2-乙酰基-3-甲基喹噁啉-1,4-二氧化物的合成工艺研究

研究了2-乙酰基-3-甲基喹噁啉-1,4-二氧化物的合成工艺.以邻硝基苯胺为起始原料,经过氧化反应和Beirut反应,以86%的总收率制得产物2-乙酰基-3-甲基喹噁啉-1,4-二氧化物.反应条件温和,操作简单,收率高,具有工业应用价值.     

高效液相色谱-串联质谱法检测猪、鸡可食性组织中喹嗯啉类兽药残留标示物

为检测猪、鸡可食性组织中喹噁啉类兽药残留标示物喹噁啉-2-羧酸(QCA)和3-甲基喹噁啉-2-羧酸(MQ-CA),建立了同时检测这2种残留标示物的高效液相色谱-串联质谱法.将样品碱水解,乙酸乙酯等液-液萃取,65℃氮气吹干,甲醇:0.5%甲酸水溶液(30:70)溶解,0.45μm微孔滤膜过滤后,采用高效液相色谱-串联质谱分析.结果显示,猪、鸡可食性组织中喹噁啉类兽药残留标示物MQCA和QCA检测限为0.2～0034μg/kg和0.5～0.9μg/kg,定量限为0.5～0.61μg/kg和0.77～1.31μg/kg.相对回收率在90.07%～106.8%范围内,日内变异系数≤13.69%.日间变异系数≤15.43%.MQCA和QCA在2～100μg/kg范围内具有较好的线性关系(r~2>0.99).结果表明,本方法简单、灵敏度高.适用于猪、鸡可食性组织中喹噁啉类兽药残留标示物的定量检测.     

禁用药科普——喹乙醇

正1喹乙醇是什么?喹乙醇又名喹酰胺醇,属于喹噁啉类。于1965年由德国拜耳公司(Bayer)以邻硝基苯胺为原料合成的一种饲料添加剂,当时因其性能稳定、效果显著、用量少、被当做人工合成的喹噁啉化合物中一种理想的畜禽抗菌促生长剂。喹乙醇的化学名称为2-[N-(2-羟基-乙基)-氨基甲酰]-3-甲基-喹噁啉-1,4-二氧化物。本品为浅黄色结晶性粉末,无臭,     

“MAQO”和“MCEQO”抑菌活性及其毒性的初步观察

取代哇嗯琳-1,4-二氧化物是一类结构上完全不同于抗生素、磺胺、硝基呋喃和砷剂的抗菌物质,它具有较广的抗菌谱和较强的抗菌活性。据国外报导,在机械化养猪、养禽事业中,它是动物饲料中添加的抗菌物质的满意代用品。近年来,国外已将该类化合物广泛用作动物饲料添加剂和防治由于细菌感染而引起的多种疾病。MAQO(3-甲基-2-乙酰基-喹(?)啉-1,4-二氧化物)和MCEQO(3-甲基-2-羰乙氧基-喹(?)啉-1,4-二氧化物)是我们合成的两个羧酸酯类喹(?)啉-1,4-二氧化物,     

1,4-二氧喹醛酸酯合成及抑菌活性研究

为了合成两种具有抑菌活性的1,4-二氧喹醛酸酯,即1,4-二氧喹喔啉-3-甲基-2-甲酸苯酯和1,4-二氧喹喔啉-3-甲基-2-甲酸肉桂酯,以苯并呋咱为原料,经Beirut反应、酯交换反应,合成了两种喹醛酸酯;1,4-二氧喹喔啉-3-甲基-2-甲酸苯酯合成产率为29.3%,1,4-二氧喹喔啉-3-甲基-2-甲酸肉桂酯合成产率为18.3%。两种1,4-二氧喹醛酸酯对大肠杆菌、金葡萄球菌、青霉菌和枯草杆菌均有明显的抑菌活性。通过测定产物的熔点和光谱分析证明系为所合成的目标产物。     

仔猪乙酰甲喹中毒的诊治

乙酰甲喹又称痢菌净,是一种较新型的合成抗菌药,属于喹噁啉类药物。广谱抗菌,抗菌机理为抑制菌体的脱氧核糖核酸(DNA)的合成,其对多数细菌、密螺旋体有较强的抑制作用。临床上对猪细菌性肠炎、仔猪副伤寒、猪痢疾等病有疗效。内服或肌注均易吸收,长期或大剂量应用易引起中毒。     

