Based on HPLC-ESI-TOF-MS and Artificial Neural Network Model: Response to Climatic Factors

Woodwardia japonica is a kind of great potential edible and medicinal fern. In a previous study, it was found that flavonoid and antioxidant activity of W. japonica from different sites were different. However, the cause of the differences has still been unclear, which has restricted the utilization of W. japonica. In this paper, flavonoid and antioxidant activity of W. japonica from nine different regions were determined with the method of a colorimetric assay with UV-VIS spectrophotometry and HPLC-ESI-TOF-MS, and the effects of climate factors on flavonoids and antioxidant activities were evaluated by mathematical modeling and statistical methods. The results showed: (1) total flavonoid content (TFC) of W. japonica from Wuyi Mountain (Jiangxi) was the highest, which might be related to the low temperature; (2) the differences of antioxidant activities of W. japonica might be related to precipitation; (3) five flavonols, two flavones and one isoflavone were tentatively identified in W. japonica; (4) flavonol and isoflavone might be affected by sunshine duration, and flavones were probably related to temperature. In conclusion, the effects of climate factors on flavonoids and antioxidants are significant, which would provide an important basis for further exploring the mechanism of climate affecting secondary metabolites.

The complete chloroplast genome of a Woodwardia japonica

Woodwardia japonica is one of the diverse members of the fern group and medicinally important genus. In Korea, the natural resources of W. japonica are being exhausted by excessive exploitation and require urgent conservation. In this study, the complete chloroplast genome of W. japonica was generated, and its structure was compared with that of other members of same family. The chloroplast genome was 153224 bp long, with a typical quadripartite structure including a pair of inverted repeat regions (24591 bp) separated by a large (82480 bp) and small (21562 bp) single-copy (SC) region. The genome encodes a total of 88 protein-coding genes, 35 tRNA genes, and eight rRNA genes. Additionally we identified 87 RNA editing sites in 52 genes; most of the substitution was U to C (50 sites), while C to U conversion occurred in 37 positions. The phylogenetic analysis strongly supported the relationship of W. japonica with W. unigemmata and. A. melanocaulon (Blechnoideae).