| | 1 | Author
| M. Wink, T. Hartmann, L. Witte | Requires cookie* | | | Title
| Enzymatic Synthesis of Quinolizidine Alkaloids in Lupin Chloroplasts  | | | | Abstract
| The enzymatic sequence responsible for the biosynthesis o f tetracyclic quinolizidine alkaloids could be localized in chloroplasts isolated from Lupinus polyphyllus leaves and L. albus seedlings by differential centrifugation. U pon feeding of cadaverine to isolated chloroplasts lupanine is produced as the m ain alkaloid. Chloroplasts treated with digitonine produce sparteine and 17-oxosparteine instead o f lupanine, thus indicating that the biosynthetic sequence is interrupted. The intermediacy of 17-oxosparteine could be confirmed since exogeneous 17-oxosparteine is con verted into lupanine by intact chloroplasts. 17-Oxosparteine synthase (see Z. N aturforsch. 34 c, 704 1979) the key enzyme of quinolizidine alkaloid biosynthesis could be solubilized from chloro plasts treated with detergents or osmotic shock. | | | |
Reference
| Z. Naturforsch. 35c, 93—9 (1980); received Septem ber 26 1979 | | | |
Published
| 1980 | | | |
Keywords
| Quinolizidine Alkaloids, Enzymatic Synthesis, Isolated Chloroplasts, Lupinus polyphyllus | | | |
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| | | | | TEI-XML for
| default:Reihe_C/35/ZNC-1980-35c-0093.pdf | | | | Identifier
| ZNC-1980-35c-0093 | | | | Volume
| 35 | |
| 2 | Author
| Andrea Feld, Klaus Kobek, HartmutK. Lichtenthaler | Requires cookie* | | | Title
| Inhibition of de novo Fatty-Acid Biosynthesis in Isolated Chloroplasts by Different Antibiotics and Herbicides | | | | Abstract
| Two natural antibiotics, cerulenin and thiolactomycin, were tested for their inhibitory efficacy on de novo fatty-acid biosynthesis of chloroplasts isolated from oat and spinach seedlings and compared with that of known herbicides. With both antibiotics a strong dose-dependent inhibition of the incorporation of [l-14C]acetate into the fatty-acid fraction of the isolated plastids was detected. The /50-values for the inhibition of acetate incorporation into fatty acids are about 4 fiM in the case of thiolactomycin and about 50 ^im in the case of cerulenin for both mono-and dicotyledonous plants. These values are much higher than those of the particular graminicides cycloxydim and diclofop (0.15 and 0.1 ^im), which were developed to control grass weeds in dicotyledonous crop cultures. | | | |
Reference
| Z. Naturforsch. 44c, 976 (1989); received July 3 1989 | | | |
Published
| 1989 | | | |
Keywords
| Cerulenin, de novo Fatty-Acid Biosynthesis, Isolated Chloroplasts, Thiolactomycin | | | |
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| default:Reihe_C/44/ZNC-1989-44c-0976.pdf | | | | Identifier
| ZNC-1989-44c-0976 | | | | Volume
| 44 | |
| 3 | Author
| Bernd Listab, A.Ndrea Golza, Wilhelm Bolandb, H. Artm, K. Lichtenthaler3 | Requires cookie* | | | Title
| Inhibition of de novo Fatty-Acid Biosynthesis in Isolated Chloroplasts by the Antibiotic Cerulenin and Its Synthetic Derivatives | | | | Abstract
| The antibiotic cerulenin was shown to be a potent dose-dependent inhibitor o f de novo fatty-acid biosynthesis in intact isolated chloroplasts o f different plants (measured as [l4C]acetate incorporation into the total fatty-acid fraction). Various chemical derivatives o f cerulenin were synthesized and tested in the chloroplast assay-system o f oat, spinach and pea. M odifica tions o f the hydrocarbon chain o f cerulenin (e.g. tetrahydro-cerulenin and its short-chain c«-2,3-epoxy-4-oxoheptanam ide derivative) decreased the inhibitory activity o f cerulenin, whereas variations o f the epoxy-oxo-am ide structural element led to a com plete loss o f inhibi tion potency. The results indicate that the naturally occurring antibiotic cerulenin is the most active specific inhibitor o f de novo fatty-acid biosynthesis, but the form ation o f the hydroxy-lactam ring seems to be an essential requirement for the inhibitory activity. Those structural analogues o f cerulenin, which can no longer form a hydroxylactam ring, do not possess any inhibitory capacity. | | | |
Reference
| Z. Naturforsch. 47c, 382 (1992); received March 10 1992 | | | |
Published
| 1992 | | | |
Keywords
| Cerulenin, Cerulenin Derivatives, de novo Fatty Acid Biosynthesis, Isolated Chloroplasts | | | |
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| default:Reihe_C/47/ZNC-1992-47c-0382.pdf | | | | Identifier
| ZNC-1992-47c-0382 | | | | Volume
| 47 | |
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