Serge Romoff - temoin inconnu

En mai 1921 et à Paris depuis une quinzaine d’années, Serge Romoff est appelé comme témoin au procès fictif de Maurice Barrès monté par les Dadaïstes et les Surréalistes. Bien qu’il soit presque certain qu’il connaissait plusieurs membres des deux groupes, il n’y a aucune trace de sa participation au cours des années précédentes ni à leurs activités ni à leurs publications. Qui donc était Serge Romoff?? La documentation manque, mais il semble qu’à partir de 1920 il joue un rôle de plus en plus important dans le monde culturel et surtout dans celui des artistes émigrés russes dans le quartier de Montparnasse. Il travaille dans l’imprimerie, fait quelques traductions, collabore à plusieurs revues culturelles, organise des expositions et écrit des articles de presse, notamment pour L’Humanité. En 1928 il retourne à Moscou où il continue à faire des conférences, probablement sur la littérature française et l’art. Il est mort en février 1939, une des victimes peut-être des purges staliniennes

Development of Hamari Ligands for Practical Asymmetric Synthesisof Tailor-Made Amino Acids

Enantiomerically pure tailor-made amino acids are in extremely high demand in nearly every sector of the health-related industries. In particular, the rapidly growing number of amino-acid-based pharmaceuticals calls for the development of advanced synthetic approaches featuring practicality and commercial viability. Here we provide a brief summary of the development of axially chiral tridentate Hamari ligands and their application for general asymmetric synthesis of various structural types of amino acids. The methodological diversity includes: dynamic kinetic resolution and (S)-/(R)-interconversion of unprotected amino acids and homologation of nucleophilic glycine equivalents via alkyl halide alkylation reactions as well as multiple-step transformations allowing preparation of polyfunctional and cyclic derivatives. The practicality of these methods is critically discussed.We gratefully acknowledge the financial support from the National Natural Science Foundation of China (No. 21761132021) and IKERBASQUE, Basque Foundation for Science

Antitrypanosomal activity and evaluation of the mechanism of action of diterpenes from aerial parts of Baccharis retusa (Asteraceae)

Baccharis retusa, a medicinal Brazilian plant from Asteraceae, has been used in Brazilian folk medicine to treatment of several illnesses, including parasitic diseases. Bioactivity-guided fractionation of the n-hexane extract from the aerial parts of B. retusa resulted in the isolation and characterization of three active related diterpenes: ent-15 beta-senecioyl-oxy-kaur-16-en-19-oic acid (1), ent-kaur-16-en-19-oic (2) and ent-16-oxo-17-nor-kauran-19-oic (3) acids. The structures of isolated compounds were defined by spectroscopic analysis, including NMR and HRESIMS. Antitrypanosomal activity of 1-3 was performed against cell-derived trypomastigotes using the colorimetric resazurin assay. The obtained results demonstrated that isolated compounds displayed a reduced toxicity against NCTC cells and were effective against the trypomastigote forms of T. cruzi with IC50 values of 3.8 mu M (1), 75.3 mu M (2) and 44.2 mu M (3). Additionally, compound 3 displayed activity against amastigote forms of T. cruzi with IC50 of 83.2 mu M. Compound 1 displayed the highest selectivity index (SI) when considered the trypomastigote forms, and its effect in the plasma membrane of parasite was evaluated using the fluorescent probe SYTOX Green. A considerable permeabilization (57%) in the membrane of the parasite was observed when compared to the untreated trypomastigotes. These data demonstrate, for the first time, the antitrypanosomal activity and mechanism of action of 1 and related compounds 2 and 3, obtained from aerial parts of B. retusa.Fundacao de Amparo a Pesquisa do Estado de Sao PauloCNPq scientific research awardUniv Fed Sao Paulo, Inst Environm Chem & Pharmaceut Sci, BR-09972270 Sao Paulo, BrazilFed Univ ABC, Ctr Nat Sci & Humanities, BR-09210580 Sao Paulo, BrazilAdolfo Lutz Inst, Ctr Parasitol & Mycol, BR-01246000 Sao Paulo, BrazilUniv Prebiteriana Mackenzie, Sch Engn, BR-01302907 Sao Paulo, BrazilUniv Sao Paulo, Inst Biosci, Dept Bot, BR-05508090 Sao Paulo, BrazilUniv Fed Sao Paulo, Inst Environm Chem & Pharmaceut Sci, BR-09972270 Sao Paulo, BrazilFAPESP: 2014/08961-2, 2015/11936-2, 2015/23403-9Web of Scienc

Scale-up Synthesis of (<i>R</i>)- and (<i>S</i>)‑<i>N</i>‑(2-Benzoyl-4-chlorophenyl)-1-(3,4-dichlorobenzyl)pyrrolidine-2-carboxamide Hydrochloride, A Versatile Reagent for the Preparation of Tailor-Made α- and β‑Amino Acids in an Enantiomerically Pure Form

Unusual amino acids are of crucial importance to the synthesis of bioactive peptides and new chemical entities. Innovative methodology is always needed for the preparation of enantiomerically pure amino acids that does not rely on tedious resolution procedures. The proline-derived ligands (<i>R</i>)- and (<i>S</i>)-<i>N</i>-(2-benzoyl-4-chlorophenyl)-1-(3,4-dichlorobenzyl)­pyrrolidine-2-carboxamide are outstanding, versatile, and recyclable reagents for the synthesis of tailor-made α- and β-amino acids. Here we report initial studies of the scale-up synthesis of the HCl salt of these reagents on the 100 g scale. The results demonstrate an increased efficiency and environmental friendliness of the bench-scale procedure and provides a firm foundation for the manufacture on multikilogram and larger scales