18 research outputs found
Water-Soluble Progesterone Analogues Are Effective, Injectable Treatments in Animal Models of Traumatic Brain Injury
After more than 30 years of research and 30 failed clinical
trials
with as many different treatments, progesterone is the first agent
to demonstrate robust clinical efficacy as a treatment for traumatic
brain injuries. It is currently being investigated in two, independent
phase III clinical trials in hospital settings; however, it presents
a formidable solubility challenge that has so far prevented the identification
of a formulation that would be suitable for emergency field response
use or battlefield situations. Accordingly, we have designed and tested
a novel series of water-soluble analogues that address this critical
need. We report here the synthesis of C-20 oxime conjugates of progesterone
as therapeutic agents for traumatic brain injuries with comparable
efficacy in animal models of traumatic brain injury and improved solubility
and pharmacokinetic profiles. Pharmacodynamic analysis reveals that
a nonprogesterone steroidal analogue may be primarily responsible
for the observed activity
Discovery of Tetrahydroisoquinoline-Based CXCR4 Antagonists
A de
novo hit-to-lead effort involving the redesign of benzimidazole-containing
antagonists of the CXCR4 receptor resulted in the discovery of a novel
series of 1,2,3,4-tetrahydroisoquinoline (TIQ) analogues. In general,
this series of compounds show good potencies (3–650 nM) in
assays involving CXCR4 function, including both inhibition of attachment
of X4 HIV-1<sub>IIIB</sub> virus in MAGI-CCR5/CXCR4 cells and inhibition
of calcium release in Chem-1 cells. Series profiling permitted the
identification of TIQ-(<i>R</i>)-stereoisomer <b>15</b> as a potent and selective CXCR4 antagonist lead candidate with a
promising in vitro profile. The drug-like properties of <b>15</b> were determined in ADME in vitro studies, revealing low metabolic
liability potential. Further in vivo evaluations included pharmacokinetic
experiments in rats and mice, where <b>15</b> was shown to have
oral bioavailability (<i>F</i> = 63%) and resulted in the
mobilization of white blood cells (WBCs) in a dose-dependent manner
Sphingolipid Analogues Inhibit Development of Malaria Parasites
<i>Plasmodium</i>-infected erythrocytes have
been shown
to employ sphingolipids from both endogenous metabolism as well as
existing host pools. Therapeutic agents that limit these supplies
have thus emerged as intriguing, mechanistically distinct putative
targets for the treatment of malaria infections. In an initial screen
of our library of sphingolipid pathway modulators for efficacy against
two strains of the predominant human malaria species <i>Plasmodium
falciparum</i> and <i>Plasmodium knowlesi</i>, a series
of orally available, 1-deoxysphingoid bases were found to possess
promising in vitro antimalarial activity. To better understand the
structural requirements that are necessary for this observed activity,
a second series of modified analogues were prepared and evaluated.
Initial pharmacokinetic assessments of key analogues were investigated
to evaluate plasma and red blood cell concentrations in vivo