Interaction of hydroxycinnamic acids and their conjugates with organic anion transporters and ATP-binding cassette transporters

Scope: Hydroxycinnamic acids are abundant antioxidants in our diet. In humans, hydroxycinnamic acids are metabolized to form sulfates and glucuronides, with the majority recovered in urine. Methods and results: We assessed the potential roles of organic anion transporters (OATs) and ATP‐binding cassette (ABC) transporters in the renal uptake and efflux of hydroxycinnamic acid conjugates. Uptake studies using OAT1 (SLC22A6)‐, OAT2 (SLC22A7)‐, and OAT3 (SLC22A8)‐expressing 293H embryonic kidney cells showed that OAT1 and OAT3, but not OAT2, accepted hydroxycinnamic acid conjugates as substrates. OAT1 and OAT3 mediated the basolateral uptake of hydroxycinnamic acid sulfates and glucuronide conjugates, respectively. Hydroxycinnamic acid sulfates are substrates of OAT4 and were capable of trans‐stimulating 5‐carboxyfluorescein uptake mediated by OAT4. On the other hand, hydroxycinnamic acid conjugates are not substrates for the ABC transporters, multidrug resistance protein 2 (MRP2/ABCC2) or breast cancer resistance protein (BCRP/ABCG2), demonstrated by the inability to alter ATPase activity. Cis‐inhibition studies with OATs and MRPs revealed that hydroxycinnamic acid conjugates have limited impact on the transport of model substrates significantly at physiological concentrations. Conclusion: Concerted action of OAT1, OAT3, and OAT4 is involved in the elimination of hydroxycinnamic acid conjugates into urine, whereas MRP2 and breast cancer resistance protein are not involved in the disposition of these conjugates.     

基于光纤倏逝波传感器的磷酸根离子检测

提出了利用光纤倏逝波传感器通过光吸收方法来测量溶液中磷酸根离子浓度的新方法。将通信用标准单模光纤（SMF）局部腐蚀到接近芯层后放入不同浓度的磷钼蓝溶液中,当以磷钼蓝光吸收峰值为探测光波长时,光纤表面的倏逝波会部分被溶液吸收,通过测量光纤输出光强来计算溶液中的磷酸根离子浓度。实验结果表明,磷钼蓝溶液中磷浓度为0．04～O...     

Towards a better understanding of the pectin structure-function relationship in broccoli during processing: Part I—macroscopic and molecular analyses

To investigate the structure-function relationship of pectin during (pre)processing, broccoli samples (Brassica oleracea L. cultivar italica) were subjected to one of the following pretreatments: (i) low-temperature blanching (LTB), (ii) LTB in combination with Ca²⁺ infusion, (iii) high-pressure pretreatment (HP), (iv) HP in combination with Ca²⁺ infusion, or (v) no pretreatment (control sample), whether or not in combination with a thermal treatment of 15 min at 90 °C. The macroscopic attributes of broccoli were linked to the chemical structure of broccoli pectin. By enhancing the cross-linking of pectic polymers, both LTB and HP reduced the texture loss that occurred during thermal processing of broccoli. During these pretreatments, homogalacturonan was de-esterified by pectin methylesterase, which led to changes in pectin solubility. When LTB or HP was combined with Ca²⁺ infusion, changes in the structure of pectin occurred, however not always reflected at the macroscopic level. The degree of esterification of pectin in Ca²⁺-soaked broccoli samples was lower compared to non-Ca²⁺-soaked samples and, in addition, a higher amount of ionically cross-linked pectin was retrieved.     

707阴离子交换树脂吸附铌的性能及动力学研究

研究了707阴离子交换树脂从草酸溶液中吸附铌 草酸配合物的特性。试验结果表明,在[(NH4)2C2O4]=0 20mol/L,[K2S2O7]=0 030mol/L,[Nb]=8 0×10-5mol/L,pH=2 0条件下,铌的吸附率有最大值,测得Freundlish常数K=1 69×103,吸附速率常数k25℃=1 73×10-4s-1,吸附活化能Ea=22 1kJ/mol,树脂的饱和容量为每g干树脂123 2mg。     

T—940树脂分离富集—极谱法测定二氧化铀中痕量铋

本文采用新型T－940阴离子交换树脂进行了铋与铀及其它重金属离子的分离研究。建立了在NaOH-甘露醇-PAR体系催化极谱测定痕量铋的方法。铋的峰电位为-0.68V（相对饱和甘汞电极）。该方法灵敏度高，铋浓度在0.005～0.1μg／mL.范围内呈现良好的线性关系。用于核纯二氧化铀中痕量铋的测定，效果很好。     

