De novo biosynthesis of myricetin, kaempferol and quercetin in Streptomyces albus and Streptomyces coelicolor

Abstract

Flavonols are a flavonoid subfamily widely distributed in plants, including several ones of great importance in human and animal diet (apple, tomato, broccoli, onion, beans, tea). These polyphenolic nutraceuticals exert potent antimicrobial (membrane potential disruptors), antioxidant (free-radical scavengers), pharmacokinetic (CYP450 modulators), anti-inflammatory (lipoxygenase inhibitors), antiangiogenic (VEGF inhibitors) and antitumor (cyclin inhibitors) activities. Biotechnological production of these nutraceuticals, for example via heterologous biosynthesis in industrial actinomycetes, is favored since in plants these polyphenols appear as inactive glycosylated derivatives, in low concentrations or as part of complex mixtures with other polyphenolic compounds. In this work, we describe the de novo biosynthesis of three important flavonols, myricetin, kaempferol and quercetin, in the industrially relevant actinomycetes Streptomyces coelicolor and S. albus. De novo biosynthesis of kaempferol, myricetin and quercetin in actinomycetes has not been described before.

Discovery and evaluation of a novel step in the flavonoid biosynthesis pathway regulated by F3H gene using a yeast expression system

“…Previously it was reported naringenin conversion to dihydrokaempferol via F 3 H , which is further converted to kaempferol via flavonol synthase and at last, kaempferol is converted to conversion to quercetin via F 3 H (Crozier et al, 2009; Stahlhut et al, 2015) in higher plants. Similarly, Marín et al (2018) recently reported that naringenin is a substrate metabolized to dihydrokaempferol in the presence of naringenin 3-dioxygenase ( N 3 DOX ), which is further converted to kaempferol and also to dihydroquercetin via FLS and F 3 H , respectively. Additionally, it has been also reported that, silencing of FLS in plants reduces quercetin production which mean that without FLS quercetin can also produces (Mahajan et al, 2011).…”

“…Many downstream metabolite synthesis pathways merge from naringenin depending on the activation enzymes. However, depending on the requirement, researchers cloned the entire pathway or a target step of flavonoid pathway, in the microbial factories (Marín et al, 2018).…”

“…Previous reports showed that kaempferol and quercetin are synthesized by activation of different enzymes in different organisms. For example, functional expression of Petroselinum crispum , naringenin 3-dioxygenase ( N3DOX ) in yeast generate dihydrokaempferol which further produces dihydroquercetin kaempferol and quercetin by activation of their respective enzymes (Marín et al, 2018). Similarly, cytochrome P450 flavonoid monooxygenase ( FMO ), which was fused in-frame to the cytochrome P450 reductase ( CPR ) from Catharanthus roseus , were expressed in yeast and produced quercetin from kaempferol (Rodriguez et al, 2017).…”

Discovery and Validation of a Novel Step Catalyzed by OsF3H in the Flavonoid Biosynthesis Pathway

“…Many downstream metabolite synthesis pathways merge from naringenin depending on the activation enzymes. However, depending on the requirement, researchers have cloned the entire pathway, or a target step of the flavonoid pathway, in the microbial factories [ 16 ].…”

“…Previous reports showed that kaempferol and quercetin are synthesized by the activation of different enzymes in different organisms. For example, the functional expression of naringenin 3-dioxygenase ( N3COX ) from Petroselinum crispum , in yeast, generates dihydrokaempferol, which is further converted into dihydroquercetin, kaempferol, and quercetin under the action of the respective enzymes [ 16 ], as shown in ( Figure 1 A). Similarly, cytochrome P450 flavonoid monooxygenase ( FMO ), which was fused in-frame to the cytochrome P450 reductase ( CPR ) from Catharanthus roseus , was expressed in yeast and produced quercetin from kaempferol [ 17 ] ( Figure 1 B).…”