Synthesis of Indomorphan Pseudo-Natural Product Inhibitors of Glucose Transporters GLUT-1 and -3.

Bioactive compound design based on natural product (NP) structure may be limited because of partial coverage of NP-like chemical space and biological target space. These limitations can be overcome by combining NP-centered strategies with fragment-based compound design through combination of NP-derived fragments to afford structurally unprecedented "pseudo-natural products" (pseudo-NPs). The design, synthesis, and biological evaluation of a collection of indomorphan pseudo-NPs that combine biosynthetically unrelated indole- and morphan-alkaloid fragments are described. Indomorphane derivative Glupin was identified as a potent inhibitor of glucose uptake by selectively targeting and upregulating glucose transporters GLUT-1 and GLUT-3. Glupin suppresses glycolysis, reduces the levels of glucose-derived metabolites, and attenuates the growth of various cancer cell lines. Our findings underscore the importance of dual GLUT-1 and GLUT-3 inhibition to efficiently suppress tumor cell growth and the cellular rescue mechanism, which counteracts glucose scarcity.

Divergent solid-phase synthesis of natural product-inspired bipartite cyclodepsipeptides: total synthesis of seragamide†A.

Macrocyclic natural products (NPs) and analogues thereof often show high affinity, selectivity, and metabolic stability, and methods for the synthesis of NP-like macrocycle collections are of major current interest. We report an efficient solid-phase/cyclorelease method for the synthesis of a collection of macrocyclic depsipeptides with bipartite peptide/polyketide structure inspired by the very potent F-actin stabilizing depsipeptides of the jasplakinolide/geodiamolide class. The method includes the assembly of an acyclic precursor chain on a polymeric carrier, terminated by olefins that constitute complementary fragments of the polyketide section and cyclization by means of a relay-ring-closing metathesis (RRCM). The method was validated in the first total synthesis of the actin-stabilizing cyclodepsipeptide seragamide A and the synthesis of a collection of structurally diverse bipartite depsipeptides.

Inhibition of Glucose Transporters and Glutaminase Synergistically Impairs Tumor Cell Growth.

Cancer cells sustain growth by altering their metabolism to accelerated aerobic glycolysis accompanied by increased glucose demand and employ glutamine as additional nutrient source. This metabolic adaptation induces upregulation of glucose transporters GLUT-1 and -3, and simultaneous targeting of both transporters and of glutamine metabolism may offer a promising approach to inhibit cancer cell growth. We describe the discovery of the very potent glucose uptake inhibitor Glutor, which targets glucose transporters GLUT-1, -2, and -3, attenuates glycolytic flux and potently and selectively suppresses growth of a variety of cancer cell lines. Co-treatment of colon cancer cells with Glutor and glutaminase inhibitor CB-839 very potently and synergistically inhibits cancer cell growth. Such a dual inhibition promises to be particularly effective because it targets the metabolic plasticity as well as metabolic rescue mechanisms in cancer cells.

Combined Proteomic and In Silico Target Identification Reveal a Role for 5-Lipoxygenase in Developmental Signaling Pathways.

Identification and validation of the targets of bioactive small molecules identified in cell-based screening is challenging and often meets with failure, calling for the development of new methodology. We demonstrate that a combination of chemical proteomics with in silico target prediction employing the SPiDER method may provide efficient guidance for target candidate selection and prioritization for experimental in-depth evaluation. We identify 5-lipoxygenase (5-LO) as the target of the Wnt pathway inhibitor Lipoxygenin. Lipoxygenin is a non-redox 5-LO inhibitor, modulates the ß-catenin-5-LO complex and induces reduction of both ß-catenin and 5-LO levels in the nucleus. Lipoxygenin and the structurally unrelated 5-LO inhibitor CJ-13,610 promote cardiac differentiation of human induced pluripotent stem cells and inhibit Hedgehog, TGF-ß, BMP, and Activin A signaling, suggesting an unexpected and yet unknown role of 5-LO in these developmental pathways.

Biosynthesis of tetraoxygenated phenylphenalenones in Wachendorfia thyrsiflora.

