scholarly journals Flavonoid 3'-hydroxylase of Camellia Nitidissima Chi. Can Promote the Synthesis of Polyphenols Better Than Flavonoids

Author(s):  
Lina Jiang ◽  
Zhengqi Fan ◽  
Ran Tong ◽  
Hengfu Yin ◽  
Jiyuan Li ◽  
...  

Abstract Camellia nitidissima Chi is an ornamental plant of the genus Camellia L. Its flowers contain a lot of flavonoids and polyphenols. Flavonoid 3'-hydroxylase (F3'H) plays an important role in the synthesis of flavonoids, polyphenols and anthocyanins. We cloned CnF3'H from the petal of C. nitidissima (GenBank code: HQ290518.1). The full length of CnF3'H was 1859 bp, with an open reading frame of 1577 bp, and encoded 518 amino acid. A phylogenetic tree analysis showed that CnF3'H was closely related to Camellia sinensis L. and C. sinensis cultivar Zhonghuang. CnF3'H was expressed in flowers, leaves, fruits, sepals, petals and stamens of C. nitidissima, and during the flowering process the expression level in flower decreased initially and then increased. CnF3'H expression was significantly positive correlated with polyphenol contents in C. nitidissima. A CnF3'H-EGFP expression vector was constructed to do the subcellular localization, we found that CnF3'H was obviously localized in the nuclear envelope and cytomembrane. In transgenic tobacco flowers, the total polyphenol content and various polyphenol constituents were significantly increased with high CnF3'H expression level, while total flavonoid contents and some flavonol constituents were increased slightly. These findings suggest that CnF3'H can promote the synthesis of polyphenols better than flavonoids.

2012 ◽  
Vol 40 (1) ◽  
pp. 53 ◽  
Author(s):  
Liliana Cristina SOARE ◽  
Mariana FERDES ◽  
Stefan STEFANOV ◽  
Zapriana DENKOVA ◽  
Radosveta NICOLOVA ◽  
...  

The aim of this paper was to test the antioxidant activity, polyphenols content and antimicrobial activity of crude extracts obtained from leaves of pteridophyte species commonly found in Romania. The ORAC (Oxygen Radical Absorbance Capacity) of the investigated ferns varied between 421.90 ?mol TE (Trolox equivalents/g FW (fresh weight) in Dryopteris filix-mas and 128.18 ?mol TE/g FW in D. affinis. Methanolic extracts obtained from leaves of ferns have similar antioxidant activity to that of some medicinal plants. Polyphenols content in the leaves of ferns varies between 2340 mg Gallic acid equivalents (GAE)/100 g FW in D. filix-mas and 887 mg GAE/100 g FW in D. affinis. The correlation coefficient between ORAC and the total polyphenol content was R=0.985. This correlation suggests that phenolic compounds are major contributors to the antioxidant activity. The methanolic extract obtained from ferns inhibits the growth of Gram negative Escherichia coli ATCC 25922, Pseudomonas aeruginosa NBJMCC1390, Salmonella abony and Gram positive Staphyllococcus aureus ATCC 25093 and Enterococcus faecalis. The highest antimicrobial activity was determined for the Dryopteris extract. The antimicrobial activity of methanolic extracts obtained from leaves of D. filix-mas and D. affinis is better than the A. filix-femina in the case of Brevibacterium flavum ATCC 14067, Sarcina sp., Bacillus cereus ATCC 1390, Saccharomyces cerevisiae and Aspergillus niger. The tested ferns could be used as cosmetic ingredients, as preservatives in food or in antimicrobial therapy.


2020 ◽  
Author(s):  
zhang chenfei ◽  
Xie XiaoHong ◽  
Jia YongHong ◽  
Wang QingHao ◽  
Wang WenJing ◽  
...  

Abstract Background: Rhododendron fortunei belongs to a scented Rhododendron species native to China, which produces fragrant flowers of great ornamental and environmental values. However, the scents in R. fortunei have not yet been investigated. Results: The results showed that three main VOCs measured from highest to lowest are methyl benzoates, terpenes and fatty acid derivatives. Their content increased after the flower bud opening and reached the highest at half to full blossom. In a flower most VOC contents were measured in petals and only trace amount in other tissues such as stamen, pistil. A small amount of VOCs was determined in leaves as well. All aromatic values were almost corresponded to the contents of three main VOCs, indicating that the flower fragrance arises truly from these VOC components. To understand the mechanism of the formation of this main type fragrance and its regulation, we firstly isolate a gene of RfBAMT from petal of R. fortunei by using homologous cloning and RACE technology. The full length of its cDNA was 1383 bp,with an open reading frame of 1104 bp, encoding a total of 368 amino acids. The phylogenetic tree analysis showed that RfBAMT was the closest to the BSMT of Camellia japonica, belonging to methyltransferases family. Then we measured the expression level of RfBAMT again at four flower developmental stages and in different flower tissues and leaves. The results showed that the expression level of this gene was highly positively correlated with the emitted content of methyl benzoates in the flowering, implying that RfBAMT plays a pivotal role in the formation and regulation of methyl benzoates in R. fortunei . Conclusions: This research showed that the RfBAMT was cloned and identified in our study and its expression level was highly positively correlated with the emitted content of methyl benzoates in the flowers and leaves, which indicated this gene may play an important role on regulation of methyl benzoate synthesis in R. fortunei .


