Enzymatic Synthesis of 4′-and 3′, 4′ -Hydroxylated Flavanones and Flavones with Flower Extracts of Sinningia cardinalis

1987 ◽  
Vol 42 (11-12) ◽  
pp. 1193-1199 ◽  
Author(s):  
K. Stich ◽  
G. Forkmann
Keyword(s):  
Enzymatic Synthesis ◽  
Microsomal Fraction ◽  
Chalcone Synthase ◽  
Condensation Reaction ◽  
Flavonoid Biosynthesis ◽  
Hydroxylase Activity ◽  
Key Enzyme ◽  
Flavone Synthase ◽  
Flavone Synthase Ii ◽  
Cytochrome P 450

Flowers of Sinningia (syn. Rechsteineria) cardinalis contain glycosides of the flavones apigenin (4′-OH) and luteolin (3′,4′-OH) respectively, and of the related 3-deoxyanthocyanidins apigeninidin and luteolinidin. Studies on substrate specificity of the key enzyme of flavonoid biosynthesis, chalcone synthase, revealed that the 3′,4′-hydroxylated flavonoids are formed by hydroxylation of flavonoid compounds rather than by incorporation of caffeoyl-CoA into the flavonoid skeleton during the condensation reaction. In fact, flavonoid 3′-hydroxylase activity could be demonstrat­ed in the microsomal fraction of the flower extracts. The enzyme catalyses hydroxylation of naringenin and apigenin in the 3′-position to eriodictyol and luteolin, respectively, with NADPH as cofactor. Besides flavanone 3′-hydroxylase a further NADPH-dependent enzyme activity (flavone synthase II) was observed in the microsomal fraction catalysing the oxidation of naringenin to apigenin and of eriodictyol to luteolin. The Cytochrome P-450 inhibitor ancymidol was found to abolish completely flavone synthase II activity, whereas flavonoid 3′-hydroxylase activity was not impaired.

Studies on Columnidin Biosynthesis with Flower Extracts from Columnea hybrida

1988 ◽  
Vol 43 (3-4) ◽  
pp. 311-314 ◽  
Author(s):  
K. Stich ◽  
G. Forkmann
Keyword(s):  
Enzyme Preparation ◽  
Microsomal Fraction ◽  
Chalcone Synthase ◽  
Hydroxyl Group ◽  
Soluble Enzyme ◽  
Hydroxylase Activity ◽  
Flavone Synthase ◽  
Flavone Synthase Ii ◽  
Characteristic 3 ◽  
Ring Hydroxylation

Columnidin, the characteristic 3-deoxyanthocyanidin of some Columnea species, possesses the 3′,4′-B-ring hydroxylation pattern of luteolinidin and an additional hydroxyl group at the A-ring, most likely in the 8-position. Studies on substrate specificity of chalcone synthase and flavanone 4-reductase and the demonstration of high flavonoid 3′-hydroxylase activity revealed that the 3′-hydroxyl group of the B-ring of columnidin is introduced at the flavanone stage by hydroxylation of naringenin to eriodictyol. Enzymatic hydroxylation of the A-ring, however, could neither be observed with soluble enzyme preparation nor with microsomal fraction. Most probably this step first occurs at the anthocyanidin level. Besides flavonoid 3′-hydroxylase the microsomal fraction of Columnea flower extracts contains flavone synthase II activity catalysing desaturation of flavanones to flavones with NADPH as co-factor. The presence of some apigenin, appreciable amounts of luteolin and of the 3′,4′-hydroxylated flavan-4-ol luteoforol in the flowers confirm the enzymatic data.

scholarly journals Unraveling the Biochemical Base of Dahlia Flower Coloration

2008 ◽  
Vol 3 (8) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Heidi Halbwirth ◽  
Gerlinde Muster ◽  
Karl Stich
Keyword(s):  
Chalcone Synthase ◽  
Flower Color ◽  
Chalcone Isomerase ◽  
Anthocyanin Content ◽  
Anthocyanin Accumulation ◽  
Enzyme Preparations ◽  
Yellow Color ◽  
Flavone Synthase ◽  
Flavone Synthase Ii ◽  
Related Compounds