The biosynthetic origin of 1,2,5,6-tetraoxygenated phenylphenalenones and the sequence according to which their oxygen functionalities are introduced during the biosynthesis in Wachendorfia thyrsiflora were studied using two approaches. (1) Oxygenated phenylpropanoids were probed as substrates of recombinant W. thyrsiflora polyketide synthase 1 (WtPKS1), which is involved in the diarylheptanoid and phenylphenalenone biosynthetic pathways, (2) Root cultures of W. thyrsiflora were incubated with (13)C-labelled precursors in an (18)O2 atmosphere to observe incorporation of the two isotopes at defined biosynthetic steps. NMR- and HRESIMS-based analyses were used to unravel the isotopologue composition of the biosynthetic products, lachnanthoside aglycone and its allophanyl glucoside. Current results suggest that the oxygen atoms decorating the phenalenone tricycle are introduced at different biosynthetic stages in the sequence O-1→O-2→O-5. In addition, the incubation of W. thyrsiflora root cultures with (13)C-labelled lachnanthocarpone established a direct biosynthetic precursor-product relationship with 1,2,5,6-tetraoxygenated phenylphenalenones.

NMR-based metabolic profiling of Anigozanthos floral nectar.

Nuclear magnetic resonance spectroscopic methods have been used to characterize the chemical composition of floral nectar of Anigozanthos species with a minimum of sample preparation and without derivatization. The nectar of this passerine-pollinated plant is largely dominated by glucose and fructose, while sucrose occurs only at a minor level. Tyrosine, several additional amino acids, and a variety of carboxylic acids were identified and their concentrations estimated. A linear diarylheptanoid was detected as a trace component, marking the first time this type of secondary product in Hemodoraceae has been found.

[Duration of inpatient depression treatment--fair benchmarking between hospitals]. / Faires Benchmarking der Behandlungsdauer depressiver Patienten in psychiatrisch-psychotherapeutischen Kliniken.

Process and outcome quality of inpatient treatment of depression in Germany was described in a multicenter study of 10 hospitals in North-Rhine Westphalia, Baden-Württemberg and Bavaria. The treatment of more than 2000 depressive patients was assessed by quality indicators and outcome was compared between the hospitals (benchmarking). Results show great variance in length of stay between the hospitals. While in one hospital patients with depressive episodes were discharged after 36.8 days (average), the average length of stay in another hospital was 64.3 days. Furthermore the study revealed that hospitals differ strongly regarding their case-mix. Using stepwise multiple regression analyses potential confounding variables (sociodemographics, history of previous treatment, severity of depression) were identified and their influence on length of stay was calculated. After cross validation the regression analyses model explained 7% of the variance and included 5 predictors. Length of stay is prolonged by patients with a recurrent depressive disorder, by patients with impairment of social functioning and by severity of the depression. Length of stay is reduced if the indication of inpatient treatment was crisis intervention and if there was a previous suicide attempt. It was shown that differences in patient case-mix only account for a small percentage of hospital differences in length of stay. Method, effort and benefit of the regression analyses approach are discussed.

Adherence to guidelines for treatment of depression in in-patients.

BACKGROUND: Adherence to treatment guidelines enhances treatment outcome. However, in clinical practice many patients with depression do not receive appropriate treatment. AIMS: To evaluate the treatment of depression in in-patients of German psychiatric hospitals with respect to treatment outcome and adherence to guidelines. METHOD: We recruited 1202 in-patients with depression from ten different hospitals. Quality data concerning treatment were collected at admission, during the treatment course and at discharge. RESULTS: The level of depression was significantly decreased and most patients were satisfied with treatment. Many aspects of the treatment routine adhered to guideline recommendations. Adherence to guidelines could be improved with respect to adjustment of antidepressant dosage, reduction of benzodiazepine prescription, enhanced use of electroconvulsive therapy and wider use of interpersonal therapy. CONCLUSIONS: The study reveals a high standard of psychiatric treatment of in-patients with depression. Nevertheless there is still room for improvement. Differences between hospitals in adherence to guidelines indicates the need for individual application of quality management tools.