大蒜化学成分的气-质联用分析

本文采用环己烷、乙酸乙酯和正丁醇对大蒜（Allium sativum L.）新鲜鳞茎的95%乙醇提取物进行萃取,并与水蒸气蒸馏法提取的挥发油成分进行比较,用GC-MS对其成分进行定性和定量分析.在环己烷萃取物中共检出112个成分,鉴定了38个化合物,占环己烷萃取物总量的80.08%;在乙酸乙酯萃取物中检出86个成分,鉴定了26个化合物,占乙酸乙酯萃取物总量的56.70%;在正丁醇萃取物中未检出挥发性成分.在水蒸气蒸馏法提取的挥发油中共检出109个成分,鉴定了29个化合物,占挥发油总量的83.58%.大蒜95%乙醇提取物的环己烷和乙酸乙酯萃取物及大蒜挥发油中皆以含硫化合物为主.在环己烷和乙酸乙酯萃取物中,阿霍烯的含量分别为生药的0.00395%和0.00145%,大蒜中阿霍烯含量达0.00540%.     

野葛花醇提物中异黄酮含量及其抗氧化活性测定

以葛花苷为标准品,对野葛花醇提物的氯仿、乙酸乙酯、正丁醇萃取物及水溶物4部分中的异黄酮含量进行测定,并采用DPPH·法对各萃取物进行自由基清除实验.结果显示,(1)氯仿、乙酸乙酯、正丁醇萃取物及水溶物4部分的异黄酮含量分别为35.27%、53.42%、52.13%和2.34%.(2)抗氧化实验显示, 4 部分清除DPPH·的IC50值分别为252、49、197和344 μg/mL.(3)相关性分析表明,野葛花醇提物各萃取部分的抗氧化活性主要来自于其中含有的异黄酮类化合物.研究表明野葛花醇提物的乙酸乙酯和正丁醇萃取部分异黄酮含量较高;氯仿、乙酸乙酯、正丁醇萃取物及水溶物4部分对DPPH自由基均有一定的清除作用,其中以乙酸乙酯萃取物的效果最佳;表明异黄酮是一种天然的抗氧化剂,具有较强的抗氧化作用.     

龙柏枝叶水浸提液及其萃取物除草活性的生物测定

采用培养皿滤纸法,以油菜(Brassica campestris L. )、反枝苋(Amaranthus retroflexus L. )、生菜(Lactuca sativa L. var. ramosa Hort. )、番茄(Lycopersicon esculentum Miller)和小麦(Triticum aestivum L. )为供试植物,对龙柏(Sabina chinensis 'Kaizuca')枝叶水浸提液的除草活性进行了生物测定,并以番茄为测定对象,对水浸提液的不同溶剂萃取物的除草活性也进行了生物测定;另外,采用薄层层析法对乙酸乙酯萃取物的除草活性成分进行了初步定性分析.结果显示,在0.05～0.2 g·mL-1质量浓度范围内,龙柏枝叶水浸提液对5种植物的种子萌发及幼苗根长和茎高均有一定的抑制作用,且随质量浓度的提高,抑制作用逐渐增强,其中0.2 g·mL-1水浸提液对5种植物的种子萌发及幼苗根长和茎高的抑制率均在80.00%以上, 对番茄种子萌发及幼苗根长和茎高的抑制率最高, 均达到100.00%.在龙柏枝叶水浸提液的石油醚、乙酸乙酯和水萃取物中,0.01、0.02和0.04 g·mL-1石油醚或乙酸乙酯萃取物以及0.02和0.04 g·mL-1水萃取物对番茄种子萌发及幼苗根长和茎高均有一定的抑制作用,且随质量浓度的降低,抑制率逐渐降低;其中,乙酸乙酯萃取物的抑制作用最强,水萃取物的抑制作用最低.薄层层析显色结果表明,龙柏枝叶水浸提液乙酸乙酯萃取物的主要除草活性成分为酚类成分.     

