Novel orexin receptor agonists based on arene- or pyridine-fused 1,3-dihydro-2H-imidazole-2-imines.

A structurally novel class of benzo- or pyrido-fused 1,3-dihydro-2H-imidazole-2-imines was designed and evaluated in an inositol phosphate accumulation assay for Gq signaling to measure agonistic activation of the orexin receptor type 2 (OX2R). These compounds were synthesized in 4-9 steps overall from readily available starting materials. Analogs that contain a stereogenic methyl or cyclopropyl substituent at the benzylic center, and a correctly configured alkyl ether, alkoxyalkyl ether, cyanoalkyl ether, or α-hydroxyacetamido substituted homobenzylic sidechain were identified as the most potent activators of OX2R coupled Gq signaling. Our results also indicate that agonistic activity was stereospecific at both the benzylic and homobenzylic stereogenic centra. We identified methoxyethoxy-substituted pyrido-fused dihydroimidazolimine analog 63c containing a stereogenic benzylic methyl group was the most potent agonist, registering a respectable EC50 of 339 nM and a maximal response (Emax) of 96 % in this assay. In vivo pharmacokinetic analysis indicated good brain exposure for several analogs. Our combined results provide important information towards a structurally novel class of orexin receptor agonists distinct from current chemotypes.

The structure of importin α and the nuclear localization peptide of ChREBP, and small compound inhibitors of ChREBP-importin α interactions.

The carbohydrate response element binding protein (ChREBP) is a glucose-responsive transcription factor that plays a critical role in glucose-mediated induction of genes involved in hepatic glycolysis and lipogenesis. In response to fluctuating blood glucose levels ChREBP activity is regulated mainly by nucleocytoplasmic shuttling of ChREBP. Under high glucose ChREBP binds to importin α and importin ß and translocates into the nucleus to initiate transcription. We have previously shown that the nuclear localization signal site (NLS) for ChREBP is bipartite with the NLS extending from Arg158 to Lys190. Here, we report the 2.5 Šcrystal structure of the ChREBP-NLS peptide bound to importin α. The structure revealed that the NLS binding is monopartite, with the amino acid residues K171RRI174 from the ChREBP-NLS interacting with ARM2-ARM5 on importin α. We discovered that importin α also binds to the primary binding site of the 14-3-3 proteins with high affinity, which suggests that both importin α and 14-3-3 are each competing with the other for this broad-binding region (residues 117-196) on ChREBP. We screened a small compound library and identified two novel compounds that inhibit the ChREBP-NLS/importin α interaction, nuclear localization, and transcription activities of ChREBP. These candidate molecules support developing inhibitors of ChREBP that may be useful in treatment of obesity and the associated diseases.

Synthesis and evaluation of analogs of 5'-(((Z)-4-amino-2-butenyl)methylamino)-5'-deoxyadenosine (MDL 73811, or AbeAdo) - An inhibitor of S-adenosylmethionine decarboxylase with antitrypanosomal activity.

We describe our efforts to improve the pharmacokinetic properties of a mechanism-based suicide inhibitor of the polyamine biosynthetic enzyme S-adenosylmethionine decarboxylase (AdoMetDC), essential for the survival of the eukaryotic parasite Trypanosoma brucei responsible for Human African Trypanosomiasis (HAT). The lead compound, 5'-(((Z)-4-amino-2-butenyl)methylamino)-5'-deoxyadenosine (1, also known as MDL 73811, or AbeAdo), has curative efficacy at a low dosage in a hemolymphatic model of HAT but displayed no demonstrable effect in a mouse model of the CNS stage of HAT due to poor blood-brain barrier permeation. Therefore, we prepared and evaluated an extensive set of analogs with modifications in the aminobutenyl side chain, the 5'-amine, the ribose, and the purine fragments. Although we gained valuable structure-activity insights from this comprehensive dataset, we did not gain traction on improving the prospects for CNS penetration while retaining the potent antiparasitic activity and metabolic stability of the lead compound 1.

Mental disorders and the desire for death in patients receiving palliative care for cancer.

