Development and evaluation of 4-(pyrrolidin-3-yl)benzonitrile derivatives as inhibitors of lysine specific demethylase 1

As part of our ongoing efforts to develop reversible inhibitors of LSD1, we identified a series of 4-(pyrrolidin-3-yl)benzonitrile derivatives that act as successful scaffold-hops of the literature inhibitor GSK-690. The most active compound, 21g, demonstrated a K_d value of 22 nM and a biochemical IC₅₀ of 57 nM. In addition, this compound displayed improved selectivity over the hERG ion channel compared to GSK-690, and no activity against the related enzymes MAO-A and B. In human THP-1 acute myeloid leukaemia cells, 21g was found to increase the expression of the surrogate cellular biomarker CD86. This work further demonstrates the versatility of scaffold-hopping as a method to develop structurally diverse, potent inhibitors of LSD1.     

Neutral 5-substituted 4-indazolylaminoquinazolines as potent, orally active inhibitors of erbB2 receptor tyrosine kinase

We have identified a new series of C-5 substituted indazolylaminoquinazolines as potent erbB2 kinase inhibitors. The lead compound 22 showed excellent in vitro potency, good physical properties, acceptable oral pharmacokinetics in rat and dog, and low human in vitro clearance. It showed at least equivalent activity dose for dose compared to lapatinib in various erbB2- or EGFR-driven xenograft models after chronic oral administration.     

A metachromatic dye-ATPase method for the simultaneous identification of skeletal muscle fiber types I, IIA, IIB and IIC.

The histochemical demonstration of quantitative differences in myofibrillar ATPase activity at the selective pH optima of the various types of human skeletal muscle fibers is the most widely used technique for their differentiation. The basis of the reaction is the deposition of insoluble salts of inorganic phosphate cleaved from ATP by myofibrillar ATPase(s) followed by substitution of the phosphates with less soluble chromogenic salts. Doriguzzi and associates reported using metachromatic dyes to demonstrate quantitative differences in phosphate deposition among different fiber types. Following routine ATPase histochemistry and staining with either azure A or toluidine blue, fibers with low ATPase activity (and low phosphate content) were stained metachromatically while fibers with high ATPase activity (and high phosphate content) were orthochromatic with the intensity of color proportional to the content of insoluble phosphate. The metachromasia was readily lost after immoderate washing in aqueous solutions or routine dehydration in ethanol, with consequent diminished fiber type distinction. A critical modification of this technique is reported in which incubation of frozen sections of human skeletal muscle in ATP-containing medium is carried out at room temperature (22-24 C), rather than the usual 37 C, followed by a revised washing and dehydration protocol. With these modifications, the four human skeletal muscle fiber types (types I, IIA, IIB, and IIC) can be identified rapidly and reliably in single sections, obviating the need for examination of serial sections. The tinctorial differentiation allows fiber type identification even in black and white photographs.     

Comparative effects of vasodilator drugs on flow distribution and venous return

Systemic vascular effects of hydralazine, prazosin, captopril, and nifedipine were studied in 115 anesthetized dogs. Blood flow (Q) and right atrial pressure (Pra) were independently controlled by a right heart bypass. Transient changes in central blood volume after an acute reduction in Pra at a constant Q showed that blood was draining from two vascular compartments with different time constants, one fast and the other slow. At three dose levels producing comparable reductions in systemic arterial pressure (30-40% at the highest dose), these drugs had different effects on flow distribution and venous return. Hydralazine and prazosin had parallel and balanced effects on arterial resistance of the two vascular compartments, and flow distribution was unaltered. Captopril preferentially reduced arterial resistance of the compartment with a slow time constant for venous return (-26 +/- 6%, -30 +/- 6%, -50 +/- 5% at 0.02, 0.10, and 0.50 mg X kg-1 X h-1, respectively; means +/- SEM) without altering arterial resistance of the fast time-constant compartment. Blood flow to the slow time-constant compartment was increased 43 +/- 14% at the highest dose, and central blood volume was reduced 108 +/- 15 mL. In contrast, nifedipine had a balanced effect on arterial resistance with the lowest dose (0.025 mg/kg) but caused a preferential reduction in arterial resistance of the fast time-constant compartment at higher doses (-38 +/- 4% and -55 +/- 2% at 0.05 and 0.10 mg/kg, respectively). Blood flow to the slow time-constant compartment was reduced 36 +/- 5% at the highest dose of nifedipine, and central blood volume was increased 66 +/- 12 mL. Total systemic venous compliance was unaltered or slightly reduced by each of the four drugs. These results add further evidence to the hypothesis that peripheral blood flow distribution is a major determinant of venous return to the heart.     

