Annelation of the coumarin ring was performed via cathodic reduction of 3-nitrocoumarin derivatives (1-4) by controlled potential. The reduction of 3-nitro-4-aminocoumarin, 1, gave 3,4-diaminocoumaDin, 5, and subsequent treatment with formic acid furnished tlie novel 4H [1] benzopyrano [3,4-b] imidazole-4-on ring system 6. The condensation of 5 with trifluoracetic acid anhydride, acetic acid an...

There are recorded in literature several instances in which the acylation of amino acids in the presence of pyridine proceeded abnormally. ’ We have encountered an unexpected reaction in attempting to acetylate I-tyrosine suspended in. a solution of pyridine in commercial acetic anhydride (containing 90 to 95 per cent of the pure anhydride). From the reaction product a orystalline substance, CM...

Aims: In both, forensic and clinical settings, highly specific and long-term markers of alcohol consumption are still warranted. Metabolomics in rats following administration of ethanol revealed an increase in urinary excretion of N-acetyltaurine (NAT) with alcohol dose [1]. Methods: NAT has been synthesized using a method similar to that of Johnson et al. [2]. Pyridine and acetic anhydride wer...

Mycinamicins, a new family of basic 16membered macrolide antibiotics were produced by Micromonospora griseorubida sp. nov. They consist of at least seven components, named as mycinamicin I (1), 11 (2), III (3), IV (4), V (5), VI (6) and VII (7), and possess strong antibacterial activity against Gram-positive bacteria1-4). In an earlier study, the structures and stereochemistry of mycinamicins w...

We describe a new method that permits quantification in the pmol to nmol range of three lyso-neutral glycosphingolipids (lyso-n-GSLs), glucosylsphingosine (GlcSph), galactosylsphingosine (GalSph), and lactosylsphingosine, in the same sample as neutral glycosphingolipids (n-GSLs). Lyso-n-GSLs and n-GSLs are initially obtained from a crude lipid extract using Sephadex G25 chromatography, followed...