2019 ◽  
Vol 10 (04) ◽  
pp. 646-650
Author(s):  
Hyeusoo Kim ◽  
Kyeong Won Yun

The fruit of Rosa multiflora has been used as traditional herbal medicine in Asian countries. The present investigation was undertaken to study the antimicrobial activity and total polyphenol content of hexane, ether, ethyl acetate, water fraction of methanol extract of fruit and flower from Rosa multiflora and Rosa wichuraiana. Antimicrobial activity of the mentioned fractions against 3 gram-positive and 4 gram-negative bacteria using disk diffussion method. The measurement of minimal inhibition concentration (MIC) showed that the ethyl acetate fraction of the two Rosa species is the most effective against the tested bacteria. The total polyphenol content of ethyl acetate fraction of the two Rosa species is higher than the other fractions. The results indicate the antimicrobial activity was related with the total polyphenol content and the fruit and flower of the two Rosa species can be considered as a natural source of antimicrobial agents.


2018 ◽  
Vol 15 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Maria A. Morosanova ◽  
Anton S. Fedorov ◽  
Elena I. Morosanova

Background: The consumption of antioxidants, including phenolic compounds, is considered important for preventing the oxidative damage diseases and ageing. The total polyphenol content (TPC) is the parameter used to estimate the quality of plant-derived products. Methods: Phenol oxidase activity of green bean (Phaseolus vulgaris) crude extract (in the presence of hydrogen peroxide) and banana (Musa sp.) pulp crude extract has been studied spectrophotometrically using catechol, gallic acid, caffeic acid, ferulic acid, and quercetin as substrates. All studied compounds have been oxidized in the presence of green bean crude extract and hydrogen peroxide; all studied compounds except ferulic acid have been oxidized in the presence of banana pulp crude extract. Michaelis constants (Km) and maximum reaction rates (Vmax) have been determined for oxidation in the presence of green bean crude extract and hydrogen peroxide (Km are 3.8×10-4 M, 1.6×10-3 M, 2.2×10-4 M, 2.3×10-4 M, 1.4×10-4 M and Vmax are 0.046 min-1, 0.102 min-1, 0.185 min-1, 0.053 min-1, 0.041 min-1 for catechol, gallic acid, caffeic acid, ferulic acid, and quercetin, respectively) and for oxidation in the presence of banana pulp crude extract (Km are 1.6×10-3 M, 3.8×10-3 M, 2.2×10-3 M, 4.2×10-4 M and Vmax are 0.058 min-1, 0.025 min-1, 0.027 min-1, 0.015 min-1 for catechol, gallic acid, caffeic acid, and quercetin, respectively). The influence of 3-methyl-2-benzothiazolinone hydrazone (MBTH) on the oxidation reactions kinetics has been studied: Michaelis constants values decrease and maximum reaction rates increase, which contributes to the increase in sensitivity of the determination. Results: Kinetic procedures of Total Polyphenol Content (TPC) determination using crude plants extracts in the presence of MBTH have been proposed (time of analysis is 1 min). For gallic acid (used as a standard for TPC determination) detection limit is 5.3×10-5 M, quantitation limit is 1.8×10-4 M, and linear range is 1.8×10-4 - 1.3×10-3 M for green bean crude extract; detection limit is 2.9×10-5 M, quantitation limit is 9.5×10-5 M, and linear range is 9.5×10-5 - 2.4×10-3 M for banana pulp crude extract. Proposed procedures are characterized by higher interference thresholds for sulfites, ascorbic acid, and citric acid compared to pure enzymes (horseradish peroxidase and mushroom tyrosinase) in the same conditions. Compared with standard Folin-Ciocalteu (FC) method the procedures described in this work are also characterized by less interference and more rapid determination. Conclusion: The procedures have been applied to TPC determination in tea, coffee, and wine samples. The results agree with the FC method for tea and coffee samples and are lower for wine samples, probably, due to sulfites interference.


OCL ◽  
2021 ◽  
Vol 28 ◽  
pp. 30
Author(s):  
Viktória Kapcsándi ◽  
Erika Hanczné Lakatos ◽  
Beatrix Sik ◽  
László Ádám Linka ◽  
Rita Székelyhidi

In this study, we examined the yield and oil quality of eight different grape varieties. For the experiments, the grape seeds were obtained from the Benedictine Pannonhalma Archabbey in the northwestern region of Hungary. The aim of the studies was to determine the oil yield obtained by extraction and to examine the differences between the fatty acid composition, antioxidant capacity, and total polyphenol content of the oils of different grape varieties. Based on the results, the oil content of the grape seeds varied between 99.91 g/kg and 126.74 g/kg. The grape seed oils analysed contained significant amounts of stearic acid (3.42–9.93%), palmitic acid (7.81–10.66%), oleic acid (14.29–19.92%), and linoleic acid (66.85–72.47%). Besides, the grape seed oils tested contained several other fatty acids in small amounts. There were significant differences in the total antioxidant and total polyphenol content of the oils. Total polyphenol content ranged from 0.24 to 1.13 mg GAE/g, while the total antioxidant content changed between 0.12 and 0.78 μg TEAC/g. The results show that the studied varieties are suitable for the production of table grape seed oil based on their oil yield, and the oils have favourable, health-protecting properties in terms of their quality.


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