Dahlia ( Dahlia variabilis) exists in a dazzling array of cultivars, showing red, orange, magenta, lilac, yellow and white flower color, which is exclusively based on the presence of flavonoids and biochemically related compounds. Red hues (red, orange, magenta, lilac) are a result of anthocyanin accumulation in varying concentration and composition, while a yellow color is based on the formation of 6′-deoxychalcones in the petals. Red dahlia pigments are all derived from pelargonidin and cyanidin. Delphinidin derivatives are not formed due to the absence of flavonoid 3′,5′-hydroxylase in dahlia petals, which provides an explanation for the lack of blue dahlia flowers. Orange, lilac and rose cultivars are characterized by a lower anthocyanin content compared to many red cultivars. We investigated 198 cultivars for the presence of flavonoid enzymes. The activities of chalcone isomerase (CHI), chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), flavanone 3-hydroxylase (FHT), flavone synthase II (FNSII), flavonol synthase (FLS) and flavonoid 3′-hydroxylase (F3′H) were demonstrated in enzyme preparations of dahlia petals. CHI accepted 6′-hydroxychalcones as substrates, but did not catalyze the conversion of 6′-deoxychalcones to the corresponding flavanones. White cultivars were frequently characterized by the lack of DFR activity, whereas in many yellow cultivars neither FHT nor DFR activity could be shown.

scholarly journals Flavone Synthase II (CYP93B) of Antarctic Plant Colobanthus quitensis (Kunth) Bartl.

2018 ◽  
Vol 4 (2) ◽  
pp. 196-198 ◽  
Author(s):  
Rodrigo A. Contreras ◽  
Gustavo E. Zúñiga
Keyword(s):  
Molecular Farming ◽  
Ph Stability ◽  
Biotechnological Applications ◽  
In Vitro Production ◽  
Antarctic Plants ◽  
Potential Applications ◽  
Key Enzyme ◽  
Flavone Synthase ◽  
Flavone Synthase Ii

The role of flavonoids in plant-environmental stress has many biotechnological applications, in this way Antarctic plants have an important potential for molecular farming. However, the concentration and exploitation of resource are highly restricted, for this reason the use of enzymatic machinery of the Antarctic plants have importance for in vitro flavonoid production for different biotechnological applications. Despite their potential applications, key enzymes for flavonoid biosynthesis are poorly studied in non-model plants. In this work, we studied the flavonoid key enzyme, flavone synthase II (FNS II) in C. quitensis. The results show a cooperative kinetic model for NADPH and naringenin. The temperature and pH stability assays show optimal temperature between 20-30 °C, with an operative range from 2 to 37 °C, pH stability shows an optimum of 7.0 to 8.0, with operative range from 3.0 to 8.0, demonstrating a big thermal and pH-stability, an interesting characteristic to in vitro production of flavones.

Induction and Characterization of a NADPH-Dependent Flavone Synthase from Cell Cultures of Soybean

1987 ◽  
Vol 42 (4) ◽  
pp. 343-348 ◽  
Author(s):  
Georg Kochs ◽  
Hans Grisebach
Keyword(s):  
Carbon Monoxide ◽  
Cell Cultures ◽  
Absolute Requirement ◽  
Isoflavone Synthase ◽  
Flavone Synthase ◽  
Flavone Synthase Ii ◽  
Stressed Cells ◽  
Cytochrome P 450 ◽  
Flavone Synthesis

Microsomal preparations from osmotically stressed soybean cells catalyze the conversion of (2S)-naringenin to apigenin in presence of NADPH. In contrast, such preparations from normal soybean cells or from elicitor-challenged cells catalyze the conversion of (2S)-naringenin to genistein (isoflavone synthase). It is concluded that osmotic stress of the cells causes a switch from isoflavone to flavone synthesis. The flavone synthase from osmotically stressed cells corresponds in its properties to the microsomal flavone synthase found in several flowers (G. Stotz and G. Forkmann, Z. Naturforsch. 36c, 737-741 (1981)) and differs from the flavone synthase I from parsley cell cultures which is a soluble Fe2+ and 2-oxoglutarate dependent dioxygenase. Flavone synthase II from soybean has an absolute requirement for NADPH and oxygen. It is inhibited by carbon monoxide in presence of oxygen and this inhibition is reversed by light. It is also inhibited by cytochrome c and by a number of cytochrome P-450 inhibitors. This and other properties show that flavone synthase II is a cytochrome P-450 dependent monooxygenase.

