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The flavonoids in Panax notoginseng were qualitatively analyzed by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF-MS), and the content of three main flavonoids in P. notoginseng of different specifications and grades collected from different habitats was determined by HPLC-DAD. Flavonoids and anthocyanins were analyzed by UPLC-Q-TOF-MS/MS in the positive and negative ion modes, respectively. Twelve flavonoid glycosides and one anthocyanin glycoside in P. notoginseng were identified, but no flavonoid aglycones were detected. Among them, 12 compounds were identified in the underground part of P. notoginseng for the first time and eight compounds were first reported in this plant. Moreover, six and four compounds were identified in the Panax genus and the Araliaceae family for the first time, respectively. A method for simultaneous determination of three flavonoids in P. notoginseng was established by HPLC-DAD. The content of flavonoids in 721 P. notoginseng samples of 124 specifications and grades collected from 20 different habitats was simultaneously determined. Among three flavonoids determined, the content of quercetin-3-O-(2″-β-D-xylosyl)-β-D-galactoside was the highest with the average content in the tested samples of 161.0 μg·g~(-1). The content of compounds quercetin-3-O-hexosyl-hexoside and kaempferol-3-O-pentosyl-hexoside was relatively low, with the average content of 18.5 μg·g~(-1)(calculated as quercetin-3-O-sophoroside) and 49.4 μg·g~(-1)(calculated as kaempferol-3-O-sangbu diglycoside). There were significant differences in flavonoids content of samples from different production area. The content of flavonoids in spring P. notoginseng was significantly lower than that in winter P. notoginseng when the other influencing factors such as production areas, germplasm resources, and cultivation conditions were fixed. As for P. notoginseng of different specifications, the flavonoid content in the part connecting the taproot and the aboveground stem was significantly higher than that in other parts. The results of large-scale data showed that the flavonoid content gradually increased with the increase in the number of heads. There were significant differences between the flavonoid content in most specifications and grades, especially the 20-head P. notoginseng and countless head P. notoginseng, whose content was significantly lower and significantly higher than that of other specifications and grades, respectively. This study provides a scientific basis for the study of the effective components and quality control of P. notoginseng from the perspective of flavonoids.

Anthocyanin derivatives are critical components that impart color to aging red wine. In this study, we developed a targeted metabolomic method for the simultaneously profiling of the primary thirty-seven malvidin-derived anthocyanin derivatives in red wine, including various pyranoanthocyanins and flavanols-related condensation products. First, high-performance liquid chromatography (HPLC) tandem ion trap and triple-quadrupole (QqQ) mass spectrometry were used to construct the mass spectral and chromatographic database of the anthocyanin derivatives that were formed in a model wine solution. Next, the targeted profiling analysis of these compounds was achieved on a QqQ mass spectrometer in the multiple reaction monitoring mode (MRM). The method displayed excellent linearity (R 2 0.9391-0.9998), sensitivity (0.221-0.604 μg/L of limit of detection (LOD) and 0.274-1.157 μg/L of limit of quantification (LOQ) equivalent to malvidin-3-O-glucoside (Mv-glc)), and repeatability (less than 10% and 15% for intra-day and inter-day relative standard deviation (RSD) respectively). Partial least squares discriminant analysis (PLS-DA) based on this method showed great discrimination over different vintage wines, thereby promising to be an effective tool in wine anthocyanin and aging related study., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier Ltd.)

It has been widely accepted that anthocyanidin 3,5-O-diglucosides do not exist in Vitis vinifera L. Cabernet Sauvignon (CS) berries. However, our anthocyanin analyses using HPLC-ESI-MS/MS detected the existence of a low level of anthocyanidin 3,5-O-diglucosides in the Cabernet Sauvignon grape berries grown in China. The authenticity of these samples was confirmed with microsatellite markers. The existence of anthocyanidin 3,5-O-diglucoside was further verified by the enzymatic evidence for the first time. Four putative 5-O-glucosyltransferase (5GT) genes were isolated from the Cabernet Sauvignon berries. The enzymatic analysis showed that a recombinant protein (designated as Vv5GT3) glucosylated the 3-O- and 5-O-positions of anthocyanidins and flavonols. A phylogenetic analysis revealed that this bifunctional enzyme belongs to the 5GT subfamily of UDP-glycosyltransferases. This finding brought a new understanding of the anthocyanins' profile and their biosynthesis in V. vinifera and would be helpful for further investigations of the mechanism of accumulation of anthocyanidin diglucosides in Cabernet Sauvignon berries in China's wine-producing regions.