OBJECTIVES: The desire for death in terminally ill patients is associated with depression and anxiety, but not all patients who report it meet criteria for mental disorders. We examined the characteristics of subgroups of palliative cancer patients who expressed a desire for death that occurred either with or without a concurrent depressive or anxiety disorder. DESIGN: Cross-sectional survey. SETTING: Eight Canadian palliative care programs. PARTICIPANTS: 377 patients with cancer. MAIN OUTCOME MEASURES: Desire for Death Rating Scale; Structured Interview of Symptoms and Concerns. RESULTS: Most participants (69.5%) had no desire for death. Of the remainder, 69 (18.3%) acknowledged occasional transient thoughts, and 46 (12.2%) reported an apparently genuine desire to die. In the latter group, 24 individuals (52.2%) were diagnosed with a mental disorder and 22 (44.8%) were not. Individuals with no serious desire for death and no mental disorder reported the least distress in physical, social, existential, and psychological symptoms and concerns; those with a mental disorder and a significant desire for death reported the most. The subgroup of patients with a serious desire for death but no concurrent mental disorders still reported increased distress due to physical symptoms and social concerns, as well as a higher prevalence of global suffering. CONCLUSIONS: The expression of a desire for death by a terminally ill patient should raise a suspicion about mental health problems, but is not in itself clearly indicative of one. Nevertheless, it may serve as a catalyst to review the individual's physical symptom management and interpersonal concerns, and overall sense of suffering.

In silico derived small molecules bind the filovirus VP35 protein and inhibit its polymerase cofactor activity.

The Ebola virus (EBOV) genome only encodes a single viral polypeptide with enzymatic activity, the viral large (L) RNA-dependent RNA polymerase protein. However, currently, there is limited information about the L protein, which has hampered the development of antivirals. Therefore, antifiloviral therapeutic efforts must include additional targets such as protein-protein interfaces. Viral protein 35 (VP35) is multifunctional and plays important roles in viral pathogenesis, including viral mRNA synthesis and replication of the negative-sense RNA viral genome. Previous studies revealed that mutation of key basic residues within the VP35 interferon inhibitory domain (IID) results in significant EBOV attenuation, both in vitro and in vivo. In the current study, we use an experimental pipeline that includes structure-based in silico screening and biochemical and structural characterization, along with medicinal chemistry, to identify and characterize small molecules that target a binding pocket within VP35. NMR mapping experiments and high-resolution x-ray crystal structures show that select small molecules bind to a region of VP35 IID that is important for replication complex formation through interactions with the viral nucleoprotein (NP). We also tested select compounds for their ability to inhibit VP35 IID-NP interactions in vitro as well as VP35 function in a minigenome assay and EBOV replication. These results confirm the ability of compounds identified in this study to inhibit VP35-NP interactions in vitro and to impair viral replication in cell-based assays. These studies provide an initial framework to guide development of antifiloviral compounds against filoviral VP35 proteins.

Development of proneurogenic, neuroprotective small molecules.

Degeneration of the hippocampus is associated with Alzheimer's disease and occurs very early in the progression of the disease. Current options for treating the cognitive symptoms associated with Alzheimer's are inadequate, giving urgency to the search for novel therapeutic strategies. Pharmacologic agents that safely enhance hippocampal neurogenesis may provide new therapeutic approaches. We discovered the first synthetic molecule, named P7C3, which protects newborn neurons from apoptotic cell death, and thus promotes neurogenesis in mice and rats in the subgranular zone of the hippocampal dentate gyrus, the site of normal neurogenesis in adult mammals. We describe the results of a medicinal chemistry campaign to optimize the potency, toxicity profile, and stability of P7C3. Systematic variation of nearly every position of the lead compound revealed elements conducive toward increases in activity and regions subject to modification. We have discovered compounds that are orally available, nontoxic, stable in mice, rats, and cell culture, and capable of penetrating the blood-brain barrier. The most potent compounds are active at nanomolar concentrations. Finally, we have identified derivatives that may facilitate mode-of-action studies through affinity chromatography or photo-cross-linking.

Discovery of a proneurogenic, neuroprotective chemical.

