Publications

• Use of 3-Deoxy-D-arabino-heptulosonic acid 7-phosphate Synthase (DAHP Synthase) to Enhance the Heterologous Biosynthesis of Diosmetin and Chrysoeriol in an Engineered Strain of <i>Streptomyces albidoflavus</i>.

  Perez-Valero A., Serna-Diestro J., Villar C.J., Lombo F.

  Flavonoids are a large family of polyphenolic compounds with important agro-industrial, nutraceutical, and pharmaceutical applications. Among the structural diversity found in the flavonoid family, methylated flavonoids show interesting characteristics such as greater stability and improved oral b ... >> More

  Flavonoids are a large family of polyphenolic compounds with important agro-industrial, nutraceutical, and pharmaceutical applications. Among the structural diversity found in the flavonoid family, methylated flavonoids show interesting characteristics such as greater stability and improved oral bioavailability. This work is focused on the reconstruction of the entire biosynthetic pathway of the methylated flavones diosmetin and chrysoeriol in <i>Streptomyces albidoflavus</i>. A total of eight different genes (TAL, 4CL, CHS, CHI, FNS1, F3'H/CPR, 3'-OMT, 4'-OMT) are necessary for the heterologous biosynthesis of these two flavonoids, and all of them have been integrated along the chromosome of the bacterial host. The biosynthesis of diosmetin and chrysoeriol has been achieved, reaching titers of 2.44 mg/L and 2.34 mg/L, respectively. Furthermore, an additional compound, putatively identified as luteolin 3',4'-dimethyl ether, was produced in both diosmetin and chrysoeriol-producing strains. With the purpose of increasing flavonoid titers, a 3-Deoxy-D-arabino-heptulosonic acid 7-phosphate synthase (DAHP synthase) from an antibiotic biosynthetic gene cluster (BGC) from <i>Amycolatopsis balhimycina</i> was heterologously expressed in <i>S. albidoflavus</i>, enhancing diosmetin and chrysoeriol production titers of 4.03 mg/L and 3.13 mg/L, which is an increase of 65% and 34%, respectively. To the best of our knowledge, this is the first report on the de novo biosynthesis of diosmetin and chrysoeriol in a heterologous host. << Less

  Int J Mol Sci 25:2776-2776(2024) [PubMed] [EuropePMC]

  This publication is cited by 7 other entries.

• Identification of the Arabidopsis thaliana flavonoid 3'-hydroxylase gene and functional expression of the encoded P450 enzyme.

  Schoenbohm C., Martens S., Eder C., Forkmann G., Weisshaar B.

  The phenylpropanoid pathway results in the synthesis of thousands of compounds, including flavonoids like flavonols, anthocyanidins and tannins. In Arabidopsis thaliana, the lack of tannins in the seed coat (testa) causes the transparent testa (tt) phenotype. In the present study, we identified th ... >> More

  The phenylpropanoid pathway results in the synthesis of thousands of compounds, including flavonoids like flavonols, anthocyanidins and tannins. In Arabidopsis thaliana, the lack of tannins in the seed coat (testa) causes the transparent testa (tt) phenotype. In the present study, we identified the gene responsible for the tt7 mutation. We show that TT7 encodes the enzyme flavonoid 3'-hydroxylase (F3'H), and demonstrate that this P450-dependent monooxygenase has F3'H activity. The availability of the AtF3'H gene and promoter sequence will allow us to study the coregulation of a complete set of flavonol and anthocyanidin biosynthesis genes in A. thaliana, and makes in vitro synthesis of hydroxylated flavonoids more feasible. << Less

  Biol. Chem. 381:749-753(2000) [PubMed] [EuropePMC]

• In vitro investigation of cytochrome P450-mediated metabolism of dietary flavonoids.

  Breinholt V.M., Offord E.A., Brouwer C., Nielsen S.E., Brosen K., Friedberg T.

  Human and mouse liver microsomes and membranes isolated from Escherichia coli, which expressed cytochrome P450 (CYP) 1A2, 3A4, 2C9 or 2D6, were used to investigate CYP-mediated metabolism of five selected dietary flavonoids. In human and mouse liver microsomes kaempferol, apigenin and naringenin w ... >> More

  Human and mouse liver microsomes and membranes isolated from Escherichia coli, which expressed cytochrome P450 (CYP) 1A2, 3A4, 2C9 or 2D6, were used to investigate CYP-mediated metabolism of five selected dietary flavonoids. In human and mouse liver microsomes kaempferol, apigenin and naringenin were hydroxylated at the 3'-position to yield their corresponding analogs quercetin, luteolin and eriodictyol, whereas hesperetin and tamarixetin were demethylated at the 4'-position to yield eriodictyol and quercetin, respectively. Microsomal flavonoid metabolism was potently inhibited by the CYP1A2 inhibitors, fluvoxamine and -naphthoflavone. Recombinant CYP1A2 was capable of metabolizing all five investigated flavonoids. CYP3A4 recombinant protein did not catalyze hesperetin demethylation, but showed similar metabolic profiles for the remaining compounds, as did human microsomes and recombinant CYP1A2, although the reaction rates in general were lower as compared to CYP1A2. CYP2C9 catalyzed the 4'-demethylation of tamarixetin, whereas CYP2D6 did not seem to play any role in the metabolism of the selected flavonoids. The major involvement in flavonoid metabolism of human CYP1A2, which mediates the formation of metabolites with different biochemical properties as compared to the parent compound and furthermore is known to be expressed very differently among individuals, raises the important question of whether individual differences in the CYP enzyme activity might affect the beneficial outcome of dietary flavonoids, rendering some individuals more or less refractory to the health-promoting potential of dietary flavonoids. << Less

  Food Chem Toxicol 40:609-616(2002) [PubMed] [EuropePMC]