Synthesis and biological activity of N4-phenylsubstituted-6-(2,4-dichloro phenylmethyl)-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamines as vascular endothelial growth factor receptor-2 inhibitors and antiangiogenic and antitumor agents

A series of eight N⁴-phenylsubstituted-6-(2,4-dichlorophenylmethyl)-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamines 8–15 were synthesized as vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitors with varied substitutions in the phenyl ring of the 4-anilino moiety. In addition, five N⁴-phenylsubstituted-6-phenylmethylsubstituted-7H-pyrrolo[2,3-d]pyrimidin-4-amines 16–20 were synthesized to evaluate the importance of the 2-NH₂ moiety for multiple receptor tyrosine kinase (RTK) inhibition. Cyclocondensation of α-halomethylbenzylketones with 2,6-diamino-4-hydroxypyrimidine afforded 2-amino-6-(2,4-dichlorophenylmethyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one, 23 and reaction of α-bromomethylbenzylketones with ethylamidinoacetate followed by cyclocondensation with formamide afforded the 6-phenylmethylsubstituted-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-ones, 40–42, respectively. Chlorination of the 4-position and displacement with appropriate anilines afforded the target compounds 8–20. Compounds 8, 10 and 14 were potent VEGFR-2 inhibitors and were 100-fold, 40-fold and 8-fold more potent than the standard semaxanib, respectively. Previously synthesized multiple RTK inhibitor, 5 and the VEGFR-2 inhibitor 8 from this study, were chosen for further evaluation in a mouse orthotopic model of melanoma and showed significant inhibition of tumor growth, angiogenesis and metastasis.     

Effects of SPLAT® GM sprayable pheromone formulation on gypsy moth mating success

Several integrated pest management programs rely on the use of mating disruption tactics to control insect pests. Some programs specifically target non‐native species, such as the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae). We evaluated SPLAT^® GM, a new sprayable formulation of the gypsy moth sex pheromone disparlure, for its ability to disrupt gypsy moth mating. The study was conducted in 2006, 2007, and 2008 in forested areas in Virginia, USA. Mating success of gypsy moth females was reduced by >99% and male moth catches in pheromone‐baited traps by >90%, in plots treated with SPLAT^® GM at dosages ranging from 15 to 75 g of active ingredient (a.i.) ha^?1. Dosage‐response tests conducted in 2008 indicated that SPLAT^® GM applied at a dosage of 7.5 g a.i. ha^?1 was as effective as a 15 g a.i. ha^?1 dosage.     

QSOX contains a pseudo-dimer of functional and degenerate sulfhydryl oxidase domains

Quiescin sulfhydryl oxidase (QSOX) catalyzes formation of disulfide bonds between cysteine residues in substrate proteins. Human QSOX1 is a multi-domain, monomeric enzyme containing a module related to the single-domain sulfhydryl oxidases of the Erv family. A partial QSOX1 crystal structure reveals a single-chain pseudo-dimer mimicking the quaternary structure of Erv enzymes. However, one pseudo-dimer “subunit” has lost its cofactor and catalytic activity. In QSOX evolution, a further concatenation to a member of the protein disulfide isomerase family resulted in an enzyme capable of both disulfide formation and efficient transfer to substrate proteins.     

The KLHL12-Cullin-3 ubiquitin ligase negatively regulates the Wnt-beta-catenin pathway by targeting Dishevelled for degradation

Dishevelled is a conserved protein that interprets signals received by Frizzled receptors. Using a tandem-affinity purification strategy and mass spectrometry we have identified proteins associated with Dishevelled, including a Cullin-3 ubiquitin ligase complex containing the Broad Complex, Tramtrack and Bric à Brac (BTB) protein Kelch-like 12 (KLHL12). This E3 ubiquitin ligase complex is recruited to Dishevelled in a Wnt-dependent manner that promotes its poly-ubiquitination and degradation. Functional analyses demonstrate that regulation of Dishevelled by this ubiquitin ligase antagonizes the Wnt-beta-catenin pathway in cultured cells, as well as in Xenopus and zebrafish embryos. Considered with evidence that the distinct Cullin-1 based SCF(beta-TrCP)complex regulates beta-catenin stability, our data on the stability of Dishevelled demonstrates that two distinct ubiquitin ligase complexes regulate the Wnt-beta-catenin pathway.     