Genome-wide searches and molecular analyses highlight the unique evolutionary path of flavone synthase I (FNSI) in Apiaceae

Genome ◽  
2018 ◽  
Vol 61 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Qi-Zhi Wang ◽  
Stephen R. Downie ◽  
Zhen-Xi Chen
Keyword(s):  
Positive Selection ◽  
Function Analysis ◽  
Gene Families ◽  
Genome Wide ◽  
Key Enzyme ◽  
Flavone Synthase ◽  
Flavone Synthase Ii ◽  
Site Identification ◽  
Identification Analysis ◽  
Significant Positive Selection

Flavone synthase is a key enzyme for flavone biosynthesis and is encoded by two gene families: flavone synthase I (FNSI) and flavone synthase II (FNSII). FNSII is widely distributed in plants, while FNSI has been reported in rice (Oryza sativa) and seven species of Apiaceae. FNSI has likely evolved from the duplication of flavanone 3β-hydroxylase (F3H). In this study, we used multiple bioinformatics tools to identify putative FNSI and F3H genes from 42 publicly available genome and transcriptome datasets. Results showed that rice FNSI does not share a common ancestral sequence with other known FNSI genes and that FNSI is absent from species outside of Apiaceae. Positive selection site identification analysis revealed that four sites within the FNSI tree branches of Apiaceae evolved under significant positive selection. The putative F3H genes identified in this study provide a valuable resource for further function analysis of flavone synthase.

Purification of Chalcone Synthase from Tulip Anthers and Comparison with the Synthase from Cosmos Petals

1981 ◽  
Vol 36 (1-2) ◽  
pp. 30-34 ◽  
Author(s):  
Rainer Sütfeld ◽  
Rolf Wiermann
Keyword(s):  
Chalcone Synthase ◽  
In Vitro Assay ◽  
Flavonoid Biosynthesis ◽  
Chalcone Isomerase ◽  
Gel Chromatography ◽  
Purification Procedure ◽  
Reaction Products ◽  
Complete Elimination ◽  
Vitro Assay

Abstract Chalcone synthase was isolated from both anthers of Tulipa cv. “Apeldoorn” and petals of Cosmos sulphureus Cav. After certain prepurification steps, the enzymes were further purified using gel chromatography on Sephadex G-200 followed by repeated hydroxylapatite absorption chromatography. Both the enzymes showed the same chromatographic properties. After gel chromatography as well as after the first hydroxylapatite fractionation, the reaction products appeared as flavanones. However, after the second hydroxylapatite step, production of chalcones was observed. Like the enzyme from tulip anthers, the synthase from Cosmos petals produced the correspondingly substituted chalcones when p-coumaroyl-CoA, caffeoyl-CoA and feruloyl-CoA, respectively, were used as substractes. In both the cases, the ratios of the different chalcones produced were found to be about the same. The appearance of chalcone synthesis in this in vitro assay is caused by the complete elimination of chalcone isomerase in the purification procedure. The importance of the isomerase for flavonoid biosynthesis, particularly in plant systems which are accumulating chalcones, is discussed.

scholarly journals Loss of haem in rat liver caused by the porphyrogenic agent 2-allyl-2-isopropylacetamide

1971 ◽  
Vol 124 (4) ◽  
pp. 767-777 ◽  
Author(s):  
F. De Matteis
Keyword(s):  
Rat Liver ◽  
Microsomal Fraction ◽  
Direct Evidence ◽  
Gradual Increase ◽  
Rapid Loss ◽  
Metabolizing Enzymes ◽  
Liver Microsomal Fraction ◽  
Green Pigments ◽  
Cytochrome P 450 ◽  
Increased Activity

