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'Liliaceae' in keywords Facet   section ZfN Section C  [X]
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1982 (1)
1981 (1)
1Author    Dieter Strack, Gesine Sachs, Axel Römer, Rolf WiRequires cookie*
 Title    Ferulic Acid-Sucrose Esters from Immature Anthers of Tulipa cv. "Apeldoorn"  
 Abstract    Two ferulic acid conjugates have been isolated from the extract of immature anthers of Tulipa cv. "Apeldoorn" and their structures elucidated using chromatography, electron impact mass spectrometry, and NMR spectroscopy. These two conjugates are 6,3'-diferuloylsucrose and 6,3',4'-triferuloylsucrose. High performance liquid chromatographic analysis of the extract showed that these esters are transient major constituents of the phenylpropanoid pattern of the immature anthers and are present in the ratio of 1:2. Previous investigations showed that these components are accumulated in the loculus. 
  Reference    Z. Naturforsch. 36c, 721—723 (1981); received April 30 1981 
  Published    1981 
  Keywords    Tulipa, Liliaceae, Hydroxycinnamic Acid Conjugates, Ferulic Acid Esters, Sucrose 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0721.pdf 
 Identifier    ZNC-1981-36c-0721 
 Volume    36 
2Author    G. Kleinehollenhorst, H. Behrens, G. Pegels, N. Srunk, R. W. Ierm AnnRequires cookie*
 Title    Formation of Flavonol 3-O-Diglycosides and Flavonol 3-O-Trigly- cosides by Enzyme Extracts from Anthers of Tulipa cv. Apeldoorn Characterization and Activity o f Three D ifferent O -Glycosyltransferases during Anther Development  
 Abstract    Three distinct glycosyltransferases have been isolated and partially purified from anthers o f Tulipa cv. Apeldoorn. The following designations are proposed; UDP-glucose: flavonol 3-O-glu-cosyltransferase (GT-I), UDP-rhamnose: flavonol 3-O-glucoside rhamnosyltransferase (GT-II) and UDP-xylose: flavonol 3-glycoside xylosyltransferase (GT-III). The three enzymes exhibited an identical pH optimum within the range o f 8.5 —9.0. The estimated molecular weight of GT-I and GT-II was about 40 000, GT-III showed a molecular weight o f 30 000. GT-III required ions like NH^or Ca2+ whereas these ions have almost no influence on GT-I and GT-II activity. The en­ zymes have a slight requirement for SH-reagents, particularly DTE. As opposed to GT-II activity of GT-I and GT-III is significantly influenced by SH reagents and PCMB. Sucrose enhanced GT-III activity but only slightly GT-I activity, GT-II activity is not influenced. Flavonol aglycones can function as glycosyl acceptor for the GT-I, whereas flavonol 3-O-gly-cosides, luteolin, dihydroquercetin, naringenin, cyanidin, /»-coumaric acid and some other phenols were inactive as acceptor. The best acceptors were isorhamnetin and quercetin (Km: 0.9x10~6 m). GT-II did not accept aglycones as substrates. For this enzyme flavonol 3-O-glu-cosides were the most attractive substrates. GT-III did not have any affinity towards aglycones, too. This enzyme exhibited a high specificity for flavonol 3-O-glucosides as well as flavonol 3-0-galactosides. Both enzymes, the GT-II and GT-III, were able to glycosylate flavonol 3-O-digly-cosides forming triglycosides. UDP-glucose (K m= l.OxlO-4 m), UDP-rhamnose and UDP-xylose where shown to be the best glycosyl donors for GT-I, GT-II or GT-III respectively. The glycosyl transfer catalysed by the GT-I was shown to be a freely reversible reaction. In the whole anthers, highest specific activities o f GT-I and GT-II were found during late stages of anther development. Similar results were obtained using the contents o f anthers or the tapetum fraction. In contrary, high GT-III activity can be detected already in young stages o f anther devel­ opment. The highest activities o f the three glycosyltransferases were found in the tapetum frac­ tion, whereas the pollen fraction exhibited only poor activities. 
  Reference    Z. Naturforsch. 37c, 587—599 (1982); received March 18 1982 
  Published    1982 
  Keywords    Liliaceae, Tulipa cv Apeldoorn, Anthers, Flavonoid Metabolism, Enzymatic, O-Glycosyltransferase 
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 TEI-XML for    default:Reihe_C/37/ZNC-1982-37c-0587.pdf 
 Identifier    ZNC-1982-37c-0587 
 Volume    37