Design and synthesis of two new steroid derivatives with biological activity on heart failure via the M2-muscarinic receptor activation

Utilizing in silico and in vitro methods to identify possible binding sites of a novel ligand against Pseudomonas aeruginosa phospholipase toxin ExoU

Multi-drug resistant infections caused by the opportunistic pathogen, Pseudomonas aeruginosa (P. aeruginosa), are a continuing problem that contribute to morbidity and mortality in immunocompromised hosts such as cystic fibrosis (CF), wound and burn patients. The bacterial toxin ExoU is one of four potent toxins that P. aeruginosa secretes into the epithelial cells of hosts. In this study, NMR Saturation Transfer Difference (STD) and in silico Schrödinger Computational Modeling were used to identify a possible binding site of a novel ligand methoctramine targeting ExoU. Future project goals will be to design a structure activity relationship (SAR) study of methoctramine and ExoU and lead to a new drug solving ExoU toxicity P. aeruginosa exerts in the clinical environment.

•

STD-NMR identified a weak binding molecule for ExoU.

•

Schrödinger's SiteMap tool to identify potential binding sites of methoctramine to ExoU.

•

Positively charged protonated amines on methoctramine allows for multiple salt bridge and H-bond interactions.

•

Top ranked druggable site aligns and corresponds to ExoU C-terminus region.

Cobalt(I)-Catalyzed [6π + 2π] Cycloaddition of 1,2-Dienes and 1,3-Diynes to N-Carbocholesteroxyazepine in the Synthesis of Previously Undescribed Heterofunctional 9-Azabicyclo[4.2.1]nonadi(tri)enes

Promising heterofunctional (E)-9-azabicyclo[4.2.1]nona-2,4-dienes (79-92%) and 9-azabicyclo[4.2.1]nona-2,4,7-trienes (77-90%) containing a cholesterol fragment in the structure have been synthesized for the first time through the [6π + 2π] cycloaddition reaction of terminal 1,2-dienes and symmetric 1,3-diynes with N-carbocholesteroxyazepine under the action of the Co(acac)₂(dppe)/Zn/ZnI₂ three-component catalytic system.

Synthesis of New Functionally Substituted 9-Azabicyclo[4.2.1]nona-2,4,7-trienes by Cobalt(I)-Catalyzed [6π + 2π]-Cycloaddition of N-Carbocholesteroxyazepine to Alkynes

Catalytic [6π + 2π]-cycloaddition of N-carbocholesteroxyazepine with functionally substituted terminal alkynes and 1,4-butynediol was performed for the first time under the action of the Co(acac)2(dppe)/Zn/ZnI2 three-component catalytic system. The reaction gave previously undescribed but promising 9-azabicyclo[4.2.1]nona-2,4,7-trienes (in 79-95% yields), covalently bound to a natural metabolite, cholesterol. The structure of the synthesized azabicycles was confirmed by analysis of one- and two-dimensional (1H, 13C, DEPT 13C, COSY, NOESY, HSQC, HMBC) NMR spectra.