An in vivo screen was performed in search of chemicals capable of enhancing neuron formation in the hippocampus of adult mice. Eight of 1000 small molecules tested enhanced neuron formation in the subgranular zone of the dentate gyrus. Among these was an aminopropyl carbazole, designated P7C3, endowed with favorable pharmacological properties. In vivo studies gave evidence that P7C3 exerts its proneurogenic activity by protecting newborn neurons from apoptosis. Mice missing the gene encoding neuronal PAS domain protein 3 (NPAS3) are devoid of hippocampal neurogenesis and display malformation and electrophysiological dysfunction of the dentate gyrus. Prolonged administration of P7C3 to npas3(-/-) mice corrected these deficits by normalizing levels of apoptosis of newborn hippocampal neurons. Prolonged administration of P7C3 to aged rats also enhanced neurogenesis in the dentate gyrus, impeded neuron death, and preserved cognitive capacity as a function of terminal aging. PAPERCLIP:

Synthesis and evaluation of duocarmycin SA analogs incorporating the methyl 1,2,8,8a-tetrahydrocyclopropa[c]oxazolo[2,3-e]indol-4-one-6-carboxylate (COI) alkylation subunit.

The design, synthesis and evaluation of methyl 1,2,8,8a-tetrahydrocyclopropa[c]oxazolo[2,3-e]indol-4-one-6-carboxylate (COI) derivatives are detailed representing analogs of duocarmycin SA containing an oxazole replacement for the fused pyrrole found in the alkylation subunit.

Synthesis and evaluation of a thio analogue of duocarmycin SA.

The design, synthesis, and preliminary evaluation of methyl 1,2,8,8a-tetrahydrocyclopropa[c]thieno[3,2-e]indol-4-one-6-carboxylate (CTI) derivatives are detailed representing a single atom change (N to S) embedded in the duocarmycin SA alkylation subunit.

Prognostic acceptance and the well-being of patients receiving palliative care for cancer.

PURPOSE: To identify the impact of prognostic acceptance/nonacceptance on the physical, psychological, and existential well-being of patients with advanced cancer. PATIENTS AND METHODS: A Canadian multicenter prospective national survey was conducted of patients diagnosed with advanced cancer with an estimated survival duration of 6 months or less (n = 381) receiving palliative care services. RESULTS: Of the total number of participants, 74% reported accepting their situation and 8.6% reported accepting with "moderate" to "extreme" difficulty. More participants with acceptance difficulties than without acceptance difficulties met diagnostic criteria for a depressive or anxiety disorder (chi(2) = 8.67; P < .01). Nonacceptors were younger (t = 4.13; P < .000), had more than high school education (chi(2) = 4.69; P < .05), and had smaller social networks (t = 2.53; P < .05) than Acceptors. Of the Nonacceptors, 42% described their experience as one of "moderate" to "extreme" suffering compared with 24.1% of Acceptors (chi(2) = 5.28; P < .05). More than one third (37.5%) of Nonacceptors reported feeling hopeless compared with 8.6% who had no difficulty accepting (chi(2) = 24.76; P < .000). Qualitatively, participants described active and passive coping strategies that helped them accept what was happening to them, as well as barriers that made it difficult to come to terms with their current situation. CONCLUSION: The challenge of coming to terms with a terminal prognosis is a complex interplay between one's basic personality, the availability of social support, and one's spiritual and existential views on life. Nonacceptance appears to be highly associated with feelings of hopelessness, a sense of suffering, depression, and anxiety, along with difficulties in terms of social-relational concerns.

Prevalence and correlates of pain in the Canadian National Palliative Care Survey.

BACKGROUND: Pain is a common problem for people with cancer who are nearing the ends of their lives. OBJECTIVE: In the present multicentre Canadian study of palliative cancer care, the prevalence of pain, its perceived severity and its correlates across a range of physical, social, psychological, and existential symptoms and concerns were examined. METHODS: Semistructured interviews were conducted with 381 patients. In addition to inquiring about pain, the interview also assessed 21 other symptoms and concerns, and collected information about demographic characteristics, functional status and medication use. RESULTS: Pain of any intensity was reported by 268 (70.3%) participants, although for 139 (36.5%), the severity was rated as minimal or mild. For 129 (33.9%) individuals, pain was reported as moderate to extreme, and considered by the respondents to be an important ongoing problem. Patients who reported moderate to extreme pain were younger than other participants, but had lower functional status and a shorter median survival duration. They were more likely than other participants to be treated with opioid medications (P<0.001) and, less reliably, with benzodiazepines (P=0.079). Compared with participants with no, minimal or mild pain, those with moderate to extreme pain had a higher prevalence of distressing problems on 11 of 21 other symptoms and concerns. The strongest correlations were with general malaise (rho = 0.44), suffering (rho = 0.40), nausea (rho = 0.34), weakness (rho = 0.31), drowsiness (rho = 0.29) and anxiety (rho = 0.29). CONCLUSIONS: Pain continues to be a difficult problem for many patients who are receiving palliative cancer care, particularly younger individuals who are nearing death.

