| | 1 | Author
| K.H G Rum Bach, B. Fom | Requires cookie* | | | Title
| Chloroplast Autonomy in Acetyl-Coenzyme-A-Formation and Terpenoid Biosynthesis  | | | | Abstract
| Isolated intact spinach chloroplasts were supplied with 14C-labeled C 0 2, phosphoglycerate, phos-phoenolpyruvate, acetate and mevalonate and the incorporation o f radioactivity into /?-carotene and plastoquinone-9 assayed. All applied substrates were capable of crossing the chloroplast envelope. Except phosphoenolpyruvate all radioactive precursors were incorporated into ß-carotene and also into plastoquinone-9. It is concluded that spinach chloroplasts are autonom in acetyl-coenzyme-A-formation and terpenoid biosynthesis. There is a direct carbon flow from intermediates of the Calvin-cycle via acetyl-coenzyme-A and mevalonic acid existing in the chlo roplast leading to the carotenoids and isoprenoid side-chains o f chlorophylls and quinones. | | | |
Reference
| Z. Naturforsch. 35c, 645—648 (1980); received March 25 1980 | | | |
Published
| 1980 | | | |
Keywords
| Biosynthesis, /?-Carotene, Chloroplast, Plastoquinone-9, Terpenoids | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0645.pdf | | | | Identifier
| ZNC-1980-35c-0645 | | | | Volume
| 35 | |
| 2 | Author
| RobleyJ. Light, Klaus Hahlbrock | Requires cookie* | | | Title
| Randomization of the Flavonoid A Ring during Biosynthesis of Kaempferol from |l,2 -,3C2j Acetate in Cell Suspension Cultures of Parsley | | | | Abstract
| Cell suspension cultures o f parsley (Petroselinum hortense) were incubated with [l,2-13C2]ace-tate during a period o f active flavonoid production. The flavonoid glycosides were extracted with ethanol, hydrolyzed in dilute acid, and the aglycones purified by chromatography. Apigenin, a flavone, and kaempferol, a flavonol, were analyzed at 67.9 MHz by 13C FT NMR. The 13C enrich ment confirmed that acetate contributes primarily to the flavonoid A ring. The coupling patterns between adjacent 13C atoms o f the A ring indicate that the cyclization direction of the A ring is random in both compounds. While randomization o f apigenin could have occurred chemically through opening of the pyrone ring under the acid conditions used for glycoside hydrolysis, ran domization o f the more stable flavonol must have occurred biosynthetically. The latter result supports the conclusion that a chalcone is an intermediate in flavonoid biosynthesis. | | | |
Reference
| Z. Naturforsch. 35c, 717—721 (1980); received May 9 1980 | | | |
Published
| 1980 | | | |
Keywords
| 13C-NMR, Apigenin, Kaempferol, Flavonoid, Biosynthesis | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0717.pdf | | | | Identifier
| ZNC-1980-35c-0717 | | | | Volume
| 35 | |
| 3 | Author
| G. Forkm, W. Heller, H. Grisebach | Requires cookie* | | | Title
| Anthocyanin Biosynthesis in Flowers of Matthiola incana Flavanone 3-and Flavonoid 3'-Hydroxylases | | | | Abstract
| Enzyme preparations from flowers o f defined genotypes o f Matthiola incana contain two dif ferent hydroxylases for hydroxylation of naringenin in the 3-and 3'-position, respectively. The 3-hydroxylase is a soluble enzyme and requires as cofactors 2-oxoglutarate, Fe2+ and ascorbate. Besides naringenin eriodictyol is a substrate for the 3-hydroxylase. The 3'-hydroxylase is localized in the microsomal fraction and requires NADPH as cofactor. Naringenin and dihydro-kaempferol but not 4-coumarate or 4-coumaroyl-CoA are substrates for this enzyme. 3'-Hy-droxylase activity is present only in genetic lines of M. incana with the wild-type allele b +. | | | |
Reference
| Z. Naturforsch. 35c, 691—6 (1980); received June 25 1980 | | | |
Published
| 1980 | | | |
Keywords
| Anthocyanins, Flavonoids, Biosynthesis, Flavanon 3-Hydroxylase, Flavonoid 3'-Hydroxylase, Matthiola incana | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0691.pdf | | | | Identifier
| ZNC-1980-35c-0691 | | | | Volume
| 35 | |
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