Background: Light conditions significantly influence grape berry ripening and the accumulation of phenolic compounds, but the underlying molecular basis remains partially understood. Here, we applied integrated transcriptomics and pathway-level metabolomics analyses to investigate the effect of cluster bagging during various developmental stages on phenolic metabolism in Cabernet Sauvignon grapes. Results: Bagging treatments had limited effects on berry quality attributes at harvest and did not consistently affect phenolic acid biosynthesis between seasons. Significantly elevated flavan-3-ol and flavonol contents were detected in re-exposed berries after bagging during early-developmental stages, while bagging after véraison markedly inhibited skin anthocyanin accumulation. Several anthocyanin derivatives and flavonol glycosides were identified as marker phenolic metabolites for distinguishing bagged and non-bagged grapes. Coordinated transcriptional changes in the light signaling components CRY2 and HY5/HYHs, transcription regulator MYBA1, and enzymes LAR, ANR, UFGT and FLS4, coincided well with light-responsive biosynthesis of the corresponding flavonoids. The activation of multiple hormone signaling pathways after both light exclusion and re-exposure treatments was inconsistent with the changes in phenolic accumulation, indicating a limited role of plant hormones in mediating light/darkness-regulated phenolic biosynthesis processes. Furthermore, gene-gene and gene-metabolite network analyses discovered that the light-responsive expression of genes encoding bHLH, MYB, WRKY, NAC, and MADS-box transcription factors, and proteins involved in genetic information processing and epigenetic regulation such as nucleosome assembly and histone acetylation, showed a high positive correlation with grape berry phenolic accumulation in response to different light regimes. Conclusions: Altogether, our findings provide novel insights into the understanding of berry phenolic biosynthesis under light/darkness and practical guidance for improving grape features. [ABSTRACT FROM AUTHOR]

RATIONALE: To develop a reliable and accurate method for the identification of anthocyanins and their subsequent derivatives formed during red grape fermentation and wine maturation. METHODS: By using a Poroshell 120 EC-C18 column in a high-performance liquid chromatography/triple-quadrupole tandem mass spectrometry (HPLC/QqQ-MS/MS) system, combined with multiple reaction monitoring (MRM), it was possible to establish and validate a method for the determination of anthocyanin and a range of complex reaction products. A selected range of six 3-O-glucosidic anthocyanins were used as standards. A database was established from these results. Then various red wines were examined and quantified by this method. RESULTS: With the range of accuracy and precision being 86.97-111.39% and 0.09-4.32%, respectively, the HPLC/Qq-QMS/MS method was found to be a reliable method for anthocyanin detection. By using this HPLC/QqQ-MS/MS method combined with the inclusive database, accurate identification of 95 anthocyanin compounds of different families from various wine samples was systematically achieved in 29 min. CONCLUSIONS: By combining this analytical system with an inclusive database, it was possible to determine a wide range of anthocyanins and related complex derivatives for the first time. We consider that it should be possible to extend this method further to include more complex anthocyanins, and to other complex compounds. [ABSTRACT FROM AUTHOR]

• Blending for wine color improvement can be realized under different oxygen exposure. • The contribution of modifier wines can be anthocyanins, flavonols, or flavan-3-ols. • Modifier wine contributed flavan-3-ols lead to more color improvement visually. • Base wine with weak phenolic profile was more easily to be chromatically modified. Limited oxygenation and over-oxidation experiments were designed to compare the phenolic and chromatic characters of base wines Cabernet Franc (CF), Cabernet Sauvignon (CS), and their counterparts that blended with modifier wines Marselan (MA) and Petit Verdot (PV). In both limited oxygenation and over-oxidation conditions, all blend wines generally contained higher C* ab , a* and Red%, and lower h ab , b* and Yellow% than their base wine counterparts, because MA contributed flavonols (copigments) and anthocyanins, and PV contributed flavanols (anthocyanin derived pigments precursors). Chromatic changes that can be perceived by human eye (ΔE* ab) in CF based blend wines were more obvious than that of CS based blend wines, which indicate that base wine with lower phenolic concentrations and weak phenolic profiles (CF) might be more prone to be chromatically modified than base wine with higher phenolic concentrations and distinct phenolic profiles (CS). Chemical influences of different blending strategies on anthocyanin derivatives' formations were depending on phenolic profiles of the modifier wines and base wines, and also on the oxygen exposure. The results suggest that the chromatic improvement of base wines could be realized by blending modifier wines under different oxygen exposures. [ABSTRACT FROM AUTHOR]