吸附伏安法测定药品中对乙酰氨基酚的含量

目的建立碳糊电极(CPE)阳极吸附伏安法测定对乙酰氨基酚的方法。方法用石墨粉-液状石蜡(质量比4∶1)制备CPE,在HCl(pH=0.50)溶液中,对乙酰氨基酚在0.706 V(参比电极Ag-AgCl)产生一灵敏的吸附氧化峰。结果对乙酰氨基酚浓度在3.13×10-6～2.0×10-4mol.L-1范围内与峰电流呈良好的线性关系,r=0.999 5,检测限为6.6×10-8mol.L-1,将该法运用于实际样品的测定并取得了较好的结果。结论该法简便、快速、准确,可用于对乙酰氨基酚相关药物的质量控制。     

In vitro studies of Gynura divaricata (L.) DC extracts as inhibitors of key enzymes relevant for type 2 diabetes and hypertension

Aim of the study

To evaluate traditionally used herb, Gynura divaricata (L.) DC (Bai Bei San Qi) as in vitro inhibitors of key enzymes involved in the pathogenesis of hyperglycemia and hypertension. We also determined the distribution of enzyme inhibitory activities in different aqueous and non-aqueous extracts.

Materials and methods

The water extract (extract 1) from the aerial parts of Gynura divaricata (L.) was prepared first and then partitioned sequentially with n-butanol, ethyl acetate, and macroporous adsorptive resin (HPD-40) to yield extracts 2-4; the remaining water phase was named extract 5. Angiotensin-1 converting enzyme (ACE), α-amylase α-glycosidase inhibitory activities of the extracts were determined in vitro and chemical composition including total sugar, protein, flavonoid and total alkaloids in the extract were also evaluated.

Results

The water extract of this herb significantly inhibited (p < 0.05) ACE activity (IC₅₀ = 0.37 mg/ml) and showed a moderate potential hypoglycemic effect via in vitro α-amylase (IC₅₀ = 1.36 mg/ml) and α-glycosidase (IC₅₀ = 2.17 mg/ml) inhibition in dose-dependent manner. Further partitioning of the water extract (extracts 2-4) resulted in higher α-amylase inhibitory activities in extract 2 and 3. For α-glycosidase inhibition, extract 3 gave the highest inhibition. ACE inhibitory activities of the extracts were not improved by partitioning. Sugar, protein, flavonoid and alkaloid were found in water extract but only a small portion was partitioned in the n-butanol extract. However, a large portion of the flavonoids and alkaloids were found in ethyl acetate extract.

Conclusion

The results confirmed potential empirical use of Gynura divaricata (L.) DC for the management of hyperglycemia as well as hypertension. The active compounds for inhibition of α-amylase and α-glycosidase inhibition were flavonoids and alkaloids while ACE inhibition probably resulted from synergic effects of all the herb compounds.     

大孔吸附树脂纯化新疆大叶补血草根茎中总黄酮工艺考察

目的:利用大孔吸附树脂纯化新疆大叶补血草根茎中的总黄酮。方法:通过比较10种大孔吸附树脂对新疆大叶补血草根茎提取物中黄酮类化合物的吸附和解吸性能,综合考察不同类型的吸附树脂对总黄酮的吸附和解吸效果。结果:HPD100型大孔吸附树脂对新疆大叶补血草根茎提取物中的总黄酮具有较强的吸附性能和较好的解吸能力。当总黄酮上样质量浓度为0.25 mg·ml^-1,上样量为树脂体积的1.8倍(1.8 BV),吸附平衡后,先用2~3 BV纯化水洗去水溶性较大的成分,再用2.1 BV的70%乙醇洗脱,分段收集,可获得总黄酮含量为(43.26±2.33)%(n=5)的有效部位。结论:HPD100型大孔吸附树脂可以作为纯化新疆大叶补血草根茎提取物中的总黄酮的材料。     

固态胺吸附和解吸CO2的数值模拟

目的建立固态胺吸附床吸附和解吸CO2的数值模型并进行计算机模拟验证。方法利用多孔介质吸附理论及平衡吸附压力的概念建立固态胺吸附和解吸CO2的动力学模型,用有限体积法建立吸附床吸附和解吸CO2的一维动态数值模型,并编写模拟程序。结果利用数值模拟程序模拟了固态胺吸附床吸附和解吸CO2的过程,得到了吸附和解吸过程中吸附床及出口参数变化的特点。结论定性地验证了模型的正确性,但需要通过与实验对照改进模型及参数,提高模拟的准确性。     

碳糊电极吸附伏安法测定微量酚磺乙胺

在００５ｍｏｌ／Ｌ硫酸底液中，用碳糊电极吸附伏安法测定酚磺乙胺，阳极峰电位为０５５Ｖ（ｖｓ．ＳＣＥ），峰电位与酚磺乙胺的浓度在１０×１０－７～１０×１０－４ｍｏｌ／Ｌ范围内呈良好的线性关系。该法检测下限为５０×１０－８ｍｏｌ／Ｌ，回收范围为９５０％～１０５５％，相对标准偏差为３０％（ｎ＝１２）。对酚磺乙胺注射液用本法进行了测定，获得满意结果。本文对反应机理进行了初步探讨，酚磺乙胺在碳糊电极上是一个两电子、两质子的不可逆过程     

