何当奇
第2楼2007/03/12
An amount of 20 g (∼22 longan seeds) of freeze-dried ground longan seed was accurately weighed and refluxed three times with 50 ml of ethanol:water (50:50, v/v) in a water bath at 70 ◦C for one hour. The pooled extracts were passed through a Whatman filter paper no. 4 and the filtrate was concentrated to circa 60 ml on a rotary evaporator below 40 ◦C under reduced pressure. The aqueous residue was defatted three times with 60 ml of chloroform, and then freeze-dried.
种子提取
准确称取20-22g冻干粉碎的龙眼种子用50ml乙醇:水(50:50, v/v)在70 ◦C水浴在一小时回流三次。将合并提取物用no.4华特门滤纸过滤 并将滤液在减压的条件下在低于40℃的旋转蒸发仪中浓缩到约60ml。水性残留用60ml氯仿脱脂三次,后冷冻干燥。
2.4. Column chromatography
Fractionation was carried out according to the method described by Wettasinghe and Shahidi [27]. A 200 mg portion of the above freeze-dried aqueous residue was dissolved in 4ml of HPLC grade methanol and chromatographed on a Sephadex LH-20 column (45 cm×2.5 cm I.D.) eluted with methanol. Methanolic fractions (10 ml each) were collected in test tubes and their absorbance was measured at 280 nm by the use of UV spectrophotometer (UV mini 1240 Shidmazu).
Based on the absorbance data, eluates were pooled into major fractions, solvent evaporated and re-dissolved in 1ml of HPLC grade methanol. Samples were prepared as above in duplicate. The samples were filtered through a 0.45_m filter prior to injection (20μl) to the HPLC system.
柱色谱法
依据Wettasinghe和Shahidi提供的方法来进行分馏.并用甲醇洗脱的Sephadex LH-20柱进行层析。将甲醇化的部分 (每个10ml)收集于试管中, 并用紫外分光光度计(UV mini 1240 Shidmazu)在吸收为280nm处进行检测。根据吸光度资料, 收集合并洗提液, 蒸发溶剂,重新溶解于1ml HPLC级的甲醇中。
如上步骤制备第二份样品。
将200mg上述冻干水性残留溶于4mlHPLC级的甲醇中。Sephadex LH-20柱(45 cm×2.5 cm I.D.)甲醇洗脱(10 ml)收集于试管中,他们的吸光度在280nm紫外分光光度计。在吸光度的数据基础上,洗脱物被集中,甲醇浓缩和再溶解于1ml色谱级甲醇中。样品按照上述方法准备。在进样前,样品要经0.45μm的滤纸过滤,进量为20μl。
happyjyl
第4楼2007/03/12
其它都同意,这个refluxed three times … for one hour是指在一个小时之内回流3次,每次20分钟?还是指回流3次,每次1小时?这里说得不清楚。按常理来讲我觉得是回流3次,每次1小时,不知道对不对。
happyjyl
第6楼2007/03/12
A 200 mg portion of the above freeze-dried aqueous residue was dissolved in 4ml of HPLC grade methanol and chromatographed on a Sephadex LH-20 column (45 cm×2.5 cm I.D.) eluted with methanol.
将200mg上述冻干水性残留溶于4mlHPLC级的甲醇中,经过Sephadex LH-20柱(45 cm×2.5 cm I.D.),用甲醇洗脱。
Methanolic fractions (10 ml each) were collected in test tubes and their absorbance was measured at 280 nm by the use of UV spectrophotometer (UV mini 1240 Shidmazu).
将甲醇洗脱的样品(即样品中溶于甲醇的部分)收集于试管中(每个试管10ml),用紫外分光光度计在280nm处测定吸收度。
Based on the absorbance data, eluates were pooled into major fractions, solvent evaporated and re-dissolved in 1ml of HPLC grade methanol. Samples were prepared as above in duplicate. The samples were filtered through a 0.45_m filter prior to injection (20μl) to the HPLC system.
在吸光度的数据基础上,洗脱物被集中,将溶剂挥发,再用1mlHPLC级甲醇溶解。样品按照上述方法准备。进样前用0.45μm的滤纸过滤,进量为20μl。
Based on the absorbance data这句话让人费解。