桑叶中抗凝血活性成分的初步分离与纯化

采用乙醇分级沉淀和Sephadex G100凝胶层析的方法,结合凝血指标检测,对桑叶中的抗凝血活性成分进行了分离纯化。结果表明:桑叶的抗凝血活性主要集中在桑叶的水提取液中,能够显著延长人体血浆的活化部分凝血活酶时间(APTT)值。桑叶水提取液经30%乙醇沉淀、凝胶层析和醋酸纤维素薄膜电泳表明其抗凝血活性成分是一种多糖组分。试验还表明,高浓度乙醇处理对桑叶多糖的抗凝血活性没有影响。     

水蛭活性成分提取分离纯化方法的研究进展

水蛭是一味传统的中药材,其品种很多,不同水蛭中可提取分离出多种不同的活性成分。目前报道的水蛭提取方法主要为传统溶剂提取方法和酶解提取方法,提取物的抗凝活性强弱与原料的处理和提取方法有关。在水蛭纯化方面研究得最深入、收效最大的是水蛭素,以获得更多、更高纯度的水蛭素为主,有效成分的活性和纯度直接影响其临床应用的疗效,选择合适的提取纯化方法就显得至关重要,文章系统综述了目前水蛭中含有的多种活性成分及水蛭的提取分离纯化方法。     

变异黄芪毒性成分苦马豆素的分离与鉴定

采用植物化学成分系统研究的方法,从变异黄芪醇提总浸膏中分段萃取得到石油醚提取部分、氯仿提取部分、乙酸乙酯提取部分和正丁醇提取部分.正丁醇提取部分经聚酰胺柱和硅胶柱色谱分离、薄层层析检测和升华技术分离纯化出一种白色针状结晶,通过熔点测定和IR、MS、1HNMR、13CNMR波谱分析鉴定为苦马豆素.通过与同类植物的比较分析,证明苦马豆素就是变异黄芪的主要有毒成分.     

蒙药红珊瑚的化学成分研究

通过研究红珊瑚的化学成分,为寻找其活性成分提供基础。应用GC-MS、Sephadex LH-20、HPLC等方法进行分析与分离纯化,根据化合物的理化性质和波谱数据进行结构鉴定。并利用电感耦合等离子体质谱仪分析方法对13种无机元素进行含量测定。结果表明:从红珊瑚脂溶性成分中分析出16种化合物,含有烷烃类、脂类、醇类、角鲨烷、鲨烯等有机化合物,其中12个化合物为首次从红珊瑚脂溶性成分中分析得到;分离、鉴定出5个化合物,分别为邻苯二甲酸异丁酯、邻苯二甲酸正丁酯、咔唑、对羟基苯甲酸、6(5H)-菲啶酮,均为首次从红珊瑚中分离得到;红珊瑚含有6%左右的钙,富含镁、钠、铁、钾、锌等无机元素。     

宝兴地区虎耳草化学成分的定性鉴定

为了了解虎耳草主要化学成分在不同极性段提取物中的分布,我们分别用石油醚、乙酸乙酯、正丁醇萃取虎耳草提取液,得到包括母液在内的四段提取物．采用试管法对四段提取物．中的主要化学成分进行系统化学鉴定。结果得出：石油醚萃取物中主要为叶绿素等脂溶性杂质．可能含有生物碱;乙酸乙酯中主要含黄酮类、香豆素类或内酯类、蒽醌类物质。可能含有酚类成分;正丁醇中可能含有糖和苷类、鞣质;水溶部分主要为糖和苷类、鞣质,可能含有皂甙和生物碱。由此推断．虎耳草中大部分活性成分分布于中等极性的乙酸乙酯萃取物中。     

台湾椪柑（C.reticulata Blanco cv. Ponkan）果皮醇提取物不同极性部位组分及抗氧化活性研究

用索氏回流浸提法提取台湾椪柑果皮,得到乙醇粗提取物浸膏,蒸馏水复溶浸膏后采用梯度极性溶剂（石油醚、乙酸乙酯、正丁醇）分步萃取。用HPLC鉴定各极性部位的类黄酮组分,用DPPH、ABTS、ORAC法鉴定各极性部位的抗氧化活性。结果表明,台湾椪柑果皮醇提取物类黄酮主要富集在乙酸乙酯部分,且该部分抗氧化活性明显高于其他极性部位。说明柑橘类黄酮物质与抗氧化活性相关。     

