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51.
Procedures are deseribed for the efficient isolation of protoplasts from a variety of oil palm (Elaeis guineensis Jacq.) tissues. Various factors including donor source, composition of enzyme mixture and culture medium affected the yield and viability of the protoplasts Polyembryogenic cultures of oil palm were the most suitable starting material in terms of yield, viability and metabolic competence. Pectolyase Y-23 in association with cellulase and hemicellulase was required for the efficient release of protoplasts from the oil palm tissues. Limited cell division to form microcallus was observed at very low frequency (<0.01%) when glutathione and catalase were incorporated in the culture medium.Abbreviations 2,4-d dichlorophenoxyacetic acid - DTT dithiothreitol - MES 2[N-morpholino] ethanesulphonic acid - NAA 1-naphthalene acetic acid - PVP polyvinylpyrrolidone  相似文献   
52.
A hitherto unknown hydroxy acid has been isolated from Blepharis sindica seed oil has been characterized as 9-hydroxydodecanoic acid by IR, NMR and mass spectral studies. The structure of this acid was further supported by its chemical transformations.  相似文献   
53.
The genus Centaurea L. is one of the largest and important genera of Asteraceae family. Centaurea species have been widely used as herbal remedies in folk medicine for their antidandruff, antidiarrheic, antirheumatic, anti‐inflammatory, choleretic, diuretic, digestive, stomachic, astringent, antipyretic, cytotoxic, and antibacterial properties. Centaurea baseri Kose & Alan is a recently described local endemic species in Turkey and this is the first study on the chemical composition and bioactivity of its hydrodistilled essential oil and the crude extract. According to chromatospectral analysis, hexadecanoic acid (42.3%), nonacosane (8.2%), and heptacosane (8.0%) were the main compounds of the essential oil, while 16 compounds were determined in the MeOH extract using LC/MS. Furthermore, antimicrobial, antioxidant, and cytotoxic effects of the essential oil and the extract were evaluated in comparison with the standard agents. The extract showed strong antifungal effect against Candida utilis at the concentration of 60 μg/ml (MIC) where the EO showed growth inhibition at the concentration of 47.00 μg/ml (MIC) against pathogen Bacillus cereus. Both the essential oil and the extract did not show any selective antioxidant properties. The extract showed remarkably selective cytotoxic properties against MCF‐7, PANC‐1, A549, and C6 glioma cells.  相似文献   
54.
The National Institute on Aging Interventions Testing Program (ITP) evaluates agents hypothesized to increase healthy lifespan in genetically heterogeneous mice. Each compound is tested in parallel at three sites, and all results are published. We report the effects of lifelong treatment of mice with four agents not previously tested: Protandim, fish oil, ursodeoxycholic acid (UDCA) and metformin – the latter with and without rapamycin, and two drugs previously examined: 17‐α‐estradiol and nordihydroguaiaretic acid (NDGA), at doses greater and less than used previously. 17‐α‐estradiol at a threefold higher dose robustly extended both median and maximal lifespan, but still only in males. The male‐specific extension of median lifespan by NDGA was replicated at the original dose, and using doses threefold lower and higher. The effects of NDGA were dose dependent and male specific but without an effect on maximal lifespan. Protandim, a mixture of botanical extracts that activate Nrf2, extended median lifespan in males only. Metformin alone, at a dose of 0.1% in the diet, did not significantly extend lifespan. Metformin (0.1%) combined with rapamycin (14 ppm) robustly extended lifespan, suggestive of an added benefit, based on historical comparison with earlier studies of rapamycin given alone. The α‐glucosidase inhibitor, acarbose, at a concentration previously tested (1000 ppm), significantly increased median longevity in males and 90th percentile lifespan in both sexes, even when treatment was started at 16 months. Neither fish oil nor UDCA extended lifespan. These results underscore the reproducibility of ITP longevity studies and illustrate the importance of identifying optimal doses in lifespan studies.  相似文献   
55.
余豪  莫建初  黄求应  廖敏 《广西植物》2018,38(4):420-427
为筛选出高效防治黑翅土白蚁的天然植物精油,减少有机合成农药的使用,该文研究了大蒜精油、肉桂油、丁香油和印楝素油四种植物精油对黑翅土白蚁的触杀效果和驱避作用。结果表明:大蒜精油、肉桂油和丁香油的浓度为5和10 mg·m L~(-1)时,处理2 h后,黑翅土白蚁的校正死亡率达100%,而相同浓度的印楝素油和对照处理的黑翅土白蚁校正死亡率低于5%。随着处理时间延长,浓度为1.25和2.5 mg·m L~(-1)的大蒜精油、肉桂油和丁香油处理6 h时,黑翅土白蚁的校正死亡率仍达100%,而此时对应的印楝素油和对照处理的黑翅土白蚁校正死亡率仅为10%,说明大蒜精油、肉桂油和丁香油对黑翅土白蚁具有较强的触杀效果。大蒜精油、丁香油和肉桂油在处理黑翅土白蚁2 h后LC_(50)值(半致死量)分别为1.572、1.05和1.03mg·m L~(-1),说明肉桂油对黑翅土白蚁的毒性相对最大,触杀效果最好。此外,10 mg·m L~(-1)的大蒜精油、肉桂油、丁香油和印楝素油的驱避试验表明,处理4、6、8和12 h后,大蒜精油、肉桂油和丁香油三精油处理区的黑翅土白蚁数均显著低于对照区的,驱避率总体93%,而对应的印楝素油的驱避率总体28.5%,表明大蒜精油、丁香油和肉桂油三种植物精油对黑翅土白蚁均有显著的驱避活性。综上可知,四种植物精油中大蒜精油、肉桂油和丁香油在防治黑翅土白蚁方面应用潜力很好,是开发绿色环保白蚁防治药剂的可选材料。  相似文献   
56.
