- Pharmacological characterization of a new series of carbamoylguanidines reveals potent agonism at the H2R and D3R
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Even today, the role of the histamine H2 receptor (H2R) in the central nervous system (CNS) is widely unknown. In previous research, many dimeric, high-affinity and subtype-selective carbamoylguanidine-type ligands such as UR-NK22 (5, pKi = 8.07) were reported as H2R agonists. However, their applicability to the study of the H2R in the CNS is compromised by their molecular and pharmacokinetic properties, such as high molecular weight and, consequently, a limited bioavailability. To address the need for more drug-like H2R agonists with high affinity, we synthesized a series of monomeric (thio)carbamoylguanidine-type ligands containing various spacers and side-chain moieties. This structural simplification resulted in potent (partial) agonists (guinea pig right atrium, [35S]GTPγS and β-arrestin2 recruitment assays) with human (h) H2R affinities in the one-digit nanomolar range (pKi (139, UR-KAT523): 8.35; pKi (157, UR-MB-69): 8.69). Most of the compounds presented here exhibited an excellent selectivity profile towards the hH2R, e.g. 157 being at least 3800-fold selective within the histamine receptor family. The structural similarities of our monomeric ligands to pramipexole (6), a dopamine receptor agonist, suggested an investigation of the binding behavior at those receptors. The target compounds were (partial) agonists with moderate affinity at the hD2longR and agonists with high affinity at the hD3R (e.g. pKi (139, UR-KAT523): 7.80; pKi (157, UR-MB-69): 8.06). In summary, we developed a series of novel, more drug-like H2R and D3R agonists for the application in recombinant systems in which either the H2R or the D3R is solely expressed. Furthermore, our ligands are promising lead compounds in the development of selective H2R agonists for future in vivo studies or experiments utilizing primary tissue to unravel the role and function of the H2R in the CNS.
- Biselli, Sabrina,Bresinsky, Merlin,Buschauer, Armin,Forster, Lisa,Honisch, Claudia,Pockes, Steffen,Tropmann, Katharina,Bernhardt, Günther
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supporting information
(2021/02/12)
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- Oxime derivatives and the use thereof as latent acids
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Compounds of formula I, II and III, wherein wherein R1is for example hydrogen, C1-C12alkyl, C3-C30cycloalkyl, C2-C12alkenyl, C4-C8cycloalkenyl, phenyl, whic
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- Oxime ethers, the preparation thereof, compositions containing them and use thereof
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The invention relates to oxime ethers of the formula I STR1 wherein n is 1 or 2, each of R1 and R2 is hydrogen or C1 -C4 alkyl each of R3 and R4 is hydrogen, halogen, C1 -C4 alkyl, C1 -C4 haloalkyl, C1 -C4 alkoxy, C1 -C4 haloalkoxy, C1 -C4 alkylthio, C1 -C4 haloalkylthio, C1 -C4 alkylsulfinyl, C1 -C4 alkylsulfonyl, C1 -C4 haloalkylsulfinyl, C1 -C4 haloalkylsulfonyl or nitro; each of R5 and R6 independently of the other is hydrogen, C1 -C4 alkyl, C1 -C4 haloalkyl, phenyl or phenyl which is substituted by halogen, C1 -C4 alkyl, C1 -C4 haloalkyl, C1 -C4 alkoxy, C1 -C4 haloalkoxy, C1 -C4 alkylthio, C1 -C4 alkylsulfinyl, C1 -C4 alkylsulfonyl, carboxyl, carbamoyl, C 1 -C4 alkylcarbamoyl, nitro or cyano, or R5 and R6 together are also a 2- to 6-membered alkylene or alkenylene chain which may be substituted by C1 -C4 alkyl radicals; X is hydrogen, cyano, nitro, chlorine, C1 -C4 alkyl, C1 -C4 haloalkyl, C3 -C6 cycloalkyl, carboxyl, carbamoyl, C1 -C4 alkylcarbonyl, C1 -C4 alkoxycarbonyl or C1 -C4 alkylcarbamoyl. The oxime ethers of the formula I are able to act as antidotes or safeners to protect cultivated plants from the phytotoxic effects of herbicides. Such cultivated plants are preferably sorghum, cereals, maize and rice.
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- ENHANCED REACTIVITY OF AN α-NUCLEOPHILE IN WATER-DIMETHYL SULFOXIDE MIXTURES. A TRANSITION STATE EFFECT.
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The reactivity of the anion of α,α,α-trifluoroacetophenone oxime towards p-nitrophenylacetate is considerably enhanced relative to that of the similarly basic p-chlorophenoxide anion on addition of Me2SO to aqueous solutions.This is shown to be due to an
- Laloi-Diard, Marguerite,Verchere, Jean-Francois,Gosselin, Patrick,Terrier, Francois
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p. 1267 - 1268
(2007/10/02)
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