Synthesis and pharmacology of a novel pyrrolo[2,1,5-cd] indolizine (NNC 45-0095), a high affinity non-steroidal agonist for the estrogen receptor

1-Ethyl-2-(4-hydroxyphenyl)pyrrolo[2,1,5-cd]indolizine (NNC 45-0095) is a novel compound which represents the parent pharmacophore structure of a series of pyrrolo[2,1,5-cd]indolizine derivatives with mixed estrogen agonist/antagonist properties. NNC 45-0095 binds with high affinity to the estrogen receptor (IC50=9.5 nM) and exhibits full protection of bone loss in the ovariectomized mouse model for post-menopausal osteoporosis.     

Pre-pleistocene refugia and differentiation between populations of the caucasian salamander (Mertensiella caucasica)

A 350-bp fragment of the mitochondrial cytochrome-b gene was sequenced in the Caucasian salamander, Mertensiella caucasica, representing 10 populations from across its range along the Black Sea coast. Five haplotypes were discovered among 65 fragments analyzed, differing at 2-50 positions. The highest differentiation between haplotypes was observed in animals from the eastern part of the species' range (Borjomi) compared to those from the remainder of the species' range. Randomly amplified nuclear DNA revealed a pattern of spatial genetic variation similar to that of the mitochondrial genome. M. caucasica, as currently known, represents two evolutionary lineages that evolved independently, perhaps since the lower Pliocene. These lineages represent taxa, possibly to be described as species, distributed in the Borjomi area in central Georgia and in southwestern Georgia and northeastern Turkey. The multivariate analysis of morphological data did not reveal significant differences between the taxa. However, substantial morphological differentiation was observed within both lineages, showing parallel patterns in body proportions and coloration patterns. This variation is possibly associated with extant ecological conditions. Salamanders with reduced pigmentation from southwestern Georgia were not genetically distinguishable from neighboring populations.     

Phosphatidylserine externalization and membrane blebbing are involved in the nonclassical export of FGF1

The mechanisms of nonclassical export of signal peptide-less proteins remain insufficiently understood. Here, we demonstrate that stress-induced unconventional export of FGF1, a potent and ubiquitously expressed mitogenic and proangiogenic protein, is associated with and dependent on the formation of membrane blebs and localized cell surface exposure of phosphatidylserine (PS). In addition, we found that the differentiation of promonocytic cells results in massive FGF1 release, which also correlates with membrane blebbing and exposure of PS. These findings indicate that the externalization of acidic phospholipids could be used as a pharmacological target to regulate the availability of FGF1 in the organism.     

Strain differences in a high response-cost daily time-place learning task

Previous research has shown that rats, unlike birds, do not readily demonstrate daily time-place learning (TPL). It has been suggested, however, that rats are more successful at these tasks if the response cost (RC) is increased. Widman et al. (2000) found that female Sprague Dawley (SD) rats learned a daily TPL task in which they were required to climb different towers depending on the time of day to find a food reward. Using a similar apparatus, we found that male SD rats learned the task, while male Long Evans rats did not. While all rats quickly learned to restrict the majority of their searching to the two towers that provided food, only the SD rats learned to go to the correct location at the correct time of day. Thus, there appears to be a strain difference in the effectiveness of a high RC task to promote learning. Tests of the timing strategies used revealed individual differences with one rat using a circadian strategy and another using an ordinal strategy. Post criterion decrements in performance did not allow sufficient testing to determine the timing strategies of the remaining rats. Possible interactions between strain, response cost, species typical behaviors and dependent measures are discussed.     

Interval time-place learning in young children

While previous research has investigated the ability of animals to learn the spatial and temporal contingencies of biologically significant events (known as time-place learning), this ability has not been studied in humans. Children ranging from 5 to 10 years old were tested on a modified interval time-place learning task using a touchscreen computer. Results demonstrate the children were able to quickly learn both the timing and the sequence of this task. Despite a lack of anticipation on baseline trials, the children continued to follow the spatio-temporal contingencies in probe sessions where these contingencies were removed. Performance on the probe sessions provide strong evidence that the children had learned the spatio-temporal contingencies. Future research is needed to determine what age-related changes in iTPL occur. Furthermore, it is argued that this procedure can be used to extend interval timing in research in children, including, but not limited to, investigation of scalar timing with longer durations than have previously been investigated.