HPLC法测定150种中药材中黄曲霉毒素G2、G1、B2、B1的含量

目的:建立了HPLC法测定150种中药材中的黄曲霉毒素G₂、G₁、B₂、B₁含量。方法:样品经70%甲醇提取、免疫亲和色谱柱净化后,用HPLC-柱后衍生-荧光检测器测定结果:黄曲霉毒素G₁、B₂在0.15～6.00 ng·ml^-1范围内,黄曲霉毒素C₁、B₁在0.5～20.00 ng·ml^-1范围内线性关系良好回收率为85.6%～92.0%结论:本法操作简便,结果准确、重复性好,可用于中药材中黄曲霉毒素G₂、G₁、B₂、B₁的测定     

制貂肾中黄曲霉毒素的测定方法研究及暴露风险评估

目的:本研究基于免疫亲和柱净化样品,采用高效液相色谱法光化学衍生荧光检测器测定制貂肾中黄曲霉毒素B₁、B₂、G₁、G₂的含量并对其进行暴露风险评估。方法:样品采用70%甲醇作为提取溶剂,经免疫亲和柱净化、高效液相色谱分离、光化学柱后衍生后,通过荧光检测器测定其中黄曲霉毒素的含量。采用暴露边界比对制貂肾黄曲霉毒素的有害残留物进行风险评估。结果:结果表明黄曲霉毒素B₁的线性范围为0.010 4～0.052 0 ng(r=0.999 9)、黄曲霉毒素B₂的线性范围为0.003 8～0.019 0 ng(r=0.999 8)、黄曲霉毒素G₁的线性范围为0.010 8～0.054 0 ng(r=0.999 8)、黄曲霉毒素G₂的线性范围为0.003 8～0.019 0 ng(r=0.999 8),线性关系良好,回收率在89.31%～99.54%间,RSD≤3.1%。结论:建立的制貂肾中黄曲霉毒素检测方法具有操作简单,灵敏度...     

基于HPLC研究柏子仁中黄曲霉毒素的污染状况与风险分析

目的 基于HPLC研究柏子仁中4种黄曲霉毒素的污染情况,并进行风险分析,评估柏子仁的用药安全。方法 采用Agilent Eclipse Plus C₁₈(4.6×250 mm 5μm)为色谱柱,柱后光化学衍生法检测,以甲醇∶乙腈∶水(35∶10∶55)为流动相,流速1.0 mL·min^-1;柱温：40℃;荧光检测器检测。结果 黄曲霉毒素B₁、B₂、G₁、G₂分别在0.35～20.8μg·L^-1、0.13～7.6μg·L^-1、0.36～21.6μg·L^-1、0.13～7.6μg·L^-1范围内呈良好的线性关系,黄曲霉毒素B₁、B₂、G₁、G₂平均回收率分别为90.6%、83.46%、87.84%、86.58%,相对偏差分别为2.9%、3.6%、3.6%、4.7%。23批柏子仁中有14批检...     

人血清水溶性维生素B1、B2、B6和B9高效液相色谱串联质谱联用技术测定方法的建立和验证

目的：建立测定人血清中水溶性维生素B₁、B₂、B₆和B₉的高效液相色谱串联质谱联用法。方法：常规送检患者血清经乙酸乙酯萃取,经反相高效液相色谱分离,采用电喷雾离子化四级杆串联质谱多反应监测模式测定维生素B₁、B₂、B₆和B₉浓度。结果：维生素B₁、B₂、B₆、B₉线性范围分别为1~200,5~40,1~80,5~40 ng·mL^-1;R²值分别为0.991 6,0.996 8,0.992 2,0.991 4;最低定量限分别为1,5,1,5 ng·mL^-1;日内、日间RSD均小于8.5%。结论：所建立方法可用于常规送检患者血清水溶性维生素B₁、B₂、B₆和B₉测定。     

