光皮树籽抽出物的成分分析

为了分析光皮树籽抽提物的化学成分,采用无水乙醇、丙酮、正己烷、石油醚和乙酸乙酯分别抽提光皮树籽,抽出物经活性炭脱色后进行GC-MS 分析。结果发现,无水乙醇和丙酮抽出物中主要含有游离的棕榈酸、油酸和亚油酸,其中亚油酸相对含量最高,达到52% 以上,油酸相对含量最低,不超过8.2%。正己烷、石油醚和乙酸乙酯抽出物中甘三酯的脂肪酸组成主要是棕榈酸、硬脂酸、油酸和亚油酸,其中油酸相对含量最高,达到42% 以上,其次是亚油酸,总不饱和脂肪酸相对含量超过70%。抽出物中未发现三不饱和脂肪酸。     

一些植物提取物对烟草甲虫生物活性的影响

测定了不同浓度的植物提取物在244、8和72 h后对烟草甲成虫的触杀毒力和驱避毒力。初步研究结果表明,筛选出的巴豆乙醇提取物、巴豆丙酮提取物、巴豆乙酸乙酯提取物、巴豆石油醚提取物、草乌丙酮提取物、草乌乙酸乙酯提取物、草乌石油醚提取物、驱虫草乙醇提取物、驱虫草丙酮提取物、川乌石油醚提取物、百部乙醇提取物、百部丙酮提取物、百部乙酸乙酯提取物、百部石油醚提取物、茵陈蒿乙醇提取物、茵陈蒿丙酮提取物等对烟草甲成虫有较好的触杀毒力;巴豆乙酸乙酯提取物、巴豆石油醚提取物、天南星科植物乙酸乙酯提取物、天南星科植物石油醚提取物、百部乙酸乙酯提取物、高良姜石油醚提取物、山鸡椒乙醇提取物、山鸡椒石油醚提取物等对烟草甲成虫有较好的驱避毒力。     

Antioxidant activity of extracts from Gevuina avellana and Rosa rubiginosa defatted seeds

Chilean hazelnuts (Gevuina avellana Mol) and mosqueta rose (Rosa aff. Rubiginosa L.) meals were extracted with methanol, ethanol, acidified water, acetone, butanol, diethyl ether and ethyl acetate. Ethanol and methanol extracted the highest amount of soluble substances from both seed meals. The highest concentration of total polyphenols was found in the ethanolic extracts, although that of acetone from R. rubiginosa presented similar values. The antioxidant activity of the extracts evaluated by the β-carotene assay and with as hydrogen radical scavenging ability showed that the activity of the butanol and methanol extracts from G. avellana was comparable to those of synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The 2,2,-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging activity of the G. avellana methanol, ethanol and water extracts was 2–3 times lower than those of BHT and BHA, respectively. The activity of R. rubiginosa extracts ranged from that of BHT for the water extracts to 80% inhibition in respect to control achieved with the ethanol extracts.     

红檵木叶抑菌活性物提取分离研究

用不同浓度乙醇作提取溶剂,采用正交试验,通过抑菌实验得到红檵木叶抑菌活性物质最佳提取条件为:60%乙醇、45℃、3h。提取物对金黄色葡萄球菌的最小抑菌浓度为12.5mg/ml,对痢疾杆菌为50mg/ml,对大肠杆菌为25mg/ml。提取液抑菌活性具热稳定性,但在碱性条件下不稳定。溶剂萃取以乙酸乙酯萃取物抑菌活性最强,硅胶柱层析和薄层层析进一步分离,得到三个抑菌活性较强的组分,化学反应和UV检测表明其属可水解鞣质类。     

In vivo and in vitro digestible fractions in forage

Faeces and the residues from the in vitro digestion of 13 forages were sequentially extracted with acid-pepsin, ethyl alcohol, hot water and diethyl ether and the quantity of the extracts was adjusted to a protein-free basis and expressed per 100 g of original forage organic matter. Undigested material inin vivo and in vitro experiments were respectively, 3·37 and 1·88 g (±0·12) for ethyl alcohol extracts, 1·13 and 1·10 g (±0·05) for hot water extracts, 0·15 and 0·12 g(±0·02) for diethyl ether extracts and 1·44 (±0·22) and 0g for 0·1 N -HCI extracts. The difference between values for in vivo and in vitro experiments was considered to represent endogenous material present in faeces.     

