翅茎香青中黄酮物质的提取及其抗氧化活性研究

目的:以翅茎香青的茎、叶和花为研究对象,测定其总黄酮含量及其黄酮粗提物对羟自由基(OH·)和超氧自由基(02-·)的清除能力.方法:用索氏提取法以乙醇(95%)为溶剂提取翅茎香青各部位的黄酮物质,采用紫外分光光度法对各部位总黄酮含量以及黄酮粗提物对OH·及02-·的清除率进行测定.结果:实验结果表明:翅茎香青花的总黄酮含量较高,对OH·的清除作用也较好,其叶的黄酮粗提物对O2-·的抑制作用较好.结论:翅茎香青茎、叶和花的黄酮粗提物对OH·和O2-·均具有一定的清除活性,这将为我们日后的研究工作起到铺垫及导向作用.     

虎杖根茎中蒽醌类成分的体外抗氧化活性

采用超声波提取法用体积分数80%乙醇对虎杖(Reynoutriajaponica Houtt.)根茎中的蒽醌类成分进行粗提,并利用D101大孔吸附树脂对粗提液进行纯化.以Vc为阳性对照,采用体外动物实验研究了虎杖根茎中蒽醌类成分对小白鼠肝组织匀浆中谷胱甘肽过氧化物酶(GSH-px)活力及对H2O2诱导的MDA含量和红细胞氧化溶血的影响,并采用化学模拟体系分析了其对DPPH·自由基的清除能力、对Fe3+的还原能力以及与Fe2+的螯合能力.结果表明:虎杖根茎中蒽醌类成分含量丰富,粗提物含量达到55.86 mg·g-1,纯化后含量达到44.77 mg·g-1.质量浓度l0、20、30和40μg·mL-1的蒽醌类成分可显著增强GSH-px活力、降低由H2O2诱导产生的MDA含量,并对H2O2诱导产生的红细胞氧化溶血有较强的抑制作用;质量浓度2、4、6和8μg·mL-1的蒽醌类成分对DPPH·自由基具有良好的清除能力,质量浓度6、8、12和16μg·mL-1蒽醌类成分对Fe3+具有较强的还原能力,而质量浓度5、10、15和20μg·mL-1蒽醌类成分对Fe2+则具有很强的螯合能力.随质量浓度的提高,虎杖蒽醌类成分及阳性对照Vc的各项抗氧化活性指标均逐渐增强,呈现出明显的量效关系,且虎杖根茎中蒽醌类成分的各项抗氧化指标均优于相同质量浓度的Vc.研究结果显示:虎杖根茎中的蒽醌类成分具有较强的抗氧化活性,不仅能够直接清除过量的自由基,也可以通过增强体内的抗氧化系统以抑制自由基的产生.结合他人研究结果,对虎杖资源的开发利用提出了一些建议.     

诺丽发酵果汁中抗氧化物质的研究

本实验针对茜草科植物诺丽的发酵果汁中抗氧化物质进行了定性和定量研究。采用系统预实验法对其不同极性的洗脱部位可能含有的化学成分进行预实验,探索了各个部位的化学成分。采用DPPH·自由基清除、ABTS+·自由基清除和FRAP三种实验方法对各部位洗脱物的抗氧化活性进行了测定,结果显示50%~90%乙醇洗脱部位抗氧化能力最强,此部位主要含有多酚类、黄酮类、香豆素内酯类和蒽醌类成分,并且研究表明抗氧化能力与多酚成分的含量成极显著相关。本研究结果表明多酚类物质是诺丽发酵果汁发挥抗氧化作用的主要功能成分。     