若干晶体中氧八面体结晶方位与晶体形貌

本文从结晶化学角度出发，研究了ＡＢ和Ａ２Ｂ３和ＡＢＯ３型氧化物晶体中的氧配位八面体的结晶方位与晶体结晶形貌之间的关系，提出晶体的结晶形貌是受晶体中负离子配位多面体结构和结晶方位所制约的。配位多面体顶角所对向的晶面生长速率最快，而面所对向的晶面生长速率最慢，配位体的棱所对向的晶面，生长速率居于两者之间，负离子配位多面体在晶体中的各个面族上连接和稳定性，决定了晶面的显露程度和晶体的结晶形貌。     

Application of monodispersive anion exchangers in sorption and separation of y3+ from Nd3+ and Sm3+ complexes with dcta

Rare earth complexes with trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (DCTA) of the Ln(dcta)- ype exhibited an unusual sequence of affinity on the polystyrene anion exchangers: pm3 >Nd3 >Sm3 >pr3 >Ce3 >Eu3 >Gd3 >La3 >Sc3 >Tb3 >Dy3 >Ho3 >y3 >Er3 >Tm3 >yb3 >Lu3 [1]. Taking into account the position of Y3 , Sm3 , and Nd3 in this affinity series, for the monodispersive polystyrene anion exchangers, Lewafit MonoPlus M 500, Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, Lewatit MonoPlus MP 64,and for the heterodispersive anion exchanger, Lewatit MP 62, the weight (Dg,) and bed (Dv) distribution coefficients of these complexes and working ion exchange capacities (Cw) were determined. Based on these values, purifications of Y3 from Nd3 and y3 from Sm3 in the macro-micro component system on these anion exchangers were studied. The application potential of this method was highlighted for the separation of yz3 in the presence of Nd3 and Sm3 . With 1 L of monodispersive and strongly basic polystyrene gel anion exchanger Lewatit MonoPlus M 500 in the acetate form, it is possible to obtain approximately 79 g Y2O3 purified from Nd2O3 and 70 g Y2O3 purified from Sm2O3 in the same process condition.     

A trivalent organoboron compound as one and two-photon fluorescent chemosensor for fluoride anion

The photophysical properties of a fluorene derivative with three coordinated boron and nitrogen as electron acceptor and donor group, respectively, were studied. The bonding of this compound with fluoride anion was exactly examined by linear absorption and single and two-photon-excited fluorescence technique. This compound is shown to be a two-photon fluorescent sensor for fluoride anion with high sensitivity and selectivity, which can be mainly attributed to the B–F interaction.     

Influence of the anion of promoting sodium compounds on the activity and selectivity in oxidative coupling of methane

The influence of the sodium compound anion-the promoter of the CaO/magnesiumaluminium spinel system-on the activity and selectivity in oxidative coupling of methane has been studied. It is found that the catalysts show optimal properties when the sodium compound of a weak acid is used.     

Effect of bamboo oil on antioxidative activity and nitrite scavenging activity

The purposes of this study were to investigate the effects of the bamboo oil on antioxidative activity and nitrite scavenging activity in vitro and in vivo. When the bamboo oil concentration was increased from 10 to 90 μL/mL, the DPPH scavenging rate increased from 15.6 to 98.2%. However, at bamboo oil concentrations above 110 μL/mL, it was not increased. The superoxide anion radical scavenging rate increased from 54.8 to 89.1% when the bamboo oil concentration increased from 110 to 150 μL/mL. When the bamboo oil was incubated for 20 h, the linoleic acid scavenging rate was approximately 91.2%, similar to that of ascorbic acid. The glutathione production using bamboo oil in vivo was 59.0 μM/g of liver, which was about 6.5-fold higher than that of the control. In the case of the activities of glutathione peroxidase and catalase, they were 16.8 U/mg of protein and 295 KU/mg of protein, respectively, approximately 5.6-fold higher and 3.0-fold higher than that of the control. The nitrite scavenging activity was increased from 60.1 to 93.9% at pH of 1.2 when the saturation time was increased from 2 months to 8 months. However, at more than 10 months of saturation, this level was not increased. These results suggest that the bamboo oil of Phyllostachys nigra var. henonis can be used in bioactive and functional materials.