Isolation and structural elucidation of two new glycosides from sage (Salvia officinalis L.)

Six compounds, 1-O-(2,3, 4-trihydroxy-3-methyl)butyl-6-O-feruloyl-beta-D-glucopyranoside, ethyl beta-D-glucopyranosyl tuberonate, p-hydroxybenzoic acid, (-)-hydroxyjasmonic acid, caffeic acid, and 4-hydroxyacetophenone 4-O-[5-O-(3, 5-dimethoxy-4-hydroxybenzoyl)-beta-D-apiofrunosyl]-(1-->2)-beta-D- glu copyranoside, were isolated from the n-butanol-soluble fraction of sage leaf extracts. Their structures were determined by spectral methods (MS, NMR, and 2D-NMR), and their antioxidant activities were measured. Among them, two new glycosides were elucidated. All of these compounds showed DPPH free radical scavenging activity at the concentration of 30 mM, and caffeic acid was the most active compound.     

Stability of tea polyphenol (-)-epigallocatechin-3-gallate and formation of dimers and epimers under common experimental conditions

(-)-Epigallocatechin-3-gallate (EGCG), the most abundant and biologically active compound in tea, has been extensively studied for its activities related to disease prevention in animal models and in vitro. However, its stability under different experimental conditions has not been well-characterized. In the present study, the stability of EGCG in animal drinking fluid and under cell culture conditions and the factors that affect its stability under these conditions were investigated. Our results demonstrated that auto-oxidation and epimerization are the two major reactions causing the instability of EGCG. The structures of the major oxidation products, EGCG dimers, were identified. The rates of these reactions were affected by the temperature, pH, the partial pressure of oxygen, the level of antioxidants, the concentration of EGCG, and other components of tea. In future studies with EGCG, its stability should be considered in order to avoid possible artifacts.     

pH control for dyebath reuse in dyeing of polyamide with binary mixtures of acid dyes

Hydrolyzable organic esters were compared with ammonium sulphate as an acid donor for the pH control in dye-bath-reuse system of acid dyes mixtures. The ability of pH control, levelness, dyeing properties and reproducibility in dye-bath-reuse system were investigated comparatively. Hydrolyzable organic esters showed higher exhaustion and color yield than ammonium sulphate. In addition, hydrolyzable organic ester exhibited very low conductivity less than 0.5 mS, while ammonium sulphate give high conductivity. However, we could not observe any difference in levelness of dyed samples between two kinds of acid donors in laboratory scale dyeing. Over 10 cycles of reuse, hydrolyzable organic esters showed higher reproducibility than ammonium sulphate. No deterioration of the color fastness and levelness occurs over 10 cycles of reuse.     

3份橡胶树野生种质杂交子代早期鉴定初报

为探讨巴西橡胶树野生速生种质在橡胶树新品种选育中的应用前景,2003~2005年连续采用优选的3份1981’IRRDB野生种质XJA05583、XJA05664和XJA05164作为父本与我国自主选育高产无性系热研88-13进行人工杂交授粉,于2006年进行橡胶树有性系比试验。2010年对参试3个组合的287个子代进行茎围增粗、试割产量鉴定。结果表明,所有杂交组合的子代年平均茎围增粗均较快,其中2个杂交组合子代与对照RRIM600有极显著性差异;试割干胶产量总体表现较差,其中组合热研88-13×XJA05664和热研88-13×XJA05583分别有18株和2株高于对照平均,分别占各自组合的15.65%和1.66%,最终从参试材料中初选12株优良个体进入下一阶段试验。野生种质的速生性状能够较好地遗传给后代,且存在培育高产子代的潜力,其高效利用可考虑胶木兼优品种的选育。     

Hybrid multi-scale basalt fiber-epoxy composite laminate reinforced with Electrospun polyurethane nanofibers containing carbon nanotubes

In this study, we report the fabrication and evaluation of a hybrid multi-scale basalt fiber/epoxy composite laminate reinforced with layers of electrospun carbon nanotube/polyurethane (CNT/PU) nanofibers. Electrospun polyurethane mats containing 1, 3 and 5 wt% carbon nanotubes (CNTs) were interleaved between layers of basalt fibers laminated with epoxy through vacuum-assisted resin transfer molding (VARTM) process. The strength and stiffness of composites for each configuration were tested by tensile and flexural tests, and SEM analysis was conducted to observe the morphology of the composites. The results showed increase in tensile strength (4–13 %) and tensile modulus (6–20 %), and also increase in flexural strength (6.5–17.3 %) and stiffness of the hybrid composites with the increase of CNT content in PU nanofibers. The use of surfactant to disperse CNTs in the electrospun PU reinforcement resulted to the highest increase in both tensile and flexural properties, which is attributed to the homogeneous dispersion of CNTs in the PU nanofibers and the high surface area of the nanofibers themselves. Here, the use of multi-scale reinforcement fillers with good and homogeneous dispersion for epoxy-based laminates showed increased mechanical performance of the hybrid composite laminates.     

