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1.
5-氨基乙酰丙酸是一种新型农药,由于其在环境中易降解,无残留,对人蓄无毒性,所以是一种无公害的绿色农药而倍受关注,在农业领域应用非常广泛,主要应用于植物生长调节剂、绿色除草剂、杀虫剂等方面,还可以应用到医学、有机合成等方面.本文主要综述了生物合成五氨基乙酰丙酸的途径,同时还介绍了五氨基乙酰丙酸作为一种调节剂、新型农药、杀虫剂的研究进展及在医学领域的发展.以期为科研和生产提供指导.  相似文献   

2.
5-氨基乙酰丙酸是一种新型农药,由于其在环境中易降解,无残留,对人蓄无毒性,所以是一种无公害的绿色农药而倍受关注,在农业领域应用非常广泛,主要应用于植物生长调节剂、绿色除草剂、杀虫剂等方面,还可以应用到医学、有机合成等方面。本文主要综述了生物合成五氨基乙酰丙酸的途径,同时还介绍了五氨基乙酰丙酸作为一种调节剂、新型农药、杀虫剂的研究进展及在医学领域的发展。以期为科研和生产提供指导。  相似文献   

3.
We investigated whether intrastriatal (i.s.) administration of 5-aminolevulinic acid (ALA) induces oxidative damage and whether behavioral alterations induced by i.s. administration of ALA could be affected by antioxidants. Unilateral injection of ALA (6 micromol/striatum) increased (approximately 30%) thiobarbituric acid-reactive substances (TBARS), but did not affect striatal content of total thiol groups. ALA-induced body asymmetry was not prevented by pretreatment with ascorbic acid (100 mg/kg, s.c.), dimethyl sulfoxide (DMSO, 0.5 microl/striatum, i.s.) or ebselen (10 nmol/striatum, i.s.). ALA-induced convulsions were not prevented by ascorbic acid, but were partially prevented by DMSO and completely prevented by ebselen. Ebselen completely prevented the increase of striatal TBARS induced by ALA. Results obtained suggest the involvement of reactive species in ALA-induced convulsions and may be of value in understanding the physiopathology of neurological dysfunctions associated to ALA overload.  相似文献   

4.
5氨基乙酰丙酸(ALA)是卟啉、血红素和维生素B12的类似物。ALA作为一种无公害绿色除草剂、杀虫剂、抗微生物药剂、植物生长促进剂及治疗癌症与其它疾病等而备受国外研究者及产业界的关注。本文对ALA光合细菌合成、调节途径、分子遗传学的研究作一简要综述。  相似文献   

5.
将编码光合细菌Rhodobactersphaeroides 5- 氨基乙酰丙酸合酶(ALAS)的同工酶基因hemA、hemT转入E .coli中进行高表达,并将高表达的同工酶进行分离、纯化.纯化的hemA是可溶的,并具有催化活性,而hemT大部分是不溶的,且在体外条件下无活性.与其它重组ALAS相比,R .sphaeroides的hemA活性表达需PLP作为催化因子,除去PLP或用硼酸钠破坏与PLP的连接,hemA活性下降90 % .hemA PLP的紫外 可见光谱分析表明hemA与PLP之间形成一个醛亚胺键,而hemT与PLP之间未形成该键.hemA对修饰组氨酸、精氨酸、胱氨酸残基的试剂很敏感,对可切割Arg15 1和Ser15 2的类胰蛋白酶也很敏感,PLP也不能阻止该酶的切割作用.抗血清试验表明,hemA、hemT的抗血清均可与小鼠的ALAS杂交,并都有一个抗原决定簇.  相似文献   

6.
5 氨基γ 酮戊 (ALA)及其己酯 (He ALA)具有内源生成光敏剂的特点 ,在肿瘤光动力探测及治疗中显示出了优势。ALA及He ALA对神经母细胞瘤、肝癌细胞及成纤维细胞的光动力作用被研究比较。由特征荧光光谱证实 ,经ALA或He ALA培养后 ,三种细胞内均可生成原卟啉 (PpIX)产物。激光扫描荧光显微镜显示 ,在经ALA或He ALA培养后的神经母细胞瘤中 ,PpIX均以弥散方式分布在细胞质中。PpIX在三种细胞中的积聚动力学过程不同 ,随着ALA或He ALA培育时间的增长 ,PpIX在肝癌细胞及成纤维原细胞中的积累增加 ,而在神经母细胞瘤中PpIX在 8h后已达到饱和。此外 ,在同样的培育条件下 ,神经母细胞瘤中PpIX的生成浓度明显高于肝癌细胞及成纤维细胞。经ALA培养及光照射后 ,可使近 90 %的神经母细胞瘤失活 ;而在同样条件下却只能杀伤 5 0 %左右的肝癌细胞及成纤维细胞。揭示了神经母细胞瘤对ALA光动力作用有极高的敏感性 ,并适于光动力治疗。与ALA相比 ,He ALA可在三种细胞内造成与ALA相近的杀伤率 ,但所用的药物浓度却比ALA低 10倍 ,显示He ALA具有极高的光动力灭活效率。因此在内源光动力治疗中 ,He ALA是一种极具开发前景的新药物。  相似文献   