Potent cytotoxic C-11 modified geldanamycin analogues.

17-Allylamino-17-demethoxygeldanamycin (17-AAG) inhibits the activity of Hsp90, an important target for treatment of cancers. In an effort to identify analogues of geldanamycin (GDM) with properties superior to those of 17-AAG, we synthesized C-11 modified derivatives of GDM including ethers, esters, carbazates, ketones, and oximes and measured their affinity for Hsp90 and their ability to inhibit growth of human cancer cells. In accordance with crystal structures reported for complexes of GDMs with Hsp90, bulky groups attached to C-11 interfered with Hsp90 binding while smaller groups such as 11-O-methyl allowed Hsp90 binding. In addition, these analogues also showed in vitro cytotoxicity against human cancer cell lines. Esterification of the 11-OH of 17-AAG eliminated Hsp90 binding in vitro. The readily hydrolyzed esters acted as prodrugs during the measurement of cytotoxicity. Thus, during these experiments, the esters were hydrolyzed, releasing 17-AAG. Several 11-O-methyl-17-alkylaminogeldanamycin analogues were identified with improved potency relative to 17-AAG.

Total synthesis and evaluation of iso-duocarmycin SA and iso-yatakemycin.

The total synthesis and evaluation of iso-duocarmycin SA (5) and iso-yatakemycin (6), representing key analogues of the corresponding natural products incorporating an isomeric alkylation subunit, are detailed. This pyrrole isomer of the natural alkylation subunit displayed an enhanced reaction regioselectivity and a 2-fold diminished stability. Although still exceptionally potent, the iso-duocarmycin SA derivatives and natural product analogues exhibited a corresponding approximate 3-5-fold reduction in cytotoxic activity [L1210 IC(50) for (+)-iso-duocarmycin SA = 50 pM and for (+)-iso-yatakemycin = 15 pM] consistent with their placement on a parabolic relationship correlating activity with reactivity. The DNA alkylation selectivity of the resulting key natural product analogues was unaltered by the structure modification in spite of the minor-groove presentation of a potential H-bond donor. Additionally, a unique ortho-spirocyclization with such derivatives was explored via the preparation, characterization, and evaluation of 34 that is incapable of the more conventional para-spirocyclization. Although 34 proved sufficiently stable for isolation and characterization, it displayed little stability in protic solvents (t(1/2) = 0.19 h at pH 3, t(1/2) = 0.20 h at pH 7), a pH-independent (H(+) independent) solvolysis rate profile at pH 3/4-7, and a much reduced cytotoxic potency, but a DNA alkylation selectivity and efficiency comparable to those of duocarmycin SA and iso-duocarmycin SA. The implications of these observations on the source of the DNA alkylation selectivity and catalysis for this class of natural products are discussed.

Synthesis and Preliminary Evaluation of Duocarmycin Analogues Incorporating the 1,2,11,11a-Tetrahydrocyclopropa[c]naphtho[2,3-e]indol-4-one (CNI) and 1,2,11,11a-Tetrahydrocyclopropa[c]naphtho[1,2-e]indol-4-one (iso-CNI) Alkylation Subunits.

Efficient syntheses and a preliminary evaluation of 1,2,11,11a-tetrahydrocyclopropa[c]-naphtho[2,3-e]indole (CNI) and 1,2,11,11a-tetrahydrocyclopropa[c]naphtho[1,2-e]indole (iso-CNI), and their derivatives containing an anthracene and phenanthrene variant of the CC-1065 or duocarmycin alkylation subunit are detailed.

Pathways to competence: parental adversity and the roles of parenting quality and social support.

The authors studied a representative Canadian cohort from the National Longitudinal Study of Children and Youth at 3 points in time, when the participants were aged 10-11 years (n = 2,147), 12-13 years (n = 1,976), and 14-15 years (n = 1,762). The presence of parent-related adversity appeared detrimental to young people's emotional and behavioral competence. Parents' self-reports of adversity predicted children's self-reports of their own behavioral functioning 2 years later. The authors identified parenting quality and social support as independent resource variables for young people's competence, rather than protective variables in the face of parent-related adversity. Latent variable path analyses suggested the increasing value of both resource variables over time for all young people.

