长鞭红景天化学成分研究

从高山植物长鞭红景天(Rhodiola fastigita S.H.Fu)的根茎中得到七种结晶,经红外光谱、质谱和核磁共振及化学方法鉴定为β-谷甾醇(β-sitosterol)、胡萝卜甙(daucosterol)、没食子酸乙酯(gallic acid ethyl ester)、没食子酸(gallic acid)、酪醇(p-tyrosol)、β-谷甾醇-3-β-D-半乳糖甙(β-sitosterol-3-β-D-galactoside)和草质素-8-阿拉伯糖甙(herbacetin-8-arabinoside),其中胡萝卜甙、β-谷甾醇-3-β-D-半乳糖甙和没食子酸乙酯是首次从红景天属得到的。     

蛇菰的化学成分研究

从湖北恩施地区产蛇菰(Balanophora japonicaMakino)中得到4个成分,分别鉴定为蛇麻脂醇乙酯(lupeolacetate,1)、β-香树脂醇乙酯(-βamyrin acetate,2)、没食子酸(gallic acid,3)和β-谷甾醇(-βsitosterol,4),其中化合物1、2和3为首次从该植物中得到。     

水翁花蕾化学成分的研究

从水翁花[Cleistocalyx operculatus(Roxb.)Merr.et Perry]蕾中分离出9个化合物,其中8个化合物,经理化常数分析及测定光谱(UV、IR、NMR、MS)鉴定为2,4-dihydroxy-6’-methoxy-3’,5’-dimethylchalcone(Ⅲ),5,7-dihydroxy-6,8-dimethylflavanone(Ⅳ),7-hydroxy-5-methoxy-6,8-dimethylflavanone(Ⅴ),没食子酸乙酯(ethyl gallate)(Ⅰ),没食子酸(gallic acid)(Ⅱ),乌搔酸(ursolic acid)(Ⅵ),β-谷甾醇(β-sitosterol)(Ⅷ),桂皮酸(cinnamic acid)(Ⅶ),另一个化合物尚在鉴定中。     

泽漆化学成分及其体外抗肿瘤活性研究

利用正相硅胶柱层析、葡聚糖凝胶Sephadex LH-20、制备薄层层析、反相制备色谱等离手段和1H、13C NMR等波谱技术,从泽漆(Euphorbia helioscopia L.)中分离鉴定了10个化合物,分别为β-谷甾醇(β-sitosterol,1),大戟甘(euphornin,2),大戟甘D(euphomin D,3),A(euphohelioscopin A,4),槲皮素(quercetin,5),没食子酸(gallic acid,6),咖啡酸(caffeie acid,7),没食子酸乙酯(ethyl gallate,8),杨梅素(myrecetin,9),金丝桃苷(hypero-side,10),其中化合物7、8、9是首次从该植物中分得,通过体外抗肿瘤活性研究,化合物6和10作为泽漆的抗肿瘤活性成分属首次报道.     

云南红景天的化学成分

从云南红景天(Rhodiola yunnanesis)根茎中分出15个单体成分(Ⅰ～ⅩⅤ),其中12个(Ⅰ～ⅩⅡ)分别鉴定为:黑五味子单体甙(schizandriside, ∠)、1-表没食子儿茶素-3-没食子酸酯(1-epigallocatechin-3-gallate, Ⅱ)、1-表儿茶素(1-epicatechin, Ⅲ)、大黄酚(chnysophanol, Ⅳ)、β-胡萝卜甙(daucosterot, Ⅴ)、β-谷甾醇(β-sitostecol, Ⅵ)、阿魏酸二十八烷醇酯(1-octacosanly ferulate, Ⅶ)、没食子酸(gallic acid, Ⅷ)、二十八烷醇乙酸酯(1-octasonaly acetate, Ⅸ)、蜡酸二十六烷醇酯(1-hexacosanyl cerotate, Ⅹ)、蜡酸(cerotic acid, Ⅺ)、二十六烷醇(1-hexacosanol, ⅩⅡ)。有趣的是首次从本属植物中分离出木脂素类(Ⅰ)、黄烷醇类(Ⅱ、Ⅲ)以及蒽醌类(Ⅳ)成分。     

