共查询到20条相似文献，搜索用时 234 毫秒
1.
2.
3.
大叶丁香丙酮提取物对皮氏叶螨的毒力及代谢酶活性的影响 总被引：4，自引：0，他引：4
采用叶片浸渍法和分光光度法研究了大叶丁香(Eugenia caryophyllata Thunb)丙酮提取物对皮氏叶螨(Tetranychus piercei McGrvgor)的毒力及其代谢酶活性的影响。试验结果表明:大叶丁香丙酮提取物对皮氏叶螨具有良好的毒杀作用,处理后72 h LC50值为4.31 mg/mLL;其13.33 mg/mL对皮氏叶螨的48 h和72 h校正死亡率分别为81.82％和95.35％,其6.67 mg/mL对皮氏叶螨的72 h校正死亡率为75.58％;大叶丁香丙酮提取物在5.0、4.0、3.0、2.0、1.0 μg/mL的质量浓度下,对皮氏叶螨酯酶、羧酸酯酶、碱性磷酸酯酶的活性均有抑制作用,作用大小均随处理浓度的增加而增强,但大叶丁香丙酮提取物对酸性磷酸酯酶则有一定程度的激活作用。 相似文献
4.
5.
6.
赵晨旭杨利民韩佳宏韩梅宋佳琪白洋陈浩蔡恩博 《人参研究》2022,(3):54-59
大叶小檗(Berberis amurensis Rupr)为小檗科小檗属植物,在我国北部地区分布较为广泛,在俄罗斯、朝鲜、日本亦有分布。大叶小檗主要含有生物碱类、苯丙素类、甾体、有机酸类等化合物,在抗炎、抑菌、抗肿瘤等方面具有良好的药理活性。大叶小檗以根入药,小檗根为我国常用的传统中药。本文通过查阅中外文献,对大叶小檗的本草考证、资源分布、化学成分及药理作用进行综述,旨在为进一步开发利用大叶小檗及制定小檗根药材质量标准提供参考依据。 相似文献
7.
采用完全随机区组进行大叶冬青混交试验。结果表明,大叶冬青、马尾松比较适合试验地气候、土壤,马尾松是大叶冬青的较佳混交树种,大叶冬青×马尾松混交能够促进大叶冬青和马尾松的生长,可在同立地条件林地进行推广;建柏、乳源木莲与大叶冬青混交也能不同程度地促进林木的生长,可根据具体情况营造大叶冬青和建柏或乳源木莲的混交林;光皮桦不能适应该立地条件,大叶冬青和光皮桦混交林的生长状况不良。 相似文献
8.
研究狭叶茶(Camellia angustifolia Chang)提取物对拘束负荷诱发小鼠应激性肝损伤的保护作用。采用拘束负荷小鼠应激性肝损伤模型,18h拘束负荷诱发小鼠应激性肝损伤,分别用赖氏法测定小鼠血浆和肝组织丙氨酸转移酶(ALT)活性、硫代巴比妥酸法测定丙二醛(MDA)含量、HPLC法测定谷胱甘肽(GSH)水平、比色法测定黄嘌呤氧化酶(XOD)、谷胱甘肽过氧化物酶(GPX)和谷胱甘肽S转移酶(GST)活性,荧光酶标仪测定血浆、肝组织及狭叶茶提取物体外抗氧化能力指数(ORAC)。与拘束模型组相比,狭叶茶提取物可以明显提高拘束负荷小鼠血浆与肝组织匀浆的ALT活性和抗氧化能力指数,提高GSH水平,增强GPX和GST活性,有效降低肝组织中MDA含量和XOD活性,并在体外显示出较强的抗氧化能力。说明狭叶茶提取物对拘束应激引起的小鼠肝损伤具有一定的保护作用,其作用机制可能部分来自于减少拘束负荷小鼠氧化应激水平,清除自由基和抑制脂质过氧化过程。 相似文献
9.
10.