GC法测定市售动物源性中药材地龙、水蛭中3种氯霉素类药物的残留量

为了建立柱前衍生-GC-ECD法同时测定市售动物源性中药材地龙、水蛭中氯霉素、甲砜霉素、氟甲砜霉素3种氯霉素类抗生素残留量的方法,样品经乙酸乙酯超声提取,旋转蒸干后,提取物溶于4%氯化钠溶液,经正己烷去脂,液液分配净化。再加BSTFA-TMCS衍生化反应后氮气吹干,正己烷定容进样分析,外标法定量。结果表明,氯霉素、甲砜霉素和氟甲砜霉素在0.1~20μg/L范围内线性关系良好,相关系数r~2≥0.9989;空白样品加标实验表明,氯霉素、甲砜霉素和氟甲砜霉素在1、5、10μg/kg这3个添加水平下的回收率为62.9%~100.8%,RSD16%,其检出限分别为0.05、0.1、0.1μg/kg。该方法简便快捷,准确度和精密度高,适用于地龙、水蛭中氯霉素类药物的残留测定。     

向日葵叶抗氧化成分24-亚甲基环木菠萝烷醇的分离提取

通过对向日葵叶乙酸乙酯、0.5%稀盐酸混合液提取物的氯仿萃取部分的分离纯化,得到一个化合物。经MS鉴定其分子量为440,为24-亚甲基环木菠萝烷醇,且为首次从该植物中分离得到。用普鲁士蓝法以茶多酚为对照研究该化合物的抗氧化活性。结果表明,24-亚甲基环木菠萝烷醇具有抗氧化活性,但比同浓度茶多酚的抗氧化活性要弱。     

水蛭的收捕与加工

水蛭的前端有非常发达的吸盘。人们下水田劳动、涉水过河或游泳时,常受到水蛭的袭击,常吸付叮在腿部,亦有进入尿道、阴道、肛门,甚至有钻进鼻孔、口腔吸付粘(结)膜上而流血等现象发生。水蛭是种名贵中药材。从水蛭唾液腺中提取的抗凝血物质,称之“水蛭素”。近年来还发现水蛭体内还含有抗动脉硬化物质,对血栓     

青贮苜蓿中抑菌活性乳酸菌的筛选及鉴定

研究旨在从苜蓿青贮材料中筛选出有高效抑菌活性的乳酸菌,并分析其抑菌机理。实验从苜蓿青贮材料中分离出104株乳酸菌通过牛津杯双层平板法筛选得到两株具有高效抑菌活性的菌株;在对其抑菌活性进行初步分析后发现,其中一株菌发挥抑菌活性的主要成分为蛋白类物质,另一株菌发挥抑菌活性的主要成分为有机酸。经过生理生化、碳源发酵及16S r DNA序列同源性分析,这两株乳酸菌分别被鉴定为Enterococcus mundtii及Lactobacillus plantarum。两株菌的抑菌活性物质在pH值范围及温度范围分别表现出广泛的耐受性,表明它们在苜蓿青贮中具有潜在的应用价值。     

Acaricidal activity of Palicourea marcgravii, a species from the Amazon forest, on cattle tick Rhipicephalus (Boophilus) microplus

Leaves of Palicourea marcgravii were extracted successively with hexane, ethyl acetate and ethanol in order to evaluate their acaricidal activity on larvae and adult stages of the cattle tick Rhipicephalus (Boophilus) microplus. The ethyl acetate extract showed the highest bioactivity of the tested extracts, which contained 0.12% monofluoroacetic acid. On engorged female, the ethyl acetate extract showed a lethal concentration 50% - LC(50)=30.08 mg ml(-1), inhibitory concentration 50% - IC(50)=5.79 mg ml(-1) and lethal time 50% - LT(50)=4.72 days; 100% reproduction was controlled at concentrations of 50 mg ml(-1) and on larvae the ethyl acetate extract showed a LC(50)=2.46 mg ml(-1). No alkaloids were detected in any of the extracts. This is the first report on the acaricidal activity of P. marcgravii extracts against R. microplus as well as the acaricidal properties of a plant species containing monofluoroacetic acid.     

