LC-MS/MS analysis of 2-aminothiazoline-4-carboxylic acid as a forensic biomarker for cyanide poisoning

AIM: To demonstrate the potential of using 2-aminothiazoline-4-carboxylic acid(ATCA) as a novel biomarker/forensic biomarker for cyanide poisoning. METHODS: A sensitive method was developed and employed for the identification and quantification of ATCA in biological samples, where the sample extraction and clean up were achieved by solid phase extraction(SPE). After optimization of SPE procedures, ATCA was analyzed by high performance liquid chromatographytandem mass spectrometry. ATCA levels following the administration of different doses of potassium cyanide(KCN) to mice were measured and compared to endogenous ATCA levels in order to study the significance of using ATCA as a biomarker for cyanide poisoning.RESULTS: A custom made analytical method was established for a new(mice) model when animals were exposed to increasing KCN doses. The application of this method provided important new information on ATCA as a potential cyanide biomarker. ATCA concentration in mice plasma samples were increased from 189 ± 28 ng/mL(n = 3) to 413 ± 66 ng/mL(n = 3) following a 10 mg/kg body weight dose of KCN introduced subcutaneously. The sensitivity of this analytical method proved to be a tool for measuring endogenous level of ATCA in mice organs as follows: 1.2 ± 0.1 μg/g for kidney samples, 1.6 ± 0.1 μg/g for brain samples, 1.8 ± 0.2 μg/g for lung samples, 2.9 ± 0.1 μg/g for heart samples, and 3.6 ± 0.9 μg/g for liver samples. CONCLUSION: This finding suggests that ATCA has the potential to serve as a plasma biomarker / forensic biomarker for cyanide poisoning.

Synthesis of (2S,4S)-2-Substituted-3- (3-Sulfanylpropanoyl)-6- Oxohexahydropyrimidine-4-Carboxylic Acids as Potential Antihypertensive Drugs

Proceeding from natural amino acid L-asparagine and commercially available aldehydes a stereoselective synthesis was developed of (2S,4S)-2-alkyl(aryl)-3-(3-sulfanylpropanoyl)-6-oxohexahy- dropyrimidine-4-carboxylic acids, potential antihypertensive drugs, inhibitors of the angiotensin converting enzyme.

Esterification and Chemoselective Synthesis of R-Tetrahydrothiazo-2-thione-4-carboxylic Esters Catalyzed by TiCl_4

A series of esters of R-tetrahydrothiazo-2-thione-4-carboxylic acid [ R-TTCA ] was synthesized by direct esterifica- tion of R-TTCA with alcohols（CH3OH, C2H5OH, n-C3HTOH, i-C3HTOH, n-C4H9OH, sec-C4H9OH） in the presence of TiCl4 as the catalyst at room temperature without using any other solvent or dehydrant in high yields, 91.6%-99.1% for primary alcohols and 55%- 80% for secondary alcohols. The catalyst has a strong chemoselec-tive activity for the esterification of primary alcohols with R-TTCA in the presence of secondary alcohols. Owing to high yield, high chemoselectivity, and mild conditions used, this is an efficient method for the esterification of prima-ry alcohols with R-TTCA.

Structure and Luminescent Property of a Novel 4-Hydroxyquinoline-2-carboxylate Based Zn(Ⅱ) Complex

A 3D coordination polymer [Zn2（hqc）2（H2O）]n has been obtained from the reaction of 4-hydroxyquinoline-2-carboxylic acid （H2hqc） with zinc（II） salt under hydrothermal condition, and characterized by elemental analysis, IR, TGA, PXRD and X-ray single-crystal diffraction. The complex crystallizes in the monoclinic system, space group P21/c with a = 14.305（2）, b = 9.132（2）, c = 15.356（2）, β = 103.586（7）o, V = 1949.9（4）3, Z = 4, Dc = 1.782 g/cm3, μ = 2.508 mm-1, Mr = 523.06, F（000） = 1048, T = 293（2） K, λ（MoKα） = 0.71073, S = 1.008, the final R = 0.0329 and wR = 0.0745 for 3849 observed reflections （I 〉 2σ（I））. The title complex features a 3D framework via Zn（2） linking the 1D {Zn1（hqc）2}n chains. Thermogravimetric analysis shows that its framework is highly thermally stable up to 556 ℃ in the solid state.

