Covalent Interactions of Anthocyanins with Proteins: Activity-Based Protein Profiling of Cyanidin-3-O-glucoside.

Anthocyanins are common natural pigments with a variety of physiological activities. Traditional perspectives attribute their molecular mechanism to noncovalent interactions influencing signaling pathways. However, this ignores the nature of its benzopyrylium skeleton, which readily reacts with the electron-rich groups of proteins. Here, we modified cyanidin-3-O-glucoside (C3G) via activity-based protein profiling technology by our previous synthesis route and prepared the covalent binding probe (C3G-Probe) and the noncovalent photoaffinity probe (C3G-Diazirine). The properties of C3G's covalent binding to proteins were also discovered by comparing the labeling of the two probes to the whole HepG2 cell proteome. We further explored its target proteins and enriched pathways in HepG2 and HeLa cells. Western blot analysis further confirmed the covalent binding of C3G to four target proteins: insulin-degrading enzyme, metal cation symporter ZIP14, spermatid perinuclear RNA-binding protein, and Cystatin-B. Pathway analysis showed that covalent targets of C3G were concentrated in metabolic pathways and several ribonucleoprotein complexes that were also coenriched. The results of this study provide new insights into the interaction of the naturally active molecule C3G with proteins.

Advancements in the promotion of pyranoanthocyanins formation in wine: A review of current research.

Pyranoanthocyanin (PACN) is a class of anthocyanin (ACN)-derived pigments found in aged red wines, which has certain advantages over the prototype ACN in terms of stability, and biological activity. However, the efficiency and yield of PACNs in the natural fermentation system are low. This article summarizes five frequently employed physical processing techniques that can accelerate the formation of PACN. From a mechanistic standpoint, these techniques can produce large amounts of active substances, further promoting the extracellular release of phenolics and the formation of some cofactors and PACNs' pyran rings. Precursor substances and environmental factors affecting PACN yields are also pointed out. It mainly included the parent ring substitution in ACNs, the type and quantity of glycosides, the electron donating ability and concentration of cofactors, etc. Thus, this article aims to provide an overview of the advancements in processing techniques, thereby facilitating their wider utilization in the food and beverage industry.

Silk fibroin protein-based nonwoven mats incorporating baicalein Chinese herbal extract: preparation, characterizations, and in vivo evaluation.

In this study, we demonstrated a natural silk fibroin protein (SFP) that was blended with a Chinese herbal extract (baicalein, BAI) to obtain an effective combination for producing electrospun nonwoven mats with anti-inflammatory and antibacterial functions. A series of SFP-based electrospun nonwoven mats with additives of varying compositions were produced and investigated. Performance comparisons showed that the SFP/polyvinylpyrrolidone (PVP)/BAI nonwoven mat is the optimal one. In vitro, SFP/PVP/BAI nonwoven mat is effective in inhibiting the formation of nitrite in lipopolysaccharide (LPS)-induced nitrite formation in Raw 264.7 macrophages model and the growth of Staphylococcus aureus (S. aureus). Especially in the case of SFP/PVP/BAI nonwoven mat, Bai has been proved to reach their maximum amount of releases of approximately 64.8% within 24 h of contact with water-based environment as compared to the SFP/BAI nonwoven mat (only 30.1% of release within 24 h). For in vivo experiments, a 1.2 cm × 1.2 cm wound area was created on the back of mice and seeded with 1 × 107 CFU/mL of S. aureus to induce an infected wound model. The experimental results show significant acceleration of the wound closure process in mice treated with SFP/PVP/BAI nonwoven mat (4 days of reduction as compared to the untreated group), reduction in infiltration of neutrophils, nitrite formation, and inhibition of growth of wound bacteria. Histological images of the group treated with SFP/PVP/BAI nonwoven mat showed a compete repair of skin hierarchy, increasing production of collagen fibers, and enhancement of angiogenesis. This may bring a better recovery of skin appearance after treatment. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 420-430, 2017.