The synthesis of novel 6,6'-methylene-bis-[3-(2-anilinoacetyl)-4-hydroxycoumarin] derivatives 6a-f was achieved in excellent yields from 6,6'-methylene-bis-[3-(2-bromoacetyl)-4-hydroxycoumarin] 5 and various arylamines. 5,5'-Methylene-bis-ethylsalicylate 3 was obtained by the esterfication of 5,5'-methylene-bis-salicylic acid 2 with ethanol, which was in turn obtained from salicylic acid 1 and ...

Background The protective effect of α-thalassemia, a common hematological disorder in Southeast Asia, against Plasmodium falciparum malaria has been well established. However, there is much less understanding of the effect of α-thalassemia against P. vivax. Here, we aimed to investigate the proportion of α-thalassemia including the impact of α-thalassemia and HbE on the parasitemia of P. vivax ...

Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH(3)OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield.

A ruthenium benzylidene complex with a neutral bidentate N-heterocyclic carbene was prepared and evaluated in ring-closing metathesis of diallyl substrates. Reaction with AgPF6 to generate a four-coordinate complex produced an unexpected dicationic ruthenium benzyl degradation product through nucleophilic attack of the NHC ligand on the benzylidene carbon.

The emergence of strains of Schistosoma resistant to praziquantel has drawn attention to the search for new schistosomacide drugs. Imidazolidinic derivatives have performed outstandingly against adult S. mansoni worms when evaluated in vitro. The molecular modification of imidazolidine by way of bioisosteric replacement gives rise to variations in its biological response. This study verifies th...

A complex of cerium(III) with 4-methyl-7-hydroxycoumarin was synthesized by mixing water solutions of cerium(III) nitrate and 4-methyl-7-hydroxycoumarin sodium salt in a metal-to-ligand molar ratio of 1:2. The complex was characterized and identified by elemental analysis, conductometry, IR, 1H and 13C NMR-spectroscopy, mass spectral data, DTA and TGA. Thermal analysis of the complex indicated ...

The effect of starvation and glucose addition on glucuronidation was assessed in sublobular regions of the lobule in perfused livers from phenobarbital-treated rats. Fibre-optic micro-light guides were placed on periportal and pericentral areas on the surface of livers to monitor the fluorescence (excitation 366 nm, emission 450 nm) of free 7-hydroxycoumarin from the tissue surface. After infus...

Objective: As a further part of our chemical and biological studies in this field, we describe the preparations of the properly substituted benzylidenebis-(4-hydroxycoumarin) derivatives 5a-h and 3-(6-oxo-(1H)-benzopyrano[4,3-b]benzopyran-7-yl)-4-hydroxycoumarin derivatives 6a-e. Methods: The synthesized compounds were screened for their in vitro antimicrobial activity against five strains of b...

A Pseudomonas sp. isolated from sewage by enrichment culture on quinoline metabolized this substrate by a novel pathway involving 8-hydroxycoumarin. During early growth of the organism on quinoline, 2-hydroxyquinoline accumulated as the intermediate; 8-hydroxycoumarin accumulated as the major metabolite on further incubation. 2,8-Dihydroxyquinoline and 2,3-dihydroxyphenylpropionic acid were ide...