铽(Ⅲ)金属有机骨架材料对模拟尿液中二硫化碳生物标志物2-硫代噻唑烷-4-羧酸的荧光识别

以3-(3′,5′-二羧基苯氧基)邻苯二甲酸(H4L)作配体,通过水热法合成一种铽(Ⅲ)金属有机骨架材料(Tb-MOF),采用傅里叶红外光谱法、热重分析法和X射线粉末衍射法对其结构与性能进行表征,并通过荧光分光光度法在激发波长335 nm,发射波长546 nm处分析Tb-MOF的荧光性能并用于识别模拟尿液中的2-硫代噻唑烷-4-羧酸(TTCA)。结果显示:水热法合成了Tb-MOF,其产率为37%,该材料在400℃内热稳定性良好,在12 h内水稳定性良好。TTCA能有效猝灭Tb-MOF的绿色荧光,相对荧光强度(相对于Tb-MOF)约20%,推测荧光猝灭机理为配体H4L和TTCA的竞争性吸收导致从配体转移到铽(Ⅲ)的能量变少,从而使Tb-MOF荧光强度下降。加入等体积的0.01 mol·L^(-1)的氯化铵、氯化钾、肌酸、肌酐、氯化钠、硫酸钠、葡萄糖、尿素等模拟尿液组分后,2 mL 1 g·L^(-1)的Tb-MOF分散悬浮液的相对荧光强度均在88%以上,对TTCA检测干扰不大;加入等体积的0.01 mol·L^(-1)的尿酸后,2 mL 1 g·L^(-1)的Tb-MOF分散悬浮液的相对荧光强度约60%,对TTCA检测有一定的干扰。在TTCA浓度为25~196μmol·L^(-1)时,TTCA对Tb-MOF的猝灭过程符合斯顿-伏尔莫方程,检出限为3.84×10^(-2)μmol·L^(-1)。

尿中2-硫代噻唑烷-4-羧酸排泄规律初探

对１５名二硫化碳（ＣＳ２）作业工人与１４名非接触者进行了尿２硫代噻唑烷４羧酸（ＴＴＣＡ）排泄规律研究。结果表明，随ＣＳ２接触时间与接触量的增加，ＴＴＣＡ水平逐渐增高（班前、班中、班末ＴＴＣＡ几何均数分别为１．２５７４、１．６１２０、２．１８０５／ｇｃｒ），呈剂量效应关系。停止接触后ＴＴＣＡ排泄较快，１６ｈ后基本降至前一天班前水平。班末尿ＴＴＣＡ能灵敏地反映个体近期ＣＳ２接触量。４２个非接触者尿样中有３２个检出微量ＴＴＣＡ（７６．２％），其ＴＴＣＡ排泄无明显特征。

Design, Synthesis, Antifungal Activities and SARs of （R）-2-Aryl-4,5-dihydrothiazole-4-carboxylic Acid Derivatives

Based on the structure of natural product 2-aryl-4,5-dihydrothiazole-4-carboxylic acid, a series of novel （R）-2-aryl-4,5-dihydrothiazole-4-carboxylic acid derivatives were designed and synthesized. Their structures were characterized by ^1H NMR, ^13C NMR and HRMS. The single crystal structure of compound 9b was determined by X-ray diffraction analysis. The antifungal activities were evaluated for the first time. The bioassay results indicated that most compounds exhibited moderate to good antifungal activities. The antifungal activities of compound 13a （against Cercospora arachidicola Hori）, 13d （against Alternaria solani）, and 16e （against Cercospora arachidieola Hori） were 61.9%, 67.3% and 61.9%, respectively, which are higher than those of the commercial fungicides chlorothalonil and carbendazim. Moreover, compound 13d exhibited excellent antifungal activities against 7 kinds of the fungi tested （66.7%, 77.3%, 63.0%, 87.9%, 70.0%, 70.0% and 80.0% at 50 μg/mL）. Therefore, 13d can be used as a new lead structure for the development of antifungal agents.