发酵液中多拉菌素的提取和萃取条件研究

采用单因素实验,分别研究提取试剂、发酵液放置时间、pH值和温度对发酵液中多拉菌素提取效果的影响;然后以乙酸乙酯为萃取试剂,研究萃取次数及萃取体积对多拉菌素萃取效果的影响。结果显示,甲醇为最佳提取试剂;发酵液在pH为3～11、温度为20～80℃的条件下放置144 h,多拉菌素均能稳定存在,提取得到的多拉菌素的质量浓度没有显著变化;浓缩提取液液经2倍体积乙酸乙酯萃取2次即可。该条件下多拉菌素的质量浓度和萃取率分别为151.78μg/mL和98.00%。     

苦瓜叶提取物对美洲斑潜蝇取食和产卵行为的抑制作用

美洲斑潜蝇是危害蔬菜、观赏植物的重大害虫之一.苦瓜叶乙醇提取物(浓度为2000～4000 μg·ml^-1)对美洲斑潜蝇成虫的取食和产卵都具有较强的抑制作用.用环己烷、乙酸乙酯、正丁醇和水依次对乙醇提取物进行萃取,并测试了4种萃取物对美洲斑潜蝇成虫取食和产卵的抑制作用.结果表明: 环己烷、乙酸乙酯、正丁醇和水萃取物在浓度为1000 μg·ml^-1时,处理后2 d对美洲斑潜蝇成虫的拒食率分别是11.08%、34.89%、22.99%和 0,产卵抑制率分别是0、30.91%、6.45%和 0.其中,乙酸乙酯萃取物的活性最强,当其浓度为4000 μg·ml^-1时,处理后2 d对美洲斑潜蝇成虫的拒食率和产卵忌避率分别为70.95％ 和69.49％.乙酸乙酯萃取物经硅胶柱层析分离得到(19S,23E)-5β,19-环氧-19-甲氧葫芦素-6,23-二烯-3β,25-二醇 (化合物1)、(19R,23E)-5β,19-环氧-19-甲氧葫芦素-6,23-二烯-3β,25-二醇(化合物2) 和3β,7β,25-三羟基葫芦素-5,23-二烯-19-醛缩-3-O-β-D-吡喃葡糖苷（化合物3）,3种化合物在供试的浓度（100～400 μg·ml^-1）条件下对美洲斑潜蝇的取食和产卵行为都有明显的抑制作用.在400μg·ml^-1浓度时,化合物1、化合物2和化合物3对美洲斑潜蝇成虫的拒食率分别是66.89%、53.53%和78.02%,产卵抑制率分别是76.32%、58.36%和78.36%.     

山芝麻提取物对10种植物病原真菌的抑菌活性初探

该文采用菌丝生长速率法,研究了山芝麻根、茎和叶不同溶剂萃取物在1.5 mg·mL~(-1)浓度下对10种植物病原真菌菌丝生长的抑制活性,用孢子萌发法测试了山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病菌分生孢子萌发的抑制作用,用离体法测试了山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病的防治效果,并通过气相与质谱联用技术(Gas Chromatography-Mass Spectrometer,GC-MS)分析了山芝麻根石油醚相和乙酸乙酯相萃取物的主要成分,测试了其中8种主要化合物对香蕉炭疽病菌菌丝生长的抑制活性。结果表明:山芝麻各部分萃取相对10种植物病原真菌菌丝生长均具有不同程度的抑制作用。其中:在1.5 mg·mL~(-1)浓度下,山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病菌菌丝生长的抑制率分别为87.00%和86.14%,其EC50分别为0.062 mg·mL~(-1)和0.052 mg·mL~(-1);浓度在2、4、8 mg·mL~(-1)时,山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病菌分生孢子萌发相对抑制率均在70%以上;在10 mg·mL~(-1)浓度下,山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病的防治效果分别为72.32%和59.77%。通过气相与质谱联用技术对山芝麻根石油醚相和乙酸乙酯相萃取物进行了分析,在山芝麻根石油醚相萃取物中共鉴定出36种主要化学成分,在山芝麻根乙酸乙酯相萃取物中共鉴定出17种主要化学成分。对选取的8种主要化合物,在100μg·mL~(-1)浓度下,邻苯二甲酸二异丁酯和邻苯二甲酸二丁酯对香蕉炭疽病菌菌丝生长显现出较高的抑制活性,抑制率分别为65.12%和68.07%,EC_(50)分别为56.66μg·mL~(-1)和37.04μg·mL~(-1)。     

