Antioxidant Activity of Brown Seaweeds

Antioxidant potential of three brown seaweeds, Anthophycus longifolius, Sargassum plagiophyllum, and Sargassum myriocystum, obtained from the Gulf of Mannar region of India were evaluated utilizing different in vitro systems. Ethyl acetate (EtOAc) fraction of Anthophycus longifolius registered significantly greater hydroxyl radical scavenging ability (IC₅₀ 0.19 mg/mL) and was effective in stabilizing the 2,2′-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid (IC₅₀ 1.23 mg/mL) and 1,1-diphenyl-2-picryl-hydrazil (DPPH) radicals (IC₅₀ 0.48 mg/mL) (p < 0.05). No significant differences in hydrogen peroxide (H₂O₂) scavenging and ferrous ion chelating properties of the EtOAc extracts of the seaweeds were apparent. The utilities of the reverse-phase high-performance liquid chromatography (RP-HPLC) method hyphenated to diode-array detection for analyzing the fingerprints of phenolic constituents in the solvent extracts and fractions of the seaweeds were denoted. High-performance liquid chromatographic analysis indicated the presence of phenolic acids in the solvent extracts of seaweeds. This study demonstrated the potential use of A. longifolius as candidate species to be used as a nutritional food supplement/functional foods to increase the shelf life of food items for human consumption.     

Carotenoid Profile of Edible Japanese Seaweeds: An Improved HPLC Method for Separation of Major Carotenoids

An improved multi-step gradient reverse phase high performance liquid chromatography (HPLC) method to simultaneously separate major carotenoids from natural as well as food samples was developed. Quantitative profiling of carotenoid compounds was carried out on three edible brown seaweeds (Sargassum horneri, Cystoseira hakodatensis, and Undaria pinnatifida) and three red seaweeds (Gracilaria vermiculophylla, Grateloupia asiatica, and Grateloupia livida). Fucoxanthin (Fx) was detected in all the brown seaweeds with quantities (mg g^?1 dry weight [dwt]) ranging from 1.3 ± 0.3 in C. hakodatensis to 2.4 ± 0.1 in S. horneri. U. pinnatifida, commonly known as wakame, had a Fx content of 2.3 ± 0.1 mg g^?1 dwt. In the case of red seaweeds, zeaxanthin (Zx) was the major carotenoid, and G. vermiculophylla had the highest Zx content (80.2 μg g^?1 dwt) among the red seaweeds apart from small amounts of Fx (9.1 μg g^?1 dwt). Similarly, the other two species of red seaweeds, G. asiatica and G. livida, contained (μg g^?1 dwt) lutein (Lut), Fx, and Zx as the major carotenoids (G. asiatica: Lut 10.4, Fx 1.5, Zx 1.1; G. livida: Lut 9.3, Fx 3.5, Zx 1.0). The results suggest the usefulness of edible varieties (barring wakame) of seaweeds as dietary sources of carotenoids.     

Optimized Extraction,Preliminary Characterization and Evaluation of the in Vitro Anticancer Activity of Phlorotannin-Rich Fraction from the Brown Seaweed,Cystoseira sedoides

Brown seaweeds produce useful bioactive substances with high cosmetic and pharmacological values due to the presence of antioxidant derivatives, mainly phlorotannins (PHT), which are of particular interest. A central composite rotatable design (CCRD) with three variables (extraction time, dry material-to-solvent ratio and ethanol concentration) and two responses was performed to optimize the microwave-assisted extraction (MAE) of phlorotannins from Cystoseira sedoides using response surface methodology (RSM). Results showed that the independent variables significantly affected both phlorotannin content and the scavenging capacity. The optimum operating conditions were extraction time, 101.74 sec; dry material-to-solvent ratio, 1:10 g/mL; and ethanol extraction, 50%. Under these conditions, the predicted values of PHT content and radical scavenging activity-IC50 were close to the observed values and were 383.887 µg PGE/g Dm and 18.353 µg/mL, respectively. Characterization of the phlorotannin-rich fraction was conducted by high-performance liquid chromatography and Fourier transform infrared spectroscopy. The evaluation of the anticancer activity against MCF-7 breast cancer cell line showed a potent activity to trigger apoptotic death in more than a half of the MCF-7 cells, with an estimated IC50 value of 78 μg/mL. In addition, this fraction induced a notable growth regression effect on 3D spheroids model in a concentration-dependent manner, with a growth rate of about 1.17, at 200 µg/mL.