采用高效液相色谱-串联质谱法检测鲫鱼组织3-甲基喹噁啉-2-羧酸残留量

将待测鱼肉和鱼皮匀浆样品经碱水解、液-液萃取后,采用HPLC-TMS方法对其中的3-甲基喹噁啉-2-羧酸（MQCA）残留量进行了检测。结果,此方法的最低检测限为1.16μg/kg,市售鲫鱼样品中MQCA的含量低于检测限。结果表明,HPLC-TMC灵敏,易操作,能满足鱼组织内MQCA残留量检测的要求。     

3-甲基-2-[3-(2-呋喃基)丙烯甲酰]-喹喔啉- 1,4-二氮氧化物合成研究

为改善3-甲基-2-[3-(2-呋喃基)丙烯甲酰]-喹喔啉-1,4-二氮氧化物的制备工艺,寻找一种与喹烯酮结构相似,但药效更好、毒性更低的喹喔啉类兽药,参考喹烯酮的制备工艺,对苯并呋咱-N-氧化物环氧化反应条件,乙酰甲喹制备工艺,目标物制备条件进行了研究。试验用25%氨水作为催化剂,优化了催化剂用量,缩短了反应时间,提高了目标物产率,使目标物产率达到88.95%。合成的产物理化性质和光谱分析证明系为所合成的目标物。     

养殖业中喹噁啉类抗生素残留检测研究进展

喹噁啉类抗生素,是一类具有喹噁啉-1, 4-二氧化物结构的化学合成类的抗菌促生长剂[1, 2]。具有相同的母核结构,该类的抗生素种类繁多,主要有乙酰甲喹(Mequindox, MEQ)、喹烯酮(Quinocetone,QCT)、卡巴氧(Carbadox,CBDX)、喹乙醇(Olaquindox)和喹赛多(Cyadox)等。它们都具有广谱抗菌、抗球虫、促进动物生长和提高饲料效率的作用,能够抑制细菌DNA的合成,且价格便宜,进而为生产养殖而被广泛的添加到饲料中。     

喹乙醇代谢物3-甲基-喹啉-2-羧酸的合成与鉴定

本实验研究了喹乙醇饲料添加剂的生物代谢物3-甲基-喹啉-2-羧酸的制备方法所制备的产品.主要通过利用保险粉先对原料乙酰甲喹进行脱氧,温度控制在70℃.反应过程中通过薄层色谱法(TLC)进行定性分析,得到了纯度很高的中间产物3-甲基-2-乙酰喹啉,对其进行再卤化反应,反应过程中用碘化钾试纸进行检测,得到了纯度高达99%的产物3-甲基-喹啉-2-羧酸,整个制备过程简单,易操作,且安全性高.     

绵羊抗菌肽GNLY基因多态性分析及合成多肽的生物学功能研究

试验旨在分析绵羊抗菌肽颗粒溶素（granulysin,GNLY）基因多态性,检测合成多肽的抑菌活性和抑制肿瘤细胞活性,明确绵羊抗菌肽GNLY的生物学功能。通过对GNLY基因RT-PCR产物进行测序,分析GNLY基因多态性,推导其氨基酸序列信息合成功能区多肽,利用径向扩散试验和MIC试验检测合成多肽对大肠杆菌、沙门氏菌、葡萄球菌、金黄色葡萄球菌的抑制作用;利用MTT试验观察合成多肽对人食管癌细胞（EC109）、人肾癌细胞（X786-0）的抑制作用。结果发现,MIC试验中浓度>250 μg/mL的G16对大肠杆菌、葡萄球菌均有抑制作用;浓度 ≥ 7.82 μg/mL的GS16对大肠杆菌抑制作用明显,对沙门氏菌、葡萄球菌和金黄色葡萄球菌无明显抑制作用;62.5 μg/mL GC16对大肠杆菌、沙门氏菌和金黄色葡萄球菌均有抑制作用,其中对大肠杆菌和金黄色葡萄球菌抑制作用较为明显;G22对4种细菌均无明显的抑制作用。MTT试验结果表明,合成多肽G16、GS16对癌细胞无抑制作用,G22和GC16对EC109、X786-0具有显著抑制作用,其中1 mg/mL G22和1 mg/mL GC16对EC109生长抑制率分别为88.21%和57.21%,对X786-0生长抑制率分别为96.37%和81.87%。研究显示,合成GNLY多肽对细菌和肿瘤细胞具有一定的抑制活性,本研究结果为绵羊抗菌肽作为候选抗菌药物的开发奠定了基础。     

