Optimization of the Extraction Strategy for Polyphenols from Pieris Japonica and Evaluation of Its Antioxidant Activity.

Pieris Japonica, belonging to the Rhododendron family, is known for its anti-insect and analgesic properties. Despite previous research, the components and antioxidant activity of Pieris Japonica extract remain unclear. This study aims to identify the optimal extraction process for Pieris Japonica, determine its components, and evaluate its antioxidant capacity. An L9 (34) orthogonal method was employed to optimize the Pieris Japonica extraction process, with the polyphenol content serving as the extraction efficiency index. The extracted components were identified by high-performance liquid chromatography-mass spectrometry (HPLC/MS-MS). Antioxidant activity was assessed via the DPPH test, ABTS radical scavenging test, and FRAP reduction ability test. The optimal extraction process involved soaking Pieris Japonica powder in 60% ethanol with a weight-to-volume ratio of 1:20 (g/mL), followed by eight hours of reflux at 50°C. Under these conditions, the total polyphenol content was 11.2 ± 0.6 mg/g. HPLC/MS-MS revealed that flavonoids were the primary components in the Pieris Japonica extract. The FRAP method determined the total antioxidant capacity to be 1.00 ± 0.05 µmol/mL, while the DPPH method showed a radical scavenging rate of 42.21 ± 4.02%, and the ABTS method yielded a 85.74% scavenging rate, indicating a strong antioxidant activity. The primary components of Pieris Japonica extract were flavonoids, and the extracted plant material exhibited potent antioxidant activity.

Shift of bacterial community structure along different coastal reclamation histories in Jiangsu, Eastern China.

Tideland reclamation has drastic effects on coastal ecosystem involved in soil microorganisms. However, the knowledge regarding temporal variations of microbial community along reclamation chronosequence and their environmental variable predictor is still poorly known. Using Illumina sequencing, we qualified bacterial community composition in soils collected from one tideland and four reclamation stages, i.e. 2-year, 7-year, 19-year and 39-year in Jiangsu, Eastern China. Across all samples, the dominant groups were Proteobacteria, Bacteroidete, Acidobacteria, Planctomycetes and Chloroflexi. Reclamation activity and its histories greatly altered bacterial community structure, and only 0.28% of phylotypes were shared by five soils. Specially, some typical marine bacteria (Gaetulibacter, Alcanivorax …) disappeared in reclamation soils, while other groups (Niabella, Flavisolibacter…) were gradually eminent. Generally, bacterial diversity and richness increased with reclamation histories. Bacterial community was correlated with most of soil physico-chemical properties. Amongst, mean weight diameter of soil aggregates (MWD) was detected as a primary factor predicting bacterial community composition. Together, our results indicated that effects of reclamation on bacterial community varied with diked histories, and MWD was a major factor predicting bacterial community during progressive reclamation. These findings offer predicting case study for understanding the impact of reclamation and its histories on microbial community in a coastal ecosystem.