Abbreviations: CCRD: Central composite rotatable design; Dm: Dry material; DMBA: 2,4-dimethoxy benzaldehyde; DMSO: Dimethyl sulfoxide; DPPH: 1,1-diphenyl-2-picrylhydrazyl; EDTA: Ethylene diamine tetraacetic acid; FBS: Fetal bovine serum; FT-IR: Fourier transform infrared; HPLC: High-performance liquid chromatography; IC₅₀: Half-maximal inhibitory concentration; MAE: Microwave-assisted extraction; Min: minutes; PBS: Phosphate buffered saline; PGE: Phloroglucinol equivalent; PHT: Phlorotannins; PHT-SED: phlorotannins derived from Cystoseira sedoides; PI: Propidium iodide; RSA: Radical scavenging activity; RSM: Response surface methodology; Sec: seconds     

Evaluation of Biochemical and Nutritional Potential of Seaweeds from Lakshadweep Archipelago

The variation of the proximate composition and mineral content of nine seaweeds available in the Lakshadweep group of islands were studied to evaluate their nutritional quality. The proximate composition and the mineral contents were determined as per standard methodologies. The nutritional quality was found to be comparable with common vegetables and fruits. Hansen’s nutritional quality index has shown the seaweeds U. lactuca, H. valentea, and H. muciformis, in particular, to be safe for their versatile use and that they can contribute to a healthy balanced diet.     

LC-MS/MS检测水产品源致病菌和腐败菌群体感应AHLs信号分子

为分析水产品源致病菌和腐败菌中群体感应信号分子AHLs的含量和种类,实验建立液相色谱-串联质谱(LC-MS/MS)同时检测细菌群体感应11种AHLs类信号分子的技术,并与生物报告菌法比较。结果显示,报告菌紫色杆菌CV026和根癌农杆菌A136检测发现嗜水气单胞菌和2株铜绿假单胞菌是AHLs产生菌。建立的LC-MS/MS能完全分离和检测11种AHLs,并发现假单胞菌和嗜水气单胞菌产生的AHLs信号分子含量较高,其中ATCC 9027和ATCC 15692产生3-oxo-C12-HSL,嗜水气单胞菌A2产生C4-HSL,而腐败希瓦氏菌XH4分泌的C4-HSL信号分子含量较低,沙门氏菌ATCC 14028-3、大肠杆菌O157:H7和3种弧菌的AHLs很低。随着细菌浓度的增加,铜绿假单胞菌ATCC 9027产生的AHLs含量逐步增加,在12 h达到最高。研究表明,LC-MS/MS可用于多种AHLs信号分子的定性和定量检测,具有灵敏性与准确性更高的优点。在11株水产品源致病菌和腐败菌中,假单胞菌和气单胞菌分泌的AHLs含量最高。     

Determination of selected antibiotics in farmed fish species using LC‐MS/MS

The aim of the study was to monitor the occurrence of 37 antibiotics from different classes including fluoroquinolone, tetracycline, macrolide, sulphonamide, penicillin, amphenicol and cephalosporin in three different farmed fish species (n = 75; rainbow trout, see bass, gilthead see bream) from five cities in Turkey. A method for LC‐MS/MS was optimized and validated to assess these antibiotics. As a result, 25 samples showed contamination with at least one antibiotic residue. The most detected antibiotics were norfloxacin (NOR) (18.7%), marbofloxacin (MAR) (12%), tetracycline (TC) (10.7), danofloxacin (DAN) (9.3%), oxytetracycline (OTC) (9.3%), tilmicosin (TLM) (8%) and enrofloxacin (ENR) (6.7%). A total of 17.3% of samples examined were found to be contaminated with residues exceeding the maximum residue limits (MRLs). The results indicate that antibiotics are frequently used in aquaculture production without the lack of knowledge. This study also revealed that the consumption of farmed fish could produce a public health concern as the level of residues for some antibiotics was much higher than MRLs.     

水产品中7种大环内酯类抗生素残留量的HPLC-MS/MS测定法

建立了水产品中7种大环内酯类抗生素[竹桃霉素（OLD）、红霉素（ERM）、吉他霉素（KIT）、交沙霉素（JOS）、螺旋霉素（SPI）、替米考星（TIL）和泰乐菌素（TYL）]残留检测的HPLC-MS/MS法。样品经乙腈提取,中性氧化铝和正己烷净化后,以选择反应检测模式检测,基质匹配标准工作曲线定量。在1～100 ng·mL-1范围内,7种药物的峰面积与质量浓度的线性关系良好（R2〉0.995）。试验选择不同阴性样品为试样,在4μg·kg-1、20μg·kg-1和40μg·kg-1添加水平下的回收率为75.4%～108%,相对标准偏差为0.665%～12.9%。方法的检出限为1μg·kg-1,定量限为4μg·kg-1。该方法简单,灵敏度高,重现性好,可为水产品中7种大环内酯类抗生素残留的检测提供技术支持。     

