94 research outputs found

    Hygroline derivatives from Schizanthus tricolor and their anti-trypanosomatid and antiplasmodial activities

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    Chemical investigation of the alkaloid extract of the aerial parts of Schizanthus tricolor led to the targeted isolation of 26 hygroline derivatives of which 20 were fully characterized. They have not yet been described in the literature and their structures were established by 1D and 2D NMR, UV and IR spectroscopy, and HRESIMS. The configuration was determined by Gauge-Independent Atomic Orbital NMR chemical shift calculations supported by the advanced statistical method DP4 plus, vibrational circular dichroism, and measurement of optical rotation. Their anti-trypanosomatid, antiplasmodial and cytotoxic activities were measured. Several compounds exhibited low micromolar activity against Plasmodium falciparum. None of the identified molecules was cytotoxic

    Cytotoxic flavonoids and other constituents from the stem bark of Ochna schweinfurthiana

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    Seven flavonoids, hemerocallone (1), 6,7-dimethoxy-3′,4′-dimethoxyisoflavone (2), amentoflavone (4), agathisflavone (6), cupressuflavone (8), robustaflavone (9) and epicatechin (10), together with three other compounds, lithospermoside (3), β-D- fructofuranosyl-α-D-glucopyranoside (5) and 3β-O-D-glucopyranosyl-β-stigmasterol (7), were isolated from the ethyl acetate extract of the stem bark of Ochna schweinfurthiana F. Hoffm. All the compounds were characterised by spectroscopic and mass spectrometric methods, and by comparison with literature data. Cytotoxicity of the extracts and compounds against cervical adenocarcinoma (HeLa) cells was evaluated by MTT assay. Compounds 4 and 6 exhibited good cytotoxic activity, with IC50 values of 20.7 and 10.0 μM, respectively

    Cross metathesis for the synthesis of HDAC inhibitors. Potential in multitarget drug design

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    Histone deacetylases represent a family of eleven zinc-dependant enzymes. Their over expression has been correlated to several human diseases, in particular cancers. The search for compounds able to selectively inhibit one of these HDAC is of high importance to obtain less side effect during treatment as well as avoiding of target effects. In this work we have designed a series of inhibitors using an asymmetric cross metathesis approach. We present the synthesis, some molecular modelling and the biological activities of the prepared compounds.Link ka Knjizi sažetaka se nalazi ovde - http://www.mutalig.eu/2017/06/2nd-annual-meeting-porto-september-21-24-2017

    Development of cross metathesis for the design of HDAC inhibitors

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    Epigenetic histones post translational modifications are key players in the regulation of gene expression. Amongst all possible modifications, the N-acetylation of the lysine side chains located at the N-terminal tail of histones is involved in the relaxation of chromatine and contributes to gene transcription. This acetylation status is controlled by histone acetyl transferases (HAT) and histone deacetylases (HDAC and SIRT). The abnormal expression of HDAC has been linked to the progression of several human diseases such as cancers. Therefore, the development of HDAC inhibitors has emerged as a valuable therapeutic strategy, with currently four compounds approved by the FDA and a fifth one in China. Recent data suggested that combination therapies with HDAC inhibitors may contribute to better clinical results. HDACs are zinc-dependant enzymes grouped in a family of 11 proteins (HDAC1-11), grouped in three classes: class I (HDAC1-3,8), class Il (HDAC4-7,9,10) and class IV (HDAC11). The fourth group of deacetylases contains the class Ill NADH+-dependent sirtuins (SIRT1-7). The standard pharmacophore for HDAC inhibitors involves a zinc-binding group (ZBG) linked through a spacer to a “cap” group in interaction with the external solvent accessible surface. We were interested in alternative chemistries to access HDAC inhibitors in which the intermediate spacer could be build out of two similar building blocks, one bearing the ZBG and on bearing the cap group. By selecting linear alkyl-based spacer, cross metathesis appeared to be a short and flexible strategy, provided it supports the presence of highly oxophile functional groups such as carbonyl groups. This poster summarizes our findings in the application of cross metathesis and the biological evaluations of some of the compounds obtained

    Targeting tumor-associated macrophages by anti-tumor Chinese materia medica

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    Tumor-associated macrophages (TAMs) play a key role in all stages of tumorigenesis and tumor progression. TAMs secrete different kinds of cytokines, chemokines, and enzymes to affect the progression, metastasis, and resistance to therapy depending on their state of reprogramming. Therapeutic benefit in targeting TAMs suggests that macrophages are attractive targets for cancer treatment. Chinese materia medica (CMM) is an important approach for treating cancer in China and in the Asian region. According to the theory of Chinese medicine (CM) and its practice, some prescriptions of CM regulate the body's internal environment possibly including the remodeling the tumor microenvironment (TME). Here we briefly summarize the pivotal effects of TAMs in shaping the TME and promoting tumorigenesis, invasion, metastasis and immunosuppression. Furthermore, we illustrate the effects and mechanisms of CMM targeting TAMs in antitumor therapy. Finally, we reveal the CMM's dual-regulatory and multi-targeting functions on regulating TAMs, and hopefully, provide the theoretical basis for CMM clinical practice related to cancer therapy

    The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases

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    The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article

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