Synthesis Of Podophyllotoxin Derivatives As Antitumor Agents

Tumorserious threat to human health and life.Currently, chemotherapyis is one of the primary means of treatment of cancer.The research of cancer chemotherapy drug has made great progress. Cancer patient survival time was significantly prolonged and the cure rate also was gradually improved. However, there are many problems, for example, more and more serious clinical multidrug resistance(MDR) is the important reason for the failure of chemotherapy. It is a major problem in cancer chemotherapy need to be resolved. Looking for efficiency and low toxicity, effective multi-drug resistant tumor anticancer drugs has become a hot topic in the field of anticancer drug research.Podophyllotoxin, isolated from the Berberis Branch and podophyllum genus plant has a obvious cytotoxic effect of natural active ingredients.In recent years, our group has been engaged in the transformation of podophyllotoxin and has synthesized a large number of high activity podophyllotoxin derivatives. As the research go thorough, lots of its derivatives spring up.Among them VP-16 and VM-26 has entered the clinical trial stage.Its derivatives TOP-53, NK-611, GL331 and NPF have entered clinical studies.Objective:To getantitumor agents which have little defects and best activity, modify Podophyllotoxin, then obtain new podophyllotoxin derivatives.Methods:1 The synthesis of podophyllotoxin intermediates by podophyllotoxin.Podophyllotoxin(10mmol) dissolved in anhydrous CH2Cl2 was allowed to stir around the ice bath. Then, Na N3(40mmol) was added carefully.10 ml CF3COOH must be dribbled in 30 min at 00 C. After stirring for 1 h, the mixture should be refluxed for 4 h at room temperature. To make sure the p H value of the mixture was adjusted to 7, saturated aqueous Na HCO3 was needed. Then, the organic extracts were dried over anhydrous Na2SO4, concentrated and crystallized from CH2Cl2-CH3COOC2H5(1:1) to afford a white product:4β-N3-4-deoxyepipodophyllotoxin(3.68g). And 10% Pd/C(1.00g) and HCOONH4(2.25 g, 40mmol) were added to the solution of 4β-N3-4-podophyllotoxindissolved in 50 ml CH3COOC2H5. The mixture was stirred under heat for 5 h and filtered. The filtrate was washed with saturated brine, then dried over anhydrous Na2SO4, rotary evaporated and depurated it with colume chromatography to get 4β-NH2-4-deoxyepipodophyllotoxin.4’-demethylpodophyllotoxin(10mmol) dissolved in anhydrous CH2Cl2 was allowed to stir around the ice bath. Then, Na N3(40mmol) was added carefully.10 ml CF3COOH must be dribbled in 30 min at 00 C. After stirring for 1 h, the mixture should be refluxed for 4 h at room temperature. To make sure the p H value of the mixture was adjusted to 7, saturated aqueous Na HCO3 was needed. Then, the organic extracts were dried over anhydrous Na2SO4, concentrated and crystallized from CH2Cl2-CH3COOC2H5(1:1) to afford a white product:4β-N3-4’-demethyldeoxyepipodophyllotoxin(3.54g). And 10% Pd/C(1.00g) and HCOONH4(2.25 g, 40mmol) were added to the solution of 4β-N3-4-podophyllotoxindissolved in 50 ml CH3COOC2H5. The mixture was stirred under heat for 5 h and filtered. The filtrate was washed with saturated brine, then dried over anhydrous Na2SO4, rotary evaporated and depurated it with colume chromatography to get another podophyllotoxin intermediates.It was 4β-NH2-4’-demethyldeoxyepipodophyllotoxin.2 The synthesis of 4β-imines-4-deoxyepipodophyllotoxinThe 2.4 mmol aldehyde compounds,2mmol 4β-NH2-4-deoxy- epipod ophyllotoxin and 1m L acetic acidis dissolved 5m L anhydrous methanol,t hen stirring at room temperature1-8h,then detected by TLC.The mixture was poured into a large amount of water,and the precipitate was filtered and washed with anhydrous CH3 OH to get the products A.3 The synthesis of 4β-benzylamines-4-deoxyepipodophyllotoxinThe above-mentioned imines compound(1mmol) was put into anhydrous CH3 OH.Then added Na BH4(0.15 g,4mmol), stirred in ice bath for 3-5h, detected by TLC, saturated aqueous Na HCO3 was used to make sure the p H value of the mixture was adjusted to 7. The mixture was poured into a large amount of water, and the precipitate was filtered to get the products B.4 The synthesis of 4β-imines-4-4’-demethyldeoxyepipodophyllotoxinThe 2.4mmol aldehyde compounds,1m L acetic acidis and 2 mmol 4β-NH2-4-4’-demethyldeoxyepipodophyllotoxin dissolved 5ml anhydrous meth anol, then stirring at room temperature1-8h,then detected by TLC.The mi xture was poured into a large amount of water, and the precipitate was filtered and washed with anhydrous CH3 OH to get the products C. 5 The synthesis of 4β-benzylamines-4-4’-demethyldeoxyepipodophyllot-oxi nThe above-mentioned imines compound(1mmol) was put into anhydrous CH3 OH.Then added Na BH4(0.15 g,4mmol), stirred in ice bath for 3-5h, detected by TLC, saturated aqueous Na HCO3 was used to make sure the p H value of the mixture was adjusted to 7. The mixture was poured into a large amount of water, and the precipitate was filtered to get the products D.6 The synthesis of 4β-amides-4-4’-demethyldeoxyepipodophyllotoxinThe 1mmol acids, 1.2mmol HOBT(0.139g), 1.2mmol EDCI(0.191g) was dissolved in 15 m L of dichloromethane, stirred in ice bath then slowly added 1mmol 4β-NH2-4’-demethyldeoxyepipodophyllotoxin, stirred at room temperature about 6-10 h.detected by TLC. Column chromatography to obtain the objective compounds E.7 The synthesis of 4β-amides-4-deoxy- epipodophyllotoxinThe 1mmol acids, 1.2mmol HOBT(0.139g), 1.2mmol EDCI(0.191g) was dissolved in 15 m L dichloromethane, stirred in ice bath then slowly added 1mmol 4β-NH2-4-deoxy-epipodophyllotoxin, stirred at room temper-ature about 6-10 h, detected by TLC.Column chromatography to obtain t he objective compounds F.Reault:synthesizedmore than nineteen new podophyllotoxin’s derivati-ves.all were confirmed by 1H-NMR and MS.thirteen of them’s detection data were to coincide with the design.They were two 4β-imines-4-deoxyepipodophyllotoxins,two 4β-imines-4-4’-demethyldeoxyepipodophyllotoxins,one 4β-benzylamines-4-4’-demethyldeoxyepipodophyllotoxin,four 4β-amides-4-4’-demethyldeoxyepipodophyllotoxins and four 4β-amides-4-deoxyepi-podophyllotoxins.Conclusion:these podophyllotoxin derivativestructures are to coincide with my design and forecast.I store them and ready to do activity test for find the best derivative which can resist tumers.