L-755,507

IC50: 13 nM (binding at the human β3 adrenergic receptor) [1]

Benzenesulfonamide derivative L-755,507 is a partial agonist for the human β3 receptor, with maximal activation 52% of that evoked by isoproterenol [2]. β3 adrenergic receptor is a G protein-coupled receptors which can enhancement of lipolysis in adipose tissue.

In vitro: L-755,507 displays an excellent activity profile as an extremely potent human β3 adrenergic receptor agonist (β3 EC50 0.43 nM), with >440-fold selectivity over β1 and β2 binding [1]. L-755,507 is also a potent and selective b3 partial agonist in rhesus monkeys as assessed by its affinity for the cloned b adrenergic receptors, and stimulates lipolysis in rhesus adipocytes with an EC50 = 3.9 nM [2].

In vivo: Dose rhesus monkeys with L-755,507 elicits lipolysis and metabolic rate elevation. The ED50 for glycerolemia was 0.03 mg/kg and the ED50 for tachycardia was 2.5 mg/kg, and stimulates metabolic rate by ~ 30% after acute bolus intravenous administration of 0.1 mg/kg [2].

Clinical trial: So far, no clinical study has been conducted.

References:
[1] Parmee ER, Ok HO, Candelore MR, Tota L, Deng L, Strader CD, Wyvratt MJ, Fisher MH, Weber AE.  Discovery of L-755,507: a subnanomolar human beta 3 adrenergic receptor agonist. Bioorg Med Chem Lett. 1998 May 5;8(9):1107-12.
[2] Fisher MH, Amend AM, Bach TJ, Barker JM, Brady EJ, Candelore MR, Carroll D, Cascieri MA, Chiu SH, Deng L, Forrest MJ, Hegarty-Friscino B, Guan XM, Hom GJ, Hutchins JE, Kelly LJ, Mathvink RJ, Metzger JM, Miller RR, Ok HO, Parmee ER, Saperstein R, Strader CD, Stearns RA, MacIntyre DE, et al.  A selective human beta3 adrenergic receptor agonist increases metabolic rate in rhesus monkeys. J Clin Invest. 1998 Jun 1;101(11):2387-93.

Discovery of L-755,507: a subnanomolar human beta 3 adrenergic receptor agonist.[Pubmed:9871717]

Bioorg Med Chem Lett. 1998 May 5;8(9):1107-12.

A study of 4-acylaminobenzenesulfonamides in a cloned human beta 3 adrenergic receptor assay resulted in the discovery of n-hexylurea, L-755,507 (22). This 0.43 nM beta 3 agonist, which is > 440-fold selective over both beta 1 and beta 2 binding, is among the most potent human beta 3 agonists reported to date.

Small molecules enhance CRISPR genome editing in pluripotent stem cells.[Pubmed:25658371]

Cell Stem Cell. 2015 Feb 5;16(2):142-7.

The bacterial CRISPR-Cas9 system has emerged as an effective tool for sequence-specific gene knockout through non-homologous end joining (NHEJ), but it remains inefficient for precise editing of genome sequences. Here we develop a reporter-based screening approach for high-throughput identification of chemical compounds that can modulate precise genome editing through homology-directed repair (HDR). Using our screening method, we have identified small molecules that can enhance CRISPR-mediated HDR efficiency, 3-fold for large fragment insertions and 9-fold for point mutations. Interestingly, we have also observed that a small molecule that inhibits HDR can enhance frame shift insertion and deletion (indel) mutations mediated by NHEJ. The identified small molecules function robustly in diverse cell types with minimal toxicity. The use of small molecules provides a simple and effective strategy to enhance precise genome engineering applications and facilitates the study of DNA repair mechanisms in mammalian cells.

A selective human beta3 adrenergic receptor agonist increases metabolic rate in rhesus monkeys.[Pubmed:9616210]

J Clin Invest. 1998 Jun 1;101(11):2387-93.

Activation of beta3 adrenergic receptors on the surface of adipocytes leads to increases in intracellular cAMP and stimulation of lipolysis. In brown adipose tissue, this serves to up-regulate and activate the mitochondrial uncoupling protein 1, which mediates a proton conductance pathway that uncouples oxidative phosphorylation, leading to a net increase in energy expenditure. While chronic treatment with beta3 agonists in nonprimate species leads to uncoupling protein 1 up-regulation and weight loss, the relevance of this mechanism to energy metabolism in primates, which have much lower levels of brown adipose tissue, has been questioned. With the discovery of L-755,507, a potent and selective partial agonist for both human and rhesus beta3 receptors, we now demonstrate that acute exposure of rhesus monkeys to a beta3 agonist elicits lipolysis and metabolic rate elevation, and that chronic exposure increases uncoupling protein 1 expression in rhesus brown adipose tissue. These data suggest a role for beta3 agonists in the treatment of human obesity.