The Research On The Method Of Quickly Screening Chinese Herbals That Can Interact With G-quadruplex

The end of human telomeric DNA is rich in Guanine repetitive sequences, and whenexposed to the physiological environment with univalent metal ion, it can formspontaneously G-quadruplex structure. G-quadruplex structure can destroy the locus wheretelomerase catalyzes telomere, which inhibits the activity of telomerase and inhibits tumorcell proliferation further. Any ligand who can stabilize or promote the G-quadruplexesformation can be used in the treatment of tumour as the telomerase inhibitors. China is thebirthplace of Chinese herbal medicine, where Chinese herbal medicine resources are reallyrich. What’s more, the efficacy and safety of Chinese herbal medicine has also beenre-examed to some degree. Besides, with so many advantages, the high performance liquidchromatography (HPLC) has been widely used in the analysis of Chinese herbals. Justbecause of the above-mentioned background, the present thesis wants to research a methodof quickly screening Chinese herbals that can interact with G-quadruplex DNA with thehelp of high performance liquid chromatography.First, the formation and characterization of G-quadruplex DNA. The DNA sequencerich in guanine in our study is5’-GGGGATGCAGGGGTACCAGGGGCGTACGGGG-3’.They have31bases and be purified by polyacrylamide gelelectrophoresis(PAGE). DNAsequences rich in G were dissolved in PBS K+buffer.12hours later, it was determinedusing circular dichroism spectroscopy. The results shown that the DNA sequences rich in Gformed a number of G-quadruplexs under the experiment condition.Second, the interaction of G-quadruplex DNA and the positive control triethylenetetramine(TETA). After the exploration of the high performance liquid chromatographyworking conditions, related chromatographic analysis was conducted. After interaction, thepeak time and peak absorption of the chromatographic peak vary obviously. The positivecontrol lays the foundation for the exploration of the interaction between Chinese herbalsand G-quadruplex.At last, chromatographic condition of using HPLC to analyze the Chinese herbalmedicine and G-quadruplex was explored. Then, the five Chinese herbal medicines whichcan interact with G-quadruplex were quickly screened from a range of56kinds, which are extracted by n-butanol and ethanol. And they were Panax quinquefolius L, Panax ginsengC. A. Mey, Salvia chinensis Benth, Dendranthema indicum, Ligustrum lucidum Ait. The5kinds of Chinese herbals were analyzed by ultraviolet absorption spectrum, and the resultsfurther showed that they could interact with G-quadruplex DNA.