Mangiferin is a natural xanthonoid with various biological activities. Quantification of mangiferin in fruit peel, pulp, and seed kernel was carried out in 11 Chinese mango (Mangifera indica L.) cultivars. The highest mangiferin content was found in the peel of Lvpimang (LPM) fruit (7.49 mg/g DW). Efficient purification of mangiferin from mango fruit peel was then established for the first time by combination of macroporous HPD100 resin chromatography with optimized high-speed counter-current chromatography (HSCCC). Purified mangiferin was identified by both HPLC and LC-MS, and it showed higher DPPH^• free-radical scavenging capacities and ferric reducing ability of plasma (FRAP) than by l-ascorbic acid (Vc) or Trolox. In addition, it showed significant protective effects on human umbilical vein endothelial cells (HUVEC) under H₂O₂-induced stress. Cells treated with mangiferin resulted in significant enhanced cell survival under of H₂O₂ stress. Therefore, mangiferin from mango fruit provides a promising perspective for the prevention of oxidative stress-associated diseases.

Soluble sugars, primarily fructose, glucose, sucrose, and sorbitol, are crucial determinants of fruit flavor and quality. As a core component of biological metabolism, sugar metabolism provides energy and carbon for fruit development, ultimately governing carbohydrate accumulation in mature fruits. This process requires the coordinated activities of multiple enzymes and transporters, modulated by the spatiotemporal expression patterns of their encoding genes. Therefore, it is essential to elucidate both the activities of these enzymes across different fruits and their underlying gene expression patterns. While significant progress has been made in functional genes involved in soluble sugar metabolism and deciphering their regulatory networks, an overall introduction of this knowledge remains lacking. This review presents an integrative analysis of soluble sugar accumulation during fruit development, encompassing spatiotemporal dynamics of key metabolic enzymes, functional characterization of encoding genes, signaling response mechanisms governing gene regulation, and the overarching genetic network.

Background/Objectives: Mango, which is known as the “King of Tropical Fruits”, is an evergreen plant belonging to the Anacardiaceae family. It belongs to the genus Mangifera, which comprises 69 species of plants found in tropical and subtropical regions, including India, Indonesia, the Malay Peninsula, Thailand, and South China. However, research on the structural information of complete chloroplast genomes of Mangifera is limited. Methods: The rapid advancement of high-throughput sequencing technology enables the acquisition of the entire chloroplast (cp) genome sequence, providing a molecular foundation for phylogenetic research. This work sequenced the chloroplast genomes of six Mangifera samples, performed a comparative analysis of the cp genomes, and investigated the evolutionary relationships within the Mangifera genus. Results: All six Mangifera samples showed a single circular molecule with a quadripartite structure, ranging from 157,604 bp to 158,889 bp in length. The number of RNA editing sites ranged from 60 to 61, with ndhB exhibiting the highest number of RNA editing sites across all species. Seven genes—namely, atpB, cemA, clpP, ndhD, petB, petD, and ycf15—exhibited a Ka/Ks value > 1, suggesting they may be under positive selection. Phylogenetic analysis revealed that Mangifera siamensis showed a close relationship between Mangifera indica and Mangifera sylvatica. Conclusions: Our comprehensive analysis of the whole cp genomes of the five Mangifera species offers significant insights regarding their phylogenetic reconstruction. Moreover, it elucidates the evolutionary processes of the cp genome within the Mangifera genus.

Soluble sugars are key determinants of fruit quality, directly influencing sensory attributes such as sweetness and flavor, as well as nutritional value and texture. Their content and composition are precisely regulated by sugar-metabolizing enzymes. Key enzymes, including invertase (INV), sucrose phosphate synthase (SPS), sucrose synthase (SUS), fructokinase (FRK), and hexokinase (HXK), play pivotal roles in these processes. However, a systematic and in-depth analysis of their regulatory mechanisms is currently lacking, which hinders a comprehensive understanding of the regulatory network governing fruit sugar metabolism. This review employs bibliometric analysis to systematically examine research trends in fruit sugar metabolism. Furthermore, it synthesizes recent advances in the coordinated regulatory mechanisms from the perspectives of transcriptional regulation, epigenetic modifications, and signal transduction, aiming to provide a clearer framework for future research. At the transcriptional level, transcription factor families such as MYB, WRKY, NAC, and MADS-box achieve precise regulation of sugar metabolism-related genes by specifically binding to the promoters of their target genes. Regarding epigenetic regulation, mechanisms including histone modifications, non-coding RNAs, and DNA methylation influence the expression of sugar-metabolizing enzymes at the post-transcriptional level by modulating chromatin accessibility or mRNA stability. Signaling pathways integrate hormonal signals (e.g., ABA, ethylene), environmental signals (e.g., temperature, light), and sugar-derived signals into the regulatory network, forming complex feedback mechanisms. These regulatory mechanisms not only directly affect sugar accumulation in fruits but also participate in fruit quality formation by modulating processes such as cell turgor pressure and carbon allocation. By integrating recent findings on transcriptional regulation, epigenetics, and signaling pathways, this review provides a theoretical foundation for fruit quality improvement and targeted breeding.

Despite being an economically significant fruit, the availability of Mangifera chloroplast genome sequences remains limited. In this study, we assembled, annotated, and characterized the complete chloroplast genomes of Mangifera indica ‘Guiqi’ and M. quadrifida. The chloroplast genomes of M. indica ‘Guiqi’ (157,780 bp) and M. quadrifida (158,979 bp) both exhibit a quadripartite structure, contain 87 protein-coding, 37 tRNA, and 8 rRNA genes, and have GC contents of 37.9% and 37.8%, respectively. Phylogenetic analysis confirmed the maternal origin of M. indica ‘Guiqi’ and revealed the closest affinity between M. quadrifida and M. similis, indicating widespread hybridization and introgressions.

Mango fruits are popular for their flavor. Sugar, a key component of fruit nutrition and flavor, determines fruit quality via its composition and content. While many studies explore molecular regulatory pathways of sugar metabolism in various fruits, large-scale physiological screening of related enzymes via advanced mathematical methods is largely neglected, and the physiological mechanism of sugar accumulation in mango remains unclear. This study analyzed glucose, fructose, sucrose and starch contents, and the activities of 11 sugar metabolism-related enzymes (adenosine diphosphate glucose pyrophosphorylase (AGP); sucrose synthase (SS); sucrose phosphate synthase (SPS); protein kinase (PK); starch debranching enzyme (DBE); phosphoglucomutase (PGM); α-amylase; β-amylase; isoamylase (ISA); sucrose invertase (INV); acid invertase (AI)) from fruit growth to post-ripening stages of mango cultivar ‘Renong No.1’, determined the correlations among soluble sugar, starch and enzyme activities, and constructed mathematical models of inter-group relationships using R language. The results showed that glucose, fructose and starch accumulated during fruit growth, while sucrose accumulated during post-ripening. Fructose content was significantly positively correlated with AGP, α-amylase, AI, β-amylase and SPS activities; so was glucose content and AGP activity; sucrose content and AGP, AI, PK, α-amylase, ISA, INV and SPS activities; and sweetness value and AGP, α-amylase, AI, SPS, SS and β-amylase activities. AI, AGP and α-amylase were identified as the key enzymes influencing sweetness value. Ultimately, a new visualizing and digitizing statistical approach for roles of eleven key enzymes in sweet value and soluble sugar component content during mango development was shown.