银杏叶片磷脂酰甘油脂肪酸分子种组成及其位置分布

用高效液相色谱法和酶解的方法检测了银杏叶片磷脂酰甘油（ＰＧ）脂肪酸的分子种组成和位置分布,确定银杏叶片ＰＧ主要分子种的脂肪酸组成（ｓｎ１／ｓｎ２）是１８∶３／１６∶１（３ｔ）,１８∶３／１６∶０,１８∶２／１６∶１（３ｔ）,１８∶２／１６∶０,１８∶１／１６∶１（３ｔ）,１６∶０／１６∶１（３ｔ）,１８∶１／１８∶１,１８∶１／１６∶０和１６∶０／１６∶０。银杏叶片ＰＧ脂肪酸组成和位置分布的分析结果表明,Ｃ１８脂肪酸主要位于ｓｎ１位,１６∶１（３ｔ）只分布于ｓｎ２位,１６∶０在ｓｎ１位和ｓｎ２位上均有发现。ｓｎ１位上的不饱和度∑ｕ大于ｓｎ２位上的∑ｕ。     

银杏组织培养研究Ⅰ．不同培养条件对银杏愈伤组织形成的影响

取银杏树干上萌生的幼嫩枝条的基尖、茎段和叶片分别接种到高生长素含量的ＭＳ培养基上,愈伤组织诱导频率可高达９０％。在低生长素浓度下,诱导频率较低,但能促进茎外植体顶芽和侧芽的生长。以银杏幼茎、幼叶作外植体,形成的愈伤组织形态结构不同：幼基愈伤组织较疏松,呈粒状,色浅黄,生长迅速;幼叶愈伤组织较致密,平滑,色黄绿,生长稍慢。叶片的放置方式很重要：下表皮接触培养基时,愈伤组织只从上表皮发生,而反向放置,上下表皮都不形成愈伤组织。     

Chromosome G—banding in plants by inducing with trypsin and urea

Clear G-bands were revealed by applying the TUG method on chromosomes of 5 species of higher plants(Lilium davidii,Viciafaba,Hordeum vulgare,Ginkgo biloba and Triticum monococcum).Some details of the TUG method which consisted of treating chromosomes with both trypsin and urea were also studied.The mechanisms that might account for the presence of G-bands in plants were discussed.     

银杏结实习性的观察

银杏结实习性的观察夏春森,周萍,王露（江苏淮阴市果树研究所,淮阴２２３００１）吴邦良（南京农业大学,南京２１００１４）关键词银杏,结实习性Ｏｂｓｅｒｖａｔｉｏｎｏｎｓｅｅｄ－ｓｅｔｈａｂｉｔｏｆＧｉｎｄｇｏｂｉｌｏｂａＬ．￥ＸｉａＣｈｕｎ－Ｓｅｎ;Ｚ...     

<Emphasis Type="Italic">Ginkgo biloba</Emphasis> extract (EGb761) and FK506 preserve energy metabolites in the striatum during focal cerebral ischemia and reperfusion in gerbils monitored by microdialysis

Cell death after cerebral ischemia is mediated by the accumulation of excitatory amino acids, calcium influx into cells and the generation of free radicals. The aim of this study was to evaluate changes in energy-related metabolites in the striatum of gerbils subjected to focal cerebral ischemia after pretreatment withGinkgo biloba extract (EGb761), a well-known antioxidant, and FK506, a calcium-dependent phosphatase calcineurin inhibitor. Ischemia was induced by occlusion of the right common carotid artery and the right middle cerebral artery for 60 min. A microdialysis probe was inserted into the right striatum to monitor extracellular glucose, lactate and pyruvate levels. This study showed decreases in glucose (10% of the baseline), pyruvate (20% of the baseline) and lactate (60% of the baseline), and a 5-fold increase in the lactate to pyruvate ratio during ischemia in the control group. Both EGb761 treatment and the combination (EGb761 and FK506) therapy significantly preserved glucose (50% of the baseline) and pyruvate (60% of the baseline) levels during ischemia. The marked increase in the lactate to pyruvate ratio was not observed in the combination group. These results suggest that preservation of cellular energy metabolism during cerebral ischemia and after restoration with reperfusion may contribute to the neuroprotective effects of EGb761 and FK506.     

Ginkgo biloba affords dose-dependent protection against 6-hydroxydopamine-induced parkinsonism in rats: neurobehavioural, neurochemical and immunohistochemical evidences

