胆木叶提取物的抗氧化活性研究

以胆木叶为原料,通过不同极性溶剂依次萃取50%醇提取物,分别得到石油醚萃取物(PEE)、氯仿萃取物(CE)、乙酸乙酯萃取物(EAE)、正丁醇萃取物(BE)和水萃取物(WE),它们的收率依次为0.62%、3.90%、0.68%、1.78%和6.06%.采用过氧化氢体系、超氧阴离子(O-2·)体系、羟基自由基体系(·OH)和Oyaizu法,以Vc为阳性对照,进行5个不同萃取部分抗氧化活性的测定和比较.结果表明,5种萃取部分均具有一定的抗氧化活性,随着浓度的增加而提高;且在不同的自由基产生体系中,其抗氧化活性强弱不尽相同.在过氧化氢体系中,对H2O2的清除能力强弱顺序依次为Vc>BE>CE>EAE>PEE>WE;在超氧阴离子体系中,对O-2·抗氧化活性强弱顺序依次为Vc>EAE>BE>PEE>WE>CE,在羟基自由基体系中,对·OH抗氧化活性强弱顺序依次为Vc>BE>CE>EAE>PEE>WE;而其还原能力强弱顺序依次为 BE>EAE>WE>CE>PEE.     

Knotwood and bark extracts: strong antioxidants from waste materials

The antioxidant properties of hydrophilic extracts of knotwood of several industrially important tree species were evaluated by lipid-peroxidation inhibition and peroxyl-trapping capacity tests. The results were compared with the antioxidant properties of hydrophilic extracts of bark, and pure lignans and flavonoids isolated from knotwood extracts. The knot extracts from several tree species were stronger antioxidants than the bark extracts, which can, however, also be classified as strong antioxidants. In addition, the antioxidant properties of most of the knotwood extracts are stronger than the pure compounds. It is concluded that knotwood is a rich source of natural antioxidants.     

木麻黄乙醚浸提液的分离及鉴定

采用GC—MS技术,比较木麻黄凋落物、根和根际土壤3种浸提液的成分差异和含量差异的结果表明：3种浸提液（凋落物、根系和根际土壤乙醚浸提液）中的有机化舍物化学成分有明显差别,凋落物和根际土壤的乙醚浸提液中特有成分分别为维生素E和苯酚;3种浸提液中都含有的成分是羽扇烯酮和羽扇豆醇;羽扇烯酮在浸提液中含量由高到低依次为：凋落物（7．39％）,根际土壤（2．65％）,根（2．28％）;羽扇豆醇在浸提液中含量由高到低依次为：凋落物（3．22％）,根际土壤（2．65％）,根（2．0％）。     

卷叶黄精根不同极性化感物质的化感作用

化感作用是植物通过淋溶、挥发、残茬降解和根系分泌向环境中释放化学物质,从而对自身或周围其他植物的生长产生影响的现象(孔垂华等,2001;董卓杭等,2001;翟明普等,1993;林文雄等,2001;马茂华等,1999;彭少麟等,2001).化感作用普遍存在于自然界,对其深入研究将有利于复合系统中植物配置、耕作制度和栽培措施的科学化,在植物间加强促进作用,降低抑制作用,促进生物多样性和农业可持续发展.     

提取技术对香榧假种皮提取物组成影响的研究

采用水蒸气蒸馏法、溶剂提取法和两步提取法对新鲜的和风干的香榧假种皮原料进行提取,从提取物得率、性状、组成成分和各成分含量等方面进行了研究。新鲜原料所得提取物得率高于风干原料,两步提取法所得提取物总得率高于另外两种方法。采用水蒸气蒸馏法,新鲜原料的提取得率为5.54%,风干原料为1.98%,GC和GC-MS分析结果表明新鲜原料主要成分为单萜类化合物,风干原料主要成分为倍半萜类化合物。新鲜原料的溶剂提取物得率高于水蒸气蒸馏法,且随着溶剂不同,得率略有变化,其中使用甲苯时得率为21.84%,使用正己烷时得率为16.01%,主要成分皆为二萜类物质;新鲜原料的两步法提取所得组分分为精油和提取物两部分,其中精油的得率、性状、组成与水蒸气蒸馏方法一致,提取物的得率、性状、组成接近于溶剂提取法,只是组分含量略有变化。对香榧假种皮进行两步法提取比较有利于精油和提取物的有效分离及利用。     

