Metabolism and plasma pharmacokinetics of isoorientin, a natural active ingredient, in Sprague-Dawley male rats after oral and intravenous administration

<div><p></p><p>1. Several pharmacological effects have been revealed on isoorientin, suggesting its potential medicinal prospects. The metabolic and plasma pharmacokinetic profiles of isoorientin were investigated in rats.</p><p>2. For intra-gastric gavage, parent drug and three metabolites were detected in urine and feces by HPLC–MS/MS, but only one metabolite was found in plasma and identified as isoorientin 3′- or 4′-<i>O</i>-sulfate (M1) according to MS and UV absorbance spectra.</p><p>3. After a single i.v. administration of isoorientin (5, 10, or 15 mg/kg B.W.) in rats, linear pharmacokinetic property was observed with favorable terminal half-lives (1.67 ± 1.32–2.07 ± 0.50 h). After a single p.o. administration of isoorientin (150 mg/kg B.W.) in rats, plasma isoorientin concentration was low, but the concentration of M1 was comparatively high. Low systemic exposure of oral isoorientin in rats could result from its low aqueous solubility and extensive first-pass metabolism, and plasma concentration of M1 can be used as a biomarker of isoorientin intake. Isoorientin showed low oral bioavailability (8.98 ± 1.07%), and had about 6% or 45% dose recovery in urine or feces, respectively, 72 h after intra-gastric gavage.</p><p>4. These studies are the first to describe the pharmacokinetics of isoorientin via i.v. or p.o. dosing, providing important information for understanding its process <i>in vivo</i>.</p></div

Enantioselective Assembly of Spirolactones through NHC-Catalyzed Remote γ‑Carbon Addition of Enals with Isatins

A chiral <i>N</i>-heterocyclic carbene (NHC)-catalyzed formal [4 + 2] annulation of β-methyl substituted enals with isatins was developed to construct six-membered spirolactones bearing highly congested quaternary carbon stereocentersin good yields and high enantioselectivities. The strategy realized a challenging remote γ-carbon addition of enals and chiral control of β-methyl substituted enals in the presence of the NHC catalyst only

<i>N</i>‑Heterocyclic Carbene Catalytic [4 + 2] Cyclization of 3‑Alkylenyloxindoles with Enals: γ‑Carbon Activation for Enantioselective Assembly of Spirocarbocyclic Oxindoles

The ubiquitous structure of all-carbospirocyclic oxindoles makes the development of new methods for their enantioselective and stereoselective synthesis a significant ongoing challenge. Herein, we disclose a formal [4 + 2] annulation through <i>N</i>-heterocyclic carbene (NHC) catalysis for highly enantioselective synthesis of intriguing spirocarbocyclic oxindoles in the presence of Lewis acids. This protocol features good substrates tolerance, good yields, and excellent diastereoselectivities and enantioselectivities (up to 97% ee) under mild conditions

Use of Synchrotron XANES and Cr-Doped Coal to Further Confirm the Vaporization of Organically Bound Cr and the Formation of Chromium(VI) During Coal Oxy-Fuel Combustion

Through the use of synchrotron XANES and Cr-doped brown coal, extensive efforts have been made to clarify the volatility of organically bound Cr during oxy-fuel combustion and the mode of occurrence and leachability of Cr in resulting fly ashes. As the continuation of our previous study using raw coal, the Cr-doped coal has been tested in this study to improve the signal-to-noise ratio for Cr K-edge XANES spectra, and hence the accuracy for Cr­(VI) quantification. As has been confirmed, the abundant CO₂ as a balance gas for oxy-firing has the potential to inhibit the decomposition of organically bound Cr, thereby favoring its retention in solid ash. It also has the potential to promote the oxidation of Cr­(III) to Cr­(VI) to a minor extent. Increasing the oxygen partial pressure, particularly in the coexistence of HCl in flue gas, favored the oxidation of Cr­(III) into gaseous Cr­(VI)-bearing species such as CrO₂Cl₂. Regarding the solid impurities including Na₂SO₄ and CaO, Na₂SO₄ has proven to preferentially capture the Cr­(III)-bearing species at a low furnace temperature such as 600 °C. Its promoting effect on the oxidation of Cr­(III) to Cr­(VI), although thermodynamically available at the temperatures examined here, is negligible in a lab-scale drop tube furnace (DTF), where the particle residence time is extremely short. In contrast, CaO has proven facilitating the capture of Cr­(VI)-bearing species particularly oxychloride vapors at 1000 °C, forming Ca chromate with the formulas of CaCrO₄ and Ca₃(CrO₄)₂ via a direction stabilization of Cr­(VI) oxychloride vapor by CaO particle or an indirect oxidation of Cr­(III) via the initial formation of Ca chromite. The fly ash collected from the combustion of Cr-doped coal alone has a lower water solubility (i.e., 58.7%) for its Cr­(VI) species, due to the formation of Ba/Pb chromate and/or the incorporation of Cr­(VI) vapor into a slagging phase which is water-insoluble. Adding CaO to coal increased the water-solubility of both Cr­(VI) and Cr­(III) by forming Ca chromite and chromate, respectively

Data_Sheet_1_Effects of students’ perception of teachers’ ethnic-racial socialization on students’ ethnic identity and mental health in rural China’s schools.xlsx

