Academic literature on the topic 'SCREENED FLAVONOIDS'

Lonicera maackii (Caprifoliaceae) is a large, upright shrub with fruits that contain many bioactive compounds. Flavonoids are common active substances in L. maackii. However, there is a dearth of information about the accumulation of these flavonoids and their possible medicinal value. We used targeted metabolomics analysis based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to analyze five developmental stages of L. maackii fruit. A total of 438 metabolites were identified in the five developmental stages, including 81 flavonoids and derivatives. The 81 flavonoids included 25 flavones and derivatives, 35 flavonols and derivatives, two isoflavones, three cyanidins and derivatives, eight procyanidins, and eight flavanones. In addition, we outlined the putative flavonoid biosynthesis pathway and screened their upstream metabolites. More importantly, we analyzed the accumulation patterns of several typical flavones and flavonols. The results reported here improved our understanding of the dynamic changes in flavonoids during fruit development and contributed to making full use of the medicinal value of L. maackii fruit.

Rosa roxburghii Tratt, the most popular fruit that blooms in the southwest of China, has high antioxidant properties and is rich in different flavonoids. However, the regulatory network and critical genes that regulate the flavonoid biosynthesis of R. roxburghii are still unknown. In this study, HPLC analysis revealed that total flavonoids, anthocyanins, and catechin were enriched in mature fruits, flowers, and leaves, respectively. Differentially expressed genes (DEGs) between five organs of R. roxburghii involved in flavonoid metabolism were obtained by transcriptome sequencing. A total of 1130 DEGs were identified, including 166 flavonoid pathway biosynthesis genes, 622 transcription factors (TFs), 301 transporters, and 221 cytochrome P450 proteins. A weighted gene co-expression network analysis (WGCNA) of the DEGs was conducted to construct co-expression networks. Regarding enzymes in the biosynthesis of flavonoids, cytochrome P450 CYP749A22 and CYP72A219 were highlighted in the regulation of total flavonoids of mature fruits. Anthocyanin 3-O-glucosyltransferase and F3′H were the top two critical enzymes for anthocyanin accumulation in flowers. By contrast, caffeic acid 3-O-methyltransferase, 4-coumarate-CoA ligase, and shikimate O-hydroxycinnamoyltransferase were essential for catechin accumulation in leaves. Additionally, we analyzed the eigengene network of the “black” module, which had high correlations with total flavonoids (r = 0.9, p = 5 × 10−6). There were 26 eigengenes in the “black” module, consisting of 6 flavonoid biosynthesis, 14 TFs, and 6 transporters. Among them, the transcription factors RrWRKY45 (DN142829_c1_g5), RrTCP20 (DN146443_c1_g1), and RrERF118 (DN141507_c3_g2) were screened as the hub genes, which significantly correlated with total flavonoids in R. roxburghii. The present biochemical and transcriptomic data provide insights into functional genomics for breeding R. roxburghii with flavonoid accumulation.

Neurotrophic factors are playing vital roles in survival, growth, and function of neurons. Regulation of neurotrophic factors in the brain has been considered as one of the targets in developing drug or therapy against neuronal disorders. Flavonoids, a family of multifunctional natural compounds, are well known for their neuronal beneficial effects. Here, the effects of flavonoids on regulating neurotrophic factors were analyzed in cultured rat astrocytes. Astrocyte is a major secreting source of neurotrophic factors in the brain. Thirty-three flavonoids were screened in the cultures, and calycosin, isorhamnetin, luteolin, and genistein were identified to be highly active in inducing the synthesis and secretion of neurotrophic factors, including nerve growth factor (NGF), glial-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF). The inductions were in time- and dose-dependent manners. In cultured astrocytes, the phosphorylation of estrogen receptor was triggered by application of flavonoids. The phosphorylation was blocked by an inhibitor of estrogen receptor, which in parallel reduced the flavonoid-induced expression of neurotrophic factors. The results proposed the role of flavonoids in protecting brain diseases, and therefore these flavonoids could be developed for health food supplement for patients suffering from neurodegenerative diseases.

Tetrastigma hemsleyanum Diels et Gilg (T. hemsleyanum) is an extensively used Chinese folk herb with multiple bioactivities. Among these bioactivities, flavonoids are recognized as the representative active ingredients. We previously found an elevated accumulation of flavonoids in T. hemsleyanum under water stress; however, the mechanism remains unclear. R2R3-MYB transcription factors play vital roles in the plant response to environmental stress and the regulation of secondary metabolites. Herein, a systematic transcriptome identification of R2R3-MYB family genes under water stress in T. hemsleyanum was performed to explore their potential function in the biosynthesis of flavonoids. A total of 26 R2R3-MYB genes were identified, most of which were clustered into functional branches of abiotic stress. ThMYB4 and ThMYB7 were then screened out to be associated with the biosynthesis of flavonoids through a protein-protein interaction prediction. An expression correlation analysis based on RNA-seq further confirmed that ThMYB4 and ThMYB7 were positively related to the flavonoid biosynthetic pathway genes of T. hemsleyanum. In ThMYB4- and ThMYB7-overexpression hairy roots, it was found that the expression of ThCHS and ThCHI was significantly increased, suggesting that ThMYB4 and ThMYB7 may act as regulators in flavonoid biosynthesis. This will shed new light on the promotion of flavonoid production and the medicinal value of T. hemsleyanum by manipulating transcription factors.