In vitro retinoid-induced growth inhibition and morphologic differentiation of canine osteosarcoma cells

OBJECTIVE: To determine differentiation and growth inhibition effects of retinoids on canine osteosarcoma cells. SAMPLE POPULATION: 3 osteosarcoma cell lines established from osteosarcomas in dogs. PROCEDURE: Osteosarcoma cells were incubated with various concentrations of all-trans-retinoic acid and 9-cis-retinoic acid or control medium, counted daily for 10 days, and evaluated for morphologic changes. Synthesis of DNA was measured by use of a cell proliferation ELISA. To analyze effect of retinoids on colony formation on plastic dishes, cells were cultured for 14 days, fixed, and stained; number of colonies was counted. RESULTS: In a dose-dependent manner, both retinoids induced morphologic differentiation and growth inhibition in the 3 osteosarcoma cell lines and inhibited each cell's ability to form anchorage-dependent colonies. CONCLUSION AND CLINICAL RELEVANCE: Retinoids induced differentiation of osteosarcoma cells of dogs, resulting in altered expression of their malignant phenotype. Induction of differentiation by retinoids may have potential as an adjunctive treatment for osteosarcoma in dogs.     

Expression of O6-methylguanine-DNA methyltransferase causes lomustine resistance in canine lymphoma cells

The DNA repair protein O⁶-methylguanine-DNA methyltransferase (MGMT) causes resistance to nitrosoureas in various human cancers. In this study, we analyzed the correlation between canine lymphomas and MGMT in vitro. Two of five canine lymphoma cell lines required higher concentrations of lomustine to inhibit cell growth by 50%, but their sensitivity to the drug increased when they were cultured with an MGMT inhibitor. Fluorometric oligonucleotide assay and real-time polymerase chain reaction of these cell lines revealed MGMT activity and high MGMT mRNA expression, respectively. We analyzed the methylation status of the CpG islands of the canine MGMT gene by the bisulfite-sequencing method. Unlike human cells, the canine lymphoma cell lines did not show significant correlation between methylation status and MGMT suppression levels. Our results suggest that in canine lymphoma MGMT activity may influence sensitivity to nitrosoureas; thus, inhibition of MGMT activity would benefit nitrosourea-resistant patients. Additional studies are necessary to elucidate the mechanism of regulation of MGMT expression.     

Biological activity of dihydroartemisinin in canine osteosarcoma cell lines

OBJECTIVE: To evaluate the biological activity of dihydroartemisinin on canine osteosarcoma cell lines in vitro. SAMPLE POPULATION: 4 canine osteosarcoma cell lines. PROCEDURES: Cell viability assays were performed on canine osteosarcoma cell lines OSCA2, OSCA16, OSCA50, and D17 after 24, 48, and 72 hours of treatment with dihydroartemisinin at concentrations of 0.1 to 100 microM. Apoptosis was assessed by use of an ELISA for free nuclosomal DNA fragmentation and by western blot analysis for cleavage of caspase 3. Cell cycle analysis was performed by use of staining with propidium iodide and flow cytometry. Detection of reactive oxygen species (ROS) was conducted in the D17 cell line by use of 6-carboxy-2',7'-dihydrofluorescein diacetate and flow cytometry. RESULTS: The concentration of dihydroartemisinin required for 50% inhibition of cell viability (IC50) was achieved in all 4 canine osteosarcoma cell lines and ranged from 8.7 to 43.6 microM. Induction of apoptosis was evident as an increase in nucleosomal DNA fragmentation, cleavage of caspase 3, and an increase in the population in the sub G0/G1 phase of the cell cycle detected by flow cytometry. Exposure to dihydroartemisinin also resulted in a decrease in the G0/G1 population. Iron-dependent generation of ROS was detected in dihydroartemisinin-treated D17 cells; ROS generation increased in a dose-dependent manner. CONCLUSIONS AND CLINICAL RELEVANCE: Incubation with dihydroartemisinin resulted in biological activity against canine osteosarcoma cell lines, which included induction of apoptosis and arrest of the cell cycle. Clinical trials of dihydroartemisinin in dogs with osteosarcoma should be conducted.     