IntroductionUsing students in the Liangshan Yi autonomous prefectures of southwestern China (n = 585; 13–15 years old), we examined (i) the effects of students’ perception of their teachers’ ethnic-racial socialization on their ethnic identity and mental health outcomes of depressive and stress symptoms; (ii) the effects of students’ ethnic identity on their depressive and stress symptoms; (iii) the differential associations among these factors in Yi ethnic minority versus Han cultural majority students.MethodsWe conducted a cross-sectional survey and used multistage sampling to collect the information. Chinese-validated standardized measures were used: the Patient Health Questionaires-9, Children’s Revised Impact of Event Scale-8, Multigroup Ethnic Identity Measure, Cultural Socialization Scale, and Teachers’ Attitude on Adoption of Cultural Diversity Scale. Multigroup confirmatory factor analysis and multigroup structural equation modeling were employed.ResultsComparing the findings in Yi and Han students, their perception of teachers’ ethnic-racial socialization had dissimilar effects on their ethnic identity and mental health outcomes. Three key findings comparing the differences between Yi and Han students were as follows: (i) students’ perception of their teachers’ multicultural socialization practices positively affected the ethnic identity of both Yi and Han young people; however, their perception of their teachers’ socializing them to their own cultures did not exert any effect; (ii) students’ perception of teachers’ multicultural socialization practices had different mental health effects on Yi versus Han students; and (iii) ethnic identity affected the mental health of Yi ethnic minority students only.ConclusionThe findings underscore the importance of teachers’ multicultural socialization in the ethnic identity development of both Yi ethnic minority and Han majority students. Ethnic identity serves as a linking variable bridging perceived teachers’ multicultural socialization practices and mental health in Yi ethnic minority students but not among the Han cultural majority youths. Research, practice, and policy implications relevant to the global context are also discussed.</p

Transformation of Tetracycline Antibiotics and Fe(II) and Fe(III) Species Induced by Their Complexation

Tetracycline antibiotics (TCs) are frequently detected micropollutants and are known to have a strong tendency to complex with metal ions such as Fe­(II) and Fe­(III) in aquatic environments. Experiments with Fe­(II) and TCs showed that the complexation of Fe­(II) with tetracycline (TTC), oxytetracycline (OTC), or chlorotetracycline (CTC) could lead to the accelerated oxidation of Fe­(II) and the promoted degradation of TCs simultaneously. The reaction started with complexation of Fe­(II) with TC followed by oxidation of the Fe­(II)–TC complex by dissolved oxygen to generate a Fe­(III)–TC complex and reactive oxygen species (ROS). The ROS (primarily ·OH) then degraded TC. The oxidation rate constants of Fe­(II) in the Fe^II–H₂L and Fe^II–HL complexes were 0.269 and 1.511 min^–1, respectively, at ambient conditions (pH 7, 22 °C, and <i>P</i>_O₂ of 0.21 atm), which were about 60 and 350 times of the oxidation rate of uncomplexed Fe­(II). Humic acids (HA) compete with TCs for Fe­(II), but the effect was negligible at moderate HA concentrations (≤10 mg·L^–1). Experiments with Fe­(III) and TCs showed that the complexation of Fe­(III) with TC could generate oxidized TC and Fe­(II) without the need of oxygen at a relatively slower rate compared to the reaction involving Fe­(II), O₂, and TCs. These findings indicate the mutually influenced environmental transformation of TCs and Fe­(II) and Fe­(III) induced by their complexation. These newly identified reactions could play an important role in affecting the environmental fate of TCs and cycling of Fe­(II) and Fe­(III) in TCs-contaminated water and soil systems

Measured and WASP-predicted concentrations of TSS at S2-S6 and S8-S11.

<p>Measured and WASP-predicted concentrations of TSS at S2-S6 and S8-S11.</p

Kinetics and Modeling of Degradation of Ionophore Antibiotics by UV and UV/H₂O₂

Ionophore antibiotics (IPAs), one of the major groups of pharmaceuticals used in livestock industry, have been found to contaminate agricultural runoff and surface waters via land application of animal manures as fertilizers. However, limited research has investigated the means to remove IPAs from water sources. This study investigates the degradation of IPAs by using ultraviolet (UV) photolysis and UV combined with hydrogen peroxide (UV/H₂O₂) advanced oxidation process (AOP) under low-pressure (LP) UV lamps in various water matrices. Three widely used (monensin, salinomycin, and narasin) and one model (nigericin) IPAs exhibit low light absorption in the UV range and degrade slowly at the light intensity of 3.36 × 10^–6 Einstein·L^–1·s^–1 under UV photolysis conditions. However, IPAs react with hydroxyl radicals produced by UV/H₂O₂ at fast reaction rates, with second-order reaction rate constants at (3.49–4.00) × 10⁹ M^–1·s^–1. Water matrix constituents enhanced the removal of IPAs by UV photolysis but inhibited UV/H₂O₂ process. A steady-state kinetic model successfully predicts the impact of water constituents on IPA degradation by UV/H₂O₂ and determines the optimal H₂O₂ dose by considering both energy consumption and IPA removal. LC/MS analysis of reaction products reveals the initial transformation pathways of IPAs via hydrogen atom abstraction and peroxidation during UV/H₂O₂. This study is among the first to provide a comprehensive understanding of the degradation of IPAs via UV/H₂O₂ AOP

The plotted graph of concentration of particulate metals and total metals.

<p>The plotted graph of concentration of particulate metals and total metals.</p

Plotted diagram of concentration of TSS and metals with turbidity values.

<p>Plotted diagram of concentration of TSS and metals with turbidity values.</p