(-)-(1R,2S)-肉豆蔻木脂素的不对称合成

报道了天然产物(-)-肉豆蔻木脂素的全合成. 以香草醛为起始原料, 经Wittig反应、LiAlH₄还原和Sharplass不对称双羟化等反应构建了苏式结构的中间体; 以焦性没食子酸为原料, 经Claisen重排反应制得另一种苯丙素片段; 2个中间体通过Mitsunobu反应, 缩合并使构型翻转, 得到赤式-(-)-肉豆蔻木脂素. 为赤式8-O-4′新木脂素的合成提供了一种新方法.     

连翘红茶中连翘脂素的提取方法研究

以连翘红茶为原料,对其提取分离连翘脂素方法进行研究。以连翘脂素的质量浓度作为指标,采用超高压液相色谱进行分析检测,比较不同柱材料和重结晶条件对连翘脂素的分离纯化能力。最佳方法:利用75%乙醇回流提取,水洗两次,D101大孔吸附树脂70%洗脱7BV,重结晶四次,四道工序七步操作即可得到了纯度98%的连翘脂素,总收率49%。整个提取分离方法具有得到的连翘脂素纯度高,回收率高,不使用易燃有毒的有机溶剂,对设备的要求低,操作步骤少且简单,大孔吸附树脂可重复多次使用等特点。     

利用发酵法提高连翘叶中连翘脂素含量的方法研究

利用植物自身酶对苷类化合物的酶解转化能力,采用发酵技术研究了连翘叶中连翘苷酶解转化为连翘脂素的较适宜发酵条件。首先考察了连翘叶含水量、发酵温度和发酵时间等单因素对连翘脂素转化生成量的影响,然后利用响应面优化法进一步优化了发酵转化条件。结果表明,在水分含量50%,发酵时间100 min,发酵温度30℃条件下,连翘叶中连翘苷可有效转化生成连翘脂素,且连翘脂素含量从1.67 mg·g^-1提高到46.40 mg·g^-1。本研究确定的方法可为利用连翘叶资源制备连翘脂素提供基础。     

二维晶格模型研究皂荚素二元体系形成混合胶束的分子交换能

利用二维晶格模型和相分离模型，由正规溶液理论首先推导出了二元表面活性剂形成混合胶束的分子交换能(ε~m)与混合胶束中组分A的超额化学位(μ^E~m~,~A)的关系式：μ^E~m~,~A=ε~m~gN~0(1-x~A)^2。然后导出ε~m与混合胶束中表面活性剂分子间的相互作用参数(β~m)的关系：ε~m=gRTβ~m/N~0。用该结论对皂荚素(GS)与十二烷基磺酸钠(C~1~2H~2~5SO~3Na)、十二烷基聚氧乙烯醚硫酸钠[C~1~2H~2~5(OC~2H~4)~3SO~4Na]、全氟辛酸钠(C~7F~1~5CO~2Na)、十二烷基脂肪醇聚氧乙烯(9)醚[C~1~2H~2~5(EO)~9OH]、辛基酚聚氧乙烯(10)醚[C~8H~1~7Ph(EO)~1~0OH]及十六烷基三甲基溴化铵(C~1~6H~3~3NMe~3Br)等表面活性剂混合体系的研究和计算表明：含皂荚素的二元表面活性剂形成的混合胶束，ε~m均为负值，表面活性剂分子间具有较强的协同效应。     

(S)的(R)吉尼斯蚁警戒素合成方法研究

以樟脑衍生物(-)-莰烷磺内酰胺为原料,经N-酰基莰烷-2,10-磺内酰胺与EtMgBr进行Michael加成反应,用氢化铝锂取代磺内酰胺助剂及溴化锂取代等步骤合成了(S)和(R)吉尼斯蚁警戒素,光学纯度达98%ee。     

反相液相色谱中生物大分子保留自由能及相比的测定

依据液相色谱中溶质的计量置换保留模型（SDM-R）和反相液相色谱（RPLC） 中小分子溶质柱相比的热力学新定义,建立了准确测定生物大分子柱相比的理论模 型和实验方法,准确测定了生物大分子的柱相比。同时依据计量置换参数logI和Z 具有热力学平衡常数的性质,并以logI和对1/T作图呈线性为途径,解决了生物大 分子色谱热力学研究中存在的三个难题,准确测定了七种标准蛋白质在RPLC保留过 程中的自由能变,并发现在RPLC中柱相比对保留过程中溶质总自由能变的贡献值几 乎可与溶质在RPLC保留过程中的净自由能变相当。     

HOD分子在(~C)1B1态的光解动力学:产物OH/OD的分支比以及OD键解离能

Photodissociation of jet-cooled HOD via the ? state around 124 nm has been studied using the H(D)-atom Rydberg tagging time-of-flight technique. Rotational state resolved action spectrum and the product translational energy distribution spectra have been recorded for both D+OH and H+OD dissociation channels. Product channel OH/OD branching ratios for the individual ?- X rotational transition have been determined. A comparison is also given with the B- X and ?- X transitions. In addition, the dissociation energy of the OD bond in HOD has been determined accurately to be 41751.3±5 cm^-1.     

