1.1-(1-Naphthyl)piperazine as a novel template for 5-HT6 serotonin receptor ligands.
Lee M1, Rangisetty JB, Pullagurla MR, Dukat M, Setola V, Roth BL, Glennon RA. Bioorg Med Chem Lett. 2005 Mar 15;15(6):1707-11.
4-Sulfonyl analogs of 1-(1-naphthyl)piperazine bind at human 5-HT6 receptors and represent a novel class of human 5-HT6 receptor ligands.
2.Virtual screening and biological evaluation of piperazine derivatives as human acetylcholinesterase inhibitors.
Varadaraju KR1, Kumar JR, Mallesha L, Muruli A, Mohana KN, Mukunda CK, Sharanaiah U. Int J Alzheimers Dis. 2013;2013:653962. doi: 10.1155/2013/653962. Epub 2013 Oct 28.
The piperazine derivatives have been shown to inhibit human acetylcholinesterase. Virtual screening by molecular docking of piperazine derivatives 1-(1,4-benzodioxane-2-carbonyl) piperazine (K), 4-(4-methyl)-benzenesulfonyl-1-(1,4-benzodioxane-2-carbonyl) piperazine (S1), and 4-(4-chloro)-benzenesulfonyl-1-(1,4-benzodioxane-2-carbonyl) piperazine (S3) has been shown to bind at peripheral anionic site and catalytic sites, whereas 4-benzenesulfonyl-1-(1,4-benzodioxane-2-carbonyl) piperazine (S4) and 4-(2,5-dichloro)-benzenesulfonyl-1-(1,4-benzodioxane-2-carbonyl) piperazine (S7) do not bind either to peripheral anionic site or catalytic site with hydrogen bond. All the derivatives have differed in number of H-bonds and hydrophobic interactions. The peripheral anionic site interacting molecules have proven to be potential therapeutics in inhibiting amyloid peptides aggregation in Alzheimer's disease. All the piperazine derivatives follow Lipinski's rule of five.
3.Synthesis and the biological evaluation of 2-benzenesulfonylalkyl-5-substituted-sulfanyl-[1,3,4]-oxadiazoles as potential anti-hepatitis B virus agents.
Tan TM1, Chen Y, Kong KH, Bai J, Li Y, Lim SG, Ang TH, Lam Y. Antiviral Res. 2006 Aug;71(1):7-14. Epub 2006 Mar 9.
Current treatments for chronic hepatitis B virus (HBV) infection include the use of interferon-alpha and of nucleoside analogs lamivudine, adefovir and entecavir. However, the use of interferon-alpha has many side effects while that of nucleosidic inhibitors can lead to the emergence of resistant viruses. Hence, new drugs for the treatment of HBV infection are still highly desired. Oxadiazoles have been observed to exhibit antiviral activities against RNA viruses. In this study, a facile synthesis of 2-benzenesulfonylalkyl-5-substituted-sulfanyl-[1,3,4]-oxadiazoles is reported. The compounds were then evaluated for their anti-HBV activity. 1-[2-[5-(1-Benzenesulfonyl-propyl)-[1,3,4]oxadiazol-2-yl-sulfanyl]-ethyl]-4-(2-methoxy-phenyl)-piperazine (1i) was able to inhibit the expression of the viral antigens, HBsAg and HBeAg in a concentration-dependent manner with no cytotoxic effects and without any effects on the expression of viral transcripts.
4.New 7-[4-(4-(un)substituted)piperazine-1-carbonyl]- piperazin-1-yl] derivatives of fluoroquinolone: synthesis and antimicrobial evaluation.
Chen PT1, Lin WP, Lee AR, Hu MK. Molecules. 2013 Jun 27;18(7):7557-69. doi: 10.3390/molecules18077557.
Fluoroquinolones have been a class of important synthetic antimicrobial agents broadly and effectively used in clinic for infectious diseases. In this study, the synthesis of a range of fluoroquinolone derivatives with 4-(carbopiperazin-1-yl)piperazinyl moieties at the C7 position and their inhibition of bacterial pathogens commonly disseminated in hospital environment were described. The results indicated that a 7-[4-(4-(benzoyl)carbopiperazin-1-yl)]piperazinyl derivative 5h and two 7-[4-(4- (benzenesulfonyl)carbopiperazin-1-yl)]piperazinyl derivatives 5k and 5l showed more promising growth inhibition of ciprofloxacin-resistant P. aeruginosa (CRPA) with MIC values as low as 16 μg/mL which is 16-fold more potent than ciprofloxacin, while most of other derivatives maintained potency against methicillin-resistant Staphylococcus aureus (MRSA).