Neuroprotective glucosides of magnolol and honokiol from microbial-specific glycosylation

Thirteen new glucosides (1–13) of magnolol and honokiol were obtained from specific O-glycosylation by two filamentous fungi, Cunninghamella echinulata AS 3.3400 and Rhizopus japonicus ZW-4. The glucosides' structures were determined on the basis of extensive spectroscopic (HRESIMS, 1D and 2D NMR, and CD) analyses and a chemical method. C. echinulata appeared to transfer a glucosyl moiety to 2-OH of magnolol and honokiol, whereas R. japonicus preferred to regio-specifically transfer a glucosyl moiety to 4′-OH when honokiol was as the substrate. In addition, hydroxylation by C. echinulata and specific 6″-O-acylation of the introduced glucosyl moiety by R. japonicus were observed as minor reactions. Bioassay results indicated that glucosides 1–12 together with magnolol and honokiol at 10 μM attenuated the glutamate-induced toxicity in SK-N-SH cells to levels comparable to the results for MK-801, a positive control. However, the water-solubility of major glucosylated products (1, 8, and 11) increased greatly.     

Effects of Saline-Alkaline Stress on Seed Germination and Seedling Growth of Sorghum bicolor (L.) Moench

In order to study the adaptation ability of sweet sorghum (Sorghum bicolor L. Moench) in the Yellow River Delta, the sweet sorghum variety Mart was used in this study to determine the roles of different saline-alkaline ratio stress treatment during seed germination to seedling stage. The results showed that Na⁺ concentration had a significant impact on the seed germination, seedling growth, and plant survival of sweet sorghum. Increasing Na⁺ concentration led to a decline in germination rate, final germination percentage, survival percentage, plant height, and dry weight per plant, a prolonged mean time of germination, as well as loss of improvement effect of low-Na+ concentration. The interaction effect of Na⁺ concentration and pH on the mean time of germination and germination rate was not significant (p?+ concentration (100 mM), high pH reduced the mean time of germination and increased the germination rate, without decline in final germination percentage and survival percentage. Therefore, at least in the duration of seed germination to the harvest period in the research, the sweet sorghum was resistant to the pH stress (≥9.04) when the Na⁺ concentration was below 100 mM. When suffered from the saline-alkaline stress, the seedling of sweet sorghum was characterized by ecological adaptive features, such as decreased stem ratio and chlorophyll b content in leaves and increased root ratio and chlorophyll a content, in order to maintain the uptakes of water and nutrient, and carbon assimilation. When the stress intensified, the lipid oxidation products, e.g., malondialdehyde (MDA), increased in sweet sorghum seedlings. However, the increasing of soluble protein content and antioxidant enzyme activity (superoxide dismutase (SOD), guaiacol peroxidase (POD), and gatalase (CAT)) was only founded in neutral low-Na⁺ concentration treatment (A₁), which indicated that high-salt concentration and pH all elicited harmful effects and limited the self-healing ability of sweet sorghum seedlings. In all, in order to grow sweet sorghum in the saline-alkaline soils of the Yellow River Delta, the salt concentration and pH value of the soil must be taken into consideration, and seeding density should be increased and supported by appropriate irrigation measures to reduce saline-alkaline stress so as to ensure the survival and growth of sweet sorghum seedlings.     

Domino free radical photopolymerization based on phototriggered base proliferation reaction and redox initiation

A detailed evaluation of the kinetics of domino free radical photopolymerization (DFRP) based on phototriggered base proliferation reaction and redox initiation was described in the condition of eliminating the heat of polymerization via reacting in the thin polymer films. First, domino photoinitiating system made a substantial breakthrough in the photoefficiency of amine generation in contrast to photocaged base system, exhibiting marked improvement in the photosensitivity. Second, both the structural feature of base amplifier (BA) and reaction temperature as two important factors impacting the proliferation rate have been detailed. Third, different domino photoinitiating components, such as BAs, peroxides, and acrylates, were investigated in the thin polymer films. It is shown that both primary and secondary BAs are efficient catalysts for DFRP. Furthermore, polymerization rate shows a consistent dependence on the pK_a value of the proliferated amine. Finally, remarkable post conversion after irradiation was achieved in DFRP. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1560–1569     

Simultaneous identification and analysis of cassane diterpenoids in Caesalpinia minax Hance by high‐performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry

Cassane diterpenoids were successfully and simultaneously identified in Caesalpinia minax Hance by high‐performance liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. A total of 59 peaks were detected, and among them 51 compounds, including 41 furanocassane diterpenoids, 10 furanolactone cassane diterpenoids were simultaneously identified and characterized on the basis of the protonated molecule, retention behavior, and fragments in MS². Ten compounds, including seven novel compounds, were identified or tentatively identified for the first time in C. minax. In a positive ion mode, the fragmentation pathways of cassane diterpenoids were also analyzed for the first time. The relative amounts of the five main diterpenoids (caesalpinin L, caesalpinin F₂, bondcellpin C, caesalpinin E, and ξ‐caesalmin) were simultaneously quantified by high‐performance liquid chromatography. Results showed that the newly discovered and known components of C. minax can be used to determine the material basis of bioactivity; this method can also be applied to analyze cassane diterpenoids in herbal medicines from the genus Caesalpinia belonging to the family Fabaceae.     

