OBJECTIVE This paper examines policy processes regarding why the USA and Norway have not regulated coumarin in tobacco. DESIGN A qualitative analysis of all tobacco industry documents regarding coumarin since the 1950s from the 1998 US Master Settlement Agreement and subsequent legal settlements. Additional data were collected from newspaper reports, general internet search engines, journal a...

Coumarin, a simple, commodity chemical isolated from beans in 1820, has, to date, only yielded one solid state structure. Here, we report a rich polymorphism of coumarin grown from the melt. Four new metastable forms were identified and their crystal structures were solved using a combination of computational crystal structure prediction algorithms and X-ray powder diffraction. With five crysta...

durum wheat is one of the most important cereals that culture in the west of iran and dry land from long time. in order to study of chemical stress on germination of iranian durum wheat by coumarin in 5 levels (0, 10, 20, 30, 45 mg/l), an experiment was conducted in randomized complete design as factorial with three replications on 20 iranian durum wheat, which involve two genotypes as control ...

Photocaged fluorescent molecules are important research tools for tracking molecular dynamics with high spatiotemporal resolution in biological systems. We have designed and synthesized a new class of caged coumarin fluorophores. These coumarin cages displayed more than 200-fold fluorescence enhancement after UV photolysis. Remarkably, the uncaging cross section of a 1-(2-nitrophenyl)ethyl (NPE...

A series of novel thiazolidinones have been synthesized by reaction of various Schiff bases of coumarin with thioglycolic acid. The reaction of 4-hydroxy coumarin with POCl3 yielded 4chloro coumarin 2 and 4-chloro-3, 4', 3', 4"-tercoumarin 2a. Compound 2 was reacted with pphenylene diamine to yield 4-[(4-aminophenyl)amino]-2H-chromen-2-one.Various Schiff bases of coumarin were synthesized by co...

OBJECTIVES Inflammation is an immune response toward injuries. Although inflammation is healing response, but in some condition it will lead to chronic disease such as rheumatoid arthritis, inflammatory bowel disease, atherosclerosis, Alzheimer's and various cancer. Indonesian cassia (Cinnamomum burmannil C. Nees & T. Ness) known to contain coumarin, is widely used for alternative medicine espe...

In the present work we have explored the ultrafast relaxation network of coumarin and umbelliferone (7-hydroxy-coumarin) using time-resolved femtosecond spectroscopy and quantum chemical calculations. Despite the importance of the photophysical properties of coumarin derivatives for applications in biomedicine, the low fluorescence quantum yield of coumarin itself has not been fully understood ...

Cytochrome P450 2A13-catalyzed alpha-hydroxylation is a critical step in the activation of the tobacco carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and (S)-N'-nitrosonornicotine [(S)-NNN]. In the enzyme's active site, a single polar residue, Asn297, can influence substrate binding, orientation, and metabolism. We determined the effects of N297A mutation on enzyme kinetics an...

Terpenes have various applications as fragrances, cosmetics and fuels. One of the most prominent examples is the sesquiterpene farnesene, which can be used as diesel substitute in its hydrogenated form farnesane. Recent metabolic engineering efforts have enabled efficient production of several terpenes in Saccharomyces cerevisiae and Escherichia coli. Plant terpene synthases take on an essentia...

BACKGROUND Sesquiterpenes are 15-carbon terpenes synthesized by sesquiterpene synthases using farnesyl diphosphate (FPP) as a substrate. Recently, a sesquiterpene synthase gene that encodes a 65 kDa protein was isolated from the aromatic plant Persicaria minor. Here, we report the expression, purification and characterization of recombinant P. minor sesquiterpene synthase protein (PmSTS). Insig...