Études vers la synthèse de la célogentine C

Une première partie de cette thèse décrit une approche synthétique vers la célogentine C, molécule naturelle extraite de graines de Celosia argentea, qui présente des propriétés antimitotiques intéressantes par inhibition de la polymérisation de la tubuline. La présence de liaisons inhabituelles au sein de ce composé (entre les chaînes latérales d'une leucine, d'un tryptophane et d'une histidine) procure à cet octapeptide bicyclique une structure originale. Le fragment beta-leucine-trytophane de la célogentine C a pu être préparé de manière contrôlée par une réaction d'hydrogénation asymétrique. Une deuxième partie concerne le développement de réactions catalysées par le chlorure de fer(III). L'hydroamination de styrènes par différents nucléophiles azotés désactivés et la cyclisation de 2-alkynylanilines non-protégées en indoles (dans ce cas, en association avec le palladium) ont pu être catalysées par ce complexe de fer. Le caractère acide de Lewis du fer a également été mis à profit pour la synthèse "one-pot" de bis(indolyl)méthanes.A first part of this thesis describes an approach towards the synthesis of celogentin C, a natural compound extracted from Celosia argentea, with potent antimitotic activities. The presence of unusual bonds between the side chains of a leucine, a tryptophan and a histidine gives to this bicyclic octapeptide an original structure. The beta-leucine-tryptophan residue of celogentin C has been synthesised with high selectivities using an asymmetric hydrogenation. A second part deals with iron(III) chloride catalysed reactions. Styrenes hydroamination using various deactivated nitrogen nucleophiles and non protected 2-alkynylanilines cyclisation to indoles (in this case in presence of palladium) have been catalysed using this complex. The Lewis-acidity nature of iron(III) chloride has been further used in the one-pot synthesis of bis(indolyl)methanes.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Stereocontrolled Routes to beta,beta'-disubstituted alpha-amino-acids

International audienceOwing to their significant abundance in natural products, chiral beta,beta'-disubstituted alpha-amino-acids remain an important synthetic objective. Emphasis has been focused in this review on the great diversity of enantio- and diastereo-selective methodologies to reach these highly functionalized compounds. Oldest and cutting edge synthetic methods are described in parallel to the synthesis of many relevant biologically active targets

Polyfunctional cotton fabrics with catalytic activity and antibacterial capacity

International audienceA novel, eco-friendly and cost-effective method involving cotton fabric (CF) coating with copper oxide and grafting of 3-chloropropyltriethoxisilane and diethanolamine resulted in a multifunctional material (CF@CuO-Si-N(OH)2). The latter exhibited catalytic activity in 4-nitrophenol (4-NP) reduction, Methylene Blue degradation and antibacterial activity. Scanning electron microscopy, energy dispersive X-ray-fluorescence, Fourier transform infrared and UV–visible spectroscopies, contact angle and thermogravimetric analysis revealed the key-role of amine grafting in changes in wettability, stability, morphological and thermal properties. 4-NP catalytic reduction was found to obey 1st-order kinetics, affording 98% conversion even after 7 successive reuses. CF@CuO-Si-N(OH)2 also exhibited appreciable antibacterial capacity against Staphylococcus epidermidis (S.epidermidis) and Escherichia coli (E. coli). These results open promising prospects for using textile fiber-based nanocomposites in diverse technological applications

Chan–Lam–Evans Coupling of Cbz-Protected Histidines

International audienceDirect functionalization of protected histidines with arylboronic acids is described under Chan–Lam–Evans conditions to give the corresponding N(τ)-arylhistidines in moderate to good yields (12 examples, up to 83% yield) under mild conditions

Separating Patients with SEID from Those with CFS in the French ME/CFS Association, with Some Thoughts on Nomenclature

In 2015, the American Institute of Medicine, now called the National Academy of Medicine, (IOM/NAM) proposed new diagnostic criteria for both Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and a new label: Systemic Exertion Intolerance Disease (SEID). This study aimed to evaluate the SEID criteria among members of the French Association of ME/CFS (ASFC) and their opinion about this new name. We sent an anonymous questionnaire to 494 ASFC members, using French-translated questions derived from the IOM/NAM tool kit. Among the 178/231 responding subjects who reported ME/CFS diagnosis, 150 (84%) met the criteria of SEID. For each set of questions, we identified some of them that significantly distinguished SEID from non-SEID patients concerning unrefreshing sleep, cognitive disorders, and orthostatic intolerance items. Forty-six percent of the respondents considered the “SEID” terminology as more appropriate than “CFS”, 39% considered it inappropriate, and 15% had no opinion. Some questions better identified the SEID criteria. The IOM/NAM SEID criteria captured a large part of ASFC members suffering from ME/CFS. However, this new SEID label was not well accepted by the subjects, nor were the other denominations, suggesting that a better term should be found. Pending development of specific markers, further work with patient communities is needed to find a more suitable label

Autoimmune thrombotic thrombocytopenic purpura associated with disseminated sarcoidosis: A case report

Abstract Sarcoidosis is an inflammatory disease known to be associated with multiple autoimmune disorders. There is a restricted number of descriptions of the association between sarcoidosis and autoimmune thrombotic thrombocytopenic purpura (aTTP). We present the case of a 63‐year‐old woman admitted to the hospital to investigate a possible sarcoidosis who had hemolytic anemia and thrombocytopenia, with low ADAMTS13 activity and anti‐ADAMTS13 antibodies, leading to a diagnosis of aTTP. Sarcoidosis was later confirmed and the two conditions evolved separately after 6 months, questioning the link between them. Clinicians should be aware of this rare cause of thrombocytopenia in patients with sarcoidosis, as aTTP is a life‐threatening condition