7.
Abstract

Research involving differentiated embryonic stem (ES) cells may revolutionize the study of liver disease, improve the drug discovery process, and assist in the development of stem-cell-based clinical therapies. Generation of ES cell-derived hepatic tissue has benefited from an understanding of the cytokines, growth factors and biochemical compounds that are essential in liver development, and this knowledge has been used to mimic some aspects of embryonic development in vitro. Although great progress has been made in differentiating human ES cells into liver cells, current protocols have not yet produced cells with the phenotype of a mature hepatocyte. There is a of disease models have been examined concerning whether stem cells can correct liver disease. It is a bit premature to conclude that hepatocytes can be generated from non-hepatic cells in culture that will be clinically useful. Standard criteria will need to be developed to assess the extent to which human stem cell-derived hepatocytes have been produced.  相似文献   

8.
After one month of cultivation in the dark in inorganic medium the chloroplasts of protonemata of Ceratodon purpureus have larger grana than chloroplasts from light-grown cultures. Incubation of dark-grown material with ALA increases the chlorophyll content and chlorophyll a/b ratio. On polyacrylamide-gel electrophoresis, a préferential labelling of chlorophyll-protein complex I is obtained after treatment with (3H) ALA in darkness. In contrast, in light, much higher activity is found in chlorophyll-protein complex II. The free pigment zone is highly labelled in both environments.  相似文献   

9.
10.
目的:探讨5-氨基酮戊酸声动力疗法(5-ALA-SDT)对人骨肉瘤细胞株U2-OS细胞凋亡的影响。方法:对数生长期的U2-OS细胞随机分为空白对照组(control)、声敏剂组(5-ALA)、超声组(ultrasound),声动力组(5-ALA-SDT)。采用流式细胞术检测细胞凋亡率,荧光探针及共聚焦激光扫描显微镜检测细胞内荧光定位,用DCFH-DA检测活性氧(ROS)的产生情况。结果:与单纯超声组,单纯5-氨基酮戊酸组和对照组相比较,5-氨基酮戊酸介导的声动力组细胞存活率(40.18%±1.35%)均明显下降(P0.01),细胞内荧光定位表明5-ALA扩散在细胞质和主要累积在U2-OS细胞线粒体内,并且5-氨基酮戊酸介导的声动力组ROS产生的百分率(34.3±2.4)%较单纯超声组、单纯5-氨基酮戊酸组和对照组明显升高,差异有统计学意义(P0.01)。结论:5-氨基酮戊酸介导的声动力作用可能通过线粒体途径对诱导U2-OS细胞凋亡。  相似文献   

11.
The in vivo oxidation of the C4 and C5 of 5-aminolevulinic acid (ALA) to CO2 has been studied in etiolated barley (Hordeum vulgare L. var. Larker) leaves in darkness. The rate of 14CO2 evolution from leaves fed [4-14C]ALA is strongly inhibited by aminooxyacetate, anaerobiosis, and malonate. The rate of 14CO2 evolution from leaves fed [5-14C]ALA is also inhibited by these treatments but to a lesser extent. These results suggest that (a) one step in ALA catabolism is a transamination reaction and (b) the C4 is oxidized to CO2 via the tricarboxylic acid cycle to a greater extent than is the C5.  相似文献   

12.
5-氨基酮戊酸(ALA)是体表光动力疗法的一个重要前体药物,通过代谢产物原卟啉Ⅸ(PpⅨ)介导发挥光敏作用。ALA制剂的研发和优化促生了一系列产品和技术,不仅推动了体表光动力疗法的应用,而且ALA介导的PpⅨ荧光还可用于肿瘤的荧光可视化和辅助手术。本文将对光动力诊疗中ALA及其酯类衍生物和PpⅨ的研究进展作一个系统介绍。  相似文献   

