Antioxidant activity and polyphenol content of green tea flavan-3-ols and oligomeric proanthocyanidins

The antioxidant activity and total phenolics content (TPC) of freshly prepared green tea extract (GTE) as affected by time, temperature and stirring were determined using the ferric reducing antioxidant power (FRAP) and Folin–Ciocalteu assays, respectively. Acetone–water fractions of GTE containing flavan-3-ols and oligomeric proanthocyanidins were evaluated at concentrations between 25 and 500 µg/ml. Increasing the extraction time from 3 min to 10 min resulted in a significant increase in both the FRAP values and TPC. Increasing the extraction time from 10 min to 30 min was without any significant effects on both FRAP and TPC values. Moreover, the FRAP values were correlated with the TPC. GTE fractions had widely different FRAP values that were well correlated with the TPC of the fraction. It was concluded that brewing conditions such as extraction temperature, period of extraction, ratio of tea leaves to extracting water, and stirring are important factors for determining the FRAP values and TPC in GTE. These factors should be taken into consideration during preparation for nutritional benefits during usual consumption of this beverage. Elevated FRAP and TPC values corresponded to those GTE fractions with a higher amount of phenolic compounds, which have stronger antioxidant activities.     

Antioxidant and free radical scavenging activities of some leafy vegetables

Some leafy vegetables were studied for their nutritional composition, antioxidant and free radical scavenging activities. The aerial parts of Coriandrum sativum, Spinacia oleracea, Trigonella corniculata and Trigonella foenum-graecum showed lower inhibitory concentration values (4.1–7.9 mg/ml), efficiency concentration values (178–321 mg/mg DPPH) and higher values of anti-radical power (0.31–0.51) as compared with their seeds. Thermal treatment reduced the total phenolic contents, antioxidant and free radical scavenging activities. The leaves of C. sativum were found with good amounts of caffeic acid, ferulic acid, gallic acid and chlorogenic acid.     

人血浆中环境酚类物质的液相色谱串联质谱测定法

目的建立测定人血浆中10种环境酚类物质的同位素内标-液液萃取-超高压液相色谱串联质谱测定法。方法样品经酶消解后,采用不同萃取剂进行液液萃取前处理,以含甲酸的甲醇和水为流动相,以梯度洗脱方式用C18色谱柱对目标化合物进行分离。以负离子喷雾模式电离,多反应离子监测方式进行定性及定量检测。结果该方法检测双酚A、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯、对羟基苯甲酸庚酯和对羟基苯甲酸苯酯、对羟基苯甲酸、3,4-二羟基苯甲酸和三氯生在0.05~50 ng/ml范围内满足线性需要(r=0.999)。经同位素内标校正后,酶消解-乙酸乙酯液液萃取法对10种目标化合物在两个浓度水平下的加标回收率均在90%~110%,最低检出限为0.03~0.15 ng/ml,定量限为0.10~0.50 ng/ml,日内和日间RSDs10%。结论该方法对人血浆中10种环境酚类化合物的测定具有较高的灵敏度和精确性,可满足上述化学品的人体暴露监测需要。     

菠萝叶提取物黏附漂浮微丸的制备及评价

采用挤出滚圆法,以壳聚糖为骨架黏附材料,十八醇为漂浮材料,制备菠萝叶提取物(Bolo leaf phenols,BLP)黏附漂浮微丸,评价其体外黏附性、漂浮性及体内滞留情况,并考察药物的体外释放特性。通过体外组织留存量法和直接观察法分别评价微丸的体外黏附性和漂浮性;采用体内组织留存量法和小动物活体成像法考察微丸在大鼠体内的滞留情况;对微丸中指标成分对香豆酸和咖啡酸的体外释放情况进行评价。结果显示,制备的黏附漂浮微丸体外黏附性达(73.2±3.4)%,在人工胃液中可立即起漂,持续漂浮时间在12 h以上;黏附漂浮微丸在大鼠胃内6 h时滞留率达40%以上,而普通参比微丸胃滞留率低于15%,两者相比,滞留效果具有显著性差异(P0.01);药物体外释放时间可达6 h以上,体外释药机制符合Higuchi方程。体内、外研究表明,制备的BLP黏附漂浮微丸具有良好的胃滞留效果和缓释特性。     

Accelerating bleaching in vitiligo: balancing benefits versus risks

While the goal of available treatment in vitiligo is to regain pigmentation, some patients affected by extensive and treatment‐resistant vitiligo, with a major social and emotional impact, may benefit from depigmentation therapy. However, results from such therapy may not always be satisfactory. So to achieve better, faster and complete bleaching, Webb et al. propose a synergistic approach that combines topical application of bleaching phenols which targets melanocytes and initiate local inflammation with immune adjuvants so as to obtain an enhanced immune response against remaining melanocytes. This strategy could be reliable, but should be evaluated cautiously in future studies, in terms of potential side effects and induction of undesired autoimmunity.     

