Scott Alan Jones

Benzopyrans are selective estrogen receptor Beta agonists with novel activity in models of benign prostatic hyperplasia.

Benzopyran selective estrogen receptor beta agonist-1 (SERBA-1) shows potent, selective binding and agonist function in estrogen receptor beta (ERbeta) in vitro assays. X-ray crystal structures of SERBA-1 in ERalpha and beta help explain observed beta-selectivity of this ligand. SERBA-1 in vivo demonstrates involution of the ventral prostate in CD-1 mice (ERbeta effect), while having no effect on gonadal hormone levels (ERalpha effect) at 10x the efficacious dose, consistent with in vitro properties of this molecule.

Tetrahydroquinoline-based selective estrogen receptor modulators (SERMs)

A new series of estrogen receptor ligands based on a 6-hydroxy-tetrahydroquinoline scaffold is described, in addition to their binding affinity and functional activity in MCF-7 cells. Several 1,2-disubstituted tetrahydroquinolines bearing a basic side chain were shown to be high affinity ligands and antagonists in the MCF-7 proliferation assay. Compounds lacking the basic side chain were agonists in the MCF-7 assay.

Discovery and Characterization of 2-Acylaminoimidazole Microsomal Prostaglandin E Synthase-1 Inhibitors.

As part of a program aimed at the discovery of antinociceptive therapy for inflammatory conditions, a screening hit was found to inhibit microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 17.4 μM. Structural information was used to improve enzyme potency by over 1000-fold. Addition of an appropriate substituent alleviated time-dependent cytochrome P450 3A4 (CYP3A4) inhibition. Further structure-activity relationship (SAR) studies led to 8, which had desirable potency (IC50 = 12 nM in an ex vivo human whole blood (HWB) assay) and absorption, distribution, metabolism, and excretion (ADME) properties. Studies on the formulation of 8 identified 8·H3PO4 as suitable for clinical development. Omission of a lipophilic portion of the compound led to 26, a readily orally bioavailable inhibitor with potency in HWB comparable to celecoxib. Furthermore, 26 was selective for mPGES-1 inhibition versus other mechanisms in the prostanoid pathway. These factors led to the selection of 26 as a second clinical candidate.

Novel 3-aryl indoles as progesterone receptor antagonists for uterine fibroids.

We report the synthesis and characterization of novel 3-aryl indoles as potent and efficacious progesterone receptor (PR) antagonists with potential for the treatment of uterine fibroids. These compounds demonstrated excellent selectivity over other steroid nuclear hormone receptors such as the mineralocorticoid receptor (MR). They were prepared from 2-bromo-6-nitro indole in four to six steps using a Suzuki cross-coupling as the key step. Compound 8f was orally active in the complement 3 model of progesterone antagonism in the rat uterus and demonstrated partial antagonism in the McPhail model of progesterone activity.

Discovery of Synthetic Leishmania Inhibitors by Screening of a 2-Arylbenzothiophene Library

Tamoxifen has been shown to be active in vitro against Leishmania and effective in the treatment for leishmaniasis in murine models. Through the screening of a compound library of estrogen receptor modulator analogs, we identified the major characteristics required for antileishmanial activity. To overcome the difficulties presented by tamoxifens propensity for E/Z isomerization, we used the 2‐arylbenzothiophene compound BTP as a more stable alternative. Directed screening of a small compound library based on BTP led to active compounds against Leishmania. Subsequent structure–activity data for the synthetic 2‐arylbenzothiophenes evaluated in this study indicate that optimal antileishmanial potency is dependent on the presence of two basic side chains. In addition, the primary structural features required for estrogen receptor binding, the phenols, are not required for inhibiting parasitic growth. Significantly, the most active antileishmanial benzothiophenes lack the pharmacophore for estrogen receptor activity and therefore address potential concerns about the undesirable effects of using selective estrogen receptor modulators in women and children with leishmaniasis. Three compounds selected from the screening have shown consistent activity against all species and stages of Leishmania in vitro although improvements in selectivity are needed. These compounds represent viable starting points for further optimization as antileishmanial agents.

Identification of potent and selective retinoic acid receptor gamma (RARγ) antagonists for the treatment of osteoarthritis pain using structure based drug design.

A series of triaryl pyrazoles were identified as potent pan antagonists for the retinoic acid receptors (RARs) α, β and γ. X-ray crystallography and structure-based drug design were used to improve selectivity for RARγ by targeting residue differences in the ligand binding pockets of these receptors. This resulted in the discovery of novel antagonists which maintained RARγ potency but were greater than 500-fold selective versus RARα and RARβ. The potent and selective RARγ antagonist LY2955303 demonstrated good pharmacokinetic properties and was efficacious in the MIA model of osteoarthritis-like joint pain. This compound demonstrated an improved margin to RARα-mediated adverse effects.