不同类型油茶穗条提取液中生根抑制物的研究

为给油茶无性繁殖提供理论依据,以油茶新品种‘秋霞’为试验材料,对不同月份(4月、6月)采集的不同类型穗条(8年生嫁接大树、3年生组培苗、3年生家系苗、3年生扦插苗)提取液的酸度与酚类物质的含量进行了检测与分析;并以白菜种子为试材,就不同类型穗条提取液对其发芽的生物效应进行了鉴定试验。测定结果表明:不同月份采集的不同类型穗条提取液的酸度和酚类物质含量均不同。鉴定试验结果表明:白菜种子在不同月份采集的不同类型穗条提取液原液中的发芽率不存在显著差异,但白菜种子在嫁接大树穗条提取液中的发芽率最低,而在家系苗穗条提取液中的发芽率最高。研究结果表明:不同类型穗条提取液中均存在生根抑制物质,且均存在酸类和酚类物质;嫁接大树穗条中生根抑制物质的含量较高,而家系苗穗条中生根抑制物质的含量较低。     

大型毒菌发酵液提取物对前列腺癌细胞增殖的作用

通过MTT试验,评定大型毒菌发酵液提取物的直接细胞毒活性。结果表明：3个菌株发酵液提取物两种浓度组对PC-3细胞均有很好的抑制作用,与对照相比抑制效果差异显著（P〈0.05）;不同药物、不同浓度组作用时间点均以120 h抑制率最高;不同浓度组作用120 h,以高浓度组抑制率最高。菌株CM4高浓度组给药120h对PC-3细胞的抑制活性最高,抑制率为90.23%;其次为CM4低浓度组,给药120h抑制率为86.37%。菌株CM4大型毒菌发酵液提取物对人前列腺癌细胞PC-3有明显的抗肿瘤作用。     

魔芋飞粉乙醇提取物对木材霉菌的抑制作用初探

采用生长速率法及显微观察探究不同浓度魔芋飞粉乙醇提取物及其不同有机萃取物对黑曲霉的抑菌效果。结果表明:15%和20%浓度的魔芋飞粉乙醇提取物及浓度为4%的魔芋飞粉乙醇提取物的三氯甲烷萃取物、乙酸乙酯萃取物和正丁醇萃取物对黑曲霉菌落生长有一定的抑制作用;提取物主要是通过抑制黑曲霉孢子的萌发和扩散,抑制菌丝的生长以及改变菌丝细胞壁的通透性达到对黑曲霉的抑菌效果。该研究可为开发利用魔芋飞粉制备天然木材防霉剂提供理论参考。     

海芒果、夹竹桃、黄婵、乌桕对柳蓝叶甲的毒杀活性

用索氏提取法获得了海芒果Cerbera manghas、夹竹桃Nerium indicum、黄婵Alamanda cathartica和乌桕Sapium sebiferum的叶片乙醇提取物,在室内分别测定了这4种植物不同浓度提取物对柳蓝叶甲（plagiodera versicolora）的防治效果,结果表明：4种植物提取液原液的校正死亡率最终均达到100%,尤以夹竹桃、海芒果处理的效果最为显著,其提取液处理后叶甲的校正死亡率都高于乌桕和黄婵处理的,仅1天后,供试昆虫的校正死亡率就达到100%。海芒果和夹竹桃提取物处理后叶甲的校正死亡率曲线呈现平稳上升的趋势,乌桕和黄婵处理后叶甲的校正死亡率曲线趋向于平直。试验结果为进一步在生产实践中有效应用植物杀虫剂提供参考依据。     

Antibacterial activity of Hygrophila stricta and Peperomia pellucida

The crude methanolic extracts of Hygrophila scricta and Peperomia pellucida were fractionated into petrol, dichloromethane, ethyl acetate and butanol. All the crude extracts and the fractions exhibited a very good level of broad spectrum antibacterial activity. The fractions were more active than the crude extracts. The petrol fraction of H. stricta and the butanol fraction of P. pellucida were particularly good. No activity was noticed for the moulds tested.     