Ginkgo biloba extract (EGb), a potent antioxidant and monoamine oxidase B (MAO-B) inhibitor, was evaluated for its anti-parkinsonian effects in a 6-hydroxydopamine (6-OHDA) rat model of the disease. Rats were treated with 50, 100, and 150 mg/kg EGb for 3 weeks. On day 21, 2 microL 6-OHDA (10 microg in 0.1% ascorbic acid saline) was injected into the right striatum, while the sham-operated group received 2 microL of vehicle. Three weeks after 6-OHDA injection, rats were tested for rotational behaviour, locomotor activity, and muscular coordination. After 6 weeks, they were killed to estimate the generation of thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) content, to measure activities of glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), catalase, and superoxide dismutase (SOD), and to quantify catecholamines, dopamine (DA) D2 receptor binding, and tyrosine hydroxylase-immunoreactive (TH-IR) fibre density. The increase in drug-induced rotations and deficits in locomotor activity and muscular coordination due to 6-OHDA injections were significantly and dose-dependently restored by EGb. The lesion was followed by an increased generation of TBARS and significant depletion of GSH content in substantia nigra, which was gradually restored with EGb treatment. EGb also dose-dependently restored the activities of glutathione-dependent enzymes, catalase, and SOD in striatum, which had reduced significantly by lesioning. A significant decrease in the level of DA and its metabolites and an increase in the number of dopaminergic D2 receptors in striatum were observed after 6-OHDA injection, both of which were significantly recovered following EGb treatment. Finally, all of these results were exhibited by an increase in the density of TH-IR fibers in the ipsilateral substantia nigra of the lesioned group following treatment with EGb; the lesioning had induced almost a complete loss of TH-IR fibers. Considering our behavioural studies, biochemical analysis, and immunohistochemical observation, we conclude that EGb can be used as a therapeutic approach to check the neuronal loss following parkinsonism.     

Feeding of Ginkgo biloba extract (GBE) enhances gene expression of hepatic cytochrome P-450 and attenuates the hypotensive effect of nicardipine in rats

Ginkgo biloba extract (GBE) has been used clinically for improving peripheral vascular diseases in France and Germany and is ingested widely as a herbal medicine in some countries. However, accurate information about its safety as an herbal medicine has not been sufficiently established. To address this issue, we examined the effect of GBE on hepatic drug metabolizing enzymes and their influence on hypotensive drug in rats. Male rats were fed either a control diet or diet containing GBE (0.5% w/w) for 4 weeks. The feeding of a GBE diet did not change the serum transaminase activity, but increased the liver weight and the phospholipid concentration in the liver. In addition, the GBE diet markedly increased the content of cytochrome P-450 (CYP), and the activity of glutathione S-transferase in the liver. Furthermore, the GBE diet markedly induced levels of CYP2B1/2, CYP3A1 and CYP3A2 mRNA in the liver. The levels of CYP1A1, CYP1A2, CYP2E1, CYP2C11 and CYP4A1 were unchanged. The feeding of GBE for 4 weeks significantly reduced the hypotensive effect of nicardipine that was reported to be metabolized by CYP3A2 in rats. These findings suggest that GBE reduces the therapeutic potency of the Ca2+ channel blocker, nicardipine, via enhancement of cytochrome P-450 expression.     

银杏叶产量性状相关分析及多性状选择

采用全国８６个银杏叶单株无性系、随机区组设计（ＲＢＥ）对７个数量性状的直接、间接和多性状选择进行了研究。方差分析表明,叶面积系数（Ｌａｉ）和小区叶产量（Ｙ）的遗传力（ｈ＾２）较高,直接选择Ｌａｉ、ＮＬ（叶数／株）和Ｙ的ΔＧ′（相对遗传增益）分别为８１．９４％、２９．６０％和２６．１７％。关系分析表明,长枝上的叶宽（Ｌｗ）－叶干重（Ｌｄ）、短枝上叶宽（Ｓｗ）－叶干重（Ｓｄ）、叶数／株（ＮＬ）－小区产     

Cytoskeleton in Pollen and Pollen Tubes of Ginkgo biloba L.

The distribution of F-actin and microtubules was investigated in pollen and pollen tubes of Ginkgo biloba L. using a confocal laser scanning microscope after fluorescence and immunofluorescence labeling. A dense F-actin network was found in hydrated Ginkgo pollen. When Ginkgo pollen was germinating,F-actin mesh was found under the plasma membrane from which the pollen tube would emerge. After pollen germination, F-actin bundles were distributed axially in long pollen tubes of G. biloba. Thick F-actin bundles and network were found in the tip of the Ginkgo pollen tube, which is opposite to the results reported for the pollen tubes of some angiosperms and conifers. In addition, a few circular F-actin bundles were found in Ginkgo pollen tubes. Using immunofluorescence labeling, a dense microtubule network was found in hydrated Ginkgo pollen under confocal microscope. In the Ginkgo pollen tube, the microtubules were distributed along the longitudinal axis and extended to the tip. These results suggest that the cytoskeleton may have an essential role in the germination of Ginkgo pollen and tube growth.     

秦岭南坡松栎林群落演替过程中种间联结性和相关性研究

对从银杏叶片中分离的1株具有高抗氧化活性的内生真菌SG0016,并对SG0016菌株进行形态学和分子生物学鉴定,以发酵液DPPH自由基清除率为指标,采用单因素和正交试验对SG0016菌株的接种量、培养温度、装液量、培养时间和碳源、氮源等培养条件进行优化,以提高其发酵液抗氧化活性。结果显示,SG0016菌为球毛壳菌(Chaetomium globosum);其发酵液抗氧化活性最佳培养条件为:接种量10%、培养温度23℃、装液量100 mL(250mL的三角瓶)、培养时间7d,葡萄糖为碳源,酵母膏为氮源。在此条件下,发酵液的DPPH自由基清除率最高,为96.17%,比优化前提高了23.6%。银杏内生真菌球毛壳菌SG0016代谢产物具有较好的抗氧化活性,为天然抗氧化剂的开发提供了新的来源。