Evaluation of different extracts and synthesised silver nanoparticles from leaves of Euphorbia prostrata against Haemaphysalis bispinosa and Hippobosca maculata

The present study was based on assessments of the antiparasitic activity to determine the efficacies of hexane, chloroform, ethyl acetate, acetone, methanol and aqueous leaf extracts of Euphorbia prostrata Ait. (Euphorbiaceae) and synthesised Ag nanoparticles (NPs) using aqueous leaf extract against the adult cattle tick Haemaphysalis bispinosa Neumann (Acarina: Ixodidae) and the haematophagous fly Hippobosca maculata Leach (Diptera: Hippoboscidae). Synthesised Ag NPs were characterised with ultraviolet-vis (UV-vis) spectrum, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) support the biosynthesis of Ag NPs. Parasites were exposed to varying concentrations of plant extracts and synthesised silver NPs for 24 h. All extracts showed the maximum toxic effect on parasites; however, the highest mortality was found in the hexane, chloroform, ethyl acetate, acetone, methanol and aqueous leaf extracts of E. prostrata and synthesised Ag NPs against the adult of H. bispinosa (LC(50)=45.24, 40.07, 21.91, 25.32, 19.30, 10.16 and 2.30 ppm; LC(90)=86.95, 88.66, 70.92, 83.22, 48.28, 70.27 and 8.28 ppm) and against H. maculata (LC(50)=39.37, 41.98, 19.92, 27. 93, 21.97, 9.79 and 2.55 ppm; LC(90)=89.44, 98.52, 76.59, 90.18, 55.07, 54.35 and 9.03 ppm), respectively. Mortality of 100% was found in synthesised Ag NPs at a concentration of 10 mg l(-1). UV-vis spectrograph of the colloidal solution of Ag NPs has been recorded as a function of time. The absorption spectrum of E. prostrata leaf extracts at different wavelengths ranging from 300 to 600 nm revealed a peak at 420 nm after 6 h. The FTIR spectra of Ag NPs exhibited prominent peaks at 3431; 1616; 1381; 1045; 818; 509; and 420 cm(-1). SEM analyses of the synthesised Ag NPs were rod shaped and measured 25-80 nm with an average size of 52.4 nm. The chemical composition of aqueous leaf extract was analysed by gas chromatography-mass spectrometry (GC-MS). The major chemical constituent was identified as 2-phenylethanol. These results suggest that the leaf methanol, aqueous extracts of E. prostrata and green synthesis of Ag NPs have the potential to be used as an ideal eco-friendly approach for the control of H. bispinosa and H. maculata. In addition, toxicity tests were conducted to analyse the toxicological effects of particle size on Daphnia magna and Ceriodaphnia dubia, and the animal model test was evaluated against Bos indicus for 24-h treatment. No toxicity on daphnids and no adverse effects were noted on animals after exposure to solvent extracts and synthesised Ag NPs.     

The efficacy of some wild medicinal plant extracts on the survival and development of third instar larvae of <Emphasis Type="Italic">Chrysomyia albiceps</Emphasis> (Wied) (Diptera: Calliphoridae)

Four crude wild plants extract of Artemisia herba-alba Asso, Artemisia monosperma Del., Euphorbia aegyptiaca Boiss. and Francoeuria crispa (Forsk.) extracted with four successive solvents; hexane, diethyl ether, ethyl acetate and ethanol were evaluated against the third instar larvae of Chrysomyia albiceps using dipping and thin film techniques. In dipping technique, larvae were immersed in the concentrations of plant extracts for 30 seconds. However, in thin film technique, larvae were exposed to thin layer from each plant extract in the Petri-dishes. Results showed that all extracts had toxic effects on larvae in both two treatments. Hexane and diethyl ether extracts of A. herba-alba and ethyl acetate extract of A. monosperma recorded the highest effect in both two treatments. Ethanol extracts of E. aegyptiaca and A. monosperma were the highest in dipping and thin film treatments, respectively. In dipping treatment, most plant extracts revealed extending effect on pupae especially while in thin film treatment most larvae which succeeded to develop to pupae produced normal flies. Deformed pupae were only recorded with the high concentration of diethyl extracts of A. herba-alba. Hexane, diethyl ether and ethyl acetate extracts of F. crespa only produced low percentages of deformed flies. Histological examination conducted on larvae confirmed that extracts in thin film treatment penetrated to the gut and destroyed its epithelial cells and wall. It concluded that the crude extracts of the four tested plants can be used in controlling of C. albiceps larvae while hexane extracts of E. aegyptiaca, A. herba-alba and A. monosperma are considered the most promising plant preparations against the larvae by using thin film technique.     