1. The effect of a single dose of 2-allyl-2-isopropylacetamide on the cytochrome P-450 concentration in rat liver microsomal fraction was studied. The drug caused a rapid loss of cytochrome P-450 followed by a gradual increase to above the normal concentration. 2. The loss of cytochrome P-450 was accompanied by a loss of microsomal haem and by a brown–green discoloration of the microsomal fraction suggesting that a change in the chemical constitution of the lost haem had taken place. Direct evidence for this was obtained by prelabelling the liver haems with radioactive 5-aminolaevulate: the drug caused a loss of radioactivity from the haem with an increase of radioactivity in a fraction containing certain un-identified green pigments. 3. Evidence was obtained by a dual-isotopic procedure that rapidly turning-over haem(s) may be preferentially affected. 4. The loss of cytochrome P-450 as well as the loss of microsomal haem and the discoloration of the microsomal fraction were more intense in animals pretreated with phenobarbitone and were much less evident when compound SKF 525-A (2-diethylaminoethyl 3,3-diphenylpropylacetate) was given before 2-allyl-2-isopropylacetamide, suggesting that the activity of the drug-metabolizing enzymes may be involved in these effects. 5. The relevance of the destruction of liver haem to the increased activity of 5-aminolaevulate synthetase caused by 2-allyl-2-isopropylacetamide is discussed.

Molecular and biochemical characterization of torenia flavonoid 3′-hydroxylase and flavone synthase II and modification of flower color by modulating the expression of these genes

Plant Science ◽  
2002 ◽  
Vol 163 (2) ◽  
pp. 253-263 ◽  
Author(s):  
Yukiko Ueyama ◽  
Ken-ichi Suzuki ◽  
Masako Fukuchi-Mizutani ◽  
Yuko Fukui ◽  
Kiyoshi Miyazaki ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Flower Color ◽  
Flavone Synthase ◽  
Flavone Synthase Ii

scholarly journals Characteristics of the rat liver microsomal enzyme system converting cholecalciferol into 25-hydroxycholecalciferol. Evidence for the participation of cytochrome p-450

1979 ◽  
Vol 184 (3) ◽  
pp. 491-499 ◽  
Author(s):  
T C Madhok ◽  
H F DeLuca
Keyword(s):  
Vitamin D ◽  
White Light ◽  
Microsomal Fraction ◽  
Enzyme System ◽  
Initial Reaction ◽  
Microsomal Enzyme ◽  
Reaction Velocity ◽  
Calcium And Phosphorus ◽  
Cytochrome P 450 ◽  
25 Hydroxycholecalciferol

Properties of the rat hepatic cholecalciferol 25-hydroxylase have been studied. An assay system has been developed in which 25-hydroxycholecalciferol production is linear for at least 2h in both homogenates and microsomal fraction. Furthermore, the initial reaction velocity is linearly related to the amount of liver tissue or microsomal fraction. This enzyme system also metabolizes an analogue of cholecalciferol, namely dihydrotachysterol 3, into 25-hydroxydihydrotachysterol 3. The 25-hydroxylase is in the microsomal fraction and not in mitochondria. It has a Km of 44 nM for cholecalciferol and 360 nM for dihydrotachysterol 3. Its activity is not altered by dietary concentrations of calcium and phosphorus. Vitamin D-deficient rats have higher activities of the hepatic 25-hydroxylase than those receiving 25 ng of cholecalciferol daily. The 25-hydroxylase is inhibited by metyrapone. An atmosphere of CO/O2 (9:1, v/v) inhibits the reaction by 87%. This inhibition is partially reversed by white light. Additionally, cholecalciferol and 25-hydroxycholecalciferol competitively inhibit aminopyrine demethylase. These results support the idea that the cholecalciferol 25-hydroxylase is a cytochrome P-450-dependent mono-oxygenase.

Sign in / Sign up

Export Citation Format

Share Document