大叶龙茶解剖学、肌动蛋白基因及分子标记的研究 总被引：1，自引：0，他引：1
大叶龙茶是来源于江西修水茶科所宁州群体茶园中一株自然突变体形成的大叶并无蕾无性繁殖新品种。对大叶龙茶及其母株的成熟叶片和不同时期的芽进行石蜡切片研究表明,大叶龙茶叶片栅栏组织细胞较长、海绵组织层数增加;大叶龙茶无蕾的原因是由于所有的芽始终保持营养芽的状态所致。首次克隆了茶树3个肌动蛋白基因片段(CS-ACT1,CS-ACT2,CS-ACT3),且都编码225个氨基酸,大叶龙茶与母株及500个BlastX分析获得的肌动蛋白序列在保守结构域F、G、H区有相应的四个氨基酸不同。对大叶龙茶及其母株进行AFLP分析表明,大叶龙茶总带数比母株少,并出现一部分特有带;利用EST-SSR分子标记技术对大叶龙茶及其它常见品种进行研究,表明大叶龙茶等4个修水品种与龙井43有相似的遗传基础。 相似文献
11.
Islam MS Molla MT Alam MT Habib MR 《Pakistan journal of biological sciences: PJBS》2008,11(10):1342-1347
The fish lipid was extracted from the body muscle (edible portion) of fresh Lepidocephalus guntea (Ham.) fish and the lipid content of the fish in size-1 (below 8.5 cm), size-2 (8.5-9.5 cm) and size-3 (above 9.5 cm) were found to be 2.515, 3.013 and 3.455%, respectively. The specific gravity and refractive index of the lipid were found to be 0.93 at 30 degrees C and 1.467 at 31.5 degrees C, respectively. The saponification value, saponification equivalent, iodine value, peroxide value and acetyl value of the lipid were found to be 220.325, 254.624, 96.05, 1.993 and 11.32, respectively. The acid value, percentage of free fatty acid as oleic and unsaponifiable matter present in the lipid were found to be 2.005, 1.008 and 0.593, respectively. The fatty acid composition of the lipid was determined qualitatively and quantitatively by TLC and GLC. The analysis revealed that the fatty acid composition of the lipid lies between C14 to C20. The fish lipid of Lepidocephalus guntea (Ham.) was found to contain (average value) myristic acid (3.17%), palmitoleic acid (7.45%), palmitic acid (29.16%), linolenic acid (7.13%), linoleic acid (5.57%), oleic acid (22.93%), stearic acid (17.42%), arachidonic acid (7.17%) and arachidic acid in trace amount. 相似文献
12.
玉米子粒油分及不饱和脂肪酸含量的遗传效应 总被引：2，自引：1，他引：1
用10个油分及不饱和脂肪酸含量差异较大的优良自交系,按(5×5)配成不完全双列杂交组合,研究玉米子粒油分及不饱和脂肪酸性状的遗传效应。结果表明,油分主要受胚、胚乳、细胞质效应的影响;油酸、亚油酸主要受胚、胚乳、母体效应的控制,3个性状均以加性效应占主导地位。α-亚麻酸的胚效应最小,表现为加性效应且遗传率较高。4个性状胚乳、胚的遗传率均较高,且胚乳遗传率大于胚的遗传率。330、素湾1611、ZOL-1可用于提高油分;ZOL-3、ZOL-4、ZOL-5对提高油分和油酸有极显著效果;ZNL-1、330、1072、ZOL-1、ZOL-5可用于提高亚油酸;ZOL-4可作为提高α-亚麻酸的母本;ZOL-1可以同时提高油分、油酸、亚油酸和α-亚麻酸。相关分析表明,油分与油酸极显著正相关(rP=0.612**);油分与亚油酸(rP=-0.504**)、油分与α-亚麻酸极显著负相关(rP=-0.277**),所有成对性状均以胚乳加性相关最强、胚加性相关次之。 相似文献
13.
