A core–shell-structured thermoresponsive hydrogel-supported bifunctional catalyst is developed. This catalyst enables a temperature–tuned aldol condensation/oxa-Michael addition/reduction sequential process to access chiral chromanols.

Overcoming the incompatibility of a pair of conflicting catalysts via a flow methodology has great significance in the practical applications for multistep organic transformations. In this study, a multiple continuous-flow system is developed, which can boost the reactivity and selectivity in a sequential enantioselective cascade reaction. During this process, a periodic mesoporous organosilica-supported Pd/carbene species as a Suzuki cross-coupling catalyst is packed in the first column reactor, whereas another periodic mesoporous organosilica-supported Ru/diamine species as an asymmetric transfer hydrogenation catalyst is packed in the second column reactor. As we envisioned, the initially Pd-catalyzed cross-coupling reaction of meta-/para-chloroacetophenones and aryl boronic acids followed by the subsequentially Ru-catalyzed reduction provides chiral biarylols with enhanced yields and enantioselectivities. Furthermore, the advantages of the easy handling and the simple procedure make this system an attractive application in a scale-up preparation of optically pure organic molecules under environmentally-friendly conditions.

An integrated laccase and prolines as a co-catalyst system enables an efficient oxidation/Aldol process to direct access chiral β-hydroxy carbonyls by using alcohols instead of environmentally unfriendly aldehydes and ketones.

采用UPLC-TOF MS-MS建立测定葡萄糖和甘氨酸反应体系中Fru-Gly化合物浓度的方法.以葡萄糖和甘氨酸为原料,在80℃水浴中回流1h,反应液经纯化,以Shim-pack GlST C18(2.1×75 mm,2 μm)为色谱柱,乙腈(含0.1％甲酸):水(含0.1％甲酸)为流动相,流速为0.2mL· min-1,采用电喷雾正离子(ESI+)模式测定,用于定性定量分析的离子对m/z为76/88.经方法学验证,Fru-Gly化合物在0.05～1 μg· mL-1浓度范围内,均具有良好的相关性,相关系数为0.9997,加标回收率为96.84％～102.84％,RSD为1.93％,重复性和精密度的RSD均小于3.0％.结果表明,UPLC-TOF MS-MS法重复性好,精密度高,适用于测定葡萄糖和甘氨酸反应体系中Fru-Gly化合物的浓度.

Reported is the first example of a rhodium-mediated β-sulfide elimination, which represents a new mode of reactivity for late-transition-metal chemistry. This serendipitous discovery facilitates an ene-cycloisomerization of allylic-sulfide-containing alkenylidenecyclopropanes (ACPs) to afford five-membered carbo- and heterocyclic rings with concomitant intramolecular thioether migration. Interestingly, similar selectivity is obtained with both E- and Z-allylic sulfides and the reaction is also feasible with an allylic selenide. Mechanistic studies are consistent with an inner-sphere transfer of the sulfide, which is remarkable given the propensity for sulfides to poison transition-metal catalysts. Finally, this type of atom-economical rearrangement is envisioned to prompt the development of related processes given the utility of sulfides in target-directed synthesis.

OBJECTIVE:To examine the effect of an aqueous extract of Radix Paeoniae Alba (RPA) on the formation of calcium oxalate (CaOx) stones and the potential mechanism underlying the effect. MATERIALS AND METHODS:An in vitro assay was used to determine whether the RPA extract prevents the formation of CaOx or promotes CaOx dissolution. We also investigated the efficacy of the extract in vivo as a preventive and therapeutic agent for experimentally induced CaOx nephrolithiasis in rats. Various biochemical, molecular, and histological parameters were assessed in kidney tissue and urine at the end of the in vivo experiment. RESULTS:Significant dissolution of formed crystals (8.99 ± 1.43) and inhibition of crystal formation (2.55 ± 0.21) were observed in vitro after treatment with 64 mg/mL of the RPA extract compared with a control treatment (55.10 ± 4.98 and 54.57 ± 5.84, respectively) (p < .05). In preventive protocols, the RPA extract significantly reduced urinary and renal oxalate levels and increased urinary calcium and citrate levels compared to the control. In addition, the RPA preventive protocol significantly decreased osteopontin expression, renal crystallization, and pathological changes compared to the control. These changes were not observed in rats on the therapeutic protocol. CONCLUSIONS:RPA is a useful agent that prevents the formation of CaOx kidney stones.

