Furocoumarins angular

Furan-3-one, tetrahydro, 2-methyl LP Furocoumarin, angular, 4-hydroxy-2 -methoxy LP ... 

New synthetic routes (Scheme 9) to photosensitive linear and angular furocoumarins, furoquinolones, furoquino-lines, and their analogs were the subject of a review <2004MOL50>. It focuses on the Fries rearrangement of acyloxyheteroarenes, like 70 — 71, the condensation of acylhydroxyheteroarenes with a-carbonyl compounds, like 72 73, and the transformations of dihydrofuroheteroarenes, like 74 75. 

Only one class of benzofuran derivative, natural or synthetic, shows this property—the furocoumarins-, these are important for plant biosynthesis, since they take part in the elaboration of chlorophyll.308 13 Among linear furocoumarins, psoralene (27a) is particularly active. Angelicin (28), another fundamental furocoumarin heterocycle with an angular structure, has only about 12% of the photosensitizing activity of 27a.74-75 On the other hand, it has antibiotic activity. Furochromones have no photosensitizing properties. 

Coumarins are another much investigated group. This period of review has included excited state interactions of coumarin with nucleotide bases and quenching by chloride ions A Fluorescence lifetimes of angular furocoumarins in several solvents have been measured and correlated with triplet yields 55 Structural and solvent effects on the fluorescence properties of benzodihydropyranones have been examined also. ... 

Triplet states of xanthone depend upon the composition of the solvent the presence of water enhances the yield of 2 un state Dual phosphorescence from 2-(2 -hydroxyphenyl) benzoxazole is due to keto-enol tautomerism and the kinetics multi-exponential decay is due to differences of environment . Triplet state properties and triplet state-oxygen interactions of the biologically interesting linear and angular furocoumarins are useful in view of possible clinical application . 

In the final chapter, Gambari et aL summarize the structure and biological effects of furocoumarins. The authors mainly focus on linear and angular psoralens. Borrowing from their laboratory experiences, they describe the interesting biological effects of such compounds on cell cycle, apoptosis and differentiation as well as their use for the treatment of j6-thalassemia. 

Furocoumarins. The angular furocoumarin oroselone (3) has been obtained by reaction of the iodophenol 2 with 1 in pyridine. The linear isomer can be obtained by the same method. ... 

The effects of furan substituents on the coumarin nucleus have been estimated in some angular (117) and linear (118) furocoumarins <84P697>. The effect of the furan ring on H methoxyl signals is similar to its effect on protons in the same position but an additional downfield shift is observed. 

The differences in the methoxyl chemical shifts thus provide a simple method for distinguishing between an angular and a linear furocoiunarin. Spectral H and C data for some 3,4-fused furocoumarins have also been reported recently <91MRC631). 

F. BACCICCHETTI, F. CARLASSARE. 1980. Comparative mutagenicity of linear and angular furocoumarins in Escherichia coli strains deficient in known repair functions. Chem.-Biol. Interact. 30 203-207. 

G. RODIGHIERO. 1982. Photoinactivation of enzymes by linear and angular furocoumarins. Photochem. Photobiol. 36 25-30. 

The CAN-promoted oxidative cycloaddition processes of 4-hydroxycoumarins were extended to terminal alkynes, the reactions leading in this case to mixtures of angular and linear furocoumarins (Scheme 17) [87,88]. 

Furanocoumarins (furocoumarins) are subdivided into linear furanocoumarins (psoralens) and angular furanocoumarins (angelicins). Linear furanocoumarins (LFCs) or... 

Teran, C., Miranda, R., Santana, L., Tejiera, M., and Uriarte, E., Synthesis of linear and angular furocoumarins, Synthesis, Stuttgard, 12,1384,1997. 

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