Flavonoids are major polyphenol compounds in plants and contribute substantially to the health-promoting benefits of fruit and vegetables. Peach is rich in polyphenols with flavonols as the main flavonoids. To investigate the regulation of flavonol biosynthesis in peach fruit, two R2R3-MYB transcription factor (TF) genes, PpMYB15 and PpMYBF1, were isolated and characterized. Sequence analysis revealed that the PpMYB15 and PpMYBF1 proteins are members of the flavonol clade of the R2R3-MYB family. Real-time quantitative PCR analysis showed that PpMYB15 and PpMYBF1 transcript levels correlated well with the flavonol content and the expression of flavonol synthase (PpFLS1) in different fruit samples. Dual-luciferase assays indicated that both PpMYB15 and PpMYBF1 could trans-activate promoters of flavonoid biosynthesis genes, including chalcone synthase (PpCHS1), chalcone isomerase (PpCHI1), flavanone 3-hydroxylase (PpF3H), and PpFLS1. Transient overexpression of 35S::PpMYB15 or 35S::PpMYBF1 both triggered flavonol biosynthesis but not anthocyanin and proanthocyanidin biosynthesis in tobacco leaves. In transgenic tobacco flowers, overexpression of 35S::PpMYB15 or 35S::PpMYBF1 caused a significant increase in flavonol levels and significantly reduced anthocyanin accumulation, resulting in pale-pink or pure white flowers. These results suggest that PpMYB15 and PpMYBF1 are functional flavonol-specific positive regulators in peach fruit and are important candidates for biotechnological engineering flavonol biosynthesis in plants.

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Flavonol glycosides are bioactive compounds important for plant defence and human nutrition. Glycosylation and methylation play an important role in enriching the diversity of flavonols in response to the environment. Peach flowers and fruit are rich in flavonol diglycosides such as isorhamnetin 3-O-rutinoside (I3Rut), kaempferol 3-Orutinoside and quercetin 3-O-rutinoside, and flavonol monoglycosides such as I 3-Oglucoside and Q 3-O-galactoside. UV-B irradiation of fruit significantly induced

Bergamottin is a natural furanocoumarin compound with weak polarity. Characterization and quantification of bergamottin were carried out in different fruit tissues of various citrus cultivars. Among the four citrus tissues tested, i.e., flavedo, albedo, segment membrane (SM), and juice sacs (JS) in eight citrus cultivars, the highest bergamottin content was found in the flavedo of Citrus grandis (L.) Osbeck cv. Yongjiazaoxiangyou (YJZXY, 666.54 μg·g−1 DW). A combination of silica gel column chromatography and high-speed counter-current chromatography (HSCCC) was established to efficiently purify bergamottin from the flavedo of YJZXY. Bergamottin showed significant antiproliferative activity on three cancer cell lines, i.e., human liver cancer HepG2, promyelocytic leukemia HL-60, and gastric cancer BGC-823 cells, which showed a marked inhibition effect on these cell lines in a dose-dependent manner. In addition, bergamottin significantly increased glucose consumption in HepG2 cells also in a dose-dependent manner, which is the first report of its potential in anti-diabetes applications.

Flavonol glycosides are health-promoting phytochemicals important for human nutrition and plant defence against environmental stresses. Glycosylation modification greatly enriches the diversity of flavonols. Morella rubra, a member of the Myricaceae, contains high amount of myricetin 3-O-rhamnoside (M3Rha), quercetin 3-O-rhamnoside (Q3Rha), and quercetin 3-O-galactoside (Q3Gal). In the present study, MrUGT78R1 and MrUGT78R2 were identified as two functional UDP-rhamnosyltransferases, while MrUGT78W1 was identified as a UDP-galactosyltransferase. Site-directed mutagenesis identified Pro143 and Asn386 as important residues for rhamnosyl transfer activity of MrUGT78R1 while these two corresponding positions in MrUGT78W1 (i.e. Ser147 and Asn370) also play important role for galactosyl transfer activity. Transient expression data for these three MrUGTs in Nicotiana benthamiana tested the function of MrUGT78R1 and MrUGT78R2 as rhamnosyltransferases and MrUGT78W1 as a galactosyltransferase in glycosylation of flavonols. This work enriches the diversity of UDP-rhamnosyltransferase in planta and identifies two amino acid positions important for both rhamnosyltransferase and galactosyltransferase.

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Background In recent years, due to the increase in intravenous drug injection and intracardiac and vascular interventional treatments among drug users, infective endocarditis involving the right heart of the tricuspid valve has gradually increased.At present, there is no systematic report on surgical treatment of tricuspid infective endocarditis. This paper summarizes the experience of surgical treatment of 56 patients with tricuspid infective endocarditis in our hospital and analyzes its clinical effect. Methods From January 2006 to August 2019, 56 cases of tricuspid infective endocarditis treated by tricuspid valve surgery in our hospital were analyzed retrospectively.including 23 cases of tricuspid valvuloplasty (TVP) and 33 cases of tricuspid valve replacement (TVR). All patients were complicated with tricuspid valve vegetations or moderate and severe tricuspid regurgitation and had surgical indications.The perioperative data were collected and followed up for 6 months to 14 years to summarize and analyze the clinical effect of surgical treatment of tricuspid infective endocarditis. Results Compared with TVR group, the CPB time (79.68 ± 19.02min VS 107.39 ± 25.64min, P < 0.01), ACC time (50.29 ± 16.14min VS 65.52 ± 20.62min, P < 0.01), postoperative mechanical ventilation time (18.65 ± 8.18h VS 44.85 ± 57.68h, P < 0.01) and ICU stay time (38.13 ± 21.80h VS 102.64 ± 142.11h, P = 0.015) in TVP group were shorter. The perioperative red blood cell transfusion (4.87 ± 3.81U VS 7.55 ± 5.42U, P < 0.01) and the incidence of postoperative complications (8.7% VS 33.3%, P < 0.01) were lower.Perioperative death occurred in 1 case in the TVR group, and there was no perioperative death in the TVP group, There was no significant difference between the two groups(3.03% VS 0, P = 0.855). A total of 52 cases were followed up for an average of (5.50 ± 3.79) years.The postoperative 3-year, 5-year and 7-year survival rate were 100%,100%,91.7% in TVP group and 95.2%, 93.8% and 87.5%.The 5-year and 10-year reoperation rate were 0%, 0% in TVP group and 6.7%, 20% in TVR group. Conclusion Surgical treatment of severe tricuspid valve endocarditis has achieved good mid-term clinical results, and the rate of avoiding reoperation is better in TVP group than in TVR group.