UPLC-MS/MS法与ELISA法测定胖大海中黄曲霉毒素的比较研究

目的 采用超高效液相色谱-串联质谱法(UPLC-MS/MS)和酶联免疫吸附法(ELISA)对胖大海中的黄曲霉毒素进行检测，比较 两种方法的检测结果以及方法学差异性。方法UPLC-MS/MS法测定：样品采用70%甲醇提取经过免疫亲和柱净化，色谱柱为C₁₈(100 mm×2.1 mm,1.7μm)，柱温为40℃，流动相为水含0.1%甲酸(A)-甲醇含0.1%甲酸(B)，梯度洗脱，流速为0.3 m L·min^-1，多反应检测扫描采集模式，正负离子同时扫描进行数据采集。同时采用ELISA法测定，样品采用甲醇提取，酶联免疫试剂盒反应。结果 UPLC-MS/MS法测定：黄曲霉毒素B₁、B₂、G₁、G₂线性关系良好，检测限分别为0.013 5,0.002 9,0.008 6,0.003 6μg·kg^-1，定量限分别为0.045 0,0.009 8,0.028 6,0.011 9μg·kg^-1，平均回收率分别为98.98%,10...     

决明子中黄曲霉毒素测定方法的优化

目的:优化决明子中黄曲霉毒素测定方法。方法:采用中普红ODS-H C₁₈色谱柱(250 m×4.6 mm, 5μm),以[甲醇∶乙腈(40∶18)]-水(38∶62)为流动相,流速：1.0 ml·min^-1,用1%吐温80溶液洗脱,激发波长λex=360 nm,发射波长λem=450 nm,光化学衍生法,柱温30℃,进样量20μl。并用HPLC-MS/MS进行验证。结果:有效去除决明子中假阳性的干扰成分,黄曲霉毒素B₁、B₂、G₁、G₂四个成分r值分别为0.999 7,0.999 9,0.999 9,0.999 9,线性范围分别为：0.006 48～0.054 0 ng、0.001 98～0.016 5 ng、0.006 06～0.050 5 ng、0.001 80～0.015 0 ng,平均回收率分别为92.31%,91.45%,93.27%,93.34%(RSD分别为0.92%,1.15%,1.08%,0.78%,n=9)。液质与液相测定结果一致。结论...     

淡豆豉炮制过程中黄曲霉毒素含量的动态变化规律分析

目的: 检测淡豆豉炮制过程中不同时间点样本的黄曲霉毒素(AFTs)含量,明确AFTs的动态变化规律及其产生的关键时间点。方法: 按实验室前期已建立的规范炮制工艺制备淡豆豉,获取淡豆豉炮制过程中不同时间点的样本;采用超高效液相色谱-串联质谱法(UPLC-MS/MS)检测各样本中4种AFTs [黄曲霉毒素B₁(AFB₁),AFB₂,AFG₁,AFG₂]含量。结果: 4种黄曲霉毒素在选定的质量浓度范围内与峰面积线性关系良好(R²均大于0.99),重复性相对标准偏差(RSD)0.4%~0.9%,精密度RSD 0.7%~2.6%,稳定性RSD 0.8%~1.74%,加样回收率介于95.09%~107.20%(RSD 3.14%~12.71%);AFB₁含量在淡豆豉整个炮制过程中呈先上升后下降的趋势,在"再闷"第6天时达最高值6.95 μg·kg^-1,再闷第12天后各样本均未检测出AFTs。结论: 本研究建立了简单、快速、灵敏度高且适用于淡豆豉中4种AFTs检测的UPLC-MS/MS法;淡豆豉炮制过程中AFTs含量呈动态变化,表明淡豆豉炮制中生物拮抗作用自然存在,从安全性角度证实淡豆豉炮制中"再闷"环节的重要性和"再闷"时间的合理性。     

板蓝根中外源性有害残留的全面检查及风险评估

目的 对板蓝根中外源性有害残留进行全面检查和风险评估,为板蓝根的安全用药提供参考。方法 采用气相色谱-三重四极杆质谱联用仪和液相色谱-三重四极杆质谱联用仪测定33种禁用农药,免疫亲和柱-高效液相色谱-柱后光化学衍生法测定4种黄曲霉毒素,电感耦合等离子体质谱测定5种重金属及有害元素,离子色谱法测定二氧化硫,并采用靶标危害系数法对安全风险做出评估。结果 64批样品中33种禁用农药和黄曲霉毒素B₁、B₂、G₁、G₂均未检出。二氧化硫低于《中华人民共和国药典》(2020年版)规定限度(150 mg·kg^-1),64批样品及板蓝根品种中二氧化硫和Pb、Cd、As、Hg、Cu的靶标危害系数均远低于1。基于风险评估结果提出板蓝根中Pb、Cd、As、Hg、Cu的限度分别为2、1、2、0.2、20 mg·kg^-1。结论 板蓝根中外源性有害残留风险低。     

