The biosynthesis of some furocoumarins present in Ruta graveolens has been studied administering labeled psoralen, xanthotoxin, rutaretin, marmesin and 7-hydroxycoumarin-derivatives. The results obtained indicate that the biosynthetic pathway involves not only psoralen, but also xanthotoxin and bergapten, by means of methoxylation or demethoxylation reactions. Moreover results achieved from adm...

The surgical management of patients on anticoagulant therapy is often poorly understood in all fields of medicine (not just dentistry). Until now there has been no uniform approach to managing these patients and much of the advice routinely given by medical practitioners and haematologists has fallen behind the recent evidence. Many medical conditions from atrial fibrillation to prosthetic hear...

The rational design of 4-hydroxycoumarins with tailor-made antioxidant activities is required nowadays due to the wide variety of pharmacologically significant, structurally interesting of coumarins and researcher orientation toward green chemistry and natural products. A simple and unique coumarins have been achieved by reaction of 4-hydroxycoumarin with aromatic aldehyde accompanied with the ...

A simple and efficient seven steps synthesis of brodifacoum and difethialone from phenylacetyl chloride is described. The key synthetic strategies involve Friedel-Crafts acylation, intramolecular ring cyclization and condensation reaction in the presence of Brønsted-Lowry acids. It was found that brodifacoum showed favorable inhibiting activities on LPS-stimulated nitrite production in BV-2 mic...

The reaction of 4-hydroxycoumarin (1) with some primary amines 2a-h and morpholine (2i) under microwave irradiation occurred without opening of the lactone ring to give N-substituted 4-aminocoumarins 3a-i in excellent yields. Under the same experimental conditions, 4-hydroxy-6-methyl-2-pyrone (4) reacted with benzylamine (2e) or 2-phenyl- ethylamine (2f) to give the corresponding N,N'-disubstit...

Two bioactive coumarins including 7-hydroxycoumarin (umbelliferone) and 7-hydroxyl-6-methoxy-3, 70-dicoumarylether (daphnoretin) were separated from the ethyl acetate extract of the stems of Edgeworthia chrysantha Lindl (E. papyrifera) by high speed countercurrent chromatography (HSCCC). The two-phase solvent system used was composed of n-hexane-ethyl acetate–methanol–water at an optimized volu...

Antibody against aflatoxin B1 was obtained after one multiple-site injection of bovine serum albumin-aflatoxin B1 conjugate into rabbits. The antibody has greatest binding efficiency for aflatoxin B1, less efficiency for B2, G1, and Q1, and least for aflatoxicol, G2, and M1. Sterigmatocystin, coumarin, and 4-hydroxycoumarin did not give a cross-reaction with the antibody. The sensitivity of the...

Silica gel has been used for synthesis of biscoumarin derivatives starting from 4-hydroxycoumarin and aryl aldehydes. The reaction conditions are completely in agreement with green chemistry principles including sing water as media and a recyclable and safe catalyst. This method is also simple and inexpensive and leads to high yield of products in short reaction times.

A green and efficient one-pot three component reaction of 4-hydroxycoumarin or 1,3-dimethylbarbutyric acid, aryl glyoxals and amides (thioacetamide) has been developed in the presence of BF3- SiO2 nanoparticles in water. This method has several advantages such as high to excellent product yields in short reaction time, atom economy, environment friendly, reusable catalyst and no need for chroma...

Silica gel has been used for synthesis of biscoumarin derivatives starting from 4-hydroxycoumarin and aryl aldehydes. The reaction conditions are completely in agreement with green chemistry principles including sing water as media and a recyclable and safe catalyst. This method is also simple and inexpensive and leads to high yield of products in short reaction times.