Although there was a strong steric effect,isopentenyl and geranyl moieties were successfully introduced into C3 position in flavone skeleton so as to synthesize the 3-isopentenyl flavone and 3-geranyl flavone under tw...Although there was a strong steric effect,isopentenyl and geranyl moieties were successfully introduced into C3 position in flavone skeleton so as to synthesize the 3-isopentenyl flavone and 3-geranyl flavone under two cyclization conditions（AcOH/HCl and concentrated H 2 SO 4 /MeOH） in this report.It was found that the optimum cyclization conditions for 3-isopentenyl flavone and 3-geranyl flavone were,respectively,AcOH/HCl and H 2 SO 4 /MeOH.Furthermore,the donating electron ability is in the sequence 3-geranyl flavone3-isopentenyl flavone according to the density functional theory（DFT） calculations,suggesting the longer alkyl chain at 3-position would be more favorable for enhancing the donating electron ability.The present synthetic routes might reveal potential applicability in our continued studies on the total syntheses of other natural 3-alkyl flavonoids.展开更多
Trimethylchlorosilane was used as a stereoselective reagent to determine the e or a orientation of 3-hydroxyl group of some steroids by chemical ionization mass spectrometry.
The title compounds are prepared in good yields by iodination of the corresponding flavones, thioflavones and thiochromones respectively using I_2-CAN(ceric ammonium nitrate) system. The compounds thus prepared are po...The title compounds are prepared in good yields by iodination of the corresponding flavones, thioflavones and thiochromones respectively using I_2-CAN(ceric ammonium nitrate) system. The compounds thus prepared are potentially useful precursors for the synthesis of C-3 linked binuclear compounds.展开更多
Pt(Ⅱ) and Pd(Ⅱ) complexes with 2′,3′,4′,5,7-pentahydroxy-flavone weresynthesized and characterized by elemental analysis, molar conductance, IR, ~1HNMR, TG-DTA, UV-Visspectroscopic techniques, and fluorescence an...Pt(Ⅱ) and Pd(Ⅱ) complexes with 2′,3′,4′,5,7-pentahydroxy-flavone weresynthesized and characterized by elemental analysis, molar conductance, IR, ~1HNMR, TG-DTA, UV-Visspectroscopic techniques, and fluorescence analysis. The scavenging effect on the superoxide radical(O_2^-) and the inhibitory effect on lipid peroxides were also investigated. Both the ligand andthe complexes exhibit scavenging effect on superoxide radicals, and the effect of the complexes isgreater than that of the ligand. The Pt(Ⅱ) complex exhibits the strongest scavenging efficiency.Both Pt(Ⅱ) and Pd(Ⅱ) complexes have the inhibitory effect on lipid peroxides, and the effect ofthe complexes is greater than that of the ligand, but the Pt(Ⅱ) complex has a high effect ofpromoting lipid peroxides.展开更多
研究1-苯基吡唑啉类化合物的合成及其EcMetAP酶活抑制活性。以查尔酮衍生物与苯肼为原料合成啉类化合物。利用IR、1 H NMR和MS对它们进行表征。利用分光光度法测试化合物的EcMetAP酶活性抑制作用,利用生物分子结构分析软件FieldTemplate...研究1-苯基吡唑啉类化合物的合成及其EcMetAP酶活抑制活性。以查尔酮衍生物与苯肼为原料合成啉类化合物。利用IR、1 H NMR和MS对它们进行表征。利用分光光度法测试化合物的EcMetAP酶活性抑制作用,利用生物分子结构分析软件FieldTemplater和FieldAlign计算化合物和已知的EcMetAP酶抑制剂的空间作用力场的相似性。共合成了6个1-苯基-3-(2-羟基苯基-5-芳基)-2-吡唑啉类化合物,但只有化合物5对EcMetAP酶活性有抑制作用,抑制率为31.62%,空间作用力场的相似度为0.615。说明化合物5可作为先导化合物进行结构优化,得到优良的EcMetAP酶抑制活性化合物。展开更多
基金Supported by the National Natural Science Foundation of China(No.20062001)the Natural Science Foundation of Guangxi Zhuang Autonomous Region,China(Nos.0991009 and 0447036)
文摘Although there was a strong steric effect,isopentenyl and geranyl moieties were successfully introduced into C3 position in flavone skeleton so as to synthesize the 3-isopentenyl flavone and 3-geranyl flavone under two cyclization conditions（AcOH/HCl and concentrated H 2 SO 4 /MeOH） in this report.It was found that the optimum cyclization conditions for 3-isopentenyl flavone and 3-geranyl flavone were,respectively,AcOH/HCl and H 2 SO 4 /MeOH.Furthermore,the donating electron ability is in the sequence 3-geranyl flavone3-isopentenyl flavone according to the density functional theory（DFT） calculations,suggesting the longer alkyl chain at 3-position would be more favorable for enhancing the donating electron ability.The present synthetic routes might reveal potential applicability in our continued studies on the total syntheses of other natural 3-alkyl flavonoids.
文摘Trimethylchlorosilane was used as a stereoselective reagent to determine the e or a orientation of 3-hydroxyl group of some steroids by chemical ionization mass spectrometry.
文摘The title compounds are prepared in good yields by iodination of the corresponding flavones, thioflavones and thiochromones respectively using I_2-CAN(ceric ammonium nitrate) system. The compounds thus prepared are potentially useful precursors for the synthesis of C-3 linked binuclear compounds.
文摘Pt(Ⅱ) and Pd(Ⅱ) complexes with 2′,3′,4′,5,7-pentahydroxy-flavone weresynthesized and characterized by elemental analysis, molar conductance, IR, ~1HNMR, TG-DTA, UV-Visspectroscopic techniques, and fluorescence analysis. The scavenging effect on the superoxide radical(O_2^-) and the inhibitory effect on lipid peroxides were also investigated. Both the ligand andthe complexes exhibit scavenging effect on superoxide radicals, and the effect of the complexes isgreater than that of the ligand. The Pt(Ⅱ) complex exhibits the strongest scavenging efficiency.Both Pt(Ⅱ) and Pd(Ⅱ) complexes have the inhibitory effect on lipid peroxides, and the effect ofthe complexes is greater than that of the ligand, but the Pt(Ⅱ) complex has a high effect ofpromoting lipid peroxides.
文摘研究1-苯基吡唑啉类化合物的合成及其EcMetAP酶活抑制活性。以查尔酮衍生物与苯肼为原料合成啉类化合物。利用IR、1 H NMR和MS对它们进行表征。利用分光光度法测试化合物的EcMetAP酶活性抑制作用,利用生物分子结构分析软件FieldTemplater和FieldAlign计算化合物和已知的EcMetAP酶抑制剂的空间作用力场的相似性。共合成了6个1-苯基-3-(2-羟基苯基-5-芳基)-2-吡唑啉类化合物,但只有化合物5对EcMetAP酶活性有抑制作用,抑制率为31.62%,空间作用力场的相似度为0.615。说明化合物5可作为先导化合物进行结构优化,得到优良的EcMetAP酶抑制活性化合物。
