Microbial biosynthesis of the anticoagulant precursor 4-hydroxycoumarin

Marcumar [3-(1'-phenylpropyl)-4-hydroxycoumarin]; a new anticoagulant.

Electrooxidation of iodide in the presence of 4-hydroxycoumarin: application to a simple coulometric titration of 4-hydroxycoumarin.

The electrochemical oxidation of iodide ion in the presence of 4-hydroxycoumarin (1) was studied using cyclic voltammetry and controlled-potential coulometry. The result indicates that the resulting iodine takes part in a halogenation reaction and reacts with 4-hydroxycoumarin (1). According to the obtained results, a new and simple coulometric titration method with potentiometric end-point det...

The synthesis and antimicrobial activity of some 4-hydroxycoumarin derivatives.

Due to exceptional reactivity of 4-hydroxycoumarin, the synthesis of new coumarin derivatives of dimer and tetramer type has been carried out. The synthesis was carried out from 4-hydroxycoumarin and various aromatic aldehydes. In this way, compounds of the dimer 3,3'-(benzilidene)bis (4-hydroxycoumarin) type, as well as of the tetramer 3,3',3'',3'''-(1,4-dimethylenphenyl)tetra (4-hydroxycoumar...

Precursor directed biosynthesis of aureobasidins.

The antifungal antibiotic aureobasidin A (AbA) is a cyclic depsipeptide composed of eight amino acids and a hydroxy acid. New Ab analogs were produced by feeding various amino acids to Aureobasidium pullulans R 106 c-712 in a chemically-defined medium containing glucose and ammonium sulfate. The constituent amino acids of AbA at positions 3 (L-phenylalanine), 4 (N-methyl-L-phenylalanine), 5 (L-...

A Facile Synthesis of 4-Hydroxycoumarin and 4-Hydroxy-2-quinolone Derivatives

Coumarin derivatives possessing diverse biological activities play important roles as versatile building blocks for the synthesis of natural products and biologically active compounds. In particular, 4-hydroxycoumarin derivatives, such as 4-hydroxycoumarin and 4-hydroxythiocoumarin, have been used as useful intermediates for the synthesis of anticoagulants, herbicides, and anticancer agents. Re...