A new catechin derivative from the fruits of Rosa sterilis S. D. Shi

Polysaccharides from Seedless Chestnut Rose (Rosa sterilis) Fruits: Insights into Innovative Drying Technologies and Their Structural Characteristics, Antioxidant, Antiglycation, and α-Glucosidase Inhibitory Activities

The selection of an optimal drying method is essential for extending the shelf life and enhancing the quality of Rosa sterilis fruits. This study investigated the effects of both innovative (microwave vacuum drying and infrared drying) and traditional (freeze-drying and hot air drying) techniques on the structural characteristics and bioactivities of polysaccharides from R. sterilis fruits (RSPs). Four different RSPs were obtained from fruits dried using these methods. Results demonstrated that the structural characteristics and bioactivities of RSPs varied significantly with the drying method. Notable differences were observed in extraction yield, total sugar, uronic acid content, monosaccharide molar ratios, molecular weight distribution, particle size, thermal stability, and microstructures of RSPs. Despite these variations, the types of constituent monosaccharides and major glycosidic linkages remained consistent across all methods. Notably, RSPs obtained via microwave vacuum drying (RSPs-MVD) showed a higher uronic acid content and lower molecular weight, and exhibited stronger in vitro antioxidant, α-glucosidase inhibitory, and antiglycation activities. These findings suggest that microwave vacuum drying is an effective pre-drying technique for extracting RSPs, making them suitable as bioactive ingredients in functional foods and pharmaceuticals for managing diabetes mellitus and its complications.

Component analysis and anti-pulmonary fibrosis effects of Rosa sterilis juice

Rosa sterilis is a new variety of Rosa roxburghii Tratt, and is rich in bioactive substances, but its role in pulmonary fibrosis has not been elucidated. The purpose of this study was to investigate the potential components of Rosa sterili juice (RSJ) and its anti-pulmonary fibrosis effects. We employed HPLC-Q-Exactive Orbitrap-MS, HPLC, and ICP-MS to analyze the composition of RSJ, and carried out free radical scavenging assays to determine its antioxidant activity. Then, the anti-pulmonary fibrosis effect of RSJ was evaluated using the bleomycin-induced mice model and the TGF-β1-induced cell model. A total of 49 components were identified in RSJ, and the vitamin C content was 11.29 ± 0.05 mg mL^-1. Catechin was the most abundant phenol, and potassium was the highest mineral element in RSJ. Attractively, we found that RSJ alleviated bleomycin-induced inflammation infiltration and tissue injury, and inhibited TGF-β1-induced epithelial-mesenchymal transition and fibroblast differentiation through the Smad2/3 signaling pathway. In conclusion, we discovered a new health-protective activity of Rosa sterilis, and the high levels of polyphenols, flavonoids, and vitamin C may be the basic anti-fibrosis substances.

First Isolation and Identification of Neopestalotiopsis clavispora Causing Postharvest Rot of Rosa sterilis and Its Control with Methyl Jasmonate and Calcium Chloride

Postharvest rot is a major issue in fruit. However, the cause of postharvest rot on R. sterilis fruit has not been clarified, and there are few studies on the disease control. In this study, the fungus causing postharvest rot is isolated from the symptomatic R. sterilis fruit, and identified by morphological characteristic, pathogenicity test and molecular identification. Moreover, the effects of methyl jasmonate (MeJA) or calcium chloride (CaCl2) alone and their combination on disease resistance to fruit rot were assessed by the determination of defense-related enzyme activity and other indicators. N. clavispora was identified as the main fungus causing the postharvest rot of R. sterilis fruit. The infected fruits were treated with MeJA and CaCl2, and these partially controlled the disease, were additive in effectiveness when used together, increased retention of vitamin C content and fruit firmness, and both enhanced and improved the retention of PAL, POD and PPO activities. The treatment of 500 μL/L MeJA and 3% CaCl2 resulted in the high inhibition of the disease. To our knowledge, this is the first report of N. clavispora causing R. sterilis fruit rot, and the combined treatment is a promising method for controlling postharvest rot on R. sterilis fruit.

Phylogenetic relationships and characterization of the complete chloroplast genome of Rosa sterilis

Rosa sterilis is an economically and important fruit that is extensively grown in Southwestern China. In this study, we determined the complete chloroplast genome of R. sterilis using high-throughput Illumina sequencing. The chloroplast genome of R. sterilis is 156,561 bp in size, containing a large single-copy region (LSC)(85,701 bp), a small single-copy region (SSC) (18,746 bp), and a pair of inverted repeat (IR) regions (each one of 26,057 bp). The overall GC content of the chloroplast genome is 37.23%, while the corresponding values of GC contents of the LSC, SSC, and IR regions are 35.20%, 31.37%, and 42.70%, respectively. The chloroplast genome of R. sterilis contains 130 genes, including 84 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogenetic maximum-likelihood tree revealed that Rosa chinensis or Rosa chinensis var. spontanea is the closest related to R. sterilis in the phylogenetic relationship. This complete chloroplast genome can be further used for genomic studies, evolutionary analyses, and genetic engineering studies of the family Rosaceae.

Anti-browning effect of Rosa roxburghii on apple juice and identification of polyphenol oxidase inhibitors

Enzymatic browning control of cloudy fruit juice with natural substances has received much attention for improving its nutritional and commercial value. This study explored the anti-browning potential of Rosa roxburghii in apple juice. The anti-browning effects and mechanisms were evaluated by serial measurements of appearance, browning index, polyphenol oxidase (PPO) activity, UPLC-QE-Orbitrap-MS identification, inhibition kinetics and molecular docking. The results showed that Rosa roxburghii juice (0.25%-1.25% w/w) could effectively inhibit browning and PPO activity of apple juice. Ascorbic acid (1.67 g/100 g) as a reducing agent was a main anti-browning factor. Furthermore, seven phenolic compounds in Rosa roxburghii were screened as PPO inhibitors. Representative phenolic inhibitors induced mixed or competitive inhibition of PPO, mainly driven by hydrophobic forces and hydrogen bonds. This work demonstrates that Rosa roxburghii is a promising natural anti-browning ingredient to control the browning of cloudy apple juice due to abundant ascorbic acid and PPO inhibitors.