Synthesis And Bioactivity Evaluation Of Pyrazolyl Isoflavones And Pyrrolidine-chromanone Hybrids

Cancer is a disease that seriously endangers human life and health.Lung cancer is one of the most affected cancers in the world,and it is also the primary reason for the high mortality rate of cancer.However,currently commonly used anticancer drugs have disadvantages such as toxic side effects,many adverse reactions,and easy to produce drug resistance.Therefore,it is increasingly urgent to seek safe,effective and low-toxicity drugs.Research reports,many compounds that have the natural product skeleton or inspired by natural compounds and structural modifications of the synthesis of by people more and more attention,which have the pyrazolyl skeleton compounds,isoflavones skeleton compounds,chromone skeleton compounds and spirocyclic[butyrolactone-pyrrolidine]compounds are widely existing in natural products and drug molecules,is a kind of anti-cancer,anti-inflammatory,antibacterial and other physiological active compounds,so also is the focus of many researchers.In this paper,based on the hybrid pharmacophore approach principle of drug design,compounds with both chromanone skeleton and pyrazolone skeleton were designed and synthesized through Aldol condensation reaction,and then a series of isoflavones with pyrazolone skeleton were efficiently constructed through[1,5]-Proton transfer.In the following work,pyrrolidine-chromanone hybrids were constructed by 1,3-dipole cycloaddition reaction.Subsequently,the antitumor activity of the synthesized pyrazolyl isoflavones and pyrrolidine-chromanon hybrids were evaluated in vitro.The first part is to synthesize intermediates with both chromanone and pyrazolone skeletons through Aldol condensation reaction,and the elimination reaction between intermediates and methyl sulfonyl chloride occurs under alkaline conditions.In the early stage,through the selection of reaction solvent,catalyst,reaction time and reaction dose,32 isoflavone compounds containing pyrazolinone framework were synthesized for the first time,with a total yield of 86%.These compounds provide the material basis for the development of natural drugs,and also provide an effective method for the construction of 3-pyrazolyl isoflavones.The second part is the in-situ formation of methylamine ylide 1,3-dipole byα-amino-γ-butylactone hydrochloride and benzaldehyde,the 1,3-dipole and 4-oxochromene-3-carboxylic acid dipole reacted by 1,3-dipole cycloaddition in the presence of triethylamine catalyst,successfully constructed 25 pyrrolidine-chromanone hybrids,and get up to 86%of the total yield and the diastereoselectivity is up to 20:1（dr up to 20:1）.This method mainly uses the carboxylic acid activation and decarboxylation strategies to obtain pyrrolidine-chromanone hybrids,bearing four contiguous stereogenic centers including one tetra substituted carbon.In the third part,the antitumor activities of pyrazolyl isoflavones and pyrrolidine-chromanone hybrids were evaluated in vitro.The antitumor activity of pyrazolyl isoflavones synthesized by MTT assay against human non-small cell lung cancer（NSCLC）A549 was investigated.The results showed that compound 3u and 3v had good inhibitory activity against A549 cell line and showed good anti-tumor activity,among which the IC₅₀value of compound 3u against A549 cell line was 48.12μM,the IC₅₀ value of compound 3v against A549 cell line was 37.71μM,and the IC₅₀ value of positive control drug cisplatin was 26.8μM.In addition,it was found that the removal of the pyrazolone group on the compound 3u and 3v significantly affected the activity,and the 3-pyrazolyl isoflavones with the pyrazolone group showed better activity.The in vitro activity of four pyrrolidine-chromanone hybrids in human non-small cell lung cancer cell A549 and human chronic myeloid leukemia cell K562 were studied by MTT assay.The results showed that:Compounds 6j and 6l showed good antitumor activity against A549 cell and showed good anti-tumor activity.The IC₅₀ value of compound 6j against A549 cell was 44.09μM,the IC₅₀value of compound 6l against A549 cell was 42.21μM,the IC₅₀ value of positive control drug cisplatin was 23.02μM;Compounds 6j、6k、6l、6x showed good inhibitory activity against K562 cell,the IC₅₀value of compound 6j against K562 cell was 38.30μM,the IC₅₀value of compound6k against K562 cell was 35.50μM,the IC₅₀ value of compound 6l against K562 cell was 34.90μM,the IC₅₀value of compound 6x against K562 cell was 48.51μM,and the IC₅₀ value of positive control drug cisplatin was20.57μM.Although the above activity data do not indicate the structure-activity relationship of these compounds on anti-cell proliferation,it does suggest that these pyrrolidine-chromanone hybrids are candidates for potential drug applications and add to the library of potential anti-tumor compounds.