土荆芥提取物对谷蠹和赤拟谷盗的触杀与熏蒸活性研究

采用超声波辅助冷浸提取法以4种不同极性的溶剂(100％乙醇、丙酮、乙酸乙酯和石油醚)对土荆芥活性成分进行粗提,测试粗提物对谷蠹和赤拟谷盗的触杀与熏蒸活性.结果表明:土荆芥4种溶剂提取物对谷蠹具有明显的触杀活性,在0.468 mg/cm2剂量处理3d后致试虫校正死亡率达81.67％～ 100％;丙酮和100％乙醇提取物具有显著的熏蒸活性,丙酮提取物在0.36～0.52 g/mL处理3d后均致试虫全部死亡,100％乙醇提取物在0.52 g/mL处理下致试虫校正死亡率高达94.64％.土荆芥乙醇、丙酮和石油醚提取物对赤拟谷盗具有明显的触杀活性,在1.144 mg/cm2剂量处理3d后致试虫高达91.67％～ 100％的死亡,但4种溶剂提取物的熏蒸活性不明显.     

Extractive components responsible for the discoloration of Ilomba wood (Pycnanthus angolensis Exell)

The wood of Ilomba (Pycnanthus angolensis Exell) may seriously discolor in the log after felling and also in lumber during drying. The discoloration is associated with the occurrence of bacterial metabolites. The components responsible for the discoloration were extracted completely from the wood before discoloration with hot methanol and separating into petroleum ether, diethyl ether, ethyl acetate and water soluble and insoluble fractions. Bioassays using nutrient liquids inoculated with Pseudomonas fragi revealed that the diethyl ether soluble fraction discolored most. Chemical characterization of the individual components indicated that three different types of components could be involved which are the (?)-epicatechin and (+)-catechin, the intensely red compound and the water soluble component of the methanol extracts. Their contributions to the discoloration are discussed on the basis of their colorimetric characteristics and amounts present in the wood.     

Drying ability of anhydrous sodium sulfate on wet organic solvents after liquid-liquid partition

Water concentration in organic solvents after liquid-liquid partition was determined by the Karl Fischer titration method. n-Hexane and petroleum ether showed quite low levels of water, such as 0.1 mg/mL. The water concentration in wet ethyl acetate was about 20-30 mg/mL and that in diethyl ether was about 8-10 mg/mL. Anhydrous sodium sulfate absorbed about 20-25% of the water after vigorous mixing with wet ethyl acetate or diethyl ether. Wet acetonitrile extract from wet food, which contained about 60 mg/mL water after salting out with sodium chloride, was not dried at all with anhyfrous sodium sulfate treatment. Spiking n-hexane into wet ethyl acetate or wet diethyl ether was effective to exclude water. Spiking toluene into salted acetonitrile drove out water and dissolved sodium chloride. It can be concluded that the drying ability of anhydrous sodium sulfate towards wet organic solvents is poor, but it is effective in removing suspended water in solvents.     