疏花水柏枝内生真菌QY-1的抗氧化活性分析

以从疏花水柏枝(Myricaria laxiflora)中分离的1株内生真菌QY-1为研究对象,为分析其体内及体外的抗氧化活性,对其发酵液及其提取物的活性进行了综合评价。对nr DNA内转录间隔区进行测序鉴定。分别采用总抗氧化力试剂盒、自由基清除试剂盒和还原力测定试剂盒评价发酵液及粗提物的体外抗氧化能力活性;对发酵液提取物及其主成分进行了大肠埃希菌、人神经母瘤细胞SH-SY5Y的体内抗氧化损伤保护作用分析。结果表明QY-1是1株球毛壳菌(Chaetomium globosum),其粗提物具有很高的抗氧化活性,总抗氧化活力、自由基清除率及总还原力均接近维生素C的50%,远高于国际报道水平。且其发酵液提取物有促进细胞增殖和抗氧化保护作用,显著提高大肠埃希菌细胞和神经细胞在H2O2胁迫下的存活率。其粗提物可保护神经细胞膜的完整性,有效减低乳酸脱氢酶(LDH)的渗漏率。从粗提物中分离到一种主成分SF2,可显著抑制凋亡蛋白Caspase 3和Caspase 9的活性。结果表明内生真菌球毛壳菌QY-1不管在体内还是体外都具备较强的抗氧化能力,是一种具有潜在开发价值的天然抗氧化剂资源。     

杨桃提取物体外清除氧自由基作用

从杨桃果中提取得到三种提取物为匀浆提取物、蛋白提取物和多糖提取物。采用化学发光法测定这三种提取物清除氧自由基的活性,实验结果:匀浆提取物清除羟自由基(·OH)和H2O2的活性大小相近,而清除超氧阴离子自由基(O2–·)的活性较小,其IC50约为前两者的4倍。蛋白提取物清除O2–·和·OH的活性大小相近,而清除H2O2的活性明显小于前两者,IC50约为前两者的9倍。多糖提取物清除.OH的活性明显大于清除O2–·和H2O2的活性,其IC50约为O2–·的1/22,约为H2O2的1/65。结果表明,杨桃果具有清除O2–·、·OH和H2O2的作用,不同提取物对这些活性氧自由基的清除能力有所不同。     

七种植物籽油中脂肪酸成分的比较分析(英文)

为寻求新的食用油资源,发展了一种快速可靠的气相色谱-质谱联用方法,用于植物籽油中脂肪酸成分的定性鉴定和含量测定。所建立的方法成功用于葡萄籽、南瓜籽和猕猴桃籽等七种植物籽油中的棕榈酸、十八烷酸、油酸、亚油酸和α-亚麻酸的定性定量分析。结果表明,刺葡萄籽油、普通葡萄籽油、国外葡萄籽油、南瓜籽油、枸杞籽油和西番莲籽油均具有相似的脂肪酸谱,尽管其中它们所含上述五种脂肪酸含量不同,由于均存在人体所必需的饱和与不饱和脂肪酸,故可以用作替代食用油。猕猴桃籽油因为其存在高含量的α-亚麻酸成分,可能是更好的食用油和营养油资源。本文首次对枸杞籽油、西番莲籽油和猕猴桃籽油脂肪酸成分进行绝对含量分析,为新的食用油资源的开发提供了重要的依据。     

不同取代度N,O-羧甲基壳聚糖的抗氧化性能

低聚壳聚糖经醚化得到三种取代度不同的N,O-羧甲基壳聚糖（NOA、NOB和NOC）,本文对其结构进行表征,考察了其对超氧阴离子自由基O2、DPPH自由基和过氧化氢（H2O2）的清除活性和还原能力。结果表明NOA、NOB和NOC对O2和DPPH的清除活性随-OH位置取代度的降低而升高;对H2O2的清除率随-NH2位置取代度的降低而升高;还原能力大小随其总取代度的升高而增强。     

不同取代度N,0-羧甲基壳聚糖的抗氧化性能

低聚壳聚糖经醚化得到三种取代度不同的 N,O-羧甲基壳聚糖(NOA、NOB和NOC),本文对其结构进行表征,考察了其对超氧阴离子自由基O2、DPPH 自由基和过氧化氢(H2O2)的清除活性和还原能力.结果表明NOA、NOB 和 NOC 对O2和 DPPH 的清除活性随-OH 位置取代度的降低而升高;对H2O2的清除率随一NH2位置取代度的降低而升高;还原能力大小随其总取代度的升高而增强.     