浮石修饰碳糊电极差示脉冲吸附伏安法测定盐酸普鲁卡因

目的:建立一种新型化学修饰电极吸附伏安法测定盐酸普鲁卡因的分析方法。方法:在1-25 ×10^-3mol·L^-1 KH₂PO₄ 和1-25×10^-3mol·L^-1 Na2HPO4 混合缓冲溶液(pH6-88,25 ℃) 中,用6% 浮石修饰碳糊电极,差示脉冲吸附伏安法测定盐酸普鲁卡因。结果:盐酸普鲁卡因的阳极峰电位为+ 0-98 V(vs.SCE),峰电流与盐酸普鲁卡因浓度在9-1×10- 7 ～2-6 ×10-5mol·L^-1 范围内呈良好的线性关系,检测下限为5-0 ×10^-8mol·L^-1 ,回收率为95-2%～104-8% ,RSD为3-2% 。结论:本法快速、简便、准确、灵敏度高,直接用于盐酸普鲁卡因注射液的测定,得到满意的结果。     

螃蟹甲大孔吸附树脂50%乙醇洗脱物对大鼠CCl4肝损伤的保护作用

目的:探讨螃蟹甲中大孔吸附树脂50%乙醇洗脱物对四氢化碳(CCl_4)致急性肝损伤的保护作用及其可能机制。方法:60只Wistar大鼠随机分为正常组,模型组,联苯双酯组(联苯双酯滴丸100 mg·kg~(-1)),螃蟹甲大孔吸附树脂50%乙醇洗脱物(EPY-50)高、中、低剂量组(400,200,50 mg·kg~(-1)),连续ig给药4 d,正常组和模型组均ig给予纯化水,第3天给药1 h后,ip 15%CCl_4橄榄油,正常组ip橄榄油,染毒2,22 h后再次给药,末次给药1 h后,眼眶静脉丛采血,测血清中丙氨酸转氨酶(ALT),天冬氨酸转氨酶(AST),丙二醛(MDA),超氧化物歧化酶(SOD)的水平,处死大鼠剖取肝脏,测肝指数及肝组织中MDA,SOD,谷胱甘肽还原酶(GSH)含量,并做肝脏组织病理学检查。结果:与正常组比较,模型组大鼠血清中AST,ALT水平显著增加(P0.01),肝组织匀浆液中的MDA含量明显升高(P0.05),SOD,GSH含量均明显降低(P0.05),肝脏指数显著增加(P0.01),表明CCl_4造模成功。与模型组比较,EPY-50高、中剂量组能显著降低CCl_4致急性肝损伤大鼠血清中AST,ALT水平(P0.05,P0.01),并显著减少肝组织中MDA含量,提高SOD,GSH的含量,降低肝指数(P0.05,P0.01),改善肝组织病理状态。结论:EPY-50对大鼠CCl_4致急性肝损伤有保护作用,其作用机制可能与其抗氧化活性有关。     

选择抑制苦杏仁酸吸附催化峰法测定钼

为改善平等钠化峰测钼的检出限和提高其抗干扰能力，本文提出一种基于苦杏仁酸吸附峰受抑制的定量方法。在硫酸－氯酸钾体系中，于峰电位－0．45v（VsSCE）处苦杏仁酸有一定吸附峰，钼含量在0．1－1．0ng/ml之间苦杏仁酸的一阶导数峰峰高与钼含量成良好的负线性关系。6次平行测定的相对标准偏差为2．14％－9．80％，土壤样品的加标回收率为87．0％－95．5％。本法操作简便，抗干扰能力强，适于基体复杂而钼含量低的样品测定。     

Electrochemical determination of gatifloxacin,moxifloxacin and sparfloxacin fluoroquinolonic antibiotics on glassy carbon electrode in pharmaceutical formulations

Three fluoroquinolones; gatifloxacin (GAT), moxifloxacin (MOX) and sparfloxacin (SPAR) were electrochemically studied in various buffer systems at different pH values, using a glassy carbon electrode. The three fluoroquinolones were electrochemically oxidized at potential range (0.65–1.1 V) vs Ag‐AgCl‐KCl. The oxidation was irreversible and exhibited adsorption‐controlled process behavior at all pH values and buffers studied. An electroanalytical methodology based on the adsorptive behavior of fluoroquinolones on glassy carbon electrode (GCE) and according to the linear relation between peak current and concentration using differential pulse voltammetry (DPV) method was successfully applied to the determination of the three fluoroquinolones in bulk and tablets. The proposed methods were statistically in agreement with that obtained by spectrophotometric comparison method. Copyright © 2010 John Wiley & Sons, Ltd.