为提高大豆脂肪酸品种的育种进程,使用气相色谱法测量289份大豆籽粒样品的脂肪酸含量,并用近红外谷物品质分析仪NIRFIEX N-500采集大豆样品近红外光谱值,采用主成分回归法将化学试验测定的数值与采集的光谱曲线对应拟合整理分析建立定标模型。每种脂肪酸建立11个定标标准,选取决定系数定标Q值中最高的数值为定标模型。结果显示5种脂肪酸定标模型的适宜Q值分别为:棕榈酸0.823 5、硬脂酸0.854 1、油酸0.819 6、亚油酸0.829 1、亚麻酸0.836 3。最后验证结果表明,近红外法测量值与化学试验测定值误差均在1.5%误差范围之内,证明所建立模型质量较好,具有使用价值,可用于大豆育种材料脂肪酸含量的快速测量。 相似文献
14.
The effect of marine polyunsaturated fatty acids on biofilm formation by the human pathogens Candida albicans and Candida dubliniensis was investigated. It was found that stearidonic acid (18:4 n-3), eicosapentaenoic acid (20:5 n-3), docosapentaenoic acid (22:5 n-3) and docosahexaenoic acid (22:6 n-3) have an inhibitory effect on mitochondrial metabolism of both C. albicans and C. dubliniensis and that the production of biofilm biomass by C. dubliniensis was more susceptible to these fatty acids than C. albicans. Ultrastructural differences, which may be due to increased oxidative stress, were observed between treated and untreated cells of C. albicans and C. dubliniensis with formation of rough cell walls by both species and fibrillar structures in C. dubliniensis. These results indicate that marine polyunsaturated fatty acids may be useful in the treatment and/or prevention of biofilms formed by these pathogenic yeasts. 相似文献
15.
《Industrial Crops and Products》2005,21(1):9-15
Wheat straw was pulping by an Organosolv process using a mixture of acetic acid/formic acid/water (AA/FA/water). In order to make easier the bleaching step, it was possible to improve the delignification in an efficient and selective manner by using peroxoacids in acidic organic medium. First a solution of peroxoacids was synthesized by adding hydrogen peroxide in a mixture of acetic acid/formic acid, without any inorganic acids as catalyst. Then this mixture was added to the unbleached pulp. Several parameters (temperature, extraction alkaline, reaction time …) were investigated.This simple and innovative way to use peroxoacids allows to overcome problem due to the control of their stability in aqueous medium and proves to be perfectly complementary to the cooking method in a carboxylic acid medium. Low kappa numbers and high viscosity were obtained. Strength properties of the pulp after the peroxoacids step were improved. 相似文献
16.
Unmodified polyamide 6 commonly dyed with acid dyes, and has no flame-retarded properties. So they are flammable and can be easily stained by foods or drinks that contain acid dyes. However, the acid groups react with amino groups that existed at the end of PA6 chain while using cationic dyes. Thus, the acid dyes can be washed immediately. In this study, the flame retardant and cationic dyeable polyamide 6 (FRCD-PA6) modified with 5-sulfoisophthalic acid sodium (5-SSIPA) and melamine cyanurate (MCA) was successfully prepared by the two-step-melt polymerization method. Firstly, cationic dyeable polyamide 6 (CD-PA6) was prepared with sodium salt from 5-sulfoisphthalic acid. Secondly, melamine cyanurate, as an efficient flame retardant, was blended into the reaction. The chemical and crystalline structures of FRCDPA6 were characterized by the Fourier transform infrared spectroscopy (FT-IR) and wide angle X-ray diffraction (XRD). Their thermal properties were tested by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and morphology was analyzed by SEM, respectively. It had been measured to prove the dispersion of 5-SSIPA and MCA on polyamide 6 matrix. Incorporating with 5-SSIPA created more amorphous regions and rose up the dyeing rate easily, with a highest dyeing rate for about 96.79 %. The effect of varying MCA content on the composites showed more flame retardant and made better heat-resistance. Moreover, with the appropriate addition of MCA content, the limit oxygen index (LOI) reached up to 27, less smoking, no more black smoke, droplet phenomenon was slightly, and flame resistance had greatly improved. Because of the good synergy between 5-SSIPA and MCA, a kind of novel modified polyamide 6 which own both cationic dyeable and efficient flame retardant properties was born. 相似文献
17.