免疫亲和柱净化光化学衍生高效液相色谱-荧光检测法测定动物类药材中黄曲霉毒素

目的建立动物类药材中黄曲霉毒素B1,B2,G1,G2的免疫亲和柱净化光化学衍生高效液相色谱-荧光检测(HPLC-FLD)法。方法样品经甲醇-水(80∶20)提取后,通过免疫亲和柱净化、柱后光化学衍生、高效液相色谱-荧光检测器测定。结果在优化条件下,黄曲霉毒素G2,G1,B2,B1的检出限分别为0.15,0.25,0.1,0.2μg/kg,回收率为78.8%～106.7%,RSD均低于7.1%。结论所用方法简便快速、灵敏度高、重现性好,可满足动物类药材中黄曲霉毒素检测的需要。     

注射用腺苷钴胺与维生素B1注射液的配伍稳定性考察

目的:考察在室温不同光照条件下注射用腺苷钴胺与维生素B₁注射液配伍稳定性,并与临床常用溶媒进行比较。方法:将注射用腺苷钴胺分别与维生素B₁注射液、灭菌注射用水及0.9%氯化钠注射液配伍。2 h内在室温避光、红光、部分见光及完全见光条件下,分别观察和检测各配伍液外观、不溶性微粒数及pH值变化,采用高效液相色谱法测定配伍液中腺苷钴胺及维生素B₁的含量。结果:在避光和红光条件下,注射用腺苷钴胺与维生素B₁注射液配伍2 h内外观、pH值、不溶性微粒数及含量均未发生明显变化;在部分见光及完全见光条件下,配伍液2 h内不溶性微粒数、pH值及维生素B₁含量保持稳定,但腺苷钴胺的含量明显下降。相同光照条件下,注射用腺苷钴胺分别与灭菌注射用水、0.9%氯化钠注射液配伍2 h内,pH值均随时间呈上升趋势,腺苷钴胺含量均呈明显下降趋势,且下降速度较维生素B₁配伍组更快。结论:注射用腺苷钴胺与维生素B₁注射液配伍2 h内,在避光和红光条件下稳定性良好,在部分及完全见光条件下的稳定性均优于其与灭菌注射用水或0.9%氯化钠注射液。     

Levels of fumonisin B1 in corn naturally contaminated with aflatoxins

Aflatoxins and fumonisin B₁ are hepatotoxic and carcinogenic metabolites produced by Aspergillus flavus and Fusarium moniliforme, respectively. These fungi are common natural contaminants of corn, and both aflatoxins and fumonisin B₁ have been implicated as aetiological agents in animal and human diseases. To determine whether these mycotoxins co-exist on corn under natural conditions, 28 samples from the 1991 Georgia (USA) corn crop were assayed for (total) aflatoxin and fumonisin B₁. 27 samples were positive for aflatoxin, 24 samples were positive for fumonisin B₁, and 23 samples had detectable levels of both. In the positive samples, the mean aflatoxin concentration was 73 ppb (SD = 86), and the average fumonisin B₁ concentration was 0.87 ppm (SD = 0.65). A correlation between aflatoxin and fumonisin B₁ concentrations was not evident. None the less, these results demonstrate that exposure to both mycotoxins can occur simultaneously by consumption of co-contaminated corn.     