Modification of guanine bases by nucleoside phosphoramidite reagents during the solid phase synthesis of oligonucleotides.

Nucleoside 3'-phosphoramidite and chlorophosphite reagents have been found to react with the lactam function of guanine. This reaction caused unsatisfactory results when oligodeoxyribonucleotides containing a large number of guanine bases were prepared in an automated solid phase synthesizer. The guanine modification is unstable, and leads to depurination and chain cleavage. This side reaction can be eliminated by protecting the O6-position. A new O6-p-nitrophenylethyldeoxyguanosine phosphoramidite derivative, 8, was used to prepare sequences containing up to 24 guanine bases with greatly improved results. A hexatriacontanucleotide, d(CGCGGGGTGGAGCAGCCTGGTAGCTCGTCGGGCTCA), was also prepared using O6-protected deoxyguanosine nucleosides.     

Identification and field testing of floral odorants that attract the rove beetle <Emphasis Type="Italic">Pelecomalium testaceum</Emphasis> (Mannerheim) to skunk cabbage, <Emphasis Type="Italic">Lysichiton americanus</Emphasis> (L.)

Western skunk cabbage, Lysichiton americanus (Araceae), is pollinated mainly by the rove beetle Pelecomalium testaceum (Staphylinidae). Our objective was to determine the floral semiochemical(s) of L. americanus that attract(s) P. testaceum. Porapak Q headspace volatile extracts of L. americanus inflorescences were analyzed by gas chromatographic–electroantennographic detection (GC–EAD) and GC–mass spectrometry. In GC–EAD analyses, three floral odorants [(E)-4 nonene, (E)-5-undecene, indole] elicited consistent responses from the antennae of female P. testaceum. In field experiments, traps baited with a blend of these three components (“3-CB”) captured significantly more P. testaceum than unbaited control traps. Traps baited with the 3-CB, the two hydrocarbons, or indole, each captured significantly more beetles than unbaited control traps, indicating redundancy in the semiochemical blend. Moreover, traps baited with indole captured significantly more beetles than traps baited with either the 3-CB, or the hydrocarbons, indicating that indole is a key floral attractant for P. testaceum. Many necrophilous and coprophilous insects respond to indole in search of carrion or feces, but P. testaceum has never been associated with these types of resources. Both electrophysiological and behavioral responses of P. testaceum to two hydrocarbon semiochemicals, which are not signature odorants of carrion or feces, may indicate that the beetles recognize the odor of L. americanus as an honest signal, seek and pollinate its inflorescences, and get rewarded with pollen and on-plant mating opportunities.     

Adult spinal opioid receptor μ1 expression after incision is altered by early life repetitive tactile and noxious procedures in rats

Clinical and experimental data suggests that noxious stimulation at critical stages of development results in long‐term changes on nociceptive processing in later life. Here, we use an established, well‐documented rat model of repetitive noxious procedures closely mimicking the clinical situation in the NICU. In order to understand molecular changes underlying the long‐term consequences of repetitive stimulation of the developing nociceptive system the present study aims to analyze the presence of the µ‐opioid‐receptor‐1 (OPRM1). Neonatal rats received either four needle pricks per day in the left hind‐paw from postnatal day 0–7 as a model of procedural pain in infancy. Control pups were handled in the same way but were instead tactile stimulated, or were left undisturbed. At the age of 8 weeks, all animals received an ipsilateral hind‐paw incision as a model for post‐operative pain, and mechanical sensitivity was tested at multiple time‐points. Before, and 1 or 5 days post‐incision, spinal cord tissue was collected for immunostaining of opioid receptor OPRM1. Semi‐quantitative immunocytochemical analysis of superficial laminae in lumbar spinal dorsal horn revealed that: (1) early life repetitive tactile or noxious procedures do not alter baseline levels of OPRM1 staining intensity and (2) early life repetitive tactile or noxious procedures lead to a decrease in OPRM1 staining intensity 5 days after incision in adulthood compared to undisturbed controls. We conclude that early life repetitive tactile or noxious procedures affect the intensity of OPRM1‐immunoreactivity in the lumbar superficial spinal cord dorsal horn after adulthood injury, without affecting baseline intensity. © 2018 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 78: 417–426, 2018