大花红景天多元酚类化学成分的研究

从大花红景天Rhodiola crenulata (HK.f.et thoms)H.Ohba的乙酸乙酯提取物中分离出12个多元酚类化合物。其中六个经光谱分析和化学方法鉴定为没食子酸(gallic acid,1),酪醇(p-tyrosol,2),6-氧-没食子酰基红景天甙(6-O-galloylsalidroside,3),1,2,3,4,6-五氧-没食子酰基-β-D-吡喃葡萄糖(1,2,3,4,6-penta-O-galloyl-β-D-gluco pyranoside,4),草质素-7-氧-α-L-吡喃鼠李糖甙(rhodionin,5),草质素-7-氧-(3-氧-β-D-吡喃葡萄糖基)-α-L-吡喃鼠李糖甙(rhodiosin,6),1和4具有抗毒肝素的活性,4还有抗脂质过氧化的活性,2,5,6具有提高机体抗逆境能力的活性。     

丽江产红景天的化学成分研究

从丽江产红景天粗提物中分离得到了14个化合物,经波谱数据分别鉴定为二十六烷醇(1-hexamsanol,1),β-谷甾醇(β-sitosterol,2),胡萝卜苷(daucostexol,3),酪醇(tyrosol,4),红景天苷(salidroside,5),没食子酸(galic acid,6),山奈酚(kaempferol,7),草质素-7-O-(3″-β-D-葡萄糖基)-α-L-鼠李糖苷(rhodiosin,8),德钦红景天苷(rhodionin,9),对羟基苯甲酸(4-hydroxybenzoic acid,10),geranyl 1-O-α-L-arabinopyranosyl(1→6)-β-D-glucopyranoside(11),2,7-anhydro-β-D-heptul-opyranoses(the altro isomer,12),乙酸二十六烷醇酯(cerotylacetate,13),1,2,3,4,6-五没食子酰基-β-D-喃葡萄糖(1,2,3,4,6-pentagalloyl-β-D-glucopyranose,14)。根据分离所得的单体,用HPLC对商业化粗提物色谱中的8个峰进行了指认,并测定了云南千山生物工程有限公司利用不同工艺流程所得四批粗提物中红景天苷的含量。     

柴胡红景天化学成分的研究

采用正相与反相硅胶柱色谱和薄层色谱分离纯化的方法,从景天科红景天属植物柴胡红景天(Rhodiola bupleuroides)根茎70%乙醇提取物的乙酸乙酯萃取部分中分离得到7个化合物,用光谱分析(UV,IR,MS,1H-NMR,13C-NMR)和化学反应鉴定化合物分别为:没食子酸(1)、山奈酚-7-O-α-L-吡喃鼠李糖苷(2)、草质素-7-O(3″-O-β-D-葡萄糖基)-α-L鼠李糖苷(3)、槲皮素(4)、丁香酸(5)、3,5-二甲氧基-4-羟基-苯甲酸-7-O-β-D-葡萄糖苷(6)、β-谷甾醇(7).以上化合物均为首次从该植物中分离得到,其中化合物5和6为首次从红景天属植物中发现.     

鸡尾木化学成分的研究

从鸡尾木中分出三个化合物,经光谱数据鉴定为没食子酸(Gallic acid),α-香树脂醇(α-Amyrin)和β-谷甾醇(β-Sitosterol)。     

南岭栲叶多酚类化学成分的分离与鉴定

采用Sephadex LH-20、MCI gel CHP 20P和Toyopearl Butyl-650C等柱色谱及半制备液相色谱技术,从壳斗科(Fagaceae)锥属(Castanopsis)植物南岭栲(Castanopsis fordii Hance)叶子乙醇提取物中分离得到18个多酚类化合物,运用波谱学方法解析鉴定为:没食子酸(1)、没食子酸甲酯(2)、没食子酸乙酯(3)、莽草酸-3-O-没食子酸酯(4)、3,3'-二甲基鞣花酸(5)、3,3'-二甲氧基鞣花酸-4'-O-α-D-吡喃木糖苷(6)、3-甲氧基-4'-鼠李糖鞣花酸(7)、6-O-没食子酰基熊果苷(8)、龙胆酸5-O-β-D-(6'-O-没食子酰基)-吡喃葡萄糖(9)、4-hydroxy-3-methoxyphenol 1-O-β-D-(6'-O-galloyl)glucoside(10)、1,6-二-O-没食子酰基-β-D-葡萄糖苷(11)、gallic acid 3-O-β-D-(6'-Ogalloyl)-glucopyranoside(12)、benzyl 6-O-galloyl-β-D-glucopyranoside(13)、2,3-di-O-galloyl-D-glucose(14)、gemin D(15)、特里马素(16)、丁香素(17)、viburnolide A(18)。所有化合物均为首次从该植物中分离得到。     