13.
Weeds are one of the major constraints in oilseed Brassica production. Use of effective herbicides to control weeds in the fields is one of the major objectives of agronomists. To improve weed control efficacy and minimize the application costs, complex combinations of 5-aminolevulinic acid (ALA) and a new postemergence herbicide, propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate (ZJ0273), were used to investigate their combined effects in relation to seedling growth and development of oilseed rape (Brassica napus cv. ZS 758). Brassica seeds were treated with different concentrations of ZJ0273 [100 (normal dose for rape), 200, 500, and 1000 mg/L] and ALA (0.1, 1, 10, and 50 mg/L). ALA was applied as pre- and post-treatment alone and in combination with ZJ0273. We found that ZJ0273 stress imposed negative effects on rape seedling growth. Shoot fresh weight, shoot length, and root fresh weight were inhibited significantly under ZJ0273 stress, and the rate of decline increased consistently with increased ZJ0273 concentration. Root oxidizability was also inhibited significantly under ZJ0273 stress conditions, and the higher the concentration of the herbicide ZJ0273, the lower the oxidizability. Herbicide ZJ0273 treatment produced a gradual decrease in antioxidant enzymes (peroxidase, superoxide dismutase, and ascorbate peroxidase) and an increase in peroxidation substance (malondialdehyde accumulation). The increase and decrease were consistent with the ZJ0273 dosage. Our results indicated that pre- and post-treatments with a lower dosage of ALA (1 mg/L) improved rape seedling growth and root oxidizability parameters, whereas a higher concentration of ALA (50 mg/L) depressed growth. We also found that plants treated with 1 mg/L ALA produced the highest shoot fresh weights, shoot lengths, root fresh weights, and root oxidizability when the seeds were treated with different concentrations of ZJ0273. Lower dosages of ALA improved the activities of antioxidant enzymes, whereas the highest dosage of ALA increased the accumulation of peroxidation substance. These results indicate that ALA has promotive effects in the recovery of growth and development of rape seedlings under herbicide ZJ0273 toxicity stress.  相似文献   

14.
Russian Journal of Plant Physiology - Effects of 5-aminolevulinic acid (ALA) at 200 mg/L on photosynthesis, structural organization of photosynthetic apparatus, oxygen uptake rate by the leaf...  相似文献   

15.
Recently, photodynamic therapy using 5-aminolevulinic acid (ALA-PDT) has been widely used in cancer therapy. ALA administration results in tumor-selective accumulation of the photosensitizer protoporphyrin IX (PpIX) via the heme biosynthetic pathway. Although ALA-PDT has selectivity for tumor cells, PpIX is accumulated into cultured normal cells to a small extent, causing side effects. The mechanism of tumor-selective PpIX accumulation is not well understood. The purpose of the present study was to identify the mechanism of tumor-selective PpIX accumulation after ALA administration. We focused on mitochondrial labile iron ion, which is the substrate for metabolism of PpIX to heme. We investigated differences in iron metabolism between tumor cells and normal cells and found that the amount of mitochondrial labile iron ion in cancer was lower than that in normal cells. This finding could be because of the lower expression of mitoferrins, which are the mitochondrial iron transporters. Accordingly, we added sodium ferrous citrate (SFC) with ALA as a source of iron. As a result, we observed the accumulation of PpIX only in tumor cells, and only these cells showed sensitivity to ALA-PDT. Taken together, these results suggest that the uptake abilities of iron ion into mitochondria play a key role in tumor-selective PpIX accumulation. Using SFC as a source of iron might thus increase the specificity of ALA-PDT effects.  相似文献   

16.
Developing chloroplasts isolated from cucumber (Cucumis sativus L. var Beit Alpha) cotyledons are capable of incorporating [14C]5-aminolevulinic acid into chlorophyll (Chl) b and Chl a when incubated under photosynthetic illumination. Thin layer chromatography and high pressure liquid chromatography were employed to analyze the pigments. The specific radioactivity in Chl a was over three times higher than that found in Chl b. Both Chl a and b synthesizing activities in organello decayed rapidly at approximately the same rate. We conclude that concomitant synthesis of Chl a/b-binding apoprotein is not required for Chl b synthesis.  相似文献   