Agnieszka Kosińska Kamila Penkacik Wiesław Wiczkowski Ryszard Amarowicz 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(3):270-274
Phenolic compounds were extracted from defatted flaxseeds using ethanol-dioxane (1:1, v/v). The crude extract obtained was
purified using Amberlite XAD-16 column chromatography with water and methanol as mobile phases. RP-HPLC and SE-HPLC showed
a lignan macromolecule (LM) as a dominant phenolic compound in the purified extract. After the alkaline hydrolysis of LM caffeic
acid glucoside (CaAG) was isolated using a semi-preparative HPLC and its structure was confirmed by LC-ESI-MS. In LM of the
investigated flaxseed, one molecule of caffeic acid corresponded with five molecules of p-coumaric acid and two molecules of ferulic acid. The presence of caffeic acid in the lignan molecule might be very beneficial
due to its high antioxidant activity. 相似文献
18.
高效液相色谱法测定茶叶中烟酸的含量 总被引：3，自引：0，他引：3
利用高效液相色谱法单独对茶叶中常见的水溶性维生素—烟酸进行了测定。具体方法为：用Agilent 1100高效液相色谱系统,C18 4.6mm×150mm色谱柱,流动相：甲醇∶0.05mol/L磷酸二氢钾溶液（1∶9）,流速1.0mL/min,检测波长266nm。外标法测定茶叶中烟酸的含量,检测线性关系R2=0.9915,回收率为99.38%,RSD=2.18%（n=4）。研究表明,该方法操作简便,结果准确,具有较好的重现性与稳定性,可用于茶叶提取物中烟酸含量的测定。 相似文献
19.
Lan Liao Chao-ying QiuTong-xun Liu Mou-ming ZhaoJiao-yan Ren Hai-feng Zhao 《Journal of Cereal Science》2010
The effect of acetic acid and hydrochloric acid (HCl) deamidation pretreatment on the susceptibility of wheat gluten to enzymatic hydrolysis by Pancreatin and sensory characteristics of the resultant hydrolysates was investigated. At two degrees of deamidation (24% and 60%, with or without moisture-heating, respectively), wheat gluten pretreated by acetic acid deamidation was more susceptible to be hydrolyzed as evaluated by the hydrolysis degree, nitrogen solubility index, titratable acid amount and free carbohydrate content of the hydrolysates. Wheat gluten pretreated by acetic acid deamidation at a degree of 24% exhibited the highest susceptibility to enzymatic hydrolysis. Moisture-heating (121 °C, 10 min) in the deamidation pretreatment decreased the susceptibility of wheat gluten to enzymatic hydrolysis and the peptide factions of ≤3000 Da in the hydrolysates due to the formation of larger molecule weight aggregates. The hydrolysates prepared from acetic acid deamidated wheat gluten showed more intense glutamate-like and sauce-scented taste and better nutritional characteristics. 相似文献
20.
Wheat flour was plasticized with glycerol and compounded with poly(lactic acid) in a one-step twin-screw extrusion process in the presence of citric acid with or without extra water. The influence of these additives on process parameters and thermal, mechanical and morphological properties of injected samples from the prepared blends, was then studied.Citric acid acted as a compatibilizer by promoting depolymerization of both starch and PLA. For an extrusion without extra water, the amount of citric acid (2 parts for 75 parts of flour, 25 parts of PLA and 15 parts of glycerol) has to be limited to avoid mechanical properties degradation. Water, added during the extrusion, improved the whole process, minimizing PLA depolymerization, favoring starch plasticization by citric acid and thus improving phases repartition. 相似文献