根据毛蕊花糖苷、羟基酪醇、咖啡酸的紫外吸收性质,建立了同时检测3种物质的高效液相色谱法.采用Waters e2695型高效液相色谱仪,色谱柱为Waters Symmetry C18柱(5μm,250 mm×4.6mm);流动相为甲醇(A)和体积分数0.1％甲酸水溶液(B),比例为40:60(V/V);流速0.7 mL/min;2998PDA二极管阵列检测器,检测波长280 nm,柱温35℃;进样量10μL.毛蕊花糖苷标准曲线的线性回归方程为y=4.474ρ+5.224,R2=0.9999;加样回收率为100.2％.咖啡酸标准曲线的线性回归方程为y=20.687ρ-3.392,R2=0.9995;加样回收率为100.0％;羟基酪醇标准曲线的线性回归方程为y=4.716ρ-17.901,R2=0.9999;加样回收率为102.0％;毛蕊花苷的检测限为5 ng,咖啡酸的检测限为0.8 ng,羟基酪醇的检测限为0.25 ng.

Objective. To investigate whether calcium-sensing receptor (CaSR) plays a role in calcium-oxalate-induced renal injury. Materials and Methods. HK-2 cells and rats were treated with calcium oxalate (CaOx) crystals with or without pretreatment with the CaSR-specific agonist gadolinium chloride (GdCl3) or the CaSR-specific antagonist NPS2390. Changes in oxidative stress (OS) in HK-2 cells and rat kidneys were assessed. In addition, CaSR, extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal protein kinase (JNK), and p38 expression was determined. Further, crystal adhesion assay was performed in vitro, and the serum urea and creatinine levels and crystal deposition in the kidneys were also examined. Results. CaOx increased CaSR, ERK, JNK, and p38 protein expression and OS in vitro and in vivo. These deleterious changes were further enhanced upon pretreatment with the CaSR agonist GdCl3 but were attenuated by the specific CaSR inhibitor NPS2390 compared with CaOx treatment alone. Pretreatment with GdCl3 further increased in vitro and in vivo crystal adhesion and renal hypofunction. In contrast, pretreatment with NPS2390 decreased in vitro and in vivo crystal adhesion and renal hypofunction. Conclusions. CaOx-induced renal injury is related to CaSR-mediated OS and increased mitogen-activated protein kinase (MAPK) signaling, which subsequently leads to CaOx crystal adhesion.

Purpose. To use in vitro and in vivo models to evaluate Glechoma longituba extract to provide scientific evidence for this extract's antiurolithic activity. Materials and Methods. Potassium citrate was used as a positive control group. Oxidative stress (OS) markers and the expression of osteopontin (OPN) and kidney injury molecule-1 (KIM-1) were measured to assess the protective effects of Glechoma longituba. Multiple urolithiasis-related biochemical parameters were evaluated in urine and serum. Kidneys were harvested for histological examination and the assessment of crystal deposits. Results. In vitro and in vivo experiments demonstrated that treatment with Glechoma longituba extract significantly decreased calcium oxalate- (CaOx-) induced OPN expression, KIM-1 expression, and OS compared with the positive control group (P < 0.05). Additionally, in vivo rats that received Glechoma longituba extract exhibited significantly decreased CaOx deposits and pathological alterations (P < 0.05) compared with urolithic rats. Significantly lower levels of oxalate, creatinine, and urea and increased citrate levels were observed among rats that received Glechoma longituba (P < 0.05) compared with urolithic rats. Conclusion. Glechoma longituba has antiurolithic effects due to its possible combined effects of increasing antioxidant levels, decreasing urinary stone-forming constituents and urolithiasis-related protein expression, and elevating urinary citrate levels.

研究了大孔吸附树脂对大粒车前子苯乙醇苷粗提物的富集纯化效果,并探讨了苯乙醇苷精制物调节高尿酸血症大鼠的血尿酸水平的作用.经过比较HPD400、HPD400A等9种树脂苯乙醇苷的吸附解吸效果,最终选择HPD400A树脂来精制苯乙醇苷提取物.当层析树脂柱径高为1.00 cm×33.50 cm时,优化后的富集纯化条件为:粗提物上样液质量浓度为10.3 mg/mL,吸附流速为2.7 mL/min,解吸流速为3.5 mL/min,解吸剂为30％乙醇水溶液,解吸剂体积为400 mL.从500 g车前子原料中可得到总苯乙醇苷含量达80％的精制物3.07 g,得率为0.61％.经大鼠经口给药实验表明,苯乙醇苷粗提物和精制物均能显著降低血尿酸水平和黄嘌呤氧化酶活性,且与模型组相比差异显著(p＜0.01).