夏枯草提取物的抗氧化活性

对夏枯草（Prunella vulgaris）不同溶剂提取物体外抗氧化活性进行评价,为进一步开发利用夏枯草提供参考。采用70%乙醇超声波提取,然后用等体积的乙酸乙酯、正丁醇和水萃取,得到乙酸乙酯、正丁醇和水提取物,并以BHT为对照,研究不同溶剂提取物的抗氧化活性。结果表明,夏枯草提取物具有良好的抗氧化性。不同溶剂提取物及BHT清除DPPH·的能力高低次序为乙酸乙酯提取物＞正丁醇提取物＞BHT＞水提物,清除·OH的能力高低次序为BHT＞乙酸乙酯提取物＞正丁醇提取物＞水提物,清除O-2·的能力高低次序为乙酸乙酯提取物＞水提物＞BHT＞正丁醇提取物,还原力高低次序为BHT＞乙酸乙酯提取物＞正丁醇提取物＞水提物。夏枯草乙酸乙酯提取物具有较强的抗氧化活性。     

A simple thin-layer chromatographic method for the detection of ergovaline in leaf sheaths of tall fescue (Festuca arundinacea) infected with Neotyphodium coenophialum.

A relatively simple and inexpensive thin-layer chromatographic (TLC) method is described for the detection and semiquantitative measurement of ergovaline in leaf sheaths of tall fescue (Festuca arundinacea). Samples were finely ground and extracted with methanol. The extracts were filtered and the methanol was evaporated. The aqueous residue was extracted with hexane, followed by chloroform at pH 9. The chloroform extract was concentrated and further purified on a preparative silica gel TLC plate, developed with toluene/ethyl acetate/acetonitrile (50:10:40). The ergovaline band was scraped and eluted with methanol. The eluant was concentrated and an aliquot was applied to a silica gel TLC plate. The plate was developed successively with chloroform/acetone/acetic acid (90:10:5) and chloroform/ethanol (9:1). Ergovaline was visualized with p-dimethylaminobenzaldehyde and sulfuric acid. Semiquantitation of ergovaline was achieved by comparison with a known standard of ergotamine, which was shown to have the same Rf as ergovaline in this system. Spike recovery of ergotamine averaged 60%, with a limit of detection of 200 microg/kg of dry tall fescue leaf sheaths. The method was applied to 15 tall fescue samples with varying degrees of fungal infection, and ergovaline was identified in all contaminated samples with endophyte infection above 15%. Thin-layer chromatography may be also applicable for tall fescue seed, where the ergovaline content is usually higher and the amount of interfering pigments is much lower.     

The radioprotective effects of the hexane and ethyl acetate extracts of Callophyllis japonica in mice that undergo whole body irradiation

The radioprotective activity of extracts from the red seaweed Callophyllis (C.) japonica was investigated in mice that underwent whole-body exposure to gamma radiation. A methanol extract of C. japonica and its fractions [hexane, ethyl acetate (EtOAc), butanol and the remaining H₂O] were used. Each fraction (100 mg/kg body weight) was administered intraperitoneally (i.p.) 2 times into the BALB/c mice, once at 1 and once at 24 h before exposure to 9 Gray (Gy) of gamma radiation. Pre-irradiation administration of the hexane and EtOAc fractions saved the mice, with their survival rates being greater than 80% at 30 days post-irradiation; the mice that were pretreated with the other fractions showed survival rates lower than 20% over the same time period. To examine the effect of each C. japonica fraction on the survival of intestinal and bone marrow stem cells, the number of intestinal crypts and bone marrow cells in the gamma-irradiated mice were examined. Pre-treatment of mice (i.p., 100 mg/kg body weight at 1 and 24 h before irradiation) with the hexane or EtOAc fraction prior to 6-Gy irradiation significantly protected the number of jejunal crypts and bone marrow cells at 9 days after irradiation. These findings suggest that certain extracts from C. japonica, when they are administered prior to irradiation, play an important role in the survival of irradiated mice, and this is possibly due to the extracts protecting the hematopoietic cells and intestinal stem cells against gamma irradiation.     