Molecular Dynamics Simulation of Aqueous Solutions Using Interaction Energy Components: Application to the Solvation Gibbs Energy

Molecular dynamics simulations of aqueous solutions of the solutes acetamide (AcNH₂), acetic acid (AcOH), and acetaldehyde (AcH) were made using Lennard–Jones 12-6-1 potentials to describe the solute–solvent interactions. The Morokuma decomposition scheme and the ESIE solute atomic charges were used to reproduce the exchange, polarization, and electrostatic components of the solute–water interaction energy. A nonlinear perturbation was incorporated into the “slow-growth” technique in order to improve the results for the solvation Gibbs energy that were found to be in agreement with the available experimental and theoretical values.     

Antioxidants and Bioactive Compounds in Licorice Root Extract Potentially Contribute to Improving Growth,Bulb Quality and Yield of Onion (Allium cepa)

The increasing culinary use of onion (Alium cepa) raises pressure on the current production rate, demanding sustainable approaches for increasing its productivity worldwide. Here, we aimed to investigate the beneficial effects of licorice (Glycyrrhiza glabra) root extract (LRE) in improving growth, yield, nutritional status, and antioxidant properties of two high-yielding onion cultivars, Shandaweel and Giza 20, growing under field conditions in two consecutive years. Our results revealed that pretreatments of both onion cultivars with LRE exhibited improved growth indices (plant height and number of leaves) and yield-related features (bulb length, bulb diameter, and bulb weight) in comparison with the corresponding LRE-devoid control plants. Pretreatments with LRE also improved the nutritional and antioxidant properties of bulbs of both cultivars, which was linked to improved mineral (e.g., K⁺ and Ca²⁺) acquisition, and heightened activities of enzymatic antioxidants (e.g., superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, and glutathione S-transferase) and increased levels of non-enzymatic antioxidants (e.g., ascorbic acid, reduced glutathione, phenolics, and flavonoids). LRE also elevated the contents of proline, total free amino acids, total soluble carbohydrates, and water-soluble proteins in both onion bulbs. In general, both cultivars displayed positive responses to LRE pretreatments; however, the Shandaweel cultivar performed better than the Giza 20 cultivar in terms of yield and, to some extent, bulb quality. Collectively, our findings suggest that the application of LRE as biostimulant might be an effective strategy to enhance bulb quality and ultimately the productivity of onion cultivars under field conditions.     

Effects of Temperature and Catalyst to Oil Weight Ratio on the Catalytic Conversion of Heavy Oil to Propylene Using ZSM-5 and USY Catalysts

It is useful for practical operation to study the rules of production of propylene by the catalytic conversion of heavy oil in FCC (fluid catalytic cracking). The effects of temperature and C/O ratio (catalyst to oil weight ratio) on the distribution of the product and the yield of propylene were investigated on a micro reactor unit with two model catalysts, namely ZSM-5/Al2O3 and USY/Al2O3, and Fushun vacuum gas oil (VGO) was used as the feedstock. The conversion of heavy oil over ZSM-5 catalyst can be comparable to that of USY catalyst at high temperature and high C/O ratio. The rate of conversion of heavy oil using the ZSM-5 equilibrium catalyst is lower compared with the USY equilibrium catalyst under the general FCC conditions and this can be attributed to the poor steam ability of the ZSM-5 equilibrium catalyst. The difference in pore topologies of USY and ZSM-5 is the reason why the principal products for the above two catalysts is different, namely gasoline and liquid petroleum gas (LPG), repspectively. So the LPG selectivity, especially the propylene selectivity, may decline if USY is added into the FCC catalyst for maximizing the production of propylene. Increasing the C/O ratio is the most economical method for the increase of LPG yield than the increase of the temperature of the two model catalysts, because the loss of light oil is less in the former case. There is an inverse correlation between HTC (hydrogen transfer coefficient) and the yield of propylene, and restricting the hydrogen transfer reaction is the more important measure in increasing the yield of propylene of the ZSM-5 catalyst. The ethylene yield of ZSM-5/Al2O3 is higher, but the gaseous side products with low value are not enhanced when ZSM-5 catalyst is used. Moreover, for LPG and the end products, dry gas and coke, their ranges of reaction conditions to which their yields are dependent are different, and that of end products is more severe than that of LPG. So it is clear that maximizing LPG and propylene and restricting dry gas and coke can be both achieved via increasing the severity of reaction conditions among the range of reaction conditions which LPG yield is sensitive to.