(1S)-1-Phenylethanaminium 4-{[(1S,2S)-1-hydroxy-2,3-dihydro-1H,1\u27H-[2,2\u27-biinden]-2-yl]methyl}benzoate

The title molecular salt, C(8)H(12)N(+)·C(26)H(21)O(3)(-), contains a dimeric indane pharmacophore that demonstrates potent anti-inflammatory activity. The indane group of the anion exhibits some disorder about the α-C atom, which appears common to many structures containing this group. A model to account for the slight disorder was attempted, but this was deemed unsuccessful because applying bond-length constraints to all the bonds about the α-C atom led to instability in the refinement. The absolute configuration was determined crystallographically as S,S,S by anomalous dispersion methods with reference to both the Flack parameter and Bayesian statistics on Bijvoet differences. The configuration was also determined by an a priori knowledge of the absolute configuration of the (1S)-1-phenylethanaminium counter-ion. The molecules pack in the crystal structure to form an infinite two-dimensional hydrogen-bond network in the (100) plane of the unit cell

Bioactive Indanes: Development and Validation of a Bioanalytical Method of LC-MS/MS for the Determination of PH46A, a New Potential Anti-Inflammatory Agent, in Human Plasma, Urine and Faeces

PH46A, a new chemical entity developed by our group, has shown potent anti-inflammatory activities through various pre-preclinical studies. The aim of this work was to develop and validate a sensitive and robust LC-MS/MS analytical method to determine the levels of PH46 in human plasma, urine and faeces. The linearity (0.5–500 ng/mL for plasma/urine, and 10–2000 ng/g for human faeces), accuracy (within 100 ± 15% for plasma/urine or 100 ± 20% for faeces), precision (≤ 15% CV for plasma/urine or ≤ 20% CV for faeces) and the method’s specificity were demonstrated to be acceptable. No significant matrix effects or carry-over was observed for PH46 and IStd, and the recovery was consistent. About 10- and 100-fold dilutions in control matrix were found not to affect the assays’ performance. PH46 was proven to be stable: at room temperature for >24 hrs in plasma through 3 freeze-thaw cycles, at –20°C for 83 days in plasma/32 days in urine/33 days in faeces, and at –80°C for 154 days in plasma/33 days in faeces. The re-injection reproducibility of PH46 in matrix extracts was at least 239 hrs at 4°C in plasma/25 days in urine/6.5 days in faeces. This method was successfully applied to the pharmacokinetic evaluation of the Phase I clinical studies

Bioactive Indanes: Development and validation of an LC-MS/MS bioanalytical method for the determination of PH46A, a new potential anti-inflammatory agent, in dog and rat plasma and its application to a pharmacokinetic study in dog.

A new chemical entity, which is a chiral indane dimer, PH46A, has been developed by our research group. As a clinical candidate. PH46A has recently completed Phase I clinical studies in man. Previously, during its pre-clinical development, in in vivo pre-clinical studies PH46A showed potent anti-inflammatory properties, which can be targeted at a range of diseases, including inflammatory bowel disease (IBD). To support the pre-clinical development of this drug candidate, we developed a LCMS/MS method for determining PH46 (the acid form of PH46A salt) in both dog and rat plasma using Compound 1 as internal standard (IS). Those species were selected for safety pharmacology and toxicology, as well as pharmacokinetics studies. The method was validated over the range 10?10000?ng/mL for both matrices and the linearity, accuracy, precision and specificity over this range were demonstrated to be acceptable. No significant matrix effects or carryover were observed for both PH46 and IS and recovery was consistent. PH46 was found to be stable in both dog and rat plasma under the test conditions, such as at room temperature for >24?h, through 3 freeze/thaw cycles, and at -20??C for >1 month. PH46 and IS in dog and rat plasma extracts were also found to be stable in the autosampler against fresh standard extracts on re-injection after 143.5?h and 243.5?h, respectively at 4??C. 10- and 100-fold dilutions with control matrix were found not to affect the performance of the assay. This method was successfully applied to a pharmacokinetic study in the dog. With the exception of one dog, 003?M, oral administration of PH46A in gelatine capsules was well tolerated at a dose level of 100?mg/kg. The highest Cmax was observed in animal 003?M. The rapid absorption and high plasma concentration observed for animal 003?M compared to the data for animals 001?M and 002?M may account for the sickness observed in this animal; however, the reasons for this have not been investigated