利用SSR荧光标记构建37个中国橡胶树栽培品种指纹图谱

以37个橡胶树栽培品种为材料,利用SSR荧光标记技术进行DNA指纹图谱的构建和遗传关系分析,构建我国橡胶树栽培品种的SSR指纹图谱。共计筛选和确定出34对SSR引物作为构建橡胶树品种DNA指纹图谱库的核心引物,其中30对SSR引物可用于品种鉴定,4对SSR引物可作为备选引物用于后续新选育品种的鉴定。筛选和确定出的核心SSR引物表现出较高的多态性信息含量（PIC值）,其中PIC值高于0.5的引物高达97%,PIC值大于0.7的引物多达12对,PIC值大于0.8的引物有2对。引物rbm28的多态性最高,可作为最佳引物用于鉴定中国橡胶树主栽品系的遗传多样性,其他4条引物HESR025、HESR163、H-084、H-122同时具备较高的杂合率和多态性,可考虑作为备选引物。34对核心SSR引物在37个橡胶树品种中共检测到161个等位变异,平均每对引物检测到5.4个等位基因,平均PIC值为0.65,表现出高度多态性。利用30对核心SSR引物对37份橡胶树品种进行扩增,得到相关品种的准确SSR位点信息,获得包含37个橡胶树品种的标准DNA指纹图谱库,其中33个橡胶树品种均具有唯一的DNA特征指纹,可作为各品种特定的图谱,为橡胶树品种鉴定和育种实践提供依据。     

Effect of alkyl chain length on thermochromism of novel nitro compounds

A series of novel nitro compounds containing different alkyl chain length (x=2∼5), 1,5-bis(hydroxyalkylamino)-2,4-dinitrobenzene (BDBx), are synthesized and their thermochromic behavior is investigated by using differential scanning calorimetry and optical microscopy. All the BDBx crystals synthesized show yellow color at room temperature. BDBx (x=2∼4) samples display orange color even in the solid when heated above respective thermochromic transition temperature, while the yellow color of BDB5 changes to orange with melting. The orange color of BDBx crystals returns to yellow when cooled down to room temperature, indicating that the thermochromic behavior of BDBx is reversible. The thermochromic transition temperatures of BDBx crystals are found to be decreased with increasing the alkyl chain length, exhibiting evenodd fluctuation.     

Preparation of regenerated cellulose fiber via carbonation (II)

Sodium cellulose carbonate (CC-Na) dissolved in 8.5 wt% NaOH/ZnO (100/2–3, w/w) aqueous solution was spun into some acidic coagulant systems. Diameter of regenerated cellulose fibers obtained was in the range of 15–50μm. Serrated or circular cross sectional views were obtained by controlling salt concentration or acidity in the acid/salt/water coagulant systems. Velocity ratio of take-up to spinning was controlled up to 4/1 with increasing spinning velocity from 5 to 40 m/min. Skin structure of was developed at lower acidity or higher concentration of coagulants. Fineness, tenacity and elongation of the regenerated cellulose fibers were in the range of 1.5–27 denier, 1.2–2.2 g/d, and 8–11.3%, respectively. All of CC-Na and cellulose fibers spun from CC-Na exhibited cellulose II crystalline structure. Crystallinity index was increased with increasing take-up speed.     

Comparative effects of feeding a protease inhibitor-enriched potato protein concentrate and soy flour to rats

Rats were fed casein diets to which had been added a potato protein concentrate (PPC) at a level which provided trypsin- and chymotrypsin-inhibitor activities comparable to that present at the same level (10%) of protein derived from raw soy flour. Control groups consisted of the same diets in which the unheated PPC and raw soy flour were replaced by their heated counterparts in which over 90% of the inhibitor activities had been destroyed. After 5 weeks the following measurements were made: (1) growth, (2) PER, (3) pancreas weight, (4) protein digestibility, (5) a peptide test that reflects pancreatic function, and (6) enzyme activities (trypsin, chymotrypsin, amylase, and lipase) in the pancreas and small intestine. PPC was found to produce the same general pattern of effects as raw soy flour, namely, an inhibition of growth, a decrease in PER and protein digestibility, an increase in the size of the pancreas, an increase in the recovery of p-aminobenzoic acid in the peptide test, and a depletion of enzyme in the pancreas with concomitant increases in the intestines (except for trypsin). PPC was somewhat more effective than raw soy flour in causing an increase in trypsin and chymotrypsin activities in the faces.     

液化石油气气化站设备选型的计算

液化石油气与天然气在城市燃气工程设计中有很大区别，其中在设备选型及计算方面尤为突出。两者在城市燃气管道供应中最大的不同之处在于液化石油气必须气化后才能进行管道供应，因此，液化石油气气化站内的设备选型计算十分重要。