Separation and simultaneous determination of nalidixic acid, hydroxynalidixic acid and carboxynalidixic acid in serum and urine by micellar electrokinetic capillary chromatography

Separation in capillary electrophoresis is governed by various factors, including buffer type, buffer concentration, pH, temperature, voltage and micelles. Through proper adjustment of these parameters, nalidixic acid and its two major metabolites, 7-hydroxynalidixic and 7-carboxynalidixic, could be separated by micellar electrokinetic capillary chromatography using an electrophoretic electrolyte consisting of 50 mM borate buffer (pH 9) containing 25 mM sodium dodecyl sulphate and 10% acetonitrile. A linear relationship between concentration and peak area for each compound was obtained in the concentration range 0.15–100 μg ml⁻¹, with a correlation coefficient greater than 0.999 and detection limits in the 0.2–0.7 ng ml⁻¹ range. Intra- and inter-day precision values of about 0.8–1.2% RSD (n=11) and 1.3–2.0% RSD (n=30), respectively, were obtained. The method has been applied to the analysis of nalidixic acid and its two major metabolites in serum and urine with limits of sensitivity lower than 0.8 ng ml⁻¹.     

酚酸类物质对三七幼苗的化感影响

该文研究了不同浓度的阿魏酸、对香豆酸、丁香酸、对羟基苯甲酸、香草酸5种酚酸类物质对三七幼苗生长和生理的影响。结果表明:处理后,三七幼苗的苗高、根长、可溶性蛋白质含量、根系活力、CAT以及POD活性均有所降低。其中,阿魏酸各处理组幼苗的苗高及POD活性均显著降低,50、100 mg·L~(-1)的对香豆酸以及100 mg·L~(-1)的香草酸处理组幼苗苗高也分别比对照显著降低16.19%、16.67%和29.29%;对香豆酸、丁香酸以及对羟基苯甲酸各处理组幼苗根长均显著低于对照;香草酸处理组幼苗的根系活力也显著低于对照,且幼苗的CAT活性在10、50、100 mg·L~(-1)丁香酸、对羟基苯甲酸以及香草酸处理下也达到了显著降低水平。此外,1 mg·L~(-1)阿魏酸以及100 mg·L~(-1)香草酸处理组幼苗的叶绿素含量也均显著降低;中高浓度的阿魏酸、对香豆酸、丁香酸、对羟基苯甲酸增加了三七幼苗的MDA含量,而香草酸在0.1、1、10、100 mg·L~(-1)浓度下显著降低幼苗的MDA含量;丁香酸、香草酸、对羟基苯甲酸以及中高浓度的对香豆酸增加了三七幼苗的SOD活性,且香草酸各处理组均达到了显著性水平。综上结果表明,5种酚酸类物质对三七幼苗均具有一定的化感抑制作用,但各酚酸物质的作用方式及强度并不完全一致,阿魏酸的化感影响较大,这为进一步研究三七的化感自毒作用提供了一定的理论参考。     

Comparative acid stress response of Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella Typhimurium after habituation at different pH conditions

AIMS: The aim of the study was to evaluate the effect of habituation at different pH conditions on the acid resistance of Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica serotype Typhimurium, and to identify potential differences between the adaptive responses of the three pathogens. METHODS: Stationary phase cells of L. monocytogenes, E. coli O157:H7 and S. Typhimurium, grown in glucose-free media, were exposed to pH 3.5 broth directly or after habituation for 90 min at various pH conditions from 4.0 to 6.0. Survivors at pH 3.5 were determined by plating on tryptic soy agar and incubating at 30 degrees C for 48 h. The kinetics (death rate) of the pathogens at pH 3.5 was calculated by fitting the data to an exponential model. RESULTS: Habituation to acidic environments provided protection of the pathogens against lethal acid conditions. This acid protection, however, was found to be pH dependent. For example, for E. coli O157:H7 an increased acid resistance was observed after habituation at a pH range from 4.0 to 5.5, while the maximum acid tolerance was induced at pH 5.0. Furthermore, the effect of low pH habituation was different among pathogens. For L. monocytogenes, E. coli O157:H7 and S. Typhimurium, the pH range within which habituation resulted to increased acid resistance was 5.0-6.0, 4.0-5.5 and 4.0-5.0, respectively, while the maximum acid tolerance was induced after habituation at pH 5.5, 5.0 and 4.5, respectively. SIGNIFICANCE: Acid stress conditions are common within current food processing technologies. The information on adaptive responses of L. monocytogenes, E. coli O157:H7 and S. Typhimurium after habituation to different pH environments provided in the present study, could lead to a more realistic evaluation of food safety concerns and to a better selection of processes in order to avoid adaptation phenomena and to minimize the potential for food safety risks.     