超高效液相色谱-串联质谱法测定凡纳滨对虾中的硝基呋喃代谢物残留

采用超高效液相色谱-串联质谱（UPLC-MS/MS）法,测定了凡纳滨对虾（Litopenaeus vannam ei）中氨基脲（SEM）、1-氨基-2-内酰脲（AHD）、3-氨基-2-唑烷基酮（AOZ）和5-甲基吗啉-3-氨基-2-唑烷基酮（AMOZ）4种硝基呋喃类代谢物。采用2-硝基苯甲醛作为衍生化试剂,氘、碳-13、氮-15同位素标记的SEM1-3C1-5N2、AHD1-3C3、AOZ-D4和AMOZ-D5为内标物,样品经衍生、乙酸乙酯提取、正己烷净化,以甲醇0.5 mmol.L-1乙酸铵水溶液（含0.1%甲酸）为流动相进行梯度洗脱,8 m in可将4种目标化合物完全分离并测定。结果表明,4种待测物在0.4～20.0 ng.mL-1范围内线性关系良好（R〉0.999）,检出限为0.03～0.15μg.kg-1。在0.5μg.kg-1、1.0μg.kg-1和2.0μg.kg-13个水平上进行加标回收试验,平均回收率为92.0%～107.3%,RSD为3.1%～8.7%。采用该法参加FAPAS国际水平测试,获得了满意的结果。     

液相色谱—串联质谱法研究恩诺沙星在中华草龟体内的药物代谢动力学

为研究不同给药方式下,恩诺沙星在中华草龟体内的药物代谢动力学规律,实验选取20只健康中华草龟,每组10只,随机分为2组,分别为肌注组和胃插管强制口服组,给药量均为10 mg/kg,应用液相色谱—串联质谱法测定数据,Kinetic 4.4软件的非房室模型分析药时数据。胃插管强制口服给药主要药动学参数为C_max7.49 μg/mL、T_max 12 h、T_1/2λz为99.85 h、AUC_0-∞为531.67 μg/(mL·h);肌注给药主要药动学参数为C_max 5.85 μg/mL、T_max 4 h、T_1/2λz为30.42 h、AUC_0-∞为193.6 μg/(mL·h)。2种不同给药条件下,肌注恩诺沙星比胃插管强制口服更快达到最高血药浓度,表明肌注恩诺沙星在中华草龟体内吸收更快;胃插管强制口服给药的C_max和AUC均高于肌注给药,表明胃插管强制口服恩诺沙星在中华草龟体内吸收更完全,分布更广泛,效果更好。恩诺沙星在中华草龟体内消除缓慢,滞留时间(MRT)长,胃插管强制口服给药MRT显著长于肌注给药,其血药浓度保留时间长,效果更持久。研究表明,需较快达到疗效时,建议肌注恩诺沙星;需持续给药且龟体代谢状态正常时,建议胃插管强制口服恩诺沙星;恩诺沙星在胃插管强制口服给药条件下,在中华草龟体内血药浓度高、保留时间长、生物利用度高,更适宜作为中华草龟个体疾病治疗的给药方式。     

液质联用法测定水产品中喹诺酮类药物残留量的不确定度评定

文章建立了液质联用法检测水产品中喹诺酮类药物残留量结果的不确定度评估数学模型,对测量过程中的不确定度来源进行分析评定,计算各不确定度分量、相对合成不确定度和扩展不确定度,得到喹诺酮类药物的不确定度报告。分析结果显示,该测量过程产生的不确定度主要来源于液质联用仪和标准工作液配置引入的不确定度。     

用液相色谱串联质谱法测定渔业水样中6种农药的含量

本文建立了一种快速检测渔业水质样本中酰胺类除草剂乙草胺、丙草胺、丁草胺、三嗪类除草剂莠去津、烟碱类杀虫剂噻虫嗪、三唑类杀菌剂苯醚甲环唑6种农药含量的液相色谱串联质谱法。采用乙腈-水-甲酸梯度洗脱、电喷雾电离方式、多反应监测模式测定考察检出限、线性范围、日内精密度及日间精密度。在三种加标浓度下,该方法的回收率为78.2%~104.7%。用液相色谱-四级杆-飞行时间质谱对疑似目标物质进行定性,用精确质量数、同位素丰度比和二级碎片解析方式等解析定性结构。该方法能够满足检测这六种农药的要求,能准确定性,自建的谱库可为渔业污染事故鉴定和水产品质量安全风险评估做支撑。     