Cyclopiazonic acid inhibits mutagenic action of aflatoxin B(1)

Cyclopiazonic acid and aflatoxin B₁ are mycotoxins which can both be produced by the same moulds. Men can be exposed to these mycotoxins directly via ingestion of plant-derived food, as well as, indirectly via consumption of animal products. Although it is well known that aflatoxin B₁ is mutagenic, contradictory results exist on the mutagenicity of cyclopiazonic acid. Using the Ames test cyclopiazonic acid was not found to be mutagenic either with or without metabolic activation by S9-mix of Arochlor treated rats. However, the mutagenicity of aflatoxin B₁ was inhibited in the presence of cyclopiazonic acid. Since cyclopiazonic acid inhibited the formation of certain metabolites of caffeine and testosterone, it was concluded that the reduction of the mutagenicity of aflatoxin B₁ in the presence of cyclopiazonic acid results from the inhibition of the bioactivation of aflatoxin B₁ by certain cytochrome P450 enzymes.     

Two new and four known polyphenolics obtained as new cell-cycle inhibitors from Rubus aleaefolius Poir

Two new polyphenolics, rubuphenol (1) and sanguiin H-2 ethyl ester (2), were isolated together with ellagic acid (3), ethyl gallate (4), 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose (5) and 1,2,3,6-tetra-O-galloyl-β-D-glucopyranose (6) as new cell-cycle inhibitors from Rubus aleaefolius by bioassay-guided separation procedure and the structures of 1 and 2 were elucidated by spectroscopic method. Compounds 1 - 6 inhibited the cell cycle progression of tsFT210 cells at the G₀/G₁ phase with the MIC values of 14.6 μM (1), 22.1 μM (2), 10.3 μM (3), 7.8 μM (4), 7.9 μM (5) and 6.6 μM (6).     

Immunohistochemical study of proliferating cell nuclear antigen (PCNA) in duckling liver fed with aflatoxin B1 and esterified glucomannan

The effect of esterified glucomannan on aflatoxin B₁ toxicity in ducklings was studied by immunohistochemical staining of proliferating cell nuclear antigen (PCNA) in hepatic cells on formalin-fixed paraffin-embedded liver samples. Cherry Valley ducklings were divided into five groups, 20 birds in each. One of the groups was fed with conventional feed, and the other groups were fed with diet containing 100 ppb aflatoxin B₁, that containing 0.05% esterified glucomannan, or that containing 100 ppb aflatoxin B₁ supplemented with 0.05 or 0.1% esterified glucomannan, from five days of age for one month, and subsequently all the groups were fed with conventional feed for 20 days. Four birds of each group were sacrificed on the 30th, 35th, 40th, 45th and 50th day of feeding, and PCNA on the liver tissue sections was quantitatively analyzed by immunohistochemical staining. The percentage of PCNA-positive hepatocytes was significantly higher in the group given diet containing aflatoxin B₁ than in the other groups, which were not significantly different from each other. The results demonstrate that supplementation of feed with esterified glucomannan is effective in reduction of aflatoxin B₁-induced hepatic injury in ducklings.     

姜黄素对热打击血管内皮细胞损伤的保护作用

目的:研究姜黄素对热打击导致的人脐静脉内皮细胞(HUVECs)损伤的影响。方法:建立HUVECs热打击模型,对照组细胞置于标准37℃、5%CO2细胞培养箱培养,热打击组细胞于43℃细胞培养箱中热打击2 h,热打击后继续在37℃细胞培养箱孵育。姜黄素预处理组使用不同浓度姜黄素预处理细胞后进行热打击。使用CCK-8法检测细胞增殖,流式细胞术检测细胞周期及细胞凋亡,分光光度法检测Caspase活性,ELISA法检测细胞因子。结果:热打击显著抑制HUVECs的活力(P<0.05),而姜黄素预处理能以剂量依赖的方式减轻热打击对HUVECs活力的抑制作用(P<0.05)。与正常对照组相比,热打击后HUVECs出现显著的G0/G1期阻滞(P<0.05),而姜黄素预处理能显著减少热打击诱导的G0/G1期阻滞(P<0.05)。热打击后HUVECs中凋亡细胞的比例明显升高(P<0.05),姜黄素预处理能够显著减少细胞凋亡(P<0.05)。Caspase活性检测提示姜黄素可以抑制热打击诱导的Caspase活化(P<0.05)。姜黄素预处理后,热打击诱导的TNF-α、MCP-1产生明显减少(P<0.05)。结论:姜黄素能显著抑制热打击诱导的内皮细胞凋亡和炎性细胞因子产生,对热打击诱导的血管内皮细胞损伤具有保护作用。     

