mg/mL) = -4.226 + 0.275 gallated catechins + 79.551 Na + 7.321 Mn + 21.055 Ca + 0.513 caffeine - 0.129 GCG (R2 = 0.697). The contents of the main chemical components in the reversible tea sediment (RTS) and IRS were markedly different, especially the minerals. Large amount of minerals participated in the formation of irreversible green tea sediment. The amount of IRS increased with the extraction temperature.

[Literature survey on botanical origin and clinical application of traditional Tibetan medicine "Shengdeng"].

"Shengdeng" is its Tibetan transliteration referring to many medicines. Tibetan doctors and pharmacists in different areas use different drugs in formulation and clinical application, which are easily confused. In order to grasp the formula and clinical application accurately, we conduct a literature survey on history and current state of botanical origin and clinical application of "Shengdeng", making clear the application of various herbs named "Shengdeng" and providing reference to all Tibetan researchers and clinical workers in formulation and clinical application.

Expression and characterization of a constitutively active STAT6 from Tetraodon.

In this paper, we report the cloning and characterization of the STAT6 gene from the pufferfish, Tetraodon nigroviridis. The TnSTAT6 gene is composed of 20 exons and 19 introns. The exon-intron organization of this gene is similar to that of HsSTAT6 except for the exons encoding the C-terminal transactivation domain. The full-length complementary (c)DNA of TnSTAT6 encodes a 794-amino acid protein that is 31% identical to human STAT6. We generated a constitutively active TnSTAT6-JH1 by fusing the kinase domain of carp JAK1 to the C-terminal end of TnSTAT6 and demonstrated that the fusion protein has specific DNA-binding ability and can activate a reporter construct carrying multiple copies of mammalian IL-4-response elements. Interestingly, TnSTAT6-JH1 associated with and phosphorylated TnSTAT6 on Tyr661. Mutation of this residue, Y661W, in TnSTAT6 abolished its association with TnSTAT6-JH1. This is consistent with the importance of the corresponding Tyr641 of HsSTAT6 in tyrosine phosphorylation and dimer formation. On the other hand, treatment of mammalian IL-4 did not induce tyrosine phosphorylation of wild-type TnSTAT6, suggesting that both the divergent N-terminal domain and coiled-coiled domain of TnSTAT6 may affect the interaction of TnSTAT6 with mammalian IL-4 receptor complexes.

Expression and purification of goat lactoferrin from Pichia pastoris expression system.

The recombinant goat lactoferrin (rGLF) was expressed in the methylotropic yeast Pichia pastoris using pGAPZalphaC vector, GAP as promoter, and Zeocin as the selective marker. After transformation of the GLF-pGAPZalphaC into Pichia pastoris X-33 expression host, the GLF-pGAPZalphaC vector was integrated into the GAP promoter locus of Pichia pastoris X-33 chromosome. The rGLF was expressed and secreted into the broth using alpha-factor preprosequence. SDS-PAGE and PAS staining analysis indicated that the rGLF could be purified to electrophoretic homogeneity by heparin-Sepharose 6 Fast Flow affinity chromatography and glycosylated by the expression host. The yield of purified rGLF was approximately 2.0 mg/L of culture broth. The N-terminal sequence was identical to the native goat lactoferrin (nGLF). The iron-binding behavior, papain-inhibiting property, and thermal stability of the purified rGLF were comparable to nGLF. This is the 1st report of intact goat lactoferrin expression using the P. pastoris system.

[Effect of luteolin on COX-2 and mPGES-1 expression in LPS-induced RAW264.7 cells].

OBJECTIVE: To study the effect of luteolin on COX-2 and mPGES-1 expression in LPS-induced RAW264.7 cells. METHODS: After being pretreated with different concentrations of luteolin for 30 min, and then incubated with 1 microg/ml LPS for 12h, the effect of luteolin on the product of PGE2 in RAW264.7 cells was measured by enzyme immunoassay (EIA). The mRNA expression of COX-2 and mPGES-1 in RAW264.7 cells were analysed by RT-PCR. The COX-2 and mPGES-1 protein expression in RAW264. 7 cells were analysed by western blotting. RESULTS: Luteolin inhibited the LPS-induced PGE, synthesis in RAW264.7 cells. The mRNA and protein expression of COX-2 and mPGES-1 in RAW264.7 cells were also decreased by luteolin. CONCLUSION: Luteolin can inhibit significantly the expression of COX-2 and mPGES-1 in PGE2 synthetic pathway.

[Evaluation of a compound with dan-shen root and azone for scar treatment].

OBJECTIVE: To evaluate the effect of the compound of Dan-shen root and azone for scar treatment. METHODS: The rat skin in vitro and the human skin in vitro and vivo were separately examined their permeability of the mixture of the Dan-shen root and azone. The 301 patients with hypertrophic scar were randomly divided into two groups: one treated with elastic cloth paste (including silicone) contained in Dan-shen root with azone, and the another treated with only elastic cloth paste (including silicone). RESULTS: The permeability of Dan-shen root with azone, passing through the rat skin in vitro and the human skin in vitro and vivo was significantly higher than both the distilled water and the normal saline (P < 0.05). In the clinical study for treatment of the hypertrophic scars, the efficient rate of the group with the Dan-shen root with azone was significantly higher than the control (91.4% vs. 71.3%) (P < 0.01). CONCLUSION: The Dan-shen root with azone could be easier to permeate the skin and more effective to treat the hypertrophic scar.