Total synthesis of indole-derived allocolchicine analogues exhibiting strong apoptosis-inducing activity.

A series of novel pyrrolo-allocolchicine derivatives (containing a 1-methyl-1H-indol-5-yl moiety replacing ring C) was synthesized. The tetracyclic ring system was constructed by Suzuki-Miyaura cross-coupling of a 1-methylindole-5-boronate with an ortho-iodo-dihydrocinnamic acid derivative and subsequent intramolecular Friedel-Crafts acylation. After reduction of the resulting ketone, the nitrogen functionality was introduced in a Mitsunobu-type reaction by using zinc azide followed by LiAlH(4) reduction. Structural assignments were supported by X-ray crystallography. The compounds synthesized were then tested against BJAB tumor cells and found to exhibit pronounced cytotoxic activity (proliferation inhibition and apoptosis induction). The ketone 24 b was even active at sub-nanomolar concentration. In addition, the antitumor potential of the compounds was confirmed by using B lymphoid cell lines.

Paraoxonase-1 is a major determinant of clopidogrel efficacy.

Clinical efficacy of the antiplatelet drug clopidogrel is hampered by its variable biotransformation into the active metabolite. The variability in the clinical response to clopidogrel treatment has been attributed to genetic factors, but the specific genes and mechanisms underlying clopidogrel bioactivation remain unclear. Using in vitro metabolomic profiling techniques, we identified paraoxonase-1 (PON1) as the crucial enzyme for clopidogrel bioactivation, with its common Q192R polymorphism determining the rate of active metabolite formation. We tested the clinical relevance of the PON1 Q192R genotype in a population of individuals with coronary artery disease who underwent stent implantation and received clopidogrel therapy. PON1 QQ192 homozygous individuals showed a considerably higher risk than RR192 homozygous individuals of stent thrombosis, lower PON1 plasma activity, lower plasma concentrations of active metabolite and lower platelet inhibition. Thus, we identified PON1 as a key factor for the bioactivation and clinical activity of clopidogrel. These findings have therapeutic implications and may be exploited to prospectively assess the clinical efficacy of clopidogrel.

Anti-inflammatory arene--chromium complexes acting as specific inhibitors of NOD2 signalling.

Inflammation is a hallmark of microbial infection in mammals and is the result of a pathogen-induced release of inflammatory effectors. In humans a variety of germ-line encoded receptors, so-called pattern-recognition receptors, respond to conserved signatures on invading pathogens, which results in the transcriptional activation of pro-inflammatory responses. Inflammation is often detrimental to the host and leads to tissue damage and/or systemic dysfunctions. Thus, specific inhibitors of these pathways are desirable for medical interventions. Herein we report on the synthesis and use of some chromium-containing compounds (arene--Cr(CO)3 complexes) with a core structure related to anti-inflammatory diterpenes produced by the sea whip Pseudopterogorgia elisabethae. By using cell-based reporter assays we identified complexes with a potent inhibitory activity on tumour necrosis factor (TNF), Toll-like receptor (TLR), and nucleotide binding domain, leucine-rich repeat-containing receptor (NLR) pathways. Moreover, we found one complex to be a specific inhibitor of inflammatory responses mediated by the NLR protein NOD2, a pivotal innate immune receptor involved in bacterial recognition. Synthesis and characterisation of a set of derivatives of this substance revealed structural requirements for NOD2 specificity. Taken together, our studies suggest this type of arene--Cr(CO)3 complex as a potential lead for the development of antiphlogistica and pharmacologically relevant NOD2 inhibitors.

trans-1,2-Bis(3,5-dimethoxy-phen-yl)ethene.

The title compound, C(18)H(20)O(4), was prepared in high yield from 3,5-dimethoxy-styrene via a Ru-catalysed homo-olefin metathesis. Exclusive formation of the E-configurated isomer was observed. Inter-estingly, one symmetric unit contains two mol-ecules adopting an s-syn-anti and and an all-s-anti conformation.

trans-Ethyl-enedi-p-phenyl-ene diacetate.

The centrosymmetric title compound, C(18)H(26)O(4), was prepared in high yield from 4-acetoxy-styrene via Ru-catalysed homo-olefin metathesis. Exclusive formation of the E-configurated isomer was observed. In the crystal, a strong C-H⋯π inter-molecular inter-action links the mol-ecules together.

Studies toward the total synthesis of mumbaistatin, a highly potent glucose-6-phosphate translocase inhibitor. Synthesis of a mumbaistatin analogue.

A strategy for the total synthesis of the highly potent glucose-6-phosphate translocase inhibitor mumbaistatin (1) and structural analogues was elaborated. Such compounds represent a lead structure in the development of potential new drugs for the treatment of diabetes. To evaluate the general strategy, the close mumbaistatin analogue 10 was synthesized in a convergent manner. The anthraquinone building block 20 was efficiently prepared via aryne/phthalide annulation. After conversion of 20 into the corresponding 9,10-dimethoxyanthracene-1-carbaldehyde derivative (13), coupling with a lithiated arene (12) and subsequent multiple oxidation under Jones conditions yielded the mumbaistatin analogue 10. The preparation of the functionalized arene intermediates was achieved exploiting highly regioselective bromination and ortho-lithiation reactions.