Carboxylesterase catalyzed 18O-labeling of carboxylic acid and its potential application in LC-MS/MS based quantification of drug metabolites

LC-MS quantification of drug metabolites is sometimes impeded by the availability of internal standards that often requires customized synthesis and/or extensive purification. Although isotopically labeled internal standards are considered ideal for LC-MS/MS based quantification, de novo synthesis using costly isotope-enriched starting materials makes it impractical for early stage of drug discovery. Therefore, quick access to these isotope-enriched compounds without chemical derivatization and purification will greatly facilitate LC-MS/MS based quantification. Herein, we report a novel ¹⁸O-labeling technique using metabolizing enzyme carboxylesterase (CES) and its potential application in metabolites quantification study. Substrates of CES typically undergo a two-step oxygen exchange with H₂¹⁸O in the presence of the enzyme, generating singly- and doubly-¹⁸O-labeled carboxylic acids; however, unexpected hydrolytic behavior was observed for three of the test compounds – indomethacin, piperacillin and clopidogrel. These unusual observations led to the discovery of several novel hydrolytic mechanisms. Finally, when used as internal standard for LC-MS/MS based quantification, these in situ labeled compounds generated accurate quantitation comparable to the conventional standard curve method. The preliminary results suggest that this method has potential to eliminate laborious chemical synthesis of isotope-labeled internal standards for carboxylic acid-containing compounds, and can be developed to facilitate quantitative analysis in early-stage drug discovery.     

Effect of magnesium lithosperamate B on D-galactosamine induced liver injury in rats

Treated the experimental acute liver injury rat induced by D-galactosamine with magnesium lithosperamate-B could significantly lower the serum activity of alanine transaminase and aspartate aminotransferase, relieve the necrosis of hepatocytes and elevate the levels of products of arachidonic acid (6-ke-to-prostaglandin 1α, prostaglandin D₂ and the total prostaglandin) in liver. These results suggested that magnesium lithosperamate B was one of the main components ofSalvia miltiorrzae in treating liver injury, the action on elevating the total prostaglandin in liver might be its mechanism.     

Looking Ahead in Renal Cell Carcinoma: Integrating New Agents in the Armamentarium of the Urologist

Urologists play a pivotal role in many aspects of the care of patients with renal cell carcinoma (RCC). However, until recently, in some European countries, they have rarely been involved in the systemic treatment of this disease or in the design of clinical trials. This is undoubtedly set to change with the emergence of new oral, molecularly targeted therapies for RCC. Sorafenib (Nexavar^®; Bayer Healthcare, West Haven, CT, USA) is one such therapy, which has already been shown to be efficacious and well tolerated for the treatment of RCC. Although targeted agents show great promise for the treatment of RCC, their precise role in the treatment of metastatic disease, and in adjuvant and neoadjuvant settings has yet to be defined. Drawing from their extensive experience of RCC, urologists will be instrumental in the design and application of clinical studies to define the role of targeted therapies in all settings of RCC and, ultimately, to integrate targeted therapies into clinical practice. Through increased understanding of the molecular pathways involved in RCC, research into diagnostic and prognostic markers, and commitment to clinical trials, urologists can be at the forefront of this progress.     

Penetration moxibustion for postpartum subinvolution of uterus: Two case reports and mechanism analysis: 透灸法成功治疗产后子宫复旧不良:两则病例报告及机制分析

This article introduced the application of penetration moxibustion in successfully treating two cases of postpartum subinvolution of uterus. The main complaint of one case was increasing volume of abnormal vaginal bleeding for five days after delivery. The bleeding stopped after the patient received 7 times treatment of warming needle and penetration moxibustion on Zhōngjí (中极CV3), Guānyuán (关元CV4) and Qìhăi (气海CV6). The other case complained about persistent abdominal pain for 15 days, which was worsening for the recent 2 days. The symptom of abdominal pain was relieved after the penetration moxibustion was applied on CV4, CV6 and Zǐgōng (子宫 EX-CA1) for 5 times for the case. Penetration moxibustion can relieve abdominal pain during the postpartum period, accelerate lochia discharge, and recovery of menstrual and uterine cavity. Àiyè (艾叶 Artemisiae Argyi Folium) was proved to have antibacterial, hemostatic, and analgesic effects. The warming function and radiation features of moxibustion can help to alleviate spasm of the smooth muscle in the uterus and enhance the metabolism of the uterine tissue by expanding microvessels and improving the circulations of both blood and lymph. It can also activate cells in the uterine tissue by increased temperature in order to enhance the decomposition and elimination of pathological wastes, such as inflammation and hematoma. In addition, it can also relieve pelvic pain by inhibiting neuronal excitability.     

