含β-环糊精单元温敏性聚合物的制备及其温敏性能测试

文章通过N-异丙基丙烯酰胺(NIPAAm)同马来酸酐(MAH)改性的β-环糊精发生共聚反应得到一种新型温敏性共聚物,表征确认其结构,并对其温敏性能进行了研究。结果:由于环糊精单元的引入,产品较NIPAAm均聚物有更高的最低临界共溶温度(LCST),环糊精单元在产品中所占的比例越多,其LCST值越大,并且在高pH和低离子浓度环境下,产品有更高的LCST。     

以L-酒石酸正己酯-硼酸配合物为反相液相色谱手性流动相添加剂分离班布特罗和妥洛特罗

以L-酒石酸正己酯-硼酸配合物为流动相添加剂,采用反相高效液相色谱法分离了班布特罗和妥洛特罗2种手性β-受体激动剂。实验考察了酒石酸正己酯和硼酸的浓度,缓冲溶液的种类、浓度、pH值,有机改性剂甲醇的含量对手性分离效果的影响。在最佳手性分离条件下,班布特罗和妥洛特罗均可以达到基线分离。     

重质松节油催化反应制备高纯度长叶烯的研究

以重质松节油通过精馏得到的长叶烯半成品为原料,通过催化反应降低原料中的β-石竹烯含量,制备含量为80%、85%、90%(色谱检测)的高纯度长叶烯产品,收率可达到97.0%。     

修饰β-环糊精与非瑟酮包合物的制备及其抗氧化活性研究

水溶液法合成β-CD顺丁烯二酸单酯,再与氯化亚砜和N,N′-二(3-氨丙基)乙二胺反应,从而制得N,N′-二(3-氨丙基)乙二胺修饰β-CD(主体)。通过饱和水溶液法制备主体与非瑟酮(客体)的包合物。采用UV、IR等表征并测定主体与客体的结合稳定常数,通过DPPH法测定包合物的抗氧化活性。结果表明,主体与客体的结合稳定常数K_S=2.1308×10⁵,包合物对DPPH自由基具有较好的抗氧化活性。     

Sulfobutylation of Beta-Cyclodextrin Enhances the Complex Formation with Mitragynine: An NMR and Chiroptical Study

Mitragynine (MTR), the main indole alkaloid of the well-known plant kratom (Mitragyna speciosa), is one of the most studied natural products nowadays, due to its remarkable biological effects. It is a partial agonist on the opioid receptors, and as such relieves pain without the well-known side-effects of the opioids applied in the clinical practice. MTR and its derivatives therefore became novel candidates for drug development. The poor aqueous solubility and low bioavailability of drugs are often improved by cyclodextrins (CyDs) as excipients through host-guest type complex formation. Among the wide variety of CyDs, sulfobutylether-beta-cyclodextrin (SBEβCyD) is frequently used and official in the European and U.S. Pharmacopoeia. Herein, the host-guest complexation of MTR with βCyD and SBEβCyD was studied using chiroptical and NMR spectroscopy. It was found by NMR measurements that MTR forms a rather weak (logβ₁₁ = 0.8) 1:1 host-guest complex with βCyD, while the co-existence of the 2MTR∙SBEβCyD and MTR∙SBEβCyD species was deducted from ¹H NMR titrations in the millimolar MTR concentration range. Sulfobutylation of βCyD significantly enhanced the affinity towards MTR. The structure of the formed inclusion complex was extensively studied by circular dichroism spectroscopy and 2D ROESY NMR. The insertion of the indole moiety was confirmed by both techniques.     

Efficient recovery of aromatic compounds from the wastewater of styrene monomer and propylene oxide co-production plant via hypercrosslinked aryl-rich starch-β-cyclodextrin polymeric sorbent

Adsorptive recovery of valuable components from industrial wastewater is highly desirable for avoiding resource wastage but remains a challenge. Herein, we develop an efficient continuous adsorption process for recovering aromatic compounds in wastewater from styrene monomer and propylene oxide coproduction(SMPO) plant. Based on our insight into the potential of bio-based porous materials for adsorption application, starch-graft-polystyrene(SPS) and aryl-modified β-cyclodextrin(ACD) were prepare...     