超高效液相色谱-电喷雾串联质谱法测定水产品中亚甲基蓝及代谢物

建立了超高效液相色谱-电喷雾串联质谱法同时检测水产品中亚甲基蓝及其代谢物的分析方法。经过条件优化,试样用10 mL乙腈提取3次,并在体系中添加盐酸羟胺、对甲苯磺酸等提高提取效率,提取液经对丙磺酸固相萃取小柱净化,按V（乙腈）：V（乙酸铵,1 mol·L-1）=1：1洗脱,采用Thermo Hypersil C18色谱柱,以甲醇和0.2%甲酸为流动相进行梯度洗脱分离,电喷雾离子源（ESI）,正离子模式,采用选择反应监测（SRM）扫描模式。结果表明,亚甲基蓝及代谢物（天青A、天青B、天青C）在0.50-100.00 μg·L-1范围内线性关系良好,相关系数R〉0.99,在10 min内实现分离,3个加标水平（2 μg·kg-1、4 μg·kg-1、10 μg·kg-1）的平均回收率为74.23%-94.40%（n=6）,相对标准偏差（RSD）为1.13%-10.28%,检测限（LOD）为0.40~0.60 μg·kg-1,定量限（LOQ）为2.00 μg·kg-1。该方法简便快捷、准确度高,易于推广应用,可作为快速测定水产品中亚甲基蓝及其代谢物的有效方法。     

超高效液相色谱-电喷雾串联质谱法同时测定鱼类加工品中12种杂环胺类化合物

建立了超高效液相色谱-电喷雾串联质谱法同时测定鱼类加工品中12种杂环胺类化合物（HAAs）的分析方法。经过条件优化,肉样选用乙酸乙酯、氨水和三乙胺提取,提取液经MCX固相萃取小柱净化,按V（甲醇）∶V（氨水）=9∶1洗脱,采用Thermo Hypersil Gold C18色谱柱,以甲醇和5 mmol.L-1乙酸铵溶液为流动相进行梯度洗脱分离,电喷雾离子源（ESI）,正离子模式,采用选择反应监测（SRM）扫描模式,内标法进行定量分析。结果表明,12种HAAs在1.0～100.0μg.L-1范围内线性关系良好,相关系数R〉0.99,在12 min内实现分离,3个加标水平的平均回收率为42.98%～125.00%（n=6）,相对标准偏差（RSD）为1.49%～9.88%,检测限（LOD）为0.3～1.0μg.kg-1。该方法简便快捷,准确度高,易推广应用,可作为快速测定鱼类加工品中多种HAAs的有效方法。     

液相色谱-三重四级杆复合线性离子阱质谱法分析恩诺沙星在鲤鱼(Cyprinus carpio)中的代谢产物

采用液相色谱-三重四级杆复合线性离子阱质谱(HPLC/Q-TRAP MS),在正离子检测模式下,对鲤鱼(Cyprinus carpio)腹腔注射恩诺沙星给药后肝脏中的代谢产物进行分析.根据保留时间和各色谱峰质谱裂解规律,推测了恩诺沙星在鲤鱼肝脏中的代谢产物,同时,根据二级质谱碎片离子推测代谢途径及代谢产物结构.结果显示,恩诺沙星进入鲤鱼肝脏后,除以恩诺沙星原形药物(M0)和N-去乙基代谢产物环丙沙星(M2)形式存在外,还有少量恩诺沙星脱羧代谢产物(M1)和恩诺沙星羟基化代谢产物(M3-1和M3-2).该研究可为深入了解恩诺沙星在水生动物体内代谢产物及代谢机理提供理论基础,为在水产养殖生产中科学、合理地使用恩诺沙星提供参考.     

超高效液相色谱-串联质谱快速测定水产品中孔雀石绿、结晶紫及其代谢物残留量

建立了超高效液相色谱-串联质谱（UPLC-MS/MS）测定水产品中孔雀石绿（MG）、结晶紫（CV）及其代谢物隐色孔雀石绿（LMG）和隐色结晶紫（LCV）残留量的快速、准确检测方法。该法在SN/T1768-2006快速检测方法的基础上,采用空白样品添加不同质量浓度标准溶液的方式绘制校准曲线,并以氘代孔雀石绿（D5-MG）和氘代隐色孔雀石绿（D6-LMG）为内标进行检测,从而大大提高了定量的准确性。结果表明,MG、CV、LMG和LCV4种待测物在0～10.0ng·mL^-1范围内线性关系良好（R〉0.99）,方法检出限均为0.1μg·kg^-1。在加标量为0.5和1.0μg.kg-1水平下4种待测物平均回收率在92.1%～111.0%之间,测定结果的相对标准偏差为2.2%～9.5%。此外,该法在FAPAS国际能力验证中得以证实,改进后的方法快速且准确,能满足水产品出口检测要求。     