Relationships between anthropometric adiposity indexes and bone mineral density in a cross-sectional Chinese study

Background ContextPrevious studies have reported conflicting results for the relationships between anthropometric adiposity indexes and bone mineral density, based on dual-energy X-ray absorptiometry (DXA). However, few studies were published based on quantitative computed tomography (QCT), especially for Chinese population.PurposeTo evaluate the associations of spine bone mineral density (BMD) with body mass index (BMI), waist circumstance (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and a body shape index (ABSI) using QCT.Study Design/SettingA Cross-sectional study.Patient SampleAround 3,457 participants in multiple communities across 7 administrative regions of China.Outcome MeasuresSpine BMD was measured using QCT, and the classification of osteoporosis was defined as follows: 1) osteoporosis if BMD <80mg/cm³, 2) osteopenia if BMD 80–119 mg/cm³, and 3) normal bone mass if BMD≥120 mg/cm³.MethodsThis study was conducted using convenient sampling between 2013 and 2017. Multivariable linear regression model and logistic regression models were used for the associations of continuous and categorical BMD, respectively.ResultsAround 3,405 participants were included in the final analyses, including 1,272 males and 2,133 females, with spine BMD of 111.00±35.47 mg/cm³ and 99.38±40.60 mg/cm³, respectively. Spine BMD decreased significantly with the increase of ABSI in females (adjusted β, ?5.74; 95% confidence interval [CI], ?8.50 to ?2.98), and this trend also was kept in females aged at less than 60 years (adjusted β, ?14.54; 95% CI, ?20.40 to ?8.68), and females with age ≥60 years (adjusted β, ?7.59; 95% CI, ?10.91 to ?4.28). However, this inverse association was observed only in males with age ≥ 60 years (adjusted β, ?5.19; 95% CI, ?10.08 to ?0.29). Except ABSI, negative associations of Spine BMD with WC (adjusted β, ?0.46; 95% CI, ?0.77 to ?0.15), WHR (adjusted β, ?6.25; 95% CI, ?10.63 to ?1.86), WHtR (adjusted β, ?6.80; 95% CI, ?11.63 to ?1.97) were shown in females aged at <60 years, and positive association with BMI in males with age ≥60 years (adjusted β, 0.92; 95% CI, 0.29–1.55).ConclusionsABSI had more remarkable association with spine BMD, compared with the other four indexes.     

染料木黄酮诱导人卵巢癌HO-8910细胞凋亡的实验研究

目的研究染料木黄酮对人HO-8910卵巢癌细胞的抑制效应和诱导凋亡作用,探讨其机制。方法将不同浓度的染料木黄酮作用于人HO-8910卵巢癌细胞,利用MTT法检测其有效作用浓度,分别采用瑞氏染色、TUNEL、流式细胞仪观察和检测HO-8910细胞凋亡情况。结果MTT法测得其IC50值为28.63 mg/L,浓度为8~128 mg/L的染料木黄酮具有诱导人HO-8910卵巢癌细胞凋亡的作用,且随药物作用时间延长凋亡率逐渐增加。结论染料木黄酮具有抗卵巢癌作用,其重要作用机制之一是诱导人HO-8910卵巢癌细胞凋亡。     

黄芪及其民间习用品DNA指纹图谱和有效成分含量的比较

 目的比较2000年版药典收载黄芪品种及其民间习用品的DNA指纹图谱和有效成分黄芪甲苷、总黄酮及总多糖的含量,对黄芪质量标准进行多维研究。方法RAPD法确定DNA指纹图谱,HPLC-ELS测定黄芪甲苷的含量,比色法测定总黄酮的含量,硫酸-苯酚法测定黄芪总多糖的含量。结果DNA指纹图谱分析表明膜荚黄芪、蒙古黄芪和梭果黄芪有着较近的遗传关系,而另外3种黄芪,即苦黄芪、黑毛多枝黄芪和直立黄芪有非常近的亲缘关系。有效成分含量的测定结果证实,黑毛多枝黄芪、直立黄芪中黄芪甲苷的含量高于膜荚黄芪和蒙古黄芪;总黄酮的含量以梭果黄芪最高;总多糖的含量以蒙古黄芪最高。结论对民间使用的黄芪品种进行多维质量研究,为开发黄芪的药用资源提供理论依据。     

中药枸骨叶脂溶性化学成分的研究

 目的研究中药枸骨叶(Ilexcornuta)的脂溶性化学成分,为其抗动脉粥样硬化活性寻找可能的先导化合物。方法利用硅胶和SephadexIH-20等柱色谱进行分离,用化合物的波谱数据鉴定其结构。结果从枸骨叶的氯仿部位分得11个脂溶性成分,其中包括7个三萜类成分即羽扇豆醇(1),11-酮基-α-香树脂醇棕榈酸酯(Ⅱ),α-香树脂醇棕榈酸酯(Ⅲ),3,28-乌索酸二醇(Ⅳ),熊果酸(Ⅴ),30-醛基羽扇豆醇(Ⅵ),30-酮基降羽扇豆醇(Ⅶ);1个链状倍半萜tanacetene(Ⅷ);1个甾醇β-谷甾醇(Ⅸ),2个有机酸类成分即正二十二烷酸(Ⅹ)和正二十六烷(Ⅺ)。结论化合物Ⅳ,Ⅶ,Ⅷ,Ⅹ和Ⅺ为首此从冬青属植物中分得,化合物Ⅱ,Ⅲ和Ⅸ为首次从该植物中分得。倍半萜类成分为首此从冬青属植物中分得的化合物类型。