苦瓜叶萃取物对亚洲玉米螟代谢酶活性的影响

苦瓜叶乙酸乙酯萃取物对多种害虫有明显的拒食、抑制生长发育和毒杀作用。为了进一步探讨其作用机制,测定了苦瓜叶乙酸乙酯萃取物对亚洲玉米螟幼虫Ostrinia furnacalis (Guenée)海藻糖酶、碱性磷酸酯酶、酸性磷酸酯酶、羧酸酯酶和谷胱甘肽-S-转移酶等代谢酶活性的影响。结果表明：苦瓜叶乙酸乙酯萃取物对亚洲玉米螟幼虫海藻糖酶、碱性磷酸酯酶和酸性磷酸酯酶活性均有明显的抑制作用,24 h-72 h,02%萃取物处理的海藻糖酶和碱性磷酸酯酶平均相对活力分别比对照减少了323%和341%;48 h和72 h,酸性磷酸酯酶相对活力分别比对照减少了568 %和380 %;005-02%萃取物处理酸性磷酸酯酶活性也明显被抑制。对羧酸酯酶活性的影响则表现为先抑制后诱导再恢复的趋势。对谷胱甘肽-S-转移酶活性表现出明显的诱导作用。结果提示苦瓜叶乙酸乙酯萃取物对亚洲玉米螟幼虫海藻糖酶、碱性磷酸酯酶和酸性磷酸酯酶等代谢酶的抑制作用可能是其抑制昆虫生长发育的主要作用机制之一。     

瑞香狼毒提取物对试验动物急性毒性及活性的初步研究

采用急性经口、眼刺激、皮肤试验方法,研究了瑞香狼毒乙酸乙酯萃取物的急性毒性作用,同时以番茄晚疫病菌为供试菌,研究了瑞香狼毒提取物的抑菌活性.初步研究表明,瑞香狼毒乙酸乙酯萃取物对小白鼠经口急性毒性为低毒,对白兔的急性皮肤刺激属无刺激性,对白兔的眼刺激属轻度刺激性,对鲫鱼的毒性属于中毒级;瑞香狼毒乙酸乙酯萃取物及其分段物流分B、c、D对番茄晚疫病菌有较好的抑制活性,这为瑞香狼毒乙酸乙酯萃取物进一步开发为产品提供了毒理学依据.     

茶蜂花粉抗氧化活性与成分

本实验研究了茶蜂花粉的抗氧化活性和功效成分。茶蜂花粉85%乙醇回流提取,经过石油醚、乙酸乙酯、正丁醇依次萃取,得到石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物以及萃余物4个部分,用D-半乳糖诱导衰老小鼠模型检测茶蜂花粉不同组分的抗氧化活性,采用多种色谱方法分离具有抗氧化活性的成分,利用核磁共振方法鉴定各单体的化学结构。结果表明:茶蜂花粉乙醇提取物、乙酸乙酯萃取物具有明显的抗氧化作用,乙酸乙酯萃取物经MCI柱层析,得到30%、50%、70%三个乙醇洗脱组分,其中30%乙醇洗脱组分具有显著抗氧化活性,从该洗脱部分得到三个单体化合物,经鉴定为:槲皮素、山奈素-3-O-芸香糖苷、山奈酚-3-O-(2″,3″,4″-O-三对羟基桂皮酰基)-β-D-吡喃葡萄糖苷,推测茶蜂花粉具有抗氧化活性的成分主要为黄酮类化合物。     

香椿嫩芽和老叶萃取物抗菌活性的比较研究

采用琼脂扩散法对香椿嫩芽和老叶萃取物的氯仿、乙酸乙酯和正丁醇萃取部分的抗菌活性进行了研究.嫩芽萃取物的抗菌活性明显高于老叶萃取物,其中嫩芽萃取物的乙酸乙酯部分表现出最强的抗菌活性,其最小抑菌浓度(MIC)为1.3 mg/mL.实验结果表明,香椿叶中的抑菌物质随着生长时间的延长而逐渐降低.     

