Umbelliferone

CgHg04. A yellow powder, darkening at 240°C and decomposing at 260°C. It occurs in asafoetida as an ester with its anhydride, umbelliferone. 

The umbelliferone ether structure 1 was suggested for a natural product which was isolated from galbanum resin Does this structure fit the NMR results 48 Is it possible to give a complete spectral assignment despite lack of resolution of the proton signals at 200 MHz What statements can be made about the relative configuration ... 

The assignment of the umbelliferone residue in A likewise follows from interpretation of the Jqh and relationships in the CH COSY and CH COLOC plots following Table 48.1. The C signals at 5c = 112.9 and 113.1 ean be distinguished with the help of the eoupled NMR spee-... 

E. Graf, M. Alexa, Planta Med. 1985, 428 [14-(umbelliferon-7-0-yl)driman-3a,8a-diol]. 

They also state that analytical studies of the oxidation products of dichroine-a indicate that the dichroines are quinazoline derivatives, as already indicated by Koepfli et al. for their alkaloids. With the probable exception of dichroine-a, these bases are active against malaria in chicks in the descending order dichroine-y (1), dichroine- (4) dichroidine quinazolone (40) the figures in brackets are effective doses (mgm./kilo.). There are also two neutral substances present, umbelliferone (dichrin-A) and dichrin-B, m.p. 179-181°. 

The action of coumarin and many of its naturally occurring analogs such as umbelliferone, aesculetin, daphnetin, scopoletin, aesculin, and limettin on root growth has been compared by several investigators (7, SI, 118). In all cases coumarin was the most inhibitory. 

Fig. 2 Increase in fluorescence of the genuine fluorescence (A) by treatment with Benedict s reagent (B) and immersion in a paraffin solution (C) and reduction of emission intensities with time for the two cumarins umbelliferone and scopoletin (curves).

Umbelliferone, pH-dependent change of fluorescence color 44 Universal reagents 4,46,195,376,402,405, 412, 430, 434 Uracil derivatives 44,45 Uranium cations 144 Uranyl acetate reagent 44 Urea... 

Methyl umbelliferone, pH-dependent change of fluorescence 91 Metoxurone 74 Mevinphos (cis/trans) 362 Microwave apparatus 96 ff Mirsol 45... 

Acetonitrile, methanol and DMSO had no apparent effect on umbelliferone glucuronidation in human hepatocytes at concentration up to 2% [32]. With HLMs or expressed UGTs, inhibitory effects of organic solvents on glucuronidation of 7-hydroxy-4-trifluoromethyl-coumarin (7-HFC) and estradiol generally followed the order acetonitrile > ethanol > methonal > DMSO [33], DMSO did not inhibit estradiol-3-glucuronidation activity at a concentration up... 

Umbelliferone Cell cultures, roots Guaiacol Aerial parts... 

Trityl alcohol, t416 Triptamine, al70 Tyramine, al73 Umbelliferone, hill... 

Perkin-Elmer LS-2B microfilter fluorometer Fluorescence is used in immunochemistry. Essentially the radioactive tag on the antigen is replaced by a fluorophore. The most commonly used tags are fluorescein and umbelliferone. 

Stanjek V, Piel J, Boland W (1999) Biosynthesis of furanocoumarins melvalonate-independent prenylation of umbelliferone in Apium graveolens (Apiaceae). Phytochemistry 50 1141-1146 Steinberg PD (1992) Geographical variation in the interaction between marine herbivores and brown algal secondary metabolites. In Paul V (ed) Ecological roles of marine natural products. Comstock, Ithaca, pp 51-92... 

Coumarin itself has a poor quantum yield, but appropriate substitution leads to fluorescent compounds emitting in the blue-green region (400-550 nm). Substitution in position 4 by a methyl group leads to umbelliferone. 7-Hydroxycoumarins are very sensitive to pH. For example, 4-methyl-7-hydroxycoumarin (4-methyl-umbelliferone) can be used as a fluorescent pH probe (see Chapter 10). 

Compounds 1 = 4-hydroxycoumarin 2 = umbelliferon 3 = 4-methyl-esculetin 4 = isopimpinellin 5 = esculin 6 = flavone 7 = a-naphtoflavone 8 = kaempferol 9 = quercetin 10 = isoquercitrin 11 = robinetin 12 = robinin 13 = myricetin 14 = luteolin 7-O-glucoside 15 = rutin 16 = hes-peretin 17 = hespiridin 18 = naringin 19 = pelargonin chloride 20 = polargonin chloride 21 = malvin chloride. 

Relatively few probes have been widely applied to FlAs. Fluorescein and rho-damine, their derivatives, and to some extent phycoerythrin have dominated immunoassays that are based on steady-state measurements. Dansyl, umbelliferone, coumarins, and pyrenes are among others that have been used. Several more commonly used dyes are shown in Figure 14.2. Shorter-wavelength dyes tend to be less useful since they excite at wavelengths where endogenous chromophores, fluorophores, and... 

Figure 6.1. Fluorescence polarization immunoassay for theophylline. (A) Effect of theophylline rabbit antiserum ( ) and normal rabbit serum (A) on the fluorescence polarization of the theophylline-umbelliferone conjugate. (B) Fluorescence polarization of the theophylline-umbelliferone conjugate in the presence of varying concentrations of theophylline. (Reprinted from Ref. 1, with permission from Academic Press.)...

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