高效液相色谱-串联质谱法测定水产品中玉米赤霉醇类激素药物残留量

文章建立用高效液相色谱-串联质谱法（HPLC—MS／MS）测定水产品中玉米赤霉醇类激素药物残留量的方法。用乙腈提取水产品中6种玉米赤霉醇类药物,正己烷脱脂,氨基固相萃取柱净化。采用电喷雾电离,负离子扫描,选择反应监测模式（SRM）监测,外标法定量。该法对6种玉米赤霉醇类药物标准曲线的线性回归系数均在0．99以上,线性范围0～25μg·kg^-1,方法定量限1．0μg·kg-1。6种玉米赤霉醇类激素药物回收率75．9％～103．8％,相对标准偏差3．90％～13．5％。该法简单、灵敏,结果可靠,可满足实验室批量样品分析的需求。     

天津市售主要经济贝类中麻痹性贝类毒素污染现状及特征分析

使用液相色谱串联质谱法(LC-MS/MS)检测9种天津市售主要经济贝类中13种麻痹性贝类毒素(paralytic shellfish poisoning,PSP)的含量,分析PSP的污染现状和成分特征。结果显示,共计6个品种(紫贻贝、虾夷扇贝、牡蛎、毛蚶、脉红螺、菲律宾蛤仔)检出PSP。其中虾夷扇贝、紫贻贝、毛蚶3个品种的检出率较高且含量较高,检出率分别为66.7%、58.3%、58.3%。PSP中检出率较高的毒素包括N-磺酰胺甲酰基类毒素C1、C2和膝沟藻毒素GTX1、GTX2、GTX3,毒力占比主要以膝沟藻毒素GTX1-4为主,毛蚶蓄积STX毒素的能力强于其他贝类。全年的PSP含量季节变化为夏季最高,冬季最低。PSP主要存在于贝类的消化腺内,全年不同月份的PSP含量均在安全食用范围内。     

石墨烯/碳纳米管复合纳米材料改良QuEChERS联合UPLC-MS/MS技术检测养殖水产品中抗生素残留的研究

[目的]为提高养殖水产品中抗生素的检测效率,[方法]本文以新型石墨烯/碳纳米管复合材料为吸附剂,采用QuEChERS前处理,通过UPLC-MS/MS建立了一种可同时实现不同养殖水产品中28种抗生素残留检测的技术方法。[结果]通过加标回收率研究了不同提取溶剂,不同吸附剂添加量,不同种类吸附剂对养殖水产品中抗生素检测效率的影响,并确定了最佳的QuEChERS操作参数。最后,根据食品法典指南(CAC/GL-71)进行方法学验证,性能指标包括线性、检测限、定量限、基质效应、回收率、日内精密度和日间精密度。[结论]结果表明,当以乙腈:甲醇(75:25,V/V)为提取剂,吸附剂的添加量为10 mg时,石墨烯/碳纳米管复合纳米材料的吸附效果达到最佳。此时,所建立技术方法的线性良好(R2^>0.99),检出限为0.06 μg/kg ~1.42 μg/kg,定量限为0.20 μg/kg~4.72 μg/kg,多数抗生素(SIA、SQX、DAN、LOM除外)基质效应较低(<10%)。在5 μg/kg~100 μg/kg的添加水平下,平均回收率为80.1%~100.4%。日内精密度< 10.3%,日间精密度< 13.4%。将该方法应用于草鱼,大口黑鲈,南美白对虾,中华绒螯蟹,厚壳贻贝中28种抗生素的检测,结果表明,所建立的方法重复性好,灵敏度高,适用于常规检测。[意义]本研究的结论表明石墨烯/碳纳米管复合纳米材料可以较好吸附养殖水产样品中的脂肪、色素等杂质,提高养殖鱼肉中抗生素的检测效率,在水产品质量安全控制方面具有较好的应用前景。     

QuEChERS-液相色谱-串联质谱法测定鲤肝脏中氟虫腈及其代谢物残留

以QuEChERS作为样品前处理方法,结合高效液相色谱-串联质谱(HPLC-MS/MS)检测技术,建立了鲤(Cyprinus carpio)肝脏中氟虫腈(fipronil)及代谢物氟甲腈(fipronil desulfinyl)、氟虫腈亚砜(fipronil sulfide)和氟虫腈砜(fipronil sulfone...