Synthesis,Structure,and Magnetic Property of One Snake-shaped Copper(Ⅱ)-organic Compound:Cu[Cu_2(PP)_2](CBPC)_2]·2(H_2O)

One novel copper（II）-organic compound,namely Cu[Cu2（PP）2]（CBPC）2]·2（H2O）（1,H2CBPC = 1-[（2＇-carboxybiphenyl-4-yl）methyl]-2-propylimidazole-4-carboxylic acid,HPP = 3-（2-pyridyl）pyrazole）,was designed and synthesized under hydrothermal conditions.X-ray diffraction analysis reveals that two Cu（II）ions in the quasi-planar dimmer of [Cu2（PP）2] are linked by the carboxylate oxygen atoms on the phenyl ring and the imidazole ring,respectively,yielding one snake-shaped structure.Magnetic measurements reveal that compound 1 shows the strongly antiferromagnetic property.Crystal data of 1：C58H52Cu3N10O10,Mr = 1239.72,monoclinic,P21/c,a = 14.900（7）,b = 15.029（7）,c = 12.308（6）,β = 102.519（9）o,V = 2691（2）3,Z = 2,Dc = 1.530 g/cm3,F（000）= 1274,μ = 1.246 mm-1,R = 0.0416,wR = 0.0780（I 2σ（I））and S = 0.999.

Hydrothermal Synthesis and Crystal Structure of One Novel 1-D Copper(Ⅱ)-organic Framework:{[Cu_2(PP)_2(CBPC)]_2·7H_2O}_n

One novel 1-D copper（Ⅱ）-organic compound,namely {[Cu2（PP）2（CBPC）]2·7H2O}n（1,H2CBPC=1-[（2＇-carboxybiphenyl-4-yl）methyl]-2-propylimidazole-4-carboxylic acid,HPP=3-（2-pyridyl）pyrazole）,was synthesized under hydrothermal conditions.X-ray diffraction analyses reveal that the two Cu（Ⅱ） ions in the distorted dimer [Cu2（PP）2] of 1 are linked by the carboxylate oxygen atoms on the phenyl and imidazole rings,respectively,forming one interesting snake-like chain.Single-crystal X-ray analyses reveal that it crystallizes in monoclinic,space group C2/c with a=30.656（8）,b=12.715（3）,c=22.405（5）,β=122.758（3）°,V=7344（3）3,Z=4,Mr=1681.65,Dc=1.521 g/cm3,F（000）=3464,μ=1.221 mm-1,the final R=0.0453 and wR=0.1023 for 4617 observed reflections with Ⅰ 〉2σ（Ⅰ）.

A Facile Synthesis of 9,10-Dimethoxybenzo[6,7]- ox-epino[3,4-<i>b</i>]quinolin-13(6<i>H</i>)-one and Its Derivatives

A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.

接触二硫化碳男工血清性激素水平及尿代谢物含量分析

为探讨长期接触二硫化碳（ＣＳ２）的粘胶纺丝男工血清性激素及尿２－硫代－噻唑啶－４－羧酸（ＴＴＣＡ）水平，应用放射免疫法测定接触工人血清性激素水平及用高效液相色谱法测定工人班末尿中ＴＴＣＡ含量。以多功能气体红外监测仪定点连续监测车间ＣＳ２浓度为（１４．４０±４．６２）ｍｇ／ｍ３（６．０１～２５．３０ｍｇ／ｍ３），平均接触工龄为１０．４年。结果显示（１）接触组血清促卵泡激素〔ＦＳＨ：（１０．９４±７．３５）ＩＵ／Ｌ）〕明显高于对照组〔（７．５０±５．０７）ＩＵ／Ｌ〕；催乳素〔ＰＲＬ（５．７２±４．１８）ｎｇ／Ｌ〕则显著低于对照组〔（６．８９±４．６２）ｎｇ／Ｌ〕；血清促黄体激素（ＬＨ）、睾丸酮（Ｔ）等两组间均无统计学显著差异。但随着暴露工龄延长，ＨＬ含量明显下降。班的轮换不影响性激素水平。（２）在该接触浓度下工人班末尿ＴＴＣＡ为（１．０７２±１．０１３）ｍｇ／ｇ肌酐，随尿ＴＴＣＡ排出量增加，血清ＦＳＨ含量明显下降，存在接触－反应关系。本研究表明，现有接触水平对男工内分泌系统功能已造成一定损害。

