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Aphanocapsa
The Experts below are selected from a list of 1623 Experts worldwide ranked by ideXlab platform
Peter Boger – One of the best experts on this subject based on the ideXlab platform.
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quantitative structure activity relationship of fluridone derivatives with phytoene desaturase
Pesticide Biochemistry and Physiology, 1992Co-Authors: Gerhard Sandmann, Susanne Kowalczykschroder, Harold M Taylor, Peter BogerAbstract:Abstract Structure-activity investigations were carried out with fluridone analogs which are inhibitors of the enzyme phytoene desaturase. The chemical modifications of the 21 bleaching compounds used were all positioned at the pyridinone ring. Inhibition of carotenoid biosynthesis was determined either with intact cells of the cyanobacterium Aphanocapsa or with isolated Aphanocapsa thylakoid membranes assaying inhibition of phytoene desaturation. Methyl was found to be a favorable N -substituent, and the aromatic nature of the heterocycle is not essential although the resulting piperidinone showed lower bleaching activity. Replacement of the keto group by either methoxy or dimethylamine resulted in lowered but still substantial inhibition. The corresponding thione or chloro derivatives were more or less inactive. Quantitative structure-activity correlations were calculated between inhibitory activity and physicochemical properties of the substituents at position 3 of the pyridinone ring. Regression analysis showed a significant correlation between cellular I 50 values and lipophilicity π and σ p . Using in vitro data the contribution of σ p to the regression was not significant.
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Quantitative structure—Activity relationship of fluridone derivatives with phytoene desaturase
Pesticide Biochemistry and Physiology, 1992Co-Authors: Gerhard Sandmann, Harold M Taylor, Susanne Kowalczyk-schröder, Peter BogerAbstract:Abstract Structure-activity investigations were carried out with fluridone analogs which are inhibitors of the enzyme phytoene desaturase. The chemical modifications of the 21 bleaching compounds used were all positioned at the pyridinone ring. Inhibition of carotenoid biosynthesis was determined either with intact cells of the cyanobacterium Aphanocapsa or with isolated Aphanocapsa thylakoid membranes assaying inhibition of phytoene desaturation. Methyl was found to be a favorable N -substituent, and the aromatic nature of the heterocycle is not essential although the resulting piperidinone showed lower bleaching activity. Replacement of the keto group by either methoxy or dimethylamine resulted in lowered but still substantial inhibition. The corresponding thione or chloro derivatives were more or less inactive. Quantitative structure-activity correlations were calculated between inhibitory activity and physicochemical properties of the substituents at position 3 of the pyridinone ring. Regression analysis showed a significant correlation between cellular I 50 values and lipophilicity π and σ p . Using in vitro data the contribution of σ p to the regression was not significant.
Gerhard Sandmann – One of the best experts on this subject based on the ideXlab platform.
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interference of fluridone with the desaturation of phytoene by membranes of the cyanobacterium Aphanocapsa
Pesticide Biochemistry and Physiology, 1992Co-Authors: Susanne Kowalczykschroder, Gerhard SandmannAbstract:Abstract The effect of the bleaching herbicide fluridone was investigated by in vivo and in vitro studies using the cyanobacterium Aphanocapsa. After application, all colored carotenoids and chlorophyll decreased, and phytoene was accumulated in the cells. Direct inhibition of phytoene desaturation was demonstrated with a membrane preparation that converts geranylgeranyl pyrophosphate into phytoene and further to β-carotene. A double-reciprocal plot of phytoene conversion into β-carotene in the presence of fluridone and binding studies with radioactive labeled fluridone showed that this herbicide is a reversible noncompetitive inhibitor of phytoene desaturase.
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quantitative structure activity relationship of fluridone derivatives with phytoene desaturase
Pesticide Biochemistry and Physiology, 1992Co-Authors: Gerhard Sandmann, Susanne Kowalczykschroder, Harold M Taylor, Peter BogerAbstract:Abstract Structure-activity investigations were carried out with fluridone analogs which are inhibitors of the enzyme phytoene desaturase. The chemical modifications of the 21 bleaching compounds used were all positioned at the pyridinone ring. Inhibition of carotenoid biosynthesis was determined either with intact cells of the cyanobacterium Aphanocapsa or with isolated Aphanocapsa thylakoid membranes assaying inhibition of phytoene desaturation. Methyl was found to be a favorable N -substituent, and the aromatic nature of the heterocycle is not essential although the resulting piperidinone showed lower bleaching activity. Replacement of the keto group by either methoxy or dimethylamine resulted in lowered but still substantial inhibition. The corresponding thione or chloro derivatives were more or less inactive. Quantitative structure-activity correlations were calculated between inhibitory activity and physicochemical properties of the substituents at position 3 of the pyridinone ring. Regression analysis showed a significant correlation between cellular I 50 values and lipophilicity π and σ p . Using in vitro data the contribution of σ p to the regression was not significant.
