鱼组织中双去甲氧基姜黄素、去甲氧基姜黄素和姜黄素含量的超高效液相色谱法测定

建立了黄颡鱼、团头鲂和草鱼血浆、肌肉、肝脏、肾脏中双去甲氧基姜黄素、去甲氧基姜黄素和姜黄素同时测定的超高效液相色谱紫外检测法(UPLC-UV)。样品经乙腈(含0.01%乙酸)提取,无水硫酸钠除水,正己烷去脂等样品处理,在ACQUIT UPLC BEH C18色谱柱上分离,428 nm波长处测定。双去甲氧基姜黄素、去甲氧基姜黄素和姜黄素在0.01~5.00 mg/L浓度范围内呈良好的线性关系,相关系数(r2)分别为0.998 7,0.999 8和0.999 6。在空白鱼组织中进行0.025,0.05,0.50,1.00 mg/kg 4个水平的加标回收实验,3种待测组分的平均回收率为64.7%~102.2%,相对标准偏差为0.69%~10.8%。鱼组织中3种待测组分的检出限(LOD)均为0.010 mg/kg,定量下限(LOQ)均为0.025 mg/kg。应用该方法研究了姜黄素在团头鲂体内的药代动力学规律。     

不对称姜黄素类似物的合成及其清除自由基的研究

姜黄素类化合物中,非对称结构的单去甲氧基姜黄素具有一些特殊的生物活性.通过碱法合成2-单取代苯亚甲基环戊酮中间体,再用酸催化合成了10不对称的单羰基姜黄素类似物,多酚羟基的类似物可以不通过羟基保护直接合成,其中,除A1外其它9个为新化合物,并测试了所合成类似物对DPPH自由基的清除能力.结果表明类似物的酚羟基对自由基清...     

姜黄素法测定微量硼

硼的吸光光度法已有不少报道,次甲基蓝法是被广泛采用的方法之一,但要使用大量有毒的二氯乙烷。其他的显色剂还有1,1′-二蒽醌亚胺、醌茜素、胭脂红酸,但操作麻烦。后来又研究了硼水杨酸-乙基紫及硼水杨酸-罗丹明6C等三元络合物的方法,但灵敏度仍提不高。所以,灵敏度很高的姜黄素法仍然是目前广泛采用的方法。蒸干法的姜黄素法较费时,我们试验了直接显色法的条件。研究结果,本法简单快速、灵敏度高、重现性好,用于粮食、水质等样品中微量硼的测定,结果满意。　 1 试验部分     

硼—姜黄素络合物的高效液相色谱研究及应用

本文研究了在非水本系中硼与质子化的姜黄素形成的络合物以无水甲醇为溶剂，在Ｃ１８色谱柱上用甲醇－水（８０：２０Ｖ／Ｖ）作流动相分离并检测，硼的校正曲线线性范围为０．４－３．２μｇ／２５ｍＬ，硼的校测限为０．０８ｎｇ。此法用于复合硼肥的分析，结果令人满意。     

Be—姜黄素—β—环糊精—Triton X—100体系的研究及应用

本文采用姜黄素为显色剂研究了此试剂在β-环糊精和Triton X-100存在下与铍形成配合物的最佳条件:在pH 10.4～11.0的NH_4Cl-NH_3·H_2O介质中,配合物的最大吸收波长为520nm,显色时间快且可稳定3h,表观摩尔吸光系数为4.73×10~4L·mol~(-1)·cm~(-1),铍含量在0～5μg/25mL范围内符合比尔定律,可用于地矿试样中微量铍的测定。     

甲亚胺与姜黄素测定土壤有效硼方法的对比研究

土壤有效硼是决定土壤供硼能力的重要指标，目前中国多以沸水浸提土壤，并用姜黄素比色测硼值作为作物硼营养丰缺诊断指标．但在长期实践中，发现作物硼营养状况与热水溶性硼的相关性不稳定，同时测定值重现性不良。为提高作物硼营养诊断和预测的准确性，本研究通过０．０１ｍｏｌ／ＬＣａＣｌ２在２６０℃、３５ｍｉｎ浸提土壤条件下，用甲亚胺比色与沸水浸提，姜黄素比色法测定土壤有效硼的对比研究，证明甲亚胺法测定结果稳定，操作方法简便，适用于低硼土壤的大批量试样的自动分析。为甲亚胺测硼方法的推广应用，本研究已研制甲亚胺粉状试剂获得成功，与进口甲亚胺比较，性能完全一致。     

荧光碳点对生物体液中姜黄素的检测及细胞成像

本文以廉价易得的橘皮和柠檬酸为原料，通过一步水热法合成荧光碳点(CDs)。对CDs的形貌、结构、元素组成和光学性能等进行了表征，考察了离子强度、光稳定性和储存时间对CDs的影响。所合成CDs为粒径约为4 nm的类球形结构，具有较好的稳定性。通过对CDs与姜黄素(CM)检测体系的选择性实验，发现常见的离子及氨基酸对CM的检测几乎无影响。基于CM对CDs选择性荧光猝灭的现象，构建了检测姜黄素的荧光探针。在最佳实验条件下，该探针对CM检测的线性范围为5～40μmol/L,检出限为9.7 nmol/L。探讨了CDs和CM作用机理，发现其主要是静态猝灭。该CDs应用于健康人体体液(血液、尿液)中微量CM的测定，其加标回收率为104.0%～115.0%。橘皮合成碳点可用于A549细胞进行成像，并表现出低细胞毒性。实验结果表明，该CDs在CM的分析检测以及细胞成像中具有较好的应用价值。     

姜黄素对食管癌KYSE410细胞的生长抑制与氧化调节

通过四氮唑蓝盐化合物(MTS)和重要氧化还原酶及其代谢物的试剂盒检测等方法, 考察了姜黄素对食管癌KYSE410细胞生长以及对细胞氧化还原状态和代谢的影响. 结果表明, 姜黄素对KYSE410细胞具有较强的抑制作用, 其IC₅₀=17.9 μmol/L. 进一步研究发现, 姜黄素可引起细胞培养上层清液中超氧化物歧化酶(SOD)和丙二醛(MDA)水平发生变化. 当姜黄素浓度为40 μmol/L时, MDA水平比对照组提高了125.1%, 而SOD水平则降低了43.2%; 同时, 乳酸水平降低了44.4%, 乳酸脱氢酶的活性下降了58.2%, 丙酮酸激酶的活性升高了216.7%. 姜黄素可能通过干扰氧化还原途径, 致使发生脂质过氧化反应, 并抑制肿瘤细胞糖酵解作用, 进而抑制食管癌KYSE410细胞增殖.     

含氮含硫姜黄素类似物的微波合成及抗氧化活性研究

利用微波辐射合成含氮含硫的姜黄素类似物,比较了化合物的抗氧化能力。以苯甲醛与环戊酮或环己酮为原料,经克莱森-斯密特缩合反应,采用微波法合成中间化合物2,6-双苯亚甲基环己酮或2,5-双苯亚甲基环戊酮,中间体与尿素或硫脲经Biginelli反应合成目标化合物。利用DPPH法比较各化合物与姜黄素的抗氧化能力。合成了2个未见文献报道的新化合物(2b,2c),结构经IR、1H NMR、13C NMR和MS表征确证;增加含氮、含硫基团的衍生物,其抗氧化能力比姜黄素母核结构高。采用微波法合成含氮含硫的姜黄素类似物可显著提高产率,产率达83%,经24 h含氮、含硫化合物b的抗氧化能力与姜黄素相当,远比姜黄素母核强。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.