荧光标记法初探植物乳杆菌ST-Ⅲ对Caco-2细胞的粘附机理

利用荧光探针CFDA-SE标记植物乳杆菌ST-Ⅲ,测定其对Caco-2细胞粘附能力的变化,提取相关物质,探讨其粘附机理。化学和酶处理ST-Ⅲ菌悬液发现,经胃蛋白酶、胰蛋白酶、氯化锂、苯酚、盐酸胍和热处理能显著降低ST-Ⅲ的粘附性,表明表面蛋白或脂磷壁酸(Lipoteichoic acid)可能参与了ST-Ⅲ对Caco-2细胞的粘附。粘附抑制试验和可逆性结合实验证实表面蛋白而非脂磷壁酸参与了ST-Ⅲ对Caco-2细胞的粘附。结果表明ST-Ⅲ的表面蛋白粗提物可能含有粘附素类的S-层蛋白(S-layer protein),经SDS-PAGE电泳分析,此粗提物主要成分的分子量分别为72.7、34.1和24.3kD。     

沙棘茶水溶性多糖抗氧化活性的研究

通过还原力、清除超氧阴离子自由基、清除羟自由基和抑制H2O2诱导红细胞氧化溶血实验来评价沙棘茶水溶性多糖(WPHT)体外抗氧化能力,并与Vc进行了比较.结果表明,WPHT具有较强的还原能力,对O-·2和·OH具有较强的清除作用,IC50分别为:394 μg/mL、182 μg/mL;对H2O2诱导红细胞氧化溶血及MDA生成有很强的抑制作用,IC50分别为:221 μg/mL、202 μg/mL.说明WPHT在一定浓度范围内具有较强的抗氧化能力.     

无菌猕猴桃种子采集方法研究

无菌的猕猴桃种子是猕猴桃胚乳培养、实生苗微嫁接等技术的基础材料,利用消毒剂灭菌是常用的无菌种子采集手段,应用最广泛的消毒剂为升汞(mercuric chloride)和次氯酸钠(NaClO)。为了避免使用消毒剂,该研究提出了一种新的无菌猕猴桃种子采集方法——无菌搅拌法,同时为探索其准确性和应用性,比较了0.2%升汞灭菌20 min、10%次氯酸钠灭菌20 min、无菌搅拌法三种方式采集无菌猕猴桃种子的效果,并对种子萌发和幼苗形成的影响进行了研究。结果表明:无菌搅拌法、0.2%升汞灭菌20 min是稳定有效的无菌猕猴桃采集方式,10%次氯酸钠灭菌20 min的采集效果不稳定;在相同的时间内,无菌搅拌法的种子发芽率最高,为89.90%,但发芽势较低,均可正常成苗; 10%次氯酸钠灭菌20 min的发芽率次之,与无菌搅拌法的种子无显著差异,发芽势和成苗率最高,分别为47.47%和67.86%,且有打破猕猴桃种子休眠的作用,整体作用类似于赤霉素(GA_3)浸种的效果; 0.2%升汞灭菌20 min对猕猴桃种子的萌发有抑制作用,各项指标均显著低于无菌搅拌法种子,且生长缓慢。此外,无菌搅拌法是物理处理,对种子、操作人员、环境均无害。这证实了无菌搅拌法的实用性和优势,发现了次氯酸钠在打破猕猴桃种子休眠方面的作用,为其它同类型果实的无菌种子采集提供了参考。     

"In vivo" and "in vitro" effects of a bacterial extract on Herpes Simplex Virus

The present studies were designed to evaluate the effects of substance or substances extracted from Escherichia coli on Herpes Simplex Virus. The "in vivo" assays show that bacterial extract introduced i.p. in mice simultaneously with HSV2 brought about 100% of survival, but the inoculation of crude extract after virus challenge brought about complete mortality of mice. "In vitro" assays show that the crude extract reduced significantly the numbers of PFU; better results were obtained when the crude extract was inoculated before the virus inoculation.     

