Design, Synthesis, and Antibacterial Activities of Neomycin−Lipid Conjugates: Polycationic Lipids with Potent Gram-Positive Activity
摘要:
Aminoglycoside antibiotics and cationic detergents constitute two classes of clinically important drugs and antiseptics. Their bacteriological and clinical efficacy, however, has decreased recently due to antibiotic resistance. We have synthesized aminoglycoside-lipid conjugates in which the aminoglycoside neomycin forms the cationic headgroup of a polycationic detergent. Our results show that neomycin-C-16 and neomycin-C-20 conjugates exhibit strong Gram-positive activity but reduced Gram-negative activity. The MIC of neomycin-C-16 (C-20) conjugates against methicillin-resistant Staphylococcus aureus (MRSA) is comparable to clinically used antiseptics.
Synthesis, Characterization, and Receptor Interaction Profiles of Enantiomeric Bile Acids
摘要:
Bile acids are endogenous steroid detergents with receptor-mediated physiologic actions including activation of the G-protein coupled receptor TGR5 and gene regulation mediated by nuclear receptors. In this study, we report the first synthesis of enantiomeric lithocholic acid (ent-LCA, ent-1) and chenodeoxycholic acid (ent-CDCA, ent-2) via ent-testosterone (3). ent-1 was synthesized in 21 total steps in 4.2% yield, whereas ent-2 was obtained in 23 total steps in 0.8% yield. Critical micelle concentrations of the enantiomeric bile acids were found to be identical to their natural counterparts. Furthermore, enantiomeric bile acids were also tested for their ability to modulate bile acid activated proteins: farnesoid X receptor, vitamin D receptor, pregnane X receptor, and TGR5. Interestingly, ent-1 and ent-2 showed differential interactions with these proteins as compared to their corresponding natural bile acids. These data highlight the potential for using enantioselectivity as away to distinguish between receptor and nonreceptor-mediated functions of natural bile acids.
Design, Synthesis, and Antibacterial Activities of Neomycin−Lipid Conjugates: Polycationic Lipids with Potent Gram-Positive Activity
作者:Smritilekha Bera、George G. Zhanel、Frank Schweizer
DOI:10.1021/jm800345u
日期:2008.10.9
Aminoglycoside antibiotics and cationic detergents constitute two classes of clinically important drugs and antiseptics. Their bacteriological and clinical efficacy, however, has decreased recently due to antibiotic resistance. We have synthesized aminoglycoside-lipid conjugates in which the aminoglycoside neomycin forms the cationic headgroup of a polycationic detergent. Our results show that neomycin-C-16 and neomycin-C-20 conjugates exhibit strong Gram-positive activity but reduced Gram-negative activity. The MIC of neomycin-C-16 (C-20) conjugates against methicillin-resistant Staphylococcus aureus (MRSA) is comparable to clinically used antiseptics.
Synthesis, Characterization, and Receptor Interaction Profiles of Enantiomeric Bile Acids
作者:Bryson W. Katona、Carolyn L. Cummins、Andrew D. Ferguson、Tingting Li、Daniel R. Schmidt、David J. Mangelsdorf、Douglas F. Covey
DOI:10.1021/jm0707931
日期:2007.11.1
Bile acids are endogenous steroid detergents with receptor-mediated physiologic actions including activation of the G-protein coupled receptor TGR5 and gene regulation mediated by nuclear receptors. In this study, we report the first synthesis of enantiomeric lithocholic acid (ent-LCA, ent-1) and chenodeoxycholic acid (ent-CDCA, ent-2) via ent-testosterone (3). ent-1 was synthesized in 21 total steps in 4.2% yield, whereas ent-2 was obtained in 23 total steps in 0.8% yield. Critical micelle concentrations of the enantiomeric bile acids were found to be identical to their natural counterparts. Furthermore, enantiomeric bile acids were also tested for their ability to modulate bile acid activated proteins: farnesoid X receptor, vitamin D receptor, pregnane X receptor, and TGR5. Interestingly, ent-1 and ent-2 showed differential interactions with these proteins as compared to their corresponding natural bile acids. These data highlight the potential for using enantioselectivity as away to distinguish between receptor and nonreceptor-mediated functions of natural bile acids.