7- Hydroxy-6-methoxycoumarin

The reaction of 2,2-dimethyl-4,6-dioxo-l,3-dioxane (Meldrum s acid 394) and its analogues with 3-dialkylaminophenols has been used to prepare some fluorescent 7-dialkylamino-4-hydroxycoumarins (Scheme 127) (77M499). The substituted malonic acid (395) or its dehydration product is a possible intermediate, since it is known that diaryl-malonic esters are accessible from phenols and the 1,3-dioxane. 3-Methoxyphenol yields the pyrano[3,2-c]benzopyran-2,5-dione (396) in this reaction, presumably by annelation of another ring on to initially formed 4-hydroxy-7-methoxycoumarin. 

Several approaches have been made to calculate 13C chemical shifts of coumarins by MO methods. Good correlations were found between the 13C chemical shift values of coumarin (also protonated) and the n charge densities calculated by the CNDO/2 method [962], and of coumarins with it charge densities calculated by the Hiickel MO method (which, however, fails for methoxylated coumarins) [965]. Chemical shifts of mono- and dimethoxycoumarins have been correlated with parameters determined by refined INDO MO calculations, in which n bond orders, atom-atom polarizabilities, excitation energies and electron-nucleus distances were taken into consideration [966], In 3-substituted 4-hydroxy and 4-hydroxy-7-methoxycoumarins chemical shifts were found to be related to Swain and Lupton s parameters iF and M [388], according to equation 5.4 (SE = Substitution Effect) ... 

Fowden et al. (1973) isolated 4-hydroxy leucine from the seeds of fenugreek. Later, Alcock et al. (1989) determined its absolute configuration as (2S, 3R, 4S). From the leaves and stems, y-schizandrin and scopo-letin (7-hydroxy-6-methoxycoumarin) were isolated by Wang et al. (1997). Shang et al. 

No or only minimal cytotoxicity of most coumarins could be detected in normal cells in contrast to the positive control gallic acid. On the other hand, several of them showed concentration-dependent cytotoxicity against tumor cell lines HSC-2 and HSC-3. Among them, 6-hydroxy-7-methoxycoumarin derivatives (C29, C30, C39, C40, C41, C42, and C43) were cytotoxic to tumor cell fine HSC-2. However, C34 and C38 were relatively non-toxic to all cell lines used. It is suggested that the presence of polar substituents such as ester and alcohol group at the C-3 and/or C-4 position was unfavorable for cytotoxicity. This observation confirms the recent findings that 3,4-dimethyl- (C17) and 3,4-cyclopentano-6-hydroxy-7-methoxycoumarin (C22) showed marked cytotoxic effects [25]. However, it should be noted that 4-methyl-6-hydroxy-... 

Rutin (= Quercetin 3-0-Rut Quercetin 3-0-Rha-Glc 3,5,7,3, 4 -Pentahydroxy-flavone 3- 0-Rut Rutoside) (flavonol O-glycoside) Salvianolic acid K (phenylpropanoid) Salviaflaside (glycosylated phenypropanoid) Scopoletin (= Chrysatropic acid Gelseminic acid 7-Hydroxy-6-methoxycoumarin ... 

Coumarins are natural compounds that contain characteristic benzo[a]pyrone (2H-benzopyran-2-one) moiety. They are especially abundant in UmbelUferae, Rutaceae, Leguminosae, and other plant families. Different coumarin derivatives have been isolated. Usually the substituents are at the positions C5, Cg, C7, and Cs [e.g., umbelliferone (7-hydroxycoumarin), hier-niarin (7-methoxycoumarin), esculetin (6,7-dihydrox-ycoumarin), scopoletin (6-methoxy-7-hydroxy-coumarin), osthenol (7-hydroxy-8-prenylcoumarin), osthol (7-methoxy-8-prenylcoumarin), and others]. 

Scopoletin (7-Hydroxy-6-methoxycoumarin) occurs in Solanaceac, Convolvulacea and various other species of plants. It can also be mad( synthetically. 