抗坏血酸对猴头菇β-葡聚糖表观黏度及结构特征的影响

采用碱提醇沉法制备猴头菇 β-葡聚糖(Hericium erinaceus alkali-extracted polysaccharide,HEAEP),系统研究了不同条件(抗坏血酸浓度、金属离子、温度、pH值等)下抗坏血酸对HEAEP表观黏度的影响,并深入分析了抗坏血酸对HEAEP结构特征的影响.研究结果表明:猴头菇...     

β-Cypermethrin Alleviated the Inhibitory Effect of Medium from RAW 264.7 Cells on 3T3-L1 Cell Maturation into Adipocytes

Studies have elucidated that pyrethroids induce adipogenesis. It is also known that macrophages can affect the homeostasis of adipose tissue. However, whether and how the β-cypermethrin (β-CYP)-mediated inhibition of the macrophages affects adipogenesis remain unknown. To explore the effects of β-CYP on adipogenesis through modulating the function of macrophages, 3T3-L1 cells, a preadipocyte cell line, were exposed to culture medium from either RAW 264.7 cells, a macrophage cell line (RM), or β-CYP-treated RAW 264.7 cells (CRM). CRM decreased the inhibitory effects of RM treatment on cell proliferation and adipogenesis, as lipid accumulation, the CEBPA content, and Fasn and Acaca expression in 3T3-L1 cells were higher following CRM treatment than following RM treatment through the higher levels of the demethylated CEBPA promoter in 3T3-L1 cells. However, the medium from β-CYP- and N-acetyl-L-cysteine-cotreated RAW 264.7 cells (CNRM) partially restored the inhibitory effects of RAW 264.7 cells on 3T3-L1 cells that had been reduced by CRM, indicating that β-CYP might reduce the cytotoxicity and inhibitory effects of RAW 264.7 cells on the adipogenesis of 3T3-L1 cells through elevating ROS levels in RAW 264.7 cells. Moreover, exposure to β-CYP downregulated the TNF-α secretion in RAW 264.7 cells. In conclusion, these data demonstrated that β-CYP affected the function of RAW 264.7 cells, alleviating their inhibitory effects on adipogenesis and CEBPA demethylation in 3T3-L1 cells. β-CYP might achieve these effects through downregulating the secretion of TNF-α via elevating ROS levels in RAW 264.7 cells. Our experiments provide a new perspective on the obesogenic effect of pyrethroids.     

重组大肠杆菌表达17β-羟基类固醇脱氢酶全细胞催化合成宝丹酮的研究

宝丹酮作为一种重要的蛋白同化雄性激素类固醇,具有提升肌肉质量和耐力的功能。宝丹酮的传统合成方法是以1,4-雄烯二酮（ADD）为底物通过化学法合成,但过程复杂、污染严重。17β-羟基类固醇脱氢酶（17β-HSD）可催化甾体化合物C-17位点的氧化还原反应,实现ADD和宝丹酮的相互转化。本研究通过基因序列同源性分析,筛选到6种不同来源的17β-HSD基因并对其在大肠杆菌中进行异源表达。利用不同重组菌转化ADD合成宝丹酮,结果表明重组菌BL21/pET28a-HSDPy的ADD转化率最高,因此选择BL21/pET28a-HSDPy进行进一步研究。鉴定了重组菌的酶学性质并优化其全细胞转化条件。结果表明在生物量为36 g·L^-1、底物浓度为5.40 g·L^-1条件下,经过两次补料,获得了3.66 g·L^-1宝丹酮,比优化前提高了4.1倍。而且在生物转化过程中未检测到副产物。为生物合成宝丹酮提供了可能。     

Effect of graphite particles as additive on the curing behaviour of β-tricalcium phosphate suspensions and scaffold fabrication by digital light processing

Reducing the viscosity of high solid-loading ceramic suspensions and controlling the resolution of ceramic green parts produced by digital light processing (DLP) 3D printing are two important concerns in the ceramic additive manufacturing industry. The presence of ceramic particles within a photopolymerizable system leads to light scattering that reduces the resolution of the ceramic green scaffolds. This study introduced a graphite additive to solve these problems and focused on the effects of graphite concentration on the viscosity, curing behaviour and scaffold fabrication of β-TCP ceramic suspensions. As a result, it was found that an appropriate addition of graphite reduced the viscosity of the ceramic suspensions, and the light scattering decreased with the increase of graphite concentration. Both the cure depth (C_d) and excess width (C_ex) also decreased with the increase of graphite concentration. But, graphite has a larger effect on the width curing than depth curing.