接触二硫化碳工人辨色错误得分水平及尿代谢物含量分析

目的 为探讨长期接触CS2 工人色觉功能及尿 2 硫代塞唑烷 4 羧酸 (TTCA)水平。方法 应用FM10 0 HUE方法检测工人辨色能力 ,高效液相色谱测定工人班末尿中TTCA含量。结果 CS2 暴露组接触CS2 时间加权平均浓度为 15 5 3± 6 2 9mg/m3。常规眼科检查未见特异损伤 ;FM10 0 HUE检查男、女工主要在 5年～工龄段总错误得分水平、绿色及蓝色区带得分水平均显著高于同工龄段对照组 (P <0 0 5 )。暴露组女工尿TTCA含量低于男工 (P <0 0 1) ;15年工龄以上工人尿TTCA含量显著增高 ;10～ 15年工龄段男工尿TTCA含量与绿色区带的错误得分水平有一定相关性 (P <0 0 5 )。结论 CS2 对作业工人辨色力有一定影响 ,提示FM10 0 HUE辩色检查可作为低浓度CS2 对视觉系统毒作用敏感的健康监测指标。

饮酒对尿2-硫代噻唑烷-4-羧酸排泄的影响

目的 观察饮酒对二硫化碳 (CS2 )接触者及非接触者尿 2 硫代噻唑烷 4 羧酸 (TTCA)排泄的影响。方法 (1)男性非接触CS2 志愿者 10人 ,一次饮用 38°白酒 15 0ml或 2 5 0ml,高效液相色谱法观察其尿TTCA排泄动态 ;(2 )CS2 作业男工 15 2人 ,非接触者 6 0人 ,分别收集班末尿和晨尿进行TTCA测定并进行问卷调查 ;同时进行个体空气采样和CS2 浓度气相色谱法测定。结果 非接触者一次饮白酒 15 0ml后 3h尿TTCA水平达峰值 ,12h后降至饮前水平 (餐前 0 .5h ,饮酒后 1、3、12h中位数分别为 0 .0 45、0 .0 6 8、0 .0 99、0 .0 46mg/gCr ,n =10 ) ;TTCA水平随饮白酒剂量的增加而增高 ,饮 0、15 0、2 5 0ml白酒者TTCA水平 (中位数 )分别为 0 .0 36、0 .0 6 4、0 .6 0 9mg/gCr(n =5 ,饮后 3h)。CS2 浓度为≤ 10 .0、10 .1～ 5 0 .0、>5 0 .0mg/m3 时 ,CS2 接触者TTCA有随CS2 浓度增高而上升的趋势 ;对照组中饮白酒和啤酒者TTCA水平似高于不饮者 ,而接触组TTCA水平则随饮酒指数的增加而呈降低趋势。结论 大量饮酒可影响尿TTCA水平 ,在进行CS2 生物监测时 ,应避免在大量饮酒后 12h内采集尿样 ,以避免饮酒对监测结果的干扰作用。

Indole Alkaloids from the Roots of Ervatamia hainanensis

Two new indole alkaloids, named ibogamine-18-carboxylic acid, 3, 4-didehydro-7, 8-dioxo-methyl ester 1, ibogamine-18-carboxylic acid, 16, 17-didehydro-9, 17-dihydro-9-hydroxy （2-oxopropyl）-methyl ester 2, were isolated from Ervatamia hainanensis. Their structures were elucidated on the basis of spectroscopic methods.

