【Objective】 Cyclocarya paliurus (Batal.) Iljinskaja is a multiple-use tree species with applications in timber, ornamental and medicinal industries. However, recently, the most common use ofC. paliurus (Batal.) Iljinskaja in the market is the preparation of nutraceutical tea with health benefits using its leaves. The objective of the present study was to select superior provenances or natural populations of C. paliurus (Batal.) Iljinskaja for medicinal purposes based on their content of key bioactive substances and their antioxidant activity. 【Method】 This study measured, using water extraction, the total flavonoid, total triterpenoid, and total polyphenol content and antioxidant activity in C. paliurus (Batal.) Iljinskaja leaves collected from 33 natural populations and analyzed the correlation between content and antioxidant activity. 【Result】The flavonoid, triterpenoid and polyphenol content exhibited significant variation in the extracts of C. paliurus (Batal.) Iljinskaja leaves collected from different natural populations. The total flavonoid content in the leaves was 6.79-20.91 mg/g, whereas the total triterpenoid and total polyphenol content was 15.67-44.63 and 10.53-33.04 mg/g, respectively. Hierarchical cluster analysis indicated that the 33 natural populations were classified into three, four and three distinct groups based on the total flavonoid, total triterpenoid and total polyphenol content in their leaves, respectively. Correlation analysis showed a significant positive correlation between total flavonoid, total triterpenoid and total polyphenol content; these key bioactive substances were also significantly correlated with DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical-scavenging activity, ABTS [2, 2'-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)] free radical-scavenging activity, and total reducing power. 【Conclusion