1. Dear Drugs-Forum readers: We are a small non-profit that runs one of the most read drug information & addiction help websites in the world. We serve over 4 million readers per month, and have costs like all popular websites: servers, hosting, licenses and software. To protect our independence we do not run ads. We take no government funds. We run on donations which average $25. If everyone reading this would donate $5 then this fund raiser would be done in an hour. If Drugs-Forum is useful to you, take one minute to keep it online another year by donating whatever you can today. Donations are currently not sufficient to pay our bills and keep the site up. Your help is most welcome. Thank you.

2-Methoxymethyl-salvinorin B is a potent kappa opioid receptor agonist with longer lasting action in

2-Methoxymethyl-salvinorin B is a potent kappa opioid receptor agonist with longer lasting action in

  1. Jatelka
    Journal of Pharmacology and Experimental Therapeutics 2008 Mar;324(3):1073-83

    Wang Y, Chen Y, Xu W, Lee DY, Ma Z, Rawls SM, Cowan A, Liu-Chen LY.

    Salvinorin (Sal) A is a naturally occurring, selective kappa opioid receptor (KOPR) agonist with a short duration of action in vivo. Pharmacological properties of a C(2) derivative, 2-methoxymethyl (MOM)-Sal B, were characterized. MOM-Sal B bound to KOPR with high selectivity and displayed approximately 3-fold higher affinity than U50,488H [(trans)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]benzeneacetamide methanesulfonate] and Sal A. It acted as a full agonist at KOPR in guanosine 5'-O-(3-[(35)S]thio)triphosphate binding and was approximately 5- and approximately 7-fold more potent than U50,488H and Sal A, respectively. In Chinese hamster ovary cells stably expressing KOPR, all three kappa agonists internalized or down-regulated KOPR to similar extents, with MOM-Sal B being the most potent. In mice, MOM-Sal B (0.05-1 mg/kg s.c.) caused immediate and dose-dependent immobility lasting approximately 3 h, which was blocked by norbinaltorphimine. In contrast, ambulation in a Y-maze was increased when rats received MOM-Sal B (1-5 mg/kg s.c.). In addition, MOM-Sal B (0.5-5 mg/kg i.p.) produced antinociception (hot-plate test) and hypothermia in a dose-dependent manner in rats. MOM-Sal B was more potent than U50,488H in both tests and more efficacious than U50,488H in the hot-plate test. These latter two in vivo effects were blocked by norbinaltorphimine, indicating KOPR-mediated actions. Sal A at 10 mg/kg elicited neither antinociception nor hypothermia 30 min after administration to rats. In summary, MOM-Sal B is a potent and efficacious KOPR agonist with longer lasting in vivo effects than Sal A.

    Discussion Thread