Synthesis And Biological Activity Of Novel Nitrogen-containing Heterocyclic Substituted 3-oxo-androst-4-ene-17β-carboxylic Acid Derivative

Steroid compounds belong to a class of important natural products.Natural products and their derivatives possess broad spectrum biological activities.For example,digoxin,as anti-heart failure medications,has potent activity in anti-heart failure therapy.Meanwhile,hydrocortisone has anti-inflammation,anti-virus,anti-shock and anti-immune suppression activity.In this paper,we desiged a series of steroid derivatives containing amide,isopropanolamine,or bisfenazide moiety,and evaluated their antibacterial activity.1.A series of 3-oxy-androstere-4-ene-17β-carboxylic acid derivatives with amide,isopropanolamine,or bishydrazide structures moiety were designed and synthesized.Meanwhile,an array of estrogen derivatives decorated isopropanolamine structure were also prepared.Above-mentioned target compounds were characterized by ¹H NMR,¹³C NMR and HRMS.2.Anti-bacterial activity:the bioassay results of target compounds towards Xoo（Xanthomonas oryzae pv.oryzae）,Xac（Xanthomonas axonopodis pv.citri）,and Psa（Pseudomonas syringae pv.actinidiae）were assayed by using turbidimetric method.Then,bioassay result showed that most of the designed target compounds showed good inhibitory activity against Xoo and Xac.Notably,as the best antibacterial lead compound,Ⅲ₂₈ had excellent activities,with EC₅₀ values of 2.38,2.10 and 9.50 mg L^-1 against Xoo,Xac and Psa,respectively,which were quite superior than that of BT(37.6 mg L^-1for Xoo,102 mg L^-1for Xac,and 213 mg L^-1 for Psa)and TC(107 mg L^-1for Xoo,141 mg L^-1for Xac,and 415 mg L^-1 for Psa).3.In vivo bioactivity:CompoundⅢ₂₈ had good activity against BLB at 200 mg L^-1（protective activity:58.75%;curative activity:56.66%.）More interestingly,after supplement with 0.1%additives,their activity could be enhanced.For example,by suplmenting silicone additive,the protective and curative activities of compoundⅢ₂₈ could increased from to 67.50%,and from to 60.83%,respectiveily.These fundings were better than BT（41.53%for protective activity,and 42.50%for curative activity）and TC（40.83%for protective activity,and 40.00%for curative activity）,respectively.Secondly,the protective and therapeutic activities of citrus potted in vivo at 200 mg L^-1 concentration were 96.65%and 51.02%,respectively,which were better than TC（52.52%and 17.09%）.Finally,the protective and therapeutic activities of kiwifruit at 200 mg L^-1 were 81.81%and 68.18%,respectively,which were much better than TC（23.80%and 38.09%）.4.After treatment with compoundⅢ₂₈,some broken Xoo cells were found in scanning electron microscope（SEM）imaging.Further cell membrane permeability experiments were verificanted that compoundⅢ₂₈ could cause Xoo cells to death through leakaging inner ingredients.In addition,fuether biochemical assays suggested that compoundⅢ₂₈ could enhance host’defense enzyme activity and salicylic acid content and subsequently leading to including host defense response.These fundings were also comfirmed by RT-q PCR experiment.