The complex Ru(CO)2(sq)2, where sq = 3,5-di-tert-butyl-l,2-benzosemiqui-none, shows shifts of 53 99 cm 1 to lower wavenumber for vCO on two-electron reduction.130 Oxidation of Ru(PPh3)2(CO)2(L), where H2L = 7,8-hydroxy-6-methoxycoumarin, to the monocation shifted vCO from 1978 and 2042 cm-1 to 2018 and 2072 cm-1.131 IR spectroelectrochemistry and resonance Raman spectroscopy were used to probe the photo- and electrochemistry of the clusters Ru3(CO)8(p-CO)2(a-di-imine), where a-di-imine = bipy, 4,4-Me2bipy or 2,2 -bipyrimidine.132... 

G.16) 2//-l-Benzopyran-2-one, 7-hydroxy-6-methoxy-, 7-hydroxy-6-methoxy-2W-chromen-2-one. 7-hydroxy-6-methoxy-2H-l-benzopyran-2-one, 7-hydroxy-6-methoxycoumarin, scopoletin, 0-methylesculetin 92-61-5 ... 

In a study of C. arietinum to identify flavonoids the ground up aerial parts were extracted and analysed. In addition to 14 and 69 already previously identified in the species the authors made the first record of coumarins in the genus, specifically scopoletin (7-hydroxy-6-methoxycoumarin) (228) and umbelliferone (7-hydroxycoumarin) (229) [95]. 

Numerous new coumarins have been identified in plants apigravin (7-hydroxy-8-methoxy-6-prenylcoumarin) occurs in the seeds of Apium graveolens 6-(2-hydroxy-3-methylbut-3-enyl)-7-methoxycoumarin (256) and 3,6-diprenyl-7-hydroxycoumarin (257), present in Amyris balsamifera, provided taxonomic evidence capensin (258) has been discovered in the aerial parts of the South African plant Phyllosma capensis ... 

Carbonyl azides react with alcoholic hydroxy compounds to form the corresponding urethanes. In the same manner, ferrocenoyl azide, and 3-fe-rrocenylpropionyl azide can derivatized, hydroxy-steroids and the resultant derivatives are determined electrochemically by LC with the detection limits at subpicomole levels. 2-[2-(Azidocarbonyl)ethyl]-3-methyl-1,4-naphthoquinone (AMQ) reacts with primary and secondary alcohols to produce carbamic acid derivatives and is used in LC with BCD and FL detections. 7-Methoxycoumarin-4-carbonyl azide (7-MC-4-CON3) and 3,4-dihydro-6,7-dimethoxy-4-methyl-3-oxoquinoxaline-2-carbonyl azide (DMEQ-CON3) are also applied to LC with FL detection as precolumn reagents. 

The reagents containing hydroxy group have been developed for FL derivatization of carboxylic acid or other activated acids. 1-Pyrenemethanol (1-PM), 4-hydroxymethyl-7-methoxycoumarin (HMC), and 5-(4-pyridyl)-2-thiophenemethanol (PTM) have been applied to carboxylic acids with LC-FL detection. 

Dihydroxy-3- 3-methyl-2-butenyl)phenyI -7-hydroxy-5-methoxy-2H-l-benzopyran-2-one, 9C1. 3- 2,4-Dihydroxy-3-prenylphenyl)-7-hydroxy-5-methoxycoumarin [155023-53-3]... 

Me ether 4- 3,4-Dihydroxyphenyl)-7-hydroxy-5-methoxycoumarin. 3, 4, 1-Trihydroxy-5-methoxyneoflavone... 

Di-Me ether 5-Hydroxy-4- 3-hydroxy-4-methoxyphenyl)- 7-methoxycoumarin. 3 5-Dihydroxy-4, 1-dimethoxyneoflavone... 

O-De-Me [61899-42-1]. 3 (lJ Dimethyl-2-propenyt)-8-hydroxy-7-methoxy-2H-l-benzopyran-2-one. 3-(l,l-Dimethylallyl)-8-hydroxy-7-methoxycoumarin C15H16O4 M 260.289 Isol. from R. spp. Mp 98-100°. 

Hydroxy-6-methoxycoumarin. Scopoletin. Aesculetin 6-methyl ether. Chrysatropic acid. Gelseminic acid, p-Methylaesculetin... 

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