Rational design, synthesis, and evaluation of key analogues of CC-1065 and the duocarmycins.

The design, synthesis, and evaluation of a predictably more potent analogue of CC-1065 entailing the substitution replacement of a single skeleton atom in the alkylation subunit are disclosed and were conducted on the basis of design principles that emerged from a fundamental parabolic relationship between chemical reactivity and cytotoxic potency. Consistent with projections, the 7-methyl-1,2,8,8a-tetrahydrocyclopropa[c]thieno[3,2-e]indol-4-one (MeCTI) alkylation subunit and its isomer 6-methyl-1,2,8,8a-tetrahydrocyclopropa[c]thieno[2,3-e]indol-4-one (iso-MeCTI) were found to be 5-6 times more stable than the MeCPI alkylation subunit found in CC-1065 and slightly more stable than even the DSA alkylation subunit found in duocarmycin SA, placing it at the point of optimally balanced stability and reactivity for this class of antitumor agents. Their incorporation into the key analogues of the natural products provided derivatives that surpassed the potency of MeCPI derivatives (3-10-fold), matching or slightly exceeding the potency of the corresponding DSA derivatives, consistent with projections made on the basis of the parabolic relationship. Notable of these, MeCTI-TMI proved to be as potent as or slightly more potent than the natural product duocarmycin SA (DSA-TMI, IC50 = 5 vs 8 pM), and MeCTI-PDE2 proved to be 3-fold more potent than the natural product CC-1065 (MeCPI-PDE2, IC50 = 7 vs 20 pM). Both exhibited efficiencies of DNA alkylation that correlate with this enhanced potency without impacting the intrinsic selectivity characteristic of this class of antitumor agents.

Systematic exploration of the structural features of yatakemycin impacting DNA alkylation and biological activity.

A systematic examination of the impact of the yatakemycin left and right subunits and their substituents is detailed along with a study of its unique three subunit arrangement (sandwiched vs extended and reversed analogues). The examination of the ca. 50 analogues prepared illustrate that within the yatakemycin three subunit structure, the subunit substituents are relatively unimportant and that it is the unique sandwiched arrangement that substantially increases the rate and optimizes the efficiency of its DNA alkylation reaction. This potentiates the cytotoxic activity of yatakemycin and its analogues overcoming limitations typically observed with more traditional compounds in the series (CC-1065, duocarmycins). Moreover, a study of the placement of the alkylation subunit within the three subunit arrangement (sandwiched vs extended and reversed analogues) indicates that it not only has a profound impact on the rate and efficiency of DNA alkylation but also controls and establishes the DNA alkylation selectivity as well, where both enantiomers of such sandwiched agents alkylate the same adenine sites exhibiting the same DNA alkylation selectivity independent of their absolute configuration.

Suffering with advanced cancer.

PURPOSE: The alleviation of suffering is a central goal of palliative care, but little research has addressed the construct of suffering as a global experience of the whole person. We inquired into the sense of suffering among patients with advanced cancer to investigate its causes and correlates. PATIENTS AND METHODS: Semistructured interviews were administered to 381 patients. The interviews inquired about physical symptoms, social concerns, psychological problems, and existential issues. We also asked, "In an overall, general sense, do you feel that you are suffering?" RESULTS: Almost half (49.3%) of respondents did not consider themselves to be suffering, and 24.9% felt that they suffered only mildly. However, 98 participants (25.7%) were suffering at a moderate-to-extreme level. The latter participants were more likely to experience significant distress on 20 of the 21 items addressing symptoms and concerns; the highest correlations were with general malaise (rho [rho]= 0.56), weakness ( = 0.42), pain ( = 0.40), and depression ( = .39). In regression analyses, physical symptoms, psychological distress, and existential concerns, but not social issues, contributed to the prediction of suffering. In qualitative narratives, physical problems accounted for approximately half (49.5%) of patient reports of suffering, with psychological, existential, and social concerns accounting for 14.0%, 17.7%, and 18.8%, respectively. CONCLUSION: Many patients with advanced cancer do not consider themselves to be suffering. For those who do, suffering is a multidimensional experience related most strongly to physical symptoms, but with contributions from psychological distress, existential concerns, and social-relational worries.