Structure–activity studies with high-affinity inhibitors of pyroglutamyl-peptidase II

Inhibitors of PPII (pyroglutamyl-peptidase II) (EC 3.4.19.6) have potential applications as investigative and therapeutic agents. The rational design of inhibitors is hindered, however, by the lack of an experimental structure for PPII. Previous studies have demonstrated that replacement of histidine in TRH (thyrotropin-releasing hormone) with asparagine produces a competitive PPII inhibitor (K(i) 17.5 μM). To gain further insight into which functional groups are significant for inhibitory activity, we investigated the effects on inhibition of structural modifications to Glp-Asn-ProNH(2) (pyroglutamyl-asparaginyl-prolineamide). Synthesis and kinetic analysis of a diverse series of carboxamide and C-terminally extended Glp-Asn-ProNH(2) analogues were undertaken. Extensive quantitative structure–activity relationships were generated, which indicated that key functionalities in the basic molecular structure of the inhibitors combine in a unique way to cause PPII inhibition. Data from kinetic and molecular modelling studies suggest that hydrogen bonding between the asparagine side chain and PPII may provide a basis for the inhibitory properties of the asparagine-containing peptides. Prolineamide appeared to be important for interaction with the S(2)′ subsite, but some modifications were tolerated. Extension of Glp-Asn-ProNH(2) with hydrophobic amino acids at the C-terminus led to a novel set of PPII inhibitors active in vitro at nanomolar concentrations. Such inhibitors were shown to enhance recovery of TRH released from rat brain slices. Glp-Asn-Pro-Tyr-Trp-Trp-7-amido-4-methylcoumarin displayed a K(i) of 1 nM, making it the most potent competitive PPII inhibitor described to date. PPII inhibitors with this level of potency should find application in exploring the biological functions of TRH and PPII, and potentially provide a basis for development of novel therapeutics

First-in-class thyrotropin-releasing hormone (TRH)-based compound binds to a pharmacologically distinct TRH receptor subtype in human brain and is effective in neurodegenerative models

JAK4D, a first-in-class thyrotropin-releasing hormone (TRH)-based compound, is a prospective therapeutic candidate offering a multifaceted approach to treating neurodegeneration and other CNS conditions. The purpose of these studies was to determine the ability of JAK4D to bind to TRH receptors in human brain and to evaluate its neuropharmacological effects in neurodegenerative animal models. Additionally, JAK4D brain permeation was examined in mouse, and initial toxicology was assessed in vivo and in vitro. We report that JAK4D bound selectively with nanomolar affinity to native TRH receptors in human hippocampal tissue and showed for the first time that these receptors are pharmacologically distinct from TRH receptors in human pituitary, thus revealing a new TRH receptor subtype which represents a promising neurotherapeutic target in human brain. Systemic administration of JAK4D elicited statistically significant and clinically-relevant neuroprotective effects in three established neurodegenerative animal models: JAK4D reduced cognitive deficits when administered post-insult in a kainate (KA)-induced rat model of neurodegeneration; it protected against free radical release and neuronal damage evoked by intrastriatal microdialysis of KA in rat; and it reduced motor decline, weight loss, and lumbar spinal cord neuronal loss in G93A-SOD1 transgenic Amyotrophic Lateral Sclerosis mice. Ability to cross the blood–brain barrier and a clean initial toxicology profile were also shown. In light of these findings, JAK4D is an important tool for investigating the hitherto-unidentified central TRH receptor subtype reported herein and an attractive therapeutic candidate for neurodegenerative disorders. •First-in-class TRH-based compound JAK4D detects new receptor subtype in human brain.•JAK4D elicits statistically significant effects in neurodegenerative animal models.•JAK4D crosses the blood–brain barrier and has a clean initial toxicology profile.•JAK4D is a tool to study central pharmacologically-distinct TRH receptor subtype.•JAK4D is an attractive therapeutic candidate for neurodegenerative diseases