Antibacterial activity of thionin Thi2.1 from Arabidopsis thaliana expressed by bovine endothelial cells against Staphylococcus aureus isolates from bovine mastitis

Bovine mastitis is mainly caused by Staphylococcus aureus and antimicrobial therapy, commonly used for its control, has resulted in an increase in the frequency of resistant staphylococci in recent years. Thus, alternative therapies are desirable and the antimicrobial peptides represent attractive control agents. In this work, we expressed the antimicrobial peptide thionin Thi2.1 cDNA from Arabidopsis thaliana in the bovine endothelial cell line BVE-E6E7 and evaluated its activity against bovine mastitis S. aureus isolates. A polyclonal population from BVE-E6E7 cells transfected with the pThi2.1 construct was obtained and thionin Thi2.1 expression was confirmed by RT-PCR. From this population, eight stably transfected cell clones were obtained and their conditioned media (CM) were evaluated against the S. aureus ATCC 27543 strain. Clones showed high antibacterial activity (>95%) relative to the activity of the polyclonal population. The C8 clone showed the highest antibacterial activity (>99%) and its CM was evaluated against eleven bovine mastitis S. aureus isolates. A 2.5microg aliquot of total protein from the C8 clone's CM inhibited the growth of S. aureus isolates (>40%) relative to the CM from BVE-E6E7 cells used as control. Growth inhibition of S. aureus isolates was dose-dependent, showing a total inhibition at concentrations higher than 3.12microg/ml. These results suggest that thionin Thi2.1 antimicrobial peptide could be use in the treatment of bovine mastitis.     

Fatty acid synthase as a potential therapeutic target in feline oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is an aggressive and treatment‐resistant malignancy in both feline and human patients. Recent work has demonstrated aberrant expression of fatty acid synthase (FASN) and an increased capacity for lipogenesis in human OSCC and other cancers. In human OSCC, inhibition of FASN decreased cell viability and growth in vitro, and diminished tumour growth and metastasis in murine preclinical models. This study aimed to characterize FASN as a therapeutic target in feline OSCC. Immunohistochemistry revealed high FASN expression in primary feline OSCC tumours, and FASN expression was detected in OSCC cell lines (3 feline and 3 human) by immunoblotting and quantitative real‐time‐polymerase chain reaction (qRT‐PCR). Orlistat, a FASN inhibitor, substantially reduced cell viability in both feline and human OSCC lines, although feline cell lines consistently displayed higher sensitivity to the drug. FASN mRNA expression among cell lines mirrored sensitivity to orlistat, with feline cell lines expressing higher levels of FASN. Consistent with this observation, diminished sensitivity to orlistat treatment and decreased FASN mRNA expression were observed in feline OSCC cells following incubation under hypoxic conditions. Treatment with orlistat did not potentiate sensitivity to carboplatin in the cell lines investigated; instead, combinations of the 2 drugs resulted in additive to antagonistic effects. Our results suggest that FASN inhibition is a viable therapeutic target for feline OSCC. Furthermore, cats may serve as a spontaneous large animal model for human oral cancer, although differences in the regulation of lipogenesis between these 2 species require further investigation.     

慧星试验检测洛克沙胂对CHL细胞的DNA损伤

利用碱性单细胞凝胶电泳技术研究洛克沙胂对中国仓鼠肺细胞(CHL)的DNA损伤影响。洛克沙胂分为10、100、500、1000mg/L剂量组,分别以磷酸盐缓冲液和10mg/L亚砷酸钠为对照组,经3、6、12、24、48h暴露后进行单细胞凝胶电泳。结果表明,慧星试验参数尾DNA含量、慧星全长、慧尾长、尾距和Olive尾距等表现出剂量-效应、时间-效应关系,不同剂量洛克沙胂、不同暴露时间下对CHL细胞有不同程度的DNA损伤。