Phenolic compounds and antioxidant activity of Brazil nut (Bertholletia excelsa)

Brazil nuts were shelled and separated as kernel and brown skin; whole nuts were also used. Soluble phenolics from each portion as well as the whole nut were extracted using 70% acetone under reflux conditions. Insoluble-bound phenolics were subsequently extracted into diethyl ether–ethyl acetate mixture (1:1, v/v) after alkaline hydrolysis. Both soluble and insoluble-bound phenolic extracts were separately examined for their total phenolics content; antioxidant activities were evaluated by trolox equivalent antioxidant capacity (TEAC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical scavenging activities using electron paramagnetic resonance (EPR), reducing power, and oxygen radical scavenging capacity (ORAC). Soluble phenolics in brown skin was 1236.07 as compared to 406.83 in kernel and 519.11 mg/100 g in whole nut. Bound phenolics content of brown skin was also 86- and 19-folds higher than kernel and whole nut, respectively. Similarly extracts from the brown skin exhibited the highest antioxidant activity. Free- and bound phenolics were identified and quantified; these included nine phenolic acids and flavonoids and their derivatives (gallic acid, gallocatechin. protocatechuic acid, catechin, vanillic acid, taxifolin, myricetin, ellagic acid, and quercetin). However, some phenolics were present only in the bound form. Furthermore, the phenolics were dominant in the brown skin.     

Citrus peel extract – A natural source of antioxidant

Citrus peel extract as a natural source of antioxidant was evaluated during 6 months storage of refined corn oil at 25 and 45 °C. Extracts of citrus peel were prepared by refluxing the dried ground peel with ethanol, methanol, acetone, hexane, diethyl ether and dichloromethane. Maximum amount of citrus peel extract was obtained with methanol. Antioxidant activity of methanolic extract was assessed by measuring free fatty acid (FFA) content peroxide value (POV) and iodine value (IV) during 6 months storage of refined corn oil at 25 and 45 °C. After 6 months of storage at 45 °C, corn oil containing 1600 and 2000 ppm citrus peel extract, showed lower FFA contents (1.5% and 1.0%), and POVs (8.38 and 7.0 meq kg⁻¹) and higher iodine values (81, 89) than the control sample (FFA 17.0% POV 101 meq kg⁻¹ IV 47). Refined corn oil containing 200 ppm of butylated hydroxy anisole (BHA) and butylated hydroxy toluene (BHT) showed FFA contents of 2.0% and 1.8%, POVs 17.0 and 12.7 meq kg⁻¹ and IVs 84 and 87, respectively, after 6 months of storage at 45 °C. These results show that methanolic extract of citrus exhibited very strong antioxidant activity, which was almost equal to synthetic antioxidants (BHA and BHA). Therefore, the use of citrus peel extract is recommended as a natural antioxidant to suppress development of rancidity in oils and fats.     

桔梗根提取物不同溶剂萃取物的抗氧化活性

该试验对桔梗根提取物用不同溶剂进行萃取,并对不同溶剂萃取物中总多酚、总黄酮的含量和抗氧化活性进行比较分析。选取石油醚、正丁醇、乙酸乙酯和正己烷对桔梗根提取物水溶液进行液-液萃取,得到样品不同溶剂萃取物。测定不同溶剂萃取物总多酚、总黄酮的含量及其抗氧化活性。桔梗根提取物正丁醇萃取物中总多酚含量最高,石油醚萃取物中总黄酮含量最高。各溶剂萃取物表现出不同程度的抗氧化活性,并呈现剂量依赖性,顺序均为:正丁醇>石油醚>乙酸乙酯>正己烷。正丁醇和石油醚萃取物可被用于总多酚和总黄酮的分离纯化;综合考虑抗氧化活性,正丁醇萃取物可被用来作为天然抗氧化剂应用于食品和药品领域。     

大蒜挥发油对米象成虫的控制作用

采用索氏提取法,分别以乙醚、正已烷作为有机溶剂提取大蒜挥发油,详细研究了其对米象成虫的控制作用。结果表明:两种有机溶剂提取的大蒜挥发油对米象成虫均具有较强的驱避、触杀、抑制和熏蒸作用,尤其是乙醚提取的大蒜挥发油的驱避作用和熏蒸作用效果最为明显。     

Metabolites of Eurotium Species, Their Antioxidative Properties and Synergism with Tocopherol

Natural antioxidants and synergists for tocopherol (Toc) have been isolated as acetone or ethyl acetate extracts from mycelial mats or culture broth of Eurotium species. The acetone extract, eluted stepwise with benzene and ethyl acetate by silica gel column chromatography, gave fractions that were synergistic with Toe. However, the benzene fraction appeared better because it was highly soluble in oil and did not change the color and taste of the oil. The metabolites in the benzene fraction differed in the various Eurotium species in their composition in respect to known metabolites with antioxidative activity.     