Biotechnological approaches to enhance the biosynthesis of ginkgolides and bilobalide in Ginkgo biloba

Ginkgo biloba is one of the oldest living tree species and its extracts or powdered leaves are one of the best selling herbal preparations. The main bioactive constituents are flavonoids and the terpene trilactones, ginkgolides and bilobalide, which are responsible for their pharmacological activity. However, there are many difficulties for ginkgo leaves supply and the chemical synthesis is far from of being applicable for commercial-scale production. G. biloba cell cultures have arisen as a useful alternative source of pharmacologically active terpene trilactones. This review sheds light on the chemistry and biosynthesis of terpene trilactones with the aim of increasing the production of these high value compounds by biotechnological approaches. Different biotechnological strategies to improve ginkgolides and bilobalide production will be discussed, including screening and selection of in vitro ginkgo cultures, cell differentiation levels of these cultures, optimization of culture conditions, feeding and elicitation strategies. Special attention will be paid in developing new methodologies to enhance ginkgo cell biomass and provide high amounts of these bioactive terpene trilactones using large-scale cell cultures.     

黄杜鹃提取物对亚洲玉米螟生物活性的研究

本文报道了闹羊花素 - ( Rhodojaponin- ,简称 R- )和黄杜鹃花乙酸乙酯 ( Et OAc)提取物对亚洲玉米螟 Ostrenia furnacalis Guenée3龄幼虫的拒食、生长抑制和毒杀作用。以饲料柱法测定 R- 和 Et OAc提取物的非选择性拒食作用 AFC50 为 77.0 2和 384 .30 mg/ kg,而以虫重法表示时 ,则分别为15.60和 2 55.4 4 mg/ kg。以 R- 2 0 0 mg/ kg连续饲喂 4天后 ,换为无毒饲料至 15天 ,试虫死亡率为86.67% ,L T50 为 2 .99天 ;以 Et OAc提取物 2 0 0 0 mg/ kg处理时 ,同期的死亡率 66.67% ,LT50 为 3.85天。R- 和 Et OAc提取物的生长抑制中浓度 IC50 分别为 9.30和 39.64mg/ kg。文中还讨论了亚洲玉米螟拒食作用的测定方法和 R- “取食后效应”等作用特点     

Gypsy moth (Lymantria dispar) larval development and survival to pupation on diet plus extractables from green ash foliage

Gypsy moth, Lymantria dispar L., rate of larval development, molting, pupal weight and survival were studied on an artificial diet containing different concentrations of green ash ethyl acetate extractables (EtOAc Exts). Insects were reared on experimental diets from egg to pupa. Addition of EtOAc Exts to artificial diet significantly prolonged larval development and reduced their survival compared to larvae reared on control diet. Weights of pupae were significantly reduced when larvae were reared on diet containing the lowest dosage of EtOAc Exts (i.e., 0.01%) versus on control diet. EtOAc Exts in diet (e.g., 0.01, 0.06 and 0.2%) frequently caused incomplete ecdysis which invariably resulted in larval death. Impaired feeding, locomotion and excretion are likely causes of death. The combination of these results with our earlier findings of repellents and feeding deterrents against gypsy moth larvae (GML) in green ash foliage shows that the non-host status of green ash to the highly polyphagous GML involves three orders of chemical defense: repellents, feeding deterrents and inhibitors of nutritional and developmental physiology. As the insect becomes sequentially exposed to these orders of defense, it incurs higher costs because the adverse effects become less reversible.     