Temporary and partial inhibition of platelets by SM-20302 prevents coronary artery thrombosis in a chronic canine model

A cDNA clone coding for the guinea pig leukotriene B₄ (BLT) receptor has been isolated from a lung cDNA library. The guinea pig BLT receptor has an open reading frame corresponding to 348 amino acids and shares 73% and 70% identity with human and mouse BLT receptors, respectively. Scatchard analysis of membranes prepared from guinea pig and human BLT receptor-transfected human embryonic kidney (HEK) 293 EBNA (Epstein–Bar Virus Nuclear Antigen) cells showed that both receptors displayed high affinity for leukotriene B₄ (K_d value of 0.4 nM) and were expressed at high levels (B_max values ranging from 9 to 12 pmol/mg protein). The rank order of potency for leukotrienes and related analogs in competition for [³H]leukotriene B₄ specific binding at the recombinant guinea pig BLT receptor is leukotriene B₄>20-OH-leukotriene B₄>12(R)-HETE ((5Z,8Z,10E,12(R)14Z)-12-hydroxyeicosatetraen-1-oic acid)>12(S)-HETE ((5Z,8Z,10E,12(S)14Z)-12-Hydroxyeicosatetraen-1-oic acid)>20-COOH-leukotriene B₄>U75302 (6-(6-(3-hydroxy-1E,5Z-undecadienyl)-2-pyridinyl)-1,5-hexanediol)leukotriene C₄=leukotriene D₄=leukotriene E₄. For the human receptor the rank order of 12(S)-HETE, 20-COOH-leukotriene B₄ and U75302 was reversed. Xenopus melanophore and HEK aequorin-based reporter gene assays were used to demonstrate that the guinea pig and human BLT receptors can couple to both the cAMP inhibitory and intracellular Ca²⁺ mobilization signaling pathways. However, in the case of the aequorin-expressing HEK cells (designated AEQ17-293) transfected with either the guinea pig or human BLT receptor, expression of G₁₆ was required to achieve a robust Ca²⁺ driven response. Leukotriene B₄ was a potent agonist in functional assays of both the guinea pig and human BLT receptors. U-75302 a leukotriene B₄ analogue which possesses both agonistic and antagonistic properties behaved as a full agonist of the guinea pig and human BLT receptors in AEQ17-293 cells and not as an antagonist. The recombinant guinea pig BLT receptor will permit the comparison of the intrinsic potencies of leukotriene B₄ receptor antagonists used in guinea pig in vivo models of allergic and inflammatory disorders.     

Sesquiterpene glucosides from anti-leukotriene B4 release fraction of Taraxacum officinale

Chemical examination of the MeOH extract of the root of Taraxacum officinale, which exhibited inhibitory activity on the formation of leukotriene B₄ from activated human neutrophils, has resulted in the isolation of 14-O-β-D-glucosyl-11,13-dihydro-taraxinic acid (1) and 14-O-β-D-glucosyl-taraxinic acid (2). The absolute stereostructure of 1 has been established by X-ray chrystallographic examination.     

Aflatoxin deposition and clearance in the eggs of laying hens

Hens fed a diet containing 3310 μg of AFB₁ and 1680 μg of AFB₂ per kg feed for 28 days showed a significant decrease in egg production and egg weights by wk 3 and 4 of feeding, respectively. Transfer of aflatoxins to the eggs occurred rapidly, reaching maximum levels after 4–5 days, and remained relatively constant throughout aflatoxin feeding. The mean values for combined residue levels in eggs were less than 0.5 μg/kg. Levels of AFB₂, AFM₁ and AFM₂ were similar in yolk and albumen while levels of B₁ and B_2a were higher in the yolk. Upon removal of the aflatoxin-containing diet, residues in eggs decreased rapidly. Clearance of aflatoxin residues from the albumen occurred faster than from the yolk. Thus, no residues were detected in the albumen and in the yolk after 5 and 7 days of withdrawal, respectively. No aflatoxin residues could be recovered from whole eggs after feeding the aflatoxin-free diet for 4 days.