Lipoxygenase inhibition by novel fatty acid ester from Annona squamosa seeds

Studies on the seeds of Annona squamosa yielded a novel lipoxygenase inhibitor fatty acid ester, (+) - annonlipoxy (1). Compound 1 was screened for its enzyme inhibitory activity against lipoxygenase (E.C.1.14.18.1), exhibiting activity with IC(50) 69.05 +/- 5.06 microm. Baicalein (IC(50) 22.6 +/- 0.5 microm) was used as a positive control. Crude extracts of Annona squamosa fruit pulp and seeds were screened for its enzyme inhibitory activity against lipoxygenase and acetylcholinesterase. The crude ethanolic extract of fruit pulp and seeds of Annona squamosa also exhibited lipoxygenase activity with 22.2 and 26.7% inhibition, while the pet.ether extract of seeds of A. squamosa exhibited 52.7% inhibition at a concentration of 40 microg/200 ml. The crude ethanolic extract of seeds of Annona squamosa was also bioassayed for acetylcholinesterase inhibition and it was found inactive.     

A note on the nutrient and mineral composition of Leucaena leucocephala in Western Nigeria

Analysis of Leucaena leucocephala from various localities in Western Nigeria shows that young leaves, pods and seeds contain more crude protein but lower crude fibre and ether extract than mature ones. The crude fat component was higher in the seeds (4.6% and 5.5% for green and ripe seeds, respectively) than in any other edible part of the plant, while the green and brown seed coats contain the least amount of ether extract and total ash. The mineral composition of the dry matter of mature leaves is 2.8% calcium, 0.26% phosphorus, 0.37% magnesium, 1.78% potassium, 0.21% sodium and 0.12% iron.     

Bruchid (Coleoptera: Bruchidae) ovicidal phenylbutanoid from Zingiber purpureum

The larvicidal activity of the dichloromethane extract of Zingiber purpureum Roscoe (Zingiberaceae) rhizome against the second instar of Aedes aegypti (L.) (Diptera: Culicidae) is shown to be due to 4-(3',4'-dimethoxyphenyl)buta-1,3-diene. The diene also showed ovicidal activity against the bruchid Callosobruchus maculatus (F.) (Coleoptera: Bruchidae). Most of the eggs laid by bruchids on treated cowpea seeds were transparent, and very few of them contained developing embryos. The few larvae produced from these embryos were unable to penetrate the seed coat and enter the seed. Similar effects were seen when adults were exposed to the compound and then placed on untreated cowpea seeds, suggesting that a new type of maternally mediated ovicidal effect was involved. Coated and impregnated granular formulations of the extract were evaluated for use in the control of bruchid infestation of stored cowpea seeds. Coated granules showed activity similar to that of the crude extract but were found to lose activity rapidly. Impregnated granules were found to be less active than the crude extract.     

The Role of Bivalent Cations on the Isolation of Allantoinase from the Soybean Seed Extracts

Allantoinases (ALNase) in the water extracts distilled from seeds and leaves of soybean (Glycine max L. cv. Keyu 10) were. remarkably heat stable. However the enzyme and non-enzyme protein in the seed extract, but not leaf extract, lost their activity and were denaturated at 75℃ for 5 min in the presence of Ca2+, Mg2+. or Mn2+ions respecitively. At room temperature over 40%～50% of the non-enzyme proteins in the seed extract could be removed by the bivalent cations without affecting the enzyme activity. This effect was weakend by the increase of concentration. Both extracts had different responses to all sorts of insoluble Ca2. salts. For the seed extract about 50 % of the non-enzyme proteins were removed by 5 % CaSO4 (W/V), without effecting the enzyme activity, while the leaf extract was sensible to Ca3 (PO4) 2. After treatment with 5 % Ca3 (PO4) 2 about 50 % of the enzyme activities and about 70% of proteins were lost. Mn2+ ions could enhance the enzyme activity in crude seed extract, but had no effect on partially purified enzyme from seeds and enzyme in crude extract from leaves. Further, EDTA had no effect on enzyme activity in both extracts.     