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Quantitative structure—Activity relationship of fluridone derivatives with phytoene desaturase
Pesticide Biochemistry and Physiology, 1992Co-Authors: Gerhard Sandmann, Harold M Taylor, Susanne Kowalczyk-schröder, Peter BogerAbstract:Abstract Structure-activity investigations were carried out with fluridone analogs which are inhibitors of the enzyme phytoene desaturase. The chemical modifications of the 21 bleaching compounds used were all positioned at the pyridinone ring. Inhibition of carotenoid biosynthesis was determined either with intact cells of the cyanobacterium Aphanocapsa or with isolated Aphanocapsa thylakoid membranes assaying inhibition of phytoene desaturation. Methyl was found to be a favorable N -substituent, and the aromatic nature of the heterocycle is not essential although the resulting piperidinone showed lower bleaching activity. Replacement of the keto group by either methoxy or dimethylamine resulted in lowered but still substantial inhibition. The corresponding thione or chloro derivatives were more or less inactive. Quantitative structure-activity correlations were calculated between inhibitory activity and physicochemical properties of the substituents at position 3 of the pyridinone ring. Regression analysis showed a significant correlation between cellular I 50 values and lipophilicity π and σ p . Using in vitro data the contribution of σ p to the regression was not significant.
Harold M Taylor – One of the best experts on this subject based on the ideXlab platform.
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quantitative structure activity relationship of fluridone derivatives with phytoene desaturase
Pesticide Biochemistry and Physiology, 1992Co-Authors: Gerhard Sandmann, Susanne Kowalczykschroder, Harold M Taylor, Peter BogerAbstract:Abstract Structure-activity investigations were carried out with fluridone analogs which are inhibitors of the enzyme phytoene desaturase. The chemical modifications of the 21 bleaching compounds used were all positioned at the pyridinone ring. Inhibition of carotenoid biosynthesis was determined either with intact cells of the cyanobacterium Aphanocapsa or with isolated Aphanocapsa thylakoid membranes assaying inhibition of phytoene desaturation. Methyl was found to be a favorable N -substituent, and the aromatic nature of the heterocycle is not essential although the resulting piperidinone showed lower bleaching activity. Replacement of the keto group by either methoxy or dimethylamine resulted in lowered but still substantial inhibition. The corresponding thione or chloro derivatives were more or less inactive. Quantitative structure-activity correlations were calculated between inhibitory activity and physicochemical properties of the substituents at position 3 of the pyridinone ring. Regression analysis showed a significant correlation between cellular I 50 values and lipophilicity π and σ p . Using in vitro data the contribution of σ p to the regression was not significant.
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Quantitative structure—Activity relationship of fluridone derivatives with phytoene desaturase
Pesticide Biochemistry and Physiology, 1992Co-Authors: Gerhard Sandmann, Harold M Taylor, Susanne Kowalczyk-schröder, Peter BogerAbstract:Abstract Structure-activity investigations were carried out with fluridone analogs which are inhibitors of the enzyme phytoene desaturase. The chemical modifications of the 21 bleaching compounds used were all positioned at the pyridinone ring. Inhibition of carotenoid biosynthesis was determined either with intact cells of the cyanobacterium Aphanocapsa or with isolated Aphanocapsa thylakoid membranes assaying inhibition of phytoene desaturation. Methyl was found to be a favorable N -substituent, and the aromatic nature of the heterocycle is not essential although the resulting piperidinone showed lower bleaching activity. Replacement of the keto group by either methoxy or dimethylamine resulted in lowered but still substantial inhibition. The corresponding thione or chloro derivatives were more or less inactive. Quantitative structure-activity correlations were calculated between inhibitory activity and physicochemical properties of the substituents at position 3 of the pyridinone ring. Regression analysis showed a significant correlation between cellular I 50 values and lipophilicity π and σ p . Using in vitro data the contribution of σ p to the regression was not significant.