油茶叶乙醇提取物清除DPPH自由基作用的研究

用二苯基苦基肼自由基(DPPH·)法测定了油茶叶乙醇提取物的抗氧化活性,并与芦丁、二丁基羟基甲苯(BHT)进行了比较,在波长517 nm、反应时间40 min的条件下测定了DPPH·的清除率为50%时抗氧化剂的质量浓度(EC50)值.结果表明,油茶叶乙醇提取物时DPPH·具有明显的清除作用,且随着油茶叶乙醇提取物纯化程度的提高,其清除能力也相应增强.测得油茶叶粗提物、油茶叶精提物、芦丁和BHT清除DPPH·的EC50值分别为12.19、6.765、9.481和37.53 mg/L,清除DPPH·能力的大小顺序依次为油茶叶精提物＞芦丁＞油茶叶粗提物＞BHT.     

Pesticidal Activity of the Leaf and Bark Extracts of Giliricidia sepium on Callosobrucus maculatus

Abstract

The effects of different concentrations of cold and hot aqueous extracts of G. sepium on C. maculatus, the storage pest of cow-pea were examined. The extracts had a killing effect on the weevils. The percentage mortality of the weevils increased with the increase in the extract concentrations. Statistical analyses at 5% level revealed that significant differences abound in the efficacies of the cold and hot aqueous extracts. The hot aqueous leaf and bark extracts tend to have more toxic effect than the cold aqueous extracts. Also, extracts from the bark tend to be more toxic to the weevils than those of the leaves.     

Insecticidal activity of certain medicinal plants

The methanol extracts of eight species of medicinal plants were tested for insecticidal activity in third instar larvae of Egyptian cottonworm (Spodoptera littoralis). All extracts showed a certain degree of larval toxicity. The extracts of Ocimum basilicum, Origanum majorana and Salvia officinalis appeared to be highly toxic. The extracts significantly affected the growth indexes [relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD)].     

南方红豆杉叶浸提液对小麦种子萌发与幼苗生长的影响

采用滤纸培养皿法研究了南方红豆杉叶浸提液对小麦种子萌发与幼苗生长的影响。研究结果发现,红豆杉叶浸提液对小麦种子的萌发和幼苗生长存在不同程度的抑制作用。低浓度的南方红豆杉浸提液促进小麦种子的萌发,高浓度浸提液抑制小麦种子的萌发。当浸提液浓度为6g/mL时,小麦种子的萌发率达到最高。南方红豆杉叶浸提液对小麦幼苗根系生长产生显著抑制作用。随着浸提液浓度的升高,小麦须根的长度逐渐下降,但不定根的数目逐渐增加。当浸提液的浓度为10g/mL时,根长抑制率达到42.48%。方差分析结果表明,南方红豆杉叶浸提液对小麦的根生长产生显著的抑制作用。对小麦幼苗的茎生长、根的生物量和茎的生物量均表现为低浓度的浸提液促进茎的生长和生物量的增加,高浓度浸提液则抑制茎的生长和生物量增加。研究结果表明,南方红豆杉浸提液表现低浓度时促进种子的萌发、须根数目的增加、茎的生物及生物量的增加,高浓度时则产生一定的抑制作用,而对根长的生长表现为显著的抑制作用。     

Antidiabetic activity of Caesalpinia bonducella seed extracts in rats

The seed extracts of Caesalpinia bonducella were subjected to screening of antidiabetic activity in alloxan induced hyperglycemia. The oral administration of the extracts (300 mg/kg) produced significant antihyperglycemic action as well as it lowered the BUN levels significantly. In the same study the action of the extracts on diabetes induced hyperlipidemia was analyzed where the extracts significantly lowered the elevated cholesterol as well as LDL level. The antihyperglycemic action of the extracts may be due to the blocking of glucose absorption. The drug has the potential to act as antidiabetic as well as antihyperlipidemic.     