Triterpene acids from Salvia and Teucrium species

The pentacyclic triterpene acids ursolic acid, oleanolic acid, micromeric acid, maslinic acid and 3-epi-maslinic acid have been isolated from several Salvia and Teucrium species.     

Temperature regulates tuber-inducing lipoxygenase-derived metabolites in potato (Solanum tuberosum)

Temperature is one of the major environmental factors affecting potato tuberization. It has been suggested that lipoxygenase (LOX) mediates between temperature and tuber induction. In this study, the contents of the LOX-derived metabolites hydroperoxylinolenic acid (HPOT), jasmonic acid (JA), tuberonic acid (TA) and tuberonic acid glucoside (TAG) were analyzed in leaves of potatoes growing at different temperatures. At low, tuber-inducing temperature, endogenous levels of JA, TA and TAG rise, indicating their crucial role in tuber induction. The concentration of 13(S)-HPOT seems not to be directly affected by temperature. Instead, the molecule has only a short half-life in leaves and is readily metabolized.     

氨基酸分析仪测定饲料添加剂——叶酸的方法

用６ｍｏｌ／Ｌ盐酸于１１０℃条件下水解饲料添加剂——叶酸,使之游离出谷氨酸,用氢氧化钠中和调节ｐＨ到２,氨基酸分析仪测定谷氨酸含量,经与标准叶酸水解样品比较,计算出叶酸的纯度。该方法重现性好,变异系数ＣＶ＝０．０８％,平均回收率为９８．３４％,浓度与峰面积呈线性相关,相关系数ｒ＝０．９９８７,可随氨基酸分析同时进行,不需改变任何分析条件。     

Effects of flaxseed,raw soybeans and calcium salts of fatty acids on apparent total tract digestibility,energy balance and milk fatty acid profile of transition cows

Oilseeds offer some protection to the access of ruminal microorganisms and may be an alternative to calcium salts of fatty acids (FA), which are not fully inert in the ruminal environment. This study aimed to evaluate the effects of different sources of FA supplementation on apparent total tract nutrient digestibility, milk yield and composition, and energy balance (EB) of cows during the transition period and early lactation. We compared diets rich in C18:2 and C18:3 FA. Multiparous Holstein cows were randomly assigned to receive one of the four diets: control (n=11); whole flaxseed (WF, n=10), 60 and 80 g/kg (diet dry matter (DM) basis) of WF during the prepartum and postpartum periods, respectively; whole raw soybeans (WS, n=10), 120 and 160 g/kg (diet DM basis) of WS during the prepartum and postpartum periods, respectively; and calcium salts of unsaturated fatty acids (CSFA, n=11), 24 and 32 g/kg (diet DM basis) of CSFA during the prepartum and postpartum periods, respectively. Dry cows fed WF had higher DM and net energy of lactation (NE_L) intake than those fed WS or CSFA. The FA supplementation did not alter DM and NDF apparent total tract digestibility, dry cows fed WF exhibited greater NDF total tract digestion than cows fed WS or CSFA. Feeding WS instead of CSFA did not alter NE_L intake and total tract digestion of nutrients, but increased milk fat yield and concentration. Calculated efficiency of milk yield was not altered by diets. FA supplementation increased EB during the postpartum period. Experimental diets increased long-chain FA (saturated and unsaturated FA) in milk. In addition, cows fed WS and CSFA had higher C18:1 trans-11 FA and C18:2 cis, and lower C18:3 FA in milk than those fed WF. Furthermore, cows fed CSFA had higher C18:1 trans-11 and cis-9, trans-11 FA than cows fed WS. Although supplemental C18:2 and C18:3 FA did not influence the milk yield of cows, they positively affected EB and increased unsaturated long-chain FA in milk fat.