Design,Synthesis And In Vitro Activity Evaluation Of Novel Steroidal Pyridine And Chalcone Derivatives

Steroids have been a research hotspot in the field of drug research and development due to their good biological activity,special stereochemical structure and multi-substitution modification sites.The construction of novel steroid compounds by introducing groups with different activities in the nucleus of the steroid body not only enriches the steroid compounds,but also synergizes with small heterocyclic molecules in the biological activity,producing unique pharmacological activities,which lays the foundation for the development of new drugs.Progesterone and dehydroepiandrosterone?DHEA?are widely studied as the common steroid drug intermediates.Firstly,based on the structure of Abiraterone,a targeted anticancer drug,cyanopyridine group was introduced into the 17 positions of progesterone,and then the 3 hydroxyl groups of these compounds were esterified.In addition,considering that the structure of chalcone in natural products is generally of good biological activities.Steroidal chalcone derivatives were synthesized on the foundation of 7?,15?-dihydroxy-DHEA,a product of biotransfomation of DHEA by fungi.In this paper,the anti-tumor,anti-viral and anti-inflammatory activities of the synthesized compounds were evaluated in vitro,and the structure-activity relationships were preliminarily summarized.The specific research contents are as follows:?1?Using pregnenolone as raw material,the 17-pregnenolone cyanopyridine derivative 2a²o was efficiently constructed with“one-pot reaction”of malononitrile,substituted formaldehyde and ammonium acetate.Then the hydroxyl groups at the 3position of these compounds were modified.Esterification is carried out to synthesize two series of 3a³m and 5a⁵o.?2?DHEA is subjected to microbial transformation,sulfur ylide reaction,oxidation and condensation to finally obtain a chalcone analog 9a⁹k which introducesabenzylidenestructureatits2-position.?15?,16?-methyleneandrost-2-substituted benzylidene-4,6-diene-3,17-dione?.?3?The in vitro cytotoxic activity of the above derivatives on PC-3,MCF-7,MGC-803,ECa-109 and A549 was evaluated by MTT assay.Among them,compounds 2j,3f and 9k showed the strongest inhibitory effects,with IC₅₀ values of2.0?M,1.39?M,and 1.91?M,respectively,which were 8.6,12.3,and 9.2 times of the positive control Abiraterone(IC₅₀=17.15?M).The cytotoxic activities of the two series of 3 and 5 were generally weak,but the evaluation of antiviral activity in vitro indicated the two series had strong anti-RSV virus effects.Among them,compound 5l showed remarkable antiviral activity and high safety,with EC₅₀0 values of 3.10?M and SI values of 116.96.In addition,by studying the effects of these synthetic compounds on the release of NO and the survival rate of BV2 microglia activated by LPS,products 9a⁹k were founded to have the ability of inhibition the release of NO to a certain extent,with concentration dependent.The IC₅₀ values of the most active two compounds 9a and 9j were 2.69?M and 3.28?M,respectively,which was better than the positive control Minocycline.To sum up,through the work of this paper,a total of 51 steroidal pyridine and steroidal chalcone derivatives were synthesized,46 of which have not been reported.The structures of all the compounds were thoroughly determined by ¹H NMR,¹³C NMR and HRMS.Through the activity evaluation,it was found that some compounds have significant anti-tumor,anti-viral or anti-inflammatory activities.The study lay the compound foundation for the further structural modification,and the discovery of steroidal drugs with more development potential.