金针菇子实体有机溶剂提取物的生物活性

分别对金针菇子实体醇提物的5个萃取分部（石油醚、氯仿、乙酸乙酯、正丁醇分部和剩余分部）进行化学成分的定性检验,以及体外抗肿瘤活性和降血糖活性的筛选。定性检验结果表明,金针菇子实体的石油醚、氯仿和乙酸乙酯萃取分部中含有生物碱类、有机酸类、甾类（或三萜）、黄酮类和蒽醌类物质,正丁醇萃取分部中含有氨基酸和蛋白类、糖类、甾类（或三萜）、有机酸类和黄酮类物质,剩余分部中含有氨基酸和蛋白类、糖类、甾类（或三萜）化合物。通过药理筛选发现,金针菇子实体的石油醚、正丁醇以及剩余分部具有体外抗肿瘤作用的潜力,而氯仿和乙酸乙酯分部则具有一定的细胞毒性;各萃取分部对DPP-IV活性均具有一定的抑制作用,其中氯仿和乙酸乙酯分部的抑制作用较强。     

Influence of the traditional Brazilian drink Ilex paraguariensis tea on glucose homeostasis

In this study we examined the acute in vivo effect and short- and long-term in vitro effects of samples from native and commercial Ilex paraguariensis on glucose homeostasis. Also, the potential effect of I. paraguariensis on serum insulin secretion was investigated. The chemical identification and quantification of methyl xanthines and polyphenols in CH(2)Cl(2), EtOAc and n-BuOH fractions of native I. paraguariensis as well as infusions of green and roasted I. paraguariensis from a commercial source was verified by high-performance liquid chromatography. The results for the serum glucose-lowering indicated that both fractions and both infusions were able to improve significantly the oral glucose tolerance curve. Additionally, both the EtOAc and n-BuOH fractions induced-insulin secretion, but EtOAc induced an early (at 15min) and late (at 60min) biphasic peak of insulin secretion similar to glipizide stimulatory effect. Both fractions increased liver glycogen content compared with fasted normal rats. Also, EtOAc and n-BuOH fractions inhibited in vitro disaccharidases activities after an acute treatment. The maximum inhibitory effect of the EtOAc and n-BuOH fractions on maltase activity (at 5min) was around 35%. The evident reduction of protein glycation by glucose or fructose with EtOAc and n-BuOH fractions increased from 7 to 28 days of in vitro incubation. Inhibition of bovine serum albumin glycation by glucose and fructose, by around 50% and 90%, respectively, was observed. Additionally, the green and roasted mate infusions reduced the formation of AGEs in a characteristic long-term effect. In conclusion, this study shows that I. paraguariensis has an anti-hyperglycemic potential role able to improve the diabetic status and is probably a source of multiple hypoglycemic compounds.     

Inhibitory effects of ethyl acetate extract of Cordyceps sinensis mycelium on various cancer cells in culture and B16 melanoma in C57BL/6 mice

The cultivated mycelium of a Cordyceps sinensis (Cs) fungus was sequentially extracted by petroleum ether (PE), ethyl acetate (EtOAc), ethanol (EtOH) and hot water. All solvent extracts except hot water extract showed a significant and dose-dependent inhibitory effect on the proliferation of four cancer cell lines, MCF-7 breast cancer, B16 mouse melanoma, HL-60 human premyelocytic leukemia and HepG2 human hepatocellular carcinoma, with IC(50) values below 132 microg/ml. The EtOAc extract, in particular, had the most potent effect against all four cancer cell lines, with IC(50) between 12 microg/ml (on B16) and 45 microg/ml (on MCF-7). In contrast, it had much lower cytotoxicity against normal mouse bone marrow cells. The EtOAc extract contained carbohydrates, adenosine, ergosterol and trace amount of cordycepin, of which ergosterol and related compounds were identified as a major class of active constituents contributing to the in vitro cytotoxicity. In an animal test, the EtOAc extract showed significant inhibiting effect on B16-induced melanoma in C57BL/6 mice, causing about 60% decrease of tumor size over 27 days. Our results suggest that the EtOAc extract of Cs fungal mycelium has strong anti-tumor activity and is a potential source of natural anti-tumor products.     