17.
The objectives of this study were to determine whether foliar application of a chlorophyll precursor, 5-aminolevulinic acid (ALA), could mitigate salinity stress damages in perennial grass species by regulating photosynthetic activities, ion content, antioxidant metabolism, or metabolite accumulation. A salinity-sensitive perennial grass species, creeping bentgrass (Agrostis stolonifera), was irrigated daily with 200 mM NaCl for 28 d, which were foliar sprayed with water or ALA (0.5 mg L−1) weekly during the experiment in growth chamber. Foliar application of ALA was effective in mitigating physiological damage resulting from salinity stress, as manifested by increased turf quality, shoot growth rate, leaf relative water content, chlorophyll content, net photosynthetic rate, stomatal conductance and transpiration rate. Foliar application of ALA also alleviated membrane damages, as shown by lower membrane electrolyte leakage and lipid peroxidation, which was associated with increases in the activities of antioxidant enzymes. Leaf content of Na+ was reduced and the ratio of K+/Na+ was increased with ALA application under salinity stress. The positive effects of ALA for salinity tolerance were also associated with the accumulation of organic acids (α-ketoglutaric acid, succinic acid, and malic acid), amino acids (alanine, 5-oxoproline, aspartic acid, and γ -aminobutyric acid), and sugars (glucose, fructose, galactose, lyxose, allose, xylose, sucrose, and maltose). ALA-mitigation of physiological damages by salinity could be due to suppression of Na+ accumulation and enhanced physiological and metabolic activities related to photosynthesis, respiration, osmotic regulation, and antioxidant defense.  相似文献   

18.
5 氨乙酰丙酸 (ALA)可在肿瘤内诱导原卟啉区 (PpIX)光敏剂形成 ,但其亲脂性极差 ,进入细胞的能力有限。脂化的ALA衍生物能增强其进入细胞的能力 ,增进细胞中PpIX的合成。比较了氨乙酰丙酸己酯 (He ALA)与ALA对肝癌细胞中PpIX的生成及光动力损伤作用。细胞的荧光显微图象显示 ,经He ALA培育后 ,细胞中生成了PpIX。PpIX分布在细胞质中 ;细胞的荧光光谱显示出PpIX的特征荧光峰 ,证实细胞中PpIX的生成。实验发现 ,0 .2mmol/L的He ALA药物浓度与 2mmol/LALA的药物浓度在细胞中生成的PpIX含量相当 ;予以相同剂量的光照射后 ,两者对细胞的光敏损伤程度相近 ,反映He ALA对癌细胞有更高的光动力损伤功效。因此在光动力治疗的应用中 ,He ALA是一种极有开发前景的新药物  相似文献   

19.
随着人造肉热潮的兴起,血红素作为其呈色物质也愈发引起研究者的兴趣。血红素是一种含Fe2+的卟啉类化合物,以5-氨基乙酰丙酸为唯一前体物,在生物体中分别通过粪卟啉依赖性、原卟啉依赖性和西罗血红素依赖性三个途径合成,被认为是一种理想的补铁剂和着色剂。与化学合成法和生物提取法相比,微生物合成法具有操作方便、环境友好等优点,因此是一种非常有前景的血红素生产方法。介绍血红素的合成途径,总结微生物以5-氨基乙酰丙酸为唯一前体物合成血红素的最新进展,并简要分析其面临的挑战和前景。  相似文献   

20.
Exogenous application of different plant growth regulators is a well-recognized strategy to alleviate stress-induced adverse effects on different crop plants by regulating a variety of physiobiochemical processes such as photosynthesis, chlorophyll biosynthesis, nutrient uptake, antioxidant metabolism, and protein synthesis, which are directly or indirectly involved in the mechanism of stress tolerance. Of various environmental factors, salinity, drought, and extreme temperature (low or high) considerably diminish plant growth and yield by modulating endogenous levels as well as signaling pathways of plant hormones. Of various plant hormones/regulators, a potential plant growth regulator, 5-aminolevulinic acid (ALA), is known to be effective in counteracting the injurious effects of various abiotic stresses in plants. Until now the mechanisms behind ALA regulation of growth under stress have not been fully elucidated. It is also not yet clear how far growth and yield in different crops can be promoted by exogenous application of ALA and whether this ALA-induced growth and yield promotion is cost-effective. Thus, in this review we discuss at length the effects of ALA in regulating growth and development in plants under a variety of abiotic stress conditions, including salinity, drought, and temperature stress. Furthermore, advances in the functional and regulatory interactions of this plant growth regulator with plant stress tolerance, as well as the effective mode of exogenous application of ALA in inducing stress tolerance in plants are also comprehensively discussed in this review. In the future, overaccumulation of ALA in plants through manipulation of gene(s) could enhance plant stress tolerance. Thus, genetic manipulation of plants with the goal of attaining increased synthesis/accumulation of ALA and hence improved stress tolerance under stress conditions is an important area for research.  相似文献   

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