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本文报道了在硫酸性介质中 ,以吐温 - 80为增溶剂 ,溴酸钾氧化姜黄催化光度法测定痕量钒 ( )的新体系。方法的检出限为 2 .6× 10 -3mg· L-1;相对标准偏差为 2 .7% (n=9) ,线性范围为 0 .0 12— 0 .0 4 0mg· L-1。可用于测定水样中痕量钒 ( ) ,结果满意 相似文献
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The computational results for curcumin at the B3LYP/6-31G(d,p) level show that the enol form of curcumin is more stable than the diketo form because of an intramolecular hydrogen bond, which extends the conjugation effect in the enol chain, formed in the enol structure. Cis-diketone form can not be obtained, presumably due to the strong repulsion between the carbonyl dipoles aligned in parallel. According to the phenolic O-H bond dissociation enthalpy, curcumin in its most stable form can be suggested to be a relatively good antioxidant. In order to avoid overcoming H-bond interaction and to improve the antioxidant activity of curcumin, a catechol moiety was incorporated into curcumin for designing a novel antioxidant. It is found that the designed molecule is much more efficient to scavenge radical than curcumin, comparable to vitamin E. Moreover, the ionization potential of the designed molecule is similar to that of curcumin, indicating that the designed molecule can not display the prooxidant effect. 相似文献
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姜黄超临界提取物的高效液相色谱分析 总被引:4,自引:0,他引:4
用液相色谱-质谱和紫外-可见光谱对姜黄超临界提取物中的3种主要成分进行了定性分析,用高效液相色谱进行了定量分析。实验条件:用Hypersil C18为分离柱,甲醇-水(体积比40:60)为流动相,检测波长428nm,柱温40℃;姜黄素进样量在0.12~1.2μg范围内与峰面积线形关系良好(r=0.9994),平均回收率102%,重现性的RSD为1、74%(n=6)。分析结果表明超临界CO2萃取的姜黄提取物中含对二脱甲氧基姜黄素、脱甲氧基姜黄素和姜黄素,姜黄提取物中的总姜黄素含量约为90%。 相似文献
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(S)-(+)-姜黄烯的立体选择性全合成 总被引:1,自引:0,他引:1
利用不对称双羟化反应和Raney镍的原位还原,高对映选择性和高产率地实现了(S)-(+)-α-姜黄烯(1)的立体选择性合成.用MsCl保护化合物7a和7b时,发现了有趣的消除和重排反应,得到对应的二烯化合物8. 相似文献
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姜科植物化学成分的色谱/质谱研究 总被引:2,自引:0,他引:2
本文研究了姜科植物11个样品,提取了挥发油,用色谱/质谱技术从挥发油中鉴定出100多种成分。其中α-蒎烯,β-蒎烯,莰烯1,8-桉油素,β-水芹烯,柠檬酸,柠檬醛,香叶醇,丁子香酚,芳樟醇,α-姜烯,β-姜烯,α-姜黄烯,β-姜黄烯,石竹烯,姜酮,β-荜澄茄烯,香芹酮,乙酸香叶酯,乙酸芳樟酯等20种化合物是多数姜科植物挥发油的共同成分。 相似文献
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Static headspace GC-MS method coupled with H/D exchange was firstly developed to determine and identifythe volatile components in the fresh root and rhizome of Curcuma wenyujin.The TIC chromatograms of 3 batchesof fresh roots harvested at different time showed significant difference in the volatile components:the constitutionwas the same but the content of them was different.More than 60 volatile components in fresh roots(Root of C.wenyujin)and rhizomes(Rhizome of C.wenyujin)of C.wenyujin were detected,of which 51 and 48 volatile com-ponents were identified respectively.The fresh roots and rhizomes of C.wenyujin were found to have the similarvolatile components.The contents of these components were calibrated by the response of β-elemene.In addition,the principal active component,β-elemene,was further confirmed and relatively quantified by its standard.γ-terpinene showed obvious allylic hydrogen/deuterium exchange using deuterium oxide which gave a new methodto identify some compounds containing allylic hydrogen.At the same time,the active hydrogen compounds werealso further confirmed.The results show that HS-GC-MS method is a fast,simple and efficient way for the analysisof volatile components from medical plants. 相似文献