Terpenoids from the rhizomes of Curcuma kwangsiensis S.G. Lee et C.F. Ling and their anti-inflammatory activities.

Three new sesquiterpenes, 4S-1-(3-hydroxybutyl)-7-(11-hydroxypropyl)-10-methyl- cyclohepta-7,5,10-trien-8-one (1), 8R-hydroxy-7-(4S-4,10-dimethyl-5-oxooct-1-en-7-yl)-11- methylfuran-12-one (2), (1S,5R,7S,10R)-1-hydroxy-7-(11-hydroxypropyl)-10-methyl-4- methyleneoctahydronaphthalen-8-one (3), along with 30 known terpenoids (4-33) were obtained from the rhizomes of Curcuma kwangsiensis S.G. Lee et C.F. Ling. Through comprehensive analysis of chemical evidence and spectral data including UV, ECD, IR, 1D and 2D NMR and HR-ESI-MS, as well as quantum chemical calculation, the structures of these novel compounds were successfully determined. Additionally, the inhibitory effects of compounds 1-2, 4-33 on NO production were evaluated in lipopolysaccharide (LPS)-induced RAW264.7 cells. Notably, compound 33 exhibited the most significant inhibitory effect with an IC50 value of 3.55 ± 0.55 µM.

Activity and safety evaluation of natural preservatives.

Synthetic preservatives are widely used in the food industry to control spoilage and growth of pathogenic microorganisms, inhibit lipid oxidation processes and extend the shelf life of food. However, synthetic preservatives have some side effects that can lead to poisoning, cancer and other degenerative diseases. With the improvement of living standards, people are developing safer natural preservatives to replace synthetic preservatives, including plant derived preservatives (polyphenols, essential oils, flavonoids), animal derived preservatives (lysozyme, antimicrobial peptide, chitosan) and microorganism derived preservatives (nisin, natamycin, ε-polylysine, phage). These natural preservatives exert antibacterial effects by disrupting microbial cell wall/membrane structures, interfering with DNA/RNA replication and transcription, and affecting protein synthesis and metabolism. This review summarizes the natural bioactive compounds (polyphenols, flavonoids and terpenoids, etc.) in these preservatives, their antioxidant and antibacterial activities, and safety evaluation in various products.

Changes in the m6A RNA methylome accompany the promotion of soybean root growth by rhizobia under cadmium stress.

Cadmium (Cd) is the most widely distributed heavy metal pollutant in soil and has significant negative effects on crop yields and human health. Rhizobia can enhance soybean growth in the presence of heavy metals, and the legume-rhizobia symbiosis has been used to promote heavy-metal phytoremediation, but much remains to be learned about the molecular networks that underlie these effects. Here, we demonstrated that soybean root growth was strongly suppressed after seven days of Cd exposure but that the presence of rhizobia largely eliminated this effect, even prior to nodule development. Moreover, rhizobia did not appear to promote root growth by limiting plant Cd uptake: seedlings with and without rhizobia had similar root Cd concentrations. Previous studies have demonstrated a role for m6A RNA methylation in the response of rice and barley to Cd stress. We therefore performed transcriptome-wide m6A methylation profiling to investigate changes in the soybean RNA methylome in response to Cd with and without rhizobia. Here, we provide some of the first data on transcriptome-wide m6a RNA methylation patterns in soybean; m6A modifications were concentrated at the 3' UTR of transcripts and showed a positive relationship with transcript abundance. Transcriptome-wide m6A RNA methylation peaks increased in the presence of Cd, and the integration of m6A methylome and transcriptome results enabled us to identify 154 genes whose transcripts were both differentially methylated and differentially expressed in response to Cd stress. Annotation results suggested that these genes were associated with Ca2+ homeostasis, ROS pathways, polyamine metabolism, MAPK signaling, hormones, and biotic stress responses. There were 176 differentially methylated and expressed transcripts under Cd stress in the presence of rhizobia. In contrast to the Cd-only gene set, they were also enriched in genes related to auxin, jasmonic acid, and brassinosteroids, as well as abiotic stress tolerance. They contained fewer genes related to Ca2+ homeostasis and also included candidates with known functions in the legume-rhizobia symbiosis. These findings offer new insights into how rhizobia promote soybean root growth under Cd stress; they provide candidate genes for research on plant heavy metal responses and for the use of legumes in phytoremediation.