不同产地腌渍萝卜化学成分分析及抑菌活性比较

利用高效液相色谱（HPLC）法分析不同产地腌渍萝卜的化学成分,使用牛津杯法对腌渍萝卜提取物进行了抑菌实验,并采用 噻唑蓝（MTT）比色法检测提取物对人正常肝细胞（LO2）和肝脏肿瘤细胞（HepG2）增殖的抑制作用。 结果表明,甲醇、乙醇、乙醚、丙 酮及乙酸乙酯提取物中分别有5种、6种、12种、11种、12种抑菌活性成分,其中乙酸乙酯提取物的抑菌活性最强。 30种提取物中,6个对 酿酒酵母（Saccharomyces cerevisiae）有抑制效果（抑菌圈直径9.11～12.76 mm）;16个对大肠杆菌（Escherichia coli）有抑制效果（抑菌 圈直径10.84～31.92 mm）;24个对金黄色葡萄球菌（Staphylococcus aureus）有抑制效果（抑菌圈直径11.11～32.23 mm）。 在提取物的质 量浓度为50 μg/mL的条件下,22种提取物对LO2细胞无毒,对HepG2细胞的抑制率在22.60%～63.63%,表明腌渍萝卜提取物中可能 存在抗癌活性成分。     

啤酒花活性成分与抗氧化活性的相关性

以3 个品种的萨斯特啤酒花为原料,比较了其石油醚、氯仿、乙酸乙酯、正丁醇和水相等不同极性溶剂提取物中α-酸、β-酸、总黄酮和总多酚的含量,采用?OH、1,1-二苯基-2-三硝基苯肼自由基、β-胡萝卜素-亚油酸3 种不同的抗氧化活性评价体系对各极性溶剂提取物的抗氧化活性进行了研究,并与其活性成分的含量进行了相关性分析。结果表明,啤酒花各极性部位均具有不同程度的抗氧化活性。α-酸、β-酸在石油醚相中含量较高,在3 个啤酒花样品中的含量范围分别为α-酸444.29～583.81 mg/g、β-酸131.83～293.19 mg/g,在氯仿相中含量相对较低,其余提取物中均未检出;相关性研究表明α-酸、β-酸是石油醚和氯仿相抗氧化活性的主要物质基础。中等极性和极性较大溶剂提取物中啤酒花总黄酮、总多酚含量较高,相关性研究也表明黄酮、多酚类物质是这类提取物抗氧化活性的主要物质基础;其中,3 个啤酒花样品中总黄酮、总多酚在乙酸乙酯相中含量最高,分别为20.43～24.13 mg/g和34.97～40.24 mg/g,正丁醇次之,分别为9.45～11.68 mg/g和12.12～19.14 mg/g。     

同时蒸馏萃取-气质联用分析养殖暗纹东方鲀肉中的挥发性成分

分别以二氯甲烷和乙醚作溶剂,同时蒸馏萃取(SDE)养殖暗纹东方鲀肉中的挥发性成分,结合气质联用(GC-MS)对挥发性成分进行定性,以2,4,6-三甲基吡啶内标定量分析,并结合主成分分析法(PCA)对挥发性成分进行数据挖掘。结果表明:乙醚为溶剂时,总共鉴定到了57种成分,含量较高的是十四醛(4 963.71ng/g)、十八醛(1 171.51ng/g)、(Z)-13-十八醛(2 007.21ng/g)、乙酸乙酯(1 148.44ng/g)、十六酸(4 639.90ng/g)等;以二氯甲烷为溶剂时,总共鉴定到了78种成分,主要是十六醛(2 381.77ng/g)、2,3-丁二酮(1 267.40ng/g)、十六酸(545.08ng/g)等。比较得出,二氯甲烷溶剂在定性方面有优势,乙醚溶剂在定量方面效果较好。2种溶剂萃取一共检测出96种化合物,其中醛类29种、酮类11种、醇类16种、含氮含硫及杂环类化合物22种、酯类7种、酸类3种、烷烃类8种。     