丙泊酚注射痛指导无痛人流术后镇痛模式的临床观察

[目的]探讨用丙泊酚注射痛指导无痛人流术后镇痛模式的可行性.[方法]选择本院2011年1～6月拟行无痛人流的患者1200例,年龄18～42岁,ASAⅠ～Ⅱ级,按照手术先后顺序分为分为三组(Ⅰ、Ⅱ、Ⅲ组),每组400例.三组均以0.5 mL/s的速率静注1%丙泊酚2 mg/kg,当丙泊酚给药量达1/4时暂停给药,采用语言等级评定量表(VRS)评分法评价丙泊酚注射痛(VRS 1分为发生注射痛,VRS≥2分为中重度注射痛),之后静注剩余量丙泊酚完成麻醉诱导,Ⅰ组所有病例未予其他特殊处理;Ⅱ、Ⅲ组中VRS≥1分者术中静注舒芬太尼0.2 μg/kg;Ⅲ组中VRS≥2分者术后另给予下腹部理疗辅助镇痛.术后30 min时采用视觉模拟评分法(VAS)评价患者无痛人流术后疼痛程度,VAS评分≥30分为发生术后疼痛.[结果]丙泊酚注射痛发生率Ⅰ组为67%,Ⅱ组为68.5%,Ⅲ组为65%,三组间差异无统计学意义( P ＞0.05);术后疼痛发生率Ⅰ组为70%,Ⅱ组为26%,Ⅲ组为11.3%,Ⅱ、Ⅲ组与Ⅰ组比较差异有显著性( P ＜0.01),说明依据丙泊酚注射痛给予舒芬太尼能明显减少术后疼痛发生率;Ⅱ组与Ⅲ组比较差异有显著性( P ＜0.01),说明依据丙泊酚注射痛程度给予不同术后镇痛模式的有效性.[结论]应用丙泊酚注射痛指导无痛人流术后镇痛的模式是一种可靠的方法.     

比色法测定不同产地傣药肾茶中主要酚类物质含量

目的：优选合适的显色体系,建立傣药肾茶中主要酚类物质的含量测定方法,对不同产地样品进行含量测定。方法以迷迭香酸为对照品、亚硝酸钠-硝酸铝-氢氧化钠为显色剂、检测波长为500 nm、采用比色法测定19个不同产地样品的主要酚类物质含量。结果迷迭香酸在8.792~17.584μg/ml范围内线性关系良好（r2=0.9993）,平均加样回收率为100.73%,相对标准偏差（RSD）为0.85%。不同产地样品中主要酚类物质的质量分数为1.16%~3.49%。结论该方法简单、准确、重复性好,适合傣药肾茶中主要酚类物质的含量测定。结果显示不同产地样品中以云南产肾茶中主要酚类物质含量相对较高。     

大孔吸附树脂分离地菍总酚的研究

目的 筛选大孔树脂分离纯化地菍中总酚类物质的最佳工艺.方法 采用静态与动态吸附-解吸方法,以紫外分光光度法测定地菍总酚的量对工艺进行评价.结果 HPD 100大孔吸附树脂分离效果较好,总酚可达50%以上.其最佳工艺为药液浓度0.2 g(生药)/mL、pH值为2.7～4.5,以3 BV/h进行吸附,5 BV的60%乙醇以3BV/h进行洗脱效果最佳.结论 该方法简便可行,分离效果好,能满足大生产的要求.     

基于UPLC-Q-TOF/MS的渴络欣胶囊化学成分研究

目的 采用超高效液相色谱-四级杆-飞行时间质谱（UPLC-Q-TOF-MS）技术对中药复方渴络欣胶囊中的化学成分进行研究。方法 采用ACQUITY UPLC HSS T3 C₁₈色谱柱（100 mm×2.1 mm,1.8 μm）,以甲醇-0.1%甲酸水溶液为流动相梯度洗脱,体积流量为0.3 mL/min;采用ESI源在正、负离子模式下分别采集数据。根据化合物精确相对分子质量及二级碎片离子信息,结合参考文献数据,鉴定渴络欣胶囊的主要化学成分。结果 从渴络欣胶囊中分离和鉴定出54个化学成分,包括蒽醌类化合物10个、黄酮类化合物10个、萜类化合物7个、酚类化合物16个等。结论 首次采用UPLC-Q-TOF/MS联用技术研究渴络欣胶囊中化学成分,进一步明确了其物质基础。     

南川木波罗根皮的化学成分

目的:研究南川木波罗根皮的化学成分。方法:采用硅胶、Diaion HP20大孔吸附树脂、MCI gel CHP 20P树脂凝胶、Sephadex LH-20凝胶、ODS等柱色谱分离手段,对南川木波罗根皮醇提物的乙酸乙酯部位进行化学成分的分离纯化,根据化合物的理化性质及光谱数据鉴定其结构。结果:分离了9个化合物,分别鉴定为4-羟基苯甲醛(p-hydroxybenzaldehyde)(1),2,4-二羟基苯甲酸(2,4-dihydroxybenzoic acid)(2),香豆酸(p-coumaric acid)(3),儿茶素[(+)catechin](4),(E)-阿魏酸甲酯[(E)-ferulic acid methyl ester](5),E-对-羟基肉桂酸甲酯(p-E-hedroxycinnamic acid methyl ester)(6),norartocarpetin(7),反式氧化白黎芦醇(trans-oxyresveratrol)(8),moracin M(9)。结论:化合物1,2,5,6为首次从桑科植物中获得,化合物3为首次在波罗蜜属植物中发现,而化合物7~9为首次从南川木波罗中分离得到。