百尾参化学成分的分离与鉴定

目的研究百尾参Disporum cantoniense的化学成分。方法利用各种色谱技术进行分离,运用现代光谱技术鉴定化合物结构。结果从百尾参中分离得到16个化合物,分别鉴定为马来酸酰亚胺-5-肟(1)、4-methylene-5-oxopyrrolidine-2-carboxylic acid(2)、胸腺嘧啶(3)、腺嘌呤核苷(4)、5′-deoxy-5′-methylamino-adenosine(5)、乙基-α-L-鼠李糖(6)、岩白菜素(7)、4-羟基-2-甲氧基苯基-6-脱氧-α-L-吡喃木糖苷(8)、(-)-表儿茶素(9)、(6R,9R)-roseoside(10)、3-(4-羟基-3,5-二甲氧基苯基)-丙烷-1,2-二醇(11)、3-羟基-5-(p-羟基苯基)-戊酸(12)、1-核糖醇基-2,3-二酮-1,2,3,4-四氢-6,7-二甲基-喹喔啉(13)、(6S,9R)-vomifoliol(14)、3,4-二羟基苯酰甲醇(15)和1,2-二羟基-1-(4-羟基-3,5-二甲基苯基)-乙烷(16)。结论化合物1、2、5~9、12~16为首次从该属植物中分离得到;化合物1、2、5~10、12~16为首次从该植物中分离得到。

Three pairs of alkaloid enantiomers from the root of Isatis indigotica

Three pairs of enantiomerically pure alkaloids with diverse structure features, named isatindigoticoic acid A and epiisatindigoticoic acid A [(—)-1 and(+)-1], phaitanthrin A and epiphaitanthrin A [(—)-2 and(+)-2], and isatindopyrromizol A and epiisatindopyrromizol A [(—)-3and(+)-3], respectively, were isolated from an aqueous extract of the roots of Isatis indigotica. Racemic and scalemic mixtures of these enantiomers were separated by HPLC on a chiral semi-preparative column.Their structures including absolute configurations were determined by extensive spectroscopic analysis in conjunction with the calculation of electronic circular dichroism(ECD) spectra. The enantiomer pairs possess parent structures of 2-oxo-1,2,3,4-tetrahydroquinoline-4-carboxylic acid, indolo[2,1-b]quinazolinone, and 3-thioxohexahydro-1H-pyrrolo[1,2-c]imidazol-1-one, respectively. Except for phaitanthrin A[(—)-2] which the configuration was previously undetermined, these compounds are new enantiomeric natural products.

Constituents from the Roots of Semiaquilegia adoxoides

In present literature search, some cyano-containing compounds, which are very rare in plants, from the traditional anticancer herb Tiankuizi were reported. To find more cyano-containing compounds in the important plant Semiaquilegia adoxoides （DC） Makino （Chinese name Tiankuizi）, the isolation of the chemical constituents was investigated for advancing the research. Two new compounds, a new alkaloid, 1,2,3,4-tetrahydro-6-hydroxy-1[（3,4-dihydroxyphenyl）methyl]-7-methoxy-2,2-dimethyl-isoquinolinium, named Semiaquilegine A （1）, and a new ester, 3-（4＇-hydroxyphenyl）-2-propenoic acid （4＂-carboxyl）-phenyl ester （2）, and four cyano-containing compounds, （Z）-6a-（β-D-glucosyloxy）-4a,5a-dihydroxy-2-cyclohexene-△^1,a-acetonitrile （3）, （L0-6α-（β-D-glucosyloxy）-4α-hydroxy-2-cyclohexene-△^1,α-acetonitrile （4）, lithospermoside （5）, ehretioside B （6）, as well as eleven known compounds, were isolated from the roots of Semiaquilegia adoxoides. The structures of new compounds 1 and 2 were elucidated mainly by 1D/2D-NMR techniques. Very unusual cyano-containing compounds 3 and 4 were first isolated from Ranunculaceae family. Hitherto, there were six cyano-containing compounds found in the herb.