57.
采用水蒸气蒸馏法及GC-MS联用技术提取并分析了深山含笑(Michelia maudiae Dunn)叶片的挥发油成分,并用杯碟法和Alamar blue法检测了其抑菌和抗肿瘤生物活性。从深山含笑挥发油中共分离出45种化合物,并鉴定出其中37种化合物,占挥发油总相对含量的97.8%;挥发油主要成分有莰烯(16.575%)、β-蒎烯(15.857%)、D-柠檬烯(12.653%)、丁香烯(11.923%)、1R-α-蒎烯(6.855%)及橙花叔醇(5.199%)等。该挥发油对金黄色葡萄球菌(Staphalococus aureus Rosenbach)和红酵母(Rhodotorula glutinisTrans.)有一定的抑制能力;对人非小细胞肺癌细胞(NCI-H460)有较强的抑制作用,浓度为100 mg.L-1,抑制率可达98.89%以上。  相似文献   
58.
Menthol is an organic compound with diverse medicinal and commercial applications, and is made either synthetically or through extraction from mint oils. The aim of the present study was to investigate menthol levels in selected menthol-producing species belonging to the Lamiaceae family, and to determine phylogenetic relationships of menthol dehydrogenase gene sequence among these species. Three genus of Lamiaceae, namely Mentha, Salvia, and Micromeria, were selected for phytochemical and phylogenetic analyses. After identification of each species based on menthol dehydrogenase gene in NCBI, BLAST software was used for the sequence alignment. MEGA4 software was used to draw phylogenetic tree for various species. Phytochemical analysis revealed that the highest and lowest amounts of both essential oil and menthol belonged to Mentha spicata and Micromeria hyssopifolia, respectively. The species Mentha spicata and Mentha piperita, which were assigned to one cluster in the dendrogram, contained the highest amounts of essential oil and menthol while Micromeria species, which was in the distinct cluster and placed in the farther evolutionary distance, contained the lowest amount of essential oil and menthol. Phylogenetic and phytochemistry analyses showed that essential oil and menthol contents of menthol-producing species are associated with menthol dehydrogenase gene sequence.  相似文献   
59.
用水蒸气蒸馏法提取陕西汉中、贵州、福建、江西4个产地的吴茱萸和汉中产小花吴茱萸的果实挥发油,并用气相色谱-质谱法(GC-MS)共鉴定出154种化学成分,主要为萜类、酯类及酰胺类等化合物。其中陕西汉中产吴茱萸果实挥发油中鉴定出48种化学成分,未知成分2种。主要成分有反式-罗勒烯(相对含量为75.05%,下同)、顺式-罗勒烯(8.10%)、β-香叶烯(6.14%)等;贵州产吴茱萸果实挥发油中鉴定出43种化学成分,未知成分3种,其主要成分有反式-罗勒烯(67.04%)、β-香叶烯(9.66%)、顺式-罗勒烯(7.98%)等;福建产吴茱萸果实挥发油中鉴定出57种化学成分,未知成分2种,主要成分有反式-罗勒烯(73.14%)、顺式-罗勒烯(8.41%)、β-香叶烯(3.82%)等;江西产吴茱萸果实挥发油中鉴定出61种化学成分,主要种类有β-香叶烯(33.49%)、反式-罗勒烯(30.27%)、β-水芹烯(18.86%)、顺式-罗勒烯(5.23%)等;陕西汉中产小花吴茱萸果实挥发油中鉴定出化学成分83种,未知成分3个,其主要成分为反式-罗勒烯(40.21%)、顺式-罗勒烯(8.99%)、β-香叶烯(6.74%)等。结果表明,不同产地吴茱萸及小花吴茱萸果实中挥发油的主要成分种类比较接近,但各自挥发油化合物组成又都含有其特有化学成分。  相似文献   
60.
以油茶EST文库为基础,采用5-′RACE技术,分离克隆了一个脱水素样基因的全长cDNA序列(GenBank接受号EU856537),同源分析表明其编码的208 aa的小分子蛋白(id号ACF72673)属于SK2型脱水素,命名为CoDHN2.CoDHN2的肽链内2个类K-片段间富含苏氨酸,有别于脱水素一般性结构特点,并且同油茶种子中另一类脱水素一样也具有一个十分保守的基序(EDDGQAGRRKK),这可能有利于脱水素的磷酸化和亚细胞定位;采用多种方法预测其二级结构,表明CoDHN2为内在性无规则蛋白,但其中远离C端的一个类K-片段可形成两亲性α-螺旋.CoDHN2含有较多的组氨酸残基以及良好的可溶性,推测它可结合金属离子从而减少活性氧的来源并清除活性氧,并在生理脱水时充当缓冲液.结合其它物种脱水素的研究进展,认为CoDHN2极有可能在油茶油脂合成高峰期同正在发育的脂体结合而保护脂体免受活性氧危害,这为油茶种子细胞的脂体发育研究提出了一个新的方向.  相似文献   
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