Anthelmintic screening of fractions of Elephantorrhiza elephantina root extract against Haemonchus contortus

In the previous work conducted, it was found that the root extract of Elephantorrhiza elephantina (Bruch.) Skeels. exhibited good anthelmintic efficacy against eggs and larvae of Haemonchus contortus. This study was therefore undertaken to screen fractions of the extracts of E. elephantina for their anthelmintic activity against adult H. contortus using a bioactivity-guided assay. The adult worm bioassay was conducted using aqueous, hexane and ethyl acetate fractions of the plant extracts at concentrations of 0.312, 0.625, 1.25, 2.5, 5 and 10 mg/ml in vitro. Albendazole and distilled water were used as positive and negative control, respectively. In vitro treatment of adult worms revealed concentration and time-dependent efficacy of the fractions of E. elephantina. The aqueous and ethyl acetate fractions showed a highly significant (P < 0.05) motility inhibition at concentrations of 2.5 mg/ml and above after 6 h of exposure, while the hexane fraction showed a significant (P < 0.05) motility inhibition at concentrations of 5 mg/ml and above. After 30 h of exposure, all the fractions showed insignificant (P > 0.05) inhibition of motility. The fractions of E. elephantina also showed mortality indexes that were not significantly different to each other, as well as to the commercial drug (albendazole). Overall, the ethyl acetate and the aqueous fractions were found to possess the highest anthelmintic activity. We therefore recommend future studies to further investigate effective dosages of these fractions in vivo, as well as a full investigation into the compounds responsible for the biological activity.     

Anthelmintic activity of Jatropha curcas L. seeds on Haemonchus contortus

The aim of this study was to evaluate the anthelmintic activity of hexane (HE), ethyl acetate (EA) and ethanol (EE) extracts obtained from the seeds of Jatropha curcas using the egg hatch inhibition assay (EHA) and the artificial larval exsheathment inhibition assay (LEIA). For the egg hatch assay, HE, EA and EE were used in concentrations of 3.12, 6.25, 12.5, 25 and 50 mg ml(-1), accompanied by a negative control (5% Tween 80) and a positive control (0.025 g ml(-1) thiabendazole). In LEIA, the extracts were tested at a concentration of 1000 μg ml(-1), accompanied by a negative control (PBS). To evaluate the effect of tannins, the extract with the greatest effect was incubated with polyvinyl polypyrrolidone (PVPP). The EE (50 mg ml(-1)) inhibited 99.8% of egg hatching. After the addition of PVPP, the ovicidal effectiveness of EE was reduced to 91.9%. Using the HE and EA, inhibition of egg hatching was 15.3% and 32.2%, respectively. In the LEIA, 18.9% of L3 incubated with EE were exsheathed (p<0.01). The addition of PVPP to EE reversed the inhibitory effect on larval exsheathment. The percentage of exsheathment of L3 incubated with HE (99.6%) and EA (97.8%) did not differ from the control group (p>0.05). The results show that the effects of EE on eggs are not solely due to the tannins. However, these secondary metabolites are implicated in blocking the larval exsheathment.     

The antiviral activity of six South African plants traditionally used against infections in ethnoveterinary medicine

Viral infections remain a major threat to humans and animals and there is a crucial need for new antiviral agents especially with the development of resistant viruses. The hexane, dichloromethane, acetone and methanol extracts of six plant species selected for their traditional use against infections were tested for in vitro antiviral activity against canine distemper virus (CDV), canine parainfluenza virus-2 (CPIV-2), feline herpesvirus-1 (FHV-1) and lumpy skin disease virus (LSDV). All extracts were tested for their cytotoxicity using a colorimetric tetrazolium-based (MTT) assay and were tested for antiviral efficacy at concentrations below CC(50) values on the various cell types used in this study. The antiviral activity of extracts was tested using virucidal and attachment assays. In the virucidal assay, extracts were incubated with virus prior to infection. The most potent inhibition was observed with the acetone and methanol extracts of Podocarpus henkelii against CDV and LSDV, which inhibited replication of the viruses by >75% at 3μg/ml with selectivity index (SI) values ranging between 12 and 45. Excellent activity was also found with the hexane extracts of Plumbago zeylanica and Carissa edulis against CDV, with the extracts reducing viral-induced CPE by 50% and 75% respectively. The hexane extract of C. edulis had moderate activity against FHV-1 with EC(50)<70μg/ml and SI value <2. Only the acetone extract of P. henkelii moderately inhibited replication of LSD virus in the attachment assay, with low activity in other extracts. Of the four extracts with significant antiviral activity, two were prepared from P. henkelii. Therefore, future work will focus on isolating and characterizing the substance(s) responsible for bioactivity in extracts of this species.