Dahlia variabilis

Dihydroflavonol 4-reductase (DFR EC 1.1.1.219) is a member of the short-chain dehydrogenase/reductase family and catalyzes the stereospecific conversion of (+)-(2R,3R)-dihydroflavonols to the corresponding (2R,3S,4S) flavan-3,4-cw-diols (leucoanthocyanidins), with NADPH as a required cofactor. The enzyme activity was first identified in cell suspension cultures of Douglas fir (Pseudotsuga menziesii) and was shown to be related to the accumulation of flavan-3-ols and proanthocyanidins [96]. Leucoanthocyanidins and DFR were later shown to be required for anthocyanidin formation by complementation of Matthiola incana mutants blocked between dihydroflavonol and anthocyanidin biosynthesis [97, 98], DFR has been purified to apparent homogeneity and biochemically analyzed from flower buds of Dahlia variabilis [99]. DFR was shown to accept different substrates depending on the plant species from which it was isolated (reviewed in 100). 

Fischer D, Stich K, Britsch L, Grisebach H (1988) Purification and characterization of (-l-)dihydroflavonol (3-hydroxyflavanone) 4-reductase from flowers of Dahlia variabilis. Arch Biochem Biophys 264(l) 40-47... 

Wimmer, G. et al., Enz5matic hydroxylation of 6 -deoxychalcones with protein preparations from petals of Dahlia variabilis. Phytochemistry, 47, 1013, 1998. 

Microsomal preparations of Dahlia variabilis flowers have been reported to catalyze the 3-hydroxylation of the 6 -deoxychalcone, isoliquiritigenin, to butein.46 This enzyme activity was shown to be a typical cytochrome P450 monooxygenase that appears to be different from the F3 H, although its occurrence in other species remains to be investigated. 

Anisochilus, Mentha, Thymus (Lamiaceae) spp., ferns [leaf surface] Digitaria exilis (Poaceae) [seed] as glycoside in Apium graveolens, Petroselinum (Apiaceae), Cosmos bipennatus, Erigeron annuus, Dahlia variabilis (Asteraceae), Amorpha fruticosa (Fabaceae)... 

Erigeron annum. Dahlia variabilis diuretic, hypotensive,... 

Biochanin A (=5,7- anruius. Dahlia variabilis (Asteraceae) Cicer arietum, Trifolium pratense, EST-R antagonist (0.5)... 

Glycyrrhiga glabra (Fabaceae) glycoside in Dahlia variabilis (Asteraceae), Glycprrhiza glabra (liquorice) (Fabaceae)... 

Inulin (Alant Starch, Dahlin, Alantin). (C6H10Os)6 H20, mw 990.86. White, hygroscopic powder or horny amorphous lumps mp 178° (decomposes beginning at 160°), d 1.35-1.4 at 20°/4°. SI sol in cold w, sol in hot w si sol in ale. May be obtained from the bulbs of Dahlia variabilis or other plants. On nitration, it gives an explosive compound... 

Inulin is extracted from the tubers of Dahlia variabilis, Helianthus, in a procedure similar to the extraction of sugar from sugar beet. 

Trigonelline, C7H7O2N, was discovered in the seeds of Trigonella foenum-graecum L. (63) but it has since been found in a wide variety of plants such as the seeds of Pisum satimm L. and Cannabis saliva L. (64) in the seeds of Strophanthus kombe Oliver (65), and in coffee (66, 67) also in the soybean (69), in potatoes (70) and in the tubers of Dahlia variabilis Des. and Scorzonera hispanica L. (73). The content of the base in known coffees is fairly constant (0.228-0.245%) (68). 

Dahlia variabilis L. Onion bulbs Allium cepa L. 

Constit. of Dalbergia stevensonii and Dahlia variabilis, Butea frondosa. Coreopsis spp., Cosmos sulphurous and others. Orange-yellow cryst. + IH2O (EtOH aq.). Mp 198°, Mp 213-215°. 

Isol. from Dahlia variabilis, also from Pterocarpus spp., Robinia pseudoacacia, Cicer arietinum, Glycyrrhiza uralensis, Pterocarbus indicus and other leguminosae. Yellow cryst. (EtOH aq.). Mp 200-204 . 4 -0-p-D-Glucopyranoside [59122-93-9]. Neoisotiquiritin C21H22O9 M 418.399... 

Isol. from Dahlia variabilis and Ulex europaeus. 2 242, 372 nm (95% EtOH). 

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