Metabolic Investigations on Pristinamycin

Direct high-performance liquid chromatographic separation of unusual secondary amino acids and a comparison of the performances of Chirobiotic T and TAG columns

“…␣-Methylproline (2, racemic [23]), 1,2,3,6-tetrahydropyridine-2-carboxylic acid (3, baïkaïne, enantiopure L [20]; d-isomer was produced via the partial racemization of l-baïkaïne by refluxing in 2 M NaOH), piperidine-2-carboxylic acid (4, pipecolic acid, Pip, enantiopure l and d [21]), 4-hydroxypipecolic acid {5, enantiopure (2S,4R) [20]; racemic [24]}, 5-hydroxypipecolic acid {6, enantiopure (2S,5R) [20]; racemic [25]}, 5-methylpiperazine-2-carboxylic acid (8, racemic [26]), morpholine-3-carboxylic acid (9, enantiopure L [21]; racemic [27]), thiomorpholine-3-carboxylic acid (10, enantiopure L [22]; racemic [28]) were synthetized by using the indicated reported literature methods.…”

Metabolism of Macromolecules in Bacteria Treated with Virginiamycin

“…Factor ' S ' of virginiamycin has a more powerful activity on bacilli and consists of a cyclopeptidic lactone ring ( Fig. I) (Vanderhaeghe & Parmentier, 1960) which resembles that of the B factor of Ostreogrycin complex (Eastwood, Snell & Todd, 1960) and of the I, component of Pristinarnycin (Jolles, Terlain & Thomas, 1965). The mechanism of the inhibitory activity of these complex antibiotics, which has been described respectively as bacteriostatic (Yamaguchi & Tanaka, I 964) and bactericidal (Chabbert & Acar, 1964;Videau, 1965;Murat & Pellerat, 1969, is still unclear.…”

Asymmetric Synthesis of (S)‐4‐Oxopipecolic Acid by a 3+3 Atom‐Unit Assembly Strategy

“…Target molecule (S)-1 was thus obtained in 70% yield after passage through an ion-exchange resin, and has spectral and physicochemical properties identical with those indicated in the literature, notably [α] D 24 ϭ Ϫ17 (c ϭ 1.0, H 2 O) {ref. [8] [α] D 25 ϭ Ϫ17 (c ϭ 1.0, H 2 O)}. In both the solid state and in aqueous solution, (S)-1 exists essentially as its hydrate 10, as evidenced by NMR, IR spectroscopic and mass spectrometric data.…”

“…Some preparations of enantiomerically pure 1 have been achieved through chemical or enzymatic resolution of derivatives of the racemate. [8,9] Asymmetric synthesis strategies have included the use of nonracemic chiral auxiliaries in olefin/iminium cyclisations, [3b] nucleophilic additions to 1-acylpyridinium salts, [5a] [2ϩ3] cycloadditions between methylenecyclopropane and a nitrone followed by thermal rearrangement of the resulting isoxazolidine, [10] or the construction of the piperidine ring from acyclic building blocks derived from the chiral pool.…”

“…[1] Recently, it has also been used as an intermediate in the synthesis of protein tyrosine phosphatase modulators, [2] NMDA receptor antagonists, [3] and thrombin inhibitors. [4] As a consequence of its increasing biological interest and its close structural and synthetic relationships with the equally important 4-hydroxypipecolic acid [5] and other ring-substituted derivatives, [6] a number of synthetic strategies have been investigated for the racemic [7,8] and enantioselective [8Ϫ15] preparation of 1 in free or protected form. Some preparations of enantiomerically pure 1 have been achieved through chemical or enzymatic resolution of derivatives of the racemate.…”