(NH4)2SiF6脱铝八面沸石酸性和1-已烯结碳研究

(NH_4)_2SiF_6液相同晶取代脱铝技术,作为沸石脱铝方法之一,自1985年提出后,己引起了人们的广泛注意.研究结果已表明:(NH_4)_2SiF_6脱铝沸石的结晶度很高,二次中孔道很少;由于在脱铝过程中扩散影响较大,使得脱铝沸石晶粒表面富硅.本文由(NH_4)_2SiF_6方法制备了骨架Si/Al 比在2.62～5.20的系列样品,用吡啶吸     

细菌生长速率的测定及其热力学性质的研究

细菌生长是一系列非常复杂的生化反应的结果。为了使问题简化、便于采用物理化学的理论和方法对其进行处理,可假设细菌在培养基中的分裂、生长分为三个阶段进行。首先是底物进行扩散,并与细菌表面的活性物质进行作用(如输运过程);其次是细菌将底物吸收到细胞内形成细胞-底物复合物;然后是细胞-底物复合物在其内部一系列酶的作用下产生酶促反应,进行分裂生长和排出代谢产物。现用下式表示:     

Sodium tanshinone IIA sulfonate depresses angiotensin II-induced cardiomyocyte hypertrophy through MEK/ERK pathway

Cardiomyocyte hypertrophy is a major cause of morbidity and mortality worldwide. The aim of this study is to determine the effects of sodium tanshinone IIA sulfonate (STS) on cardiomyocyte hypertrophy induced by angiotensin II (Ang II) in vivo and in vitro. In long-term treatment, adult Wistar rats were infused with Ang II for three weeks via osmotic mini-pumps and some of them were given intragastrically of STS. Left ventricle was isolated; the ratio of left ventricular weight to body weight and systolic blood pressure (SBP) were determined and heart morphometry was assessed after hematoxylin and eosin staining. Results indicated STS inhibited Ang II-induced increases in myocyte diameter and decreased the LVW/BW ratio independent of decreasing systolic blood pressure. In vitro, treatment of cultured cardiomyocytes with STS inhibited Ang II-induced increase in cell size, protein synthesis, ANP expression, activation of extracellular signal- regulated kinase (ERK) and ERK kinase (MEK). Then we reexamined the mechanism of STS-induced anti-hypertrophic effects. Results revealed MEK inhibitor U0126 (20 microM) markedly enhanced STS-induced depressions in [(3)H]leucine incorporation and ANP expression. In conclusion, MEK/ERK pathway plays a significant role in the anti-hypertrophic effects of STS.     

不同色浆质量分数的水性聚氨酯涂料对聚氯乙烯表皮低温爆破性能的影响

本文制备了一系列不同色浆质量分数的水性聚氨酯涂料,并将其喷涂在汽车仪表板聚氯乙烯(PVC)表皮的背面形成复合材料。 用旋转流变仪表征了涂料的粘度以评价其喷涂性能;用差示扫描量热仪表征了材料的玻璃化转变温度(T_g);利用万能材料试验机表征了材料在-30 ℃条件下的拉伸性能及抗撕裂性能;用动态热机械分析仪表征了材料的损耗比随温度的变化。 结果表明:不同色浆质量分数的涂料都能喷涂,含有涂层材料PVC表皮在-30 ℃低温爆破性能与涂层材料的T_g、低温拉伸性能、抗撕裂性能的关系并不大,而与涂层材料的阻尼性能直接相关。 材料的阻尼性能越好,其低温爆破性能越好。     

二苯基碘鎓盐引发乙烯基醚热聚合研究

合成了一种液态聚氨酯乙烯基醚预聚物 (PUE)并对其进行了表征 .研究发现二苯基碘六氟磷酸盐(PI810 )能够引发PUE和三缩乙二醇二乙烯基醚 (DVE 3)进行阳离子热聚合 ,热聚合温度远低于PI810的纯态热分解温度 ,且聚合转化率较高 .热聚合的机理初步认为是电子转移机理 .研究了乙烯基醚化合物、环氧树脂、二苯基碘六氟磷酸盐混合体系的热聚合 .