Antifungal Properties of Esters of Alkenoic and Alkynoic Acids

The antifungal property of the gas phases of a number of alkenoic and alkynoic acids and esters was investigated by placing the compounds in desiccators containing suspended bread. The following compounds inhibited mold development at a concentration of 20 mg per 2.6-liter desiccator: dimethyl fumarate, diethyl fumarate, propenoic acid, methyl and ethyl propenoate, methyl and ethyl propiolate, methyl-2,4-hexadienoate, 2,4- hexadien-1-ol, diethylethylidene malonate, 4-penten-1-ol, and 2-cyclohexen-1-one. Other compounds were active at 200 mg per desiccator: 3-methallyl alcohol; allyl acetone; diallyl ether; propiolic acid; methyl, ethyl, and vinyl crotonate; ethyl-2,4-hexadienoate; methyl and ethyl-2-hexenoate; ethyl-3-hexenoate; 1,5-hexadien-3-01; methylmaleic acid; methylmalonic acid; and 1-penten-3-ol.     

五种瓜类蔬菜提取物的抑菌活性研究

分别采用石油醚、乙酸乙酯、95% 乙醇和水作为提取溶剂,应用滤纸片法筛选南瓜、苦瓜、黄瓜、丝瓜和冬瓜五种瓜类蔬菜有机溶剂提取物及其粗多糖对大肠杆菌和金黄色葡萄球菌的抑菌活性。结果表明：南瓜乙酸乙酯提取物抑菌活性最大;将其经硅胶柱层析(CC)和薄层层析(TLC)进一步分离,获得抑菌活性最强的两个组分,它们对大肠杆菌、金黄色葡萄球菌、四联球菌、志贺氏菌、枯草芽孢杆菌、荧光假单胞菌均有广谱抗性,其中以对金黄色葡萄球菌的抑制作用最强,其最低抑制浓度(MIC)分别为1.25mg/ml 和2.5mg/ml。     

覆盆子不同极性溶剂提取物的抗氧化活性比较

为比较覆盆子不同极性溶剂提取物的抗氧化活性,分别用正丁醇、乙酸乙酯、丙酮、去离子水、50％乙醇和石油醚进行萃取,测定各提取物总多酚和总黄酮的含量,并通过清除DPPH自由基、ABTS自由基、羟基自由基和总还原能力4种体系对其体外抗氧化活性进行评价.结果显示,乙酸乙酯提取物中总多酚含量最高,50％乙醇提取物中总黄酮含量最高...     

不同溶剂提取乳苣的抗氧化作用研究

以乳苣全草为原料,75%乙醇为溶剂提取乳苣,提取液用不同极性溶剂依次萃取,得石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物,同时测定了各相提取物对羟自由基、超氧阴离子自由基、DPPH自由基的清除能力,并与VC进行比较。结果表明:各萃取物均具有一定的抗氧化活性,且随着浓度的增加而增强;对羟自由基的清除能力大小依次为乙酸乙酯萃取物>正丁醇萃取物>VC>水萃取物>石油醚萃取物;对超氧阴离子自由基清除能力大小依次为VC>正丁醇萃取物>乙酸乙酯萃取物>石油醚萃取物>水萃取物;对DPPH自由基清除能力大小依次为VC>乙酸乙酯萃取物>正丁醇萃取物>水萃取物>石油醚萃取物;各萃取物还原能力大小依次为VC>正丁醇萃取物>乙酸乙酯萃取物>水萃取物>石油醚萃取物。