Screening of some rare endemic Italian plants for inhibitory activity on 5-lipoxygenase

The extracts of four rare plants found on the islands of Sicily, Vulcano and Marettimo, Southern Italy, were screened for their inhibitory effect on the production of leukotriene B4 by 5-lipoxygenase in intact cells. The methanol extracts of pods of Cytisus aeolicus and aerial parts of Thymus richardii were the most active extracts, inhibiting almost completely the leukotriene B4 production at 200 and 50 microg/ml, respectively.     

Antimicrobial activity of some endemic plants growing in the Eastern Black Sea Region, Turkey

The Eastern Black Sea Region has an extensive flora because of ample rainfall lasting all year. In this study, antimicrobial effects of 74 crude extracts of 22 endemic plants were investigated. Among the 30 active crude extracts, water-insoluble crude extracts from Betula medwediewii, Heracleum platytaenium, Primula longipes, Anthemis cretica ssp. argaea and Centaurea helenioides were the prominent ones with their MIC values.     

肉桂、八角提取物抑菌活性研究

用纸碟法研究了桂皮、八角果以及八角叶提取物的抑菌活性.结果表明,桂皮、八角果以及八角叶提取物均具有较强的抑菌效果.其中,桂皮提取液的抑菌效果显著优于八角果、八角叶和可利鲜保鲜剂,八角果、八角叶和可利鲜保鲜剂之间则无显著差异,桂皮提取液对枯草杆菌的抑菌效果最强.     

三种木莲叶片提取物成分及其抑制氧自由基活性研究

用有机溶剂萃取法从三种木莲叶片中分离获得的提取物,经GC/MS进行成分分析和定量测定.再进行抗氧自由基活性测定.从红花木莲(Manglietia insignis (Wall) Blume)、桂南木莲(Manglietia chingii Dandy)和乳源木莲(Manglietia yuyuanensis Law)中分别鉴定出21、36和20种化合物,其中11种成分为三种木莲所共有,12种成分为两种木莲所共有.各成分的相对含量为红花木莲:萜烯类化物38.93%,烷烃类28.18%,含氮化合物15.73%,芳香族化合物7.23%.桂南木莲:萜烯类30.22%,酸类14.17%,烷烃类13.87%,芳香族化合物13.29%;乳源木莲:醇类28.00%,萜烯类25.38%,芳香族化合物18.00%. 研究结果还表明,三种木莲的提取物均有较强的抑制氧自由基的功能.在稀释100倍时,抑制超氧阴离子活力最强,稀释20倍时,抑制羟自由基活力达最大.本研究结果为进一步探索三种木莲的保健功能提供科学依据.图1表5参15.     

Cytotoxic activity of some Asarum plants

The cytotoxic activity against some tumor cell lines of 16 commonly used species of Asarum was evaluated in this study. All of these plants were widely used in Asian countries as traditional medicines or folk medicines. Their inhibitory activities against four tumor cell lines (HL-60, BGC-823, KB and Bel-7402) were compared. It was observed that 10 of the tested extracts (eight ethanol extracts and two water extracts) among 32 extracts of these plants showed cytotoxic activity. Those 95% ethanol extractions from A. caudigerellum, A. forbesii, A. inflatum and A. maximum exhibited the highest cytotoxic activity, and 95% ethanol extracts or water extracts of A. sieboldii var. seoulense, A. himalaicum, A. splendens and A. crispulatum showed selective activity against one or two cells among the tested tumor cells. This is the first report of Asarum plants possessing cytotoxic activity against tumor cell lines.