Purification of allantoinase from soybean seeds and production and characterization of anti-allantoinase antibodies.

Allantoinase catalyzes the hydrolysis of allantoin to allantoic acid, a reaction important in both biogenesis and degradation of ureides. Ureide production in cotyledons of germinating soybean (Glycine max L.) seeds has not been studied extensively but may be important in mobilizing nitrogen reserves. Allantoinase was purified approximately 2500-fold from a crude extract of soybean seeds by differential centrifugation, heat treatment, ammonium sulfate fractionation, ethanol fractionation, and fast protein liquid chromatography (Pharmacia) with Mono-Q and Superose columns. The purified enzyme had a subunit size of 30 kD. Polyclonal antibodies produced against the purified protein titrated allantoinase activity in a crude extract of seed proteins. Antibodies recognized the 30-kD band in western blot analysis of crude seed extracts, indicating that they were specific for allantoinase.     

Effect of age on seed digestion in parrots (Amazona aestiva)

The objective of this study was to compare the capacity of adult (more than 3 yr old) and young (less than 1 yr old) true parrots to digest seeds that are normally included in their diet in captivity, particularly soybean, sunflower, and corn. All the seeds were offered for 5 d with an interval of 15 d between different diets. The seeds of soybean and corn were boiled for 15 min and soaked in water at ambient temperature for 12 h before being fed to the birds. There were no differences in the digestibilities of crude protein and fats (ether extract) among animals, but the digestibilities of dry matter and crude fiber by the adult animals were higher than those of the young ones. The digestibility of carbohydrate (nitrogen-free extract) by adult birds was higher only for sunflower seeds. It is concluded that the capacity of parrots to digest fiber may change according to the age of the animal. Since the digestion of fiber depends on the action of microorganisms, these results suggest that the colonization of the gastrointestinal tract is delayed or very slow in young parrots.     

Two unusual rotenoid derivatives, 7a-O-methyl-12a-hydroxydeguelol and spiro-13-homo-13-oxaelliptone, from the seeds of Derris trifoliata

The crude methanol extract of the seeds of Derris trifoliata showed potent and dose dependent larvicidal activity against the 2nd instar larvae of Aedes aegypti. From this extract two unusual rotenoid derivatives, a rotenoloid (named 7a-O-methyl-12a-hydroxydeguelol) and a spirohomooxarotenoid (named spiro-13-homo-13-oxaelliptone), were isolated and characterised. In addition a rare natural chromanone (6,7-dimethoxy-4-chromanone) and the known rotenoids rotenone, tephrosin and dehydrodeguelin were identified. The structures were assigned on the basis of spectroscopic evidence. The larvicidal activity of the crude extract is mainly due to rotenone.     

Purification and Characterization of Six Kiwifruit Proteases Isolated with Two Ion-exchange Resins,Toyopearl-SuperQ and Bakerbond WP-PEI

Kiwifruit (Actinidia chinensis) contains a cysteine protease, actinidin, and it was suggested to contain two components, A1 and A2. However, the separation of two components was not shown, and the comparison of the two components has not been thoroughly done.

We have now shown that actinidin can be separated into six proteases, named KP1, KP2, KP3, KP4, KP5, and KP6, by improved polyacrylamide gel electrophoresis at pH 4.0. Each kiwifruit protease was purified with two ion-exchange resins, Toyopearl-SuperQ and Bakerbond WP-PEI. Before the purification of kiwifruit proteases, excess p-chloromercuribenzoate was added to crude kiwifruit protease to prevent the autodigestion.

Each kiwifruit protease had a molecular mass of 23,500 and the same amino terminal sequences from the first to the thirteenth. They had different pI’s. These six kiwifruit proteases were divided into two groups by the effects of DTT and Zn²⁺ on the activity.

These results indicated that the six components must be A1, A2, and four previously unknown proteases. Thus we have separated the kiwifruit proteases which were thought to be two, into six components.