Liquid chromatography-atmospheric pressure chemical ionisation/mass spectrometry: a rapid and selective method for the quantitative determination of ginkgolides and bilobalide in ginkgo leaf extracts and phytopharmaceuticals

In order to evaluate the composition of active constituents in phytopharmaceutical preparations, valid analytical methods are required. For the determination of the active terpene constituents of Ginkgo biloba (the ginkgolides and bilobalide), a liquid chromatography-mass spectrometry (LC-MS) method has been developed using atmospheric pressure chemical ionisation (APCI) in the negative ion mode. This detection mode was found to be much more sensitive and selective compared to UV; indeed the ginkgo terpene trilactones lack strong UV chromophores and flavonoids interfere with their UV detection. LC-APCI/MS detection allowed a considerable reduction in analysis time when compared to LC-UV, because LC resolution was only needed between the pair of isomers ginkgolide B and ginkgolide J. All compounds were selectively detected by single ion monitoring of their specific deprotonated molecules [M-H]-. The samples were directly injected without pre-purification, and a fast gradient was applied, reducing the total time of analysis to 14 min. With this method, the ginkgo terpene trilactones were detected on-line in the picogram range. Several commercial ginkgo preparations on the Swiss market were analysed, and the ginkgolide and bilobalide contents were evaluated using the method described.     

Laboratory and field evaluations of extracts from Rhododendron molle flowers as insect growth regulator to imported cabbage worm, Pieris rapae L. (Lepidoptera:Pieridae)

The insect growth regulating properties of rhodojaponin-III (Abbr. R-III) and ethyl acetate (EtOAc) extract from Rhododendron molle G. Don flowers against imported cabbage worm, Pieris rapae L., were determined under laboratory and field conditions. The values of IC₅₀ (the median of concentration for inhibiting weight increase) for R-III and EtOAc extract were 6.78 p.p.m. and 70.29 p.p.m. against 3rd instar larvae and 13.72 p.p.m. and 346.00 p.p.m. against 5th instar larvae, respectively. R-III and EtOAc extract also could reduce pupating rate, pupal weight, emergence rate and extend the duration of development. Thus development of insects was inhibited significantly and development index decreased. R-III would be superior to toosendanin as insect growth regulator. EtOAc extract 1000 p.p.m. mixture with molosultap 500 p.p.m. could achieve an effective control rate of 87.34% against P. rapae in field trials when adjusted cumulative insect-days were used as index.     

Insect growth regulator and insecticidal activity of beta-dihydroagarofurans from Maytenus spp. (Celastraceae)

From the aerial parts of Maytenus disticha, we have isolated 9beta-benzoyloxy-1alpha,2alpha,6beta,8alpha,15penta-acetoxy-dihydro-beta-agarofuran (1) and from seeds of Maytenus boaria 9beta-furoyloxy-1alpha,6beta,8alpha-triacetoxy-dihydro-beta-agarofuran (2). These compounds and their MeOH and hexane/ethyl acetate (1:1 v/v) extracts were evaluated for their effects on the fall armyworm (Spodoptera frugiperda). Toosendanin, a commercial insecticide derived from Melia azedarach was used as a positive control. When tested for activity using neonate larvae in a nochoice artificial diet bioassays, the agarofurans 1, 2 and toosendanin as well as the MeOH and hexane/EtOAc extracts caused significant growth inhibitory effects with GC50 of 7.55; 3.84; 1.75; 14.0 and 7.3 ppm at 7 days, respectively. Compounds 1 and 2 caused 100% larval mortality at 25 and 15 ppm, respectively. MeOH and hexane/EtOAc extracts caused 100% larval mortality at 25.0 ppm, respectively, they also increased the development time of surviving larvae and a significant delay for the time of pupation and adult emergence. These compounds showed comparable potency of activity with toosendanin. Acute toxicity against adults of S. frugiperda was also found, for hexane/EtOAc extract and 2 had the most potent activity with LD50 value of 4.7 and 1.9 ppm, respectively. MeOH extract, hexane/EtOAc extract, 1 and 2 caused acetylcholinesterase inhibition with 78.0, 89.2, 79.3 and 100% inhibition at 15.0 ppm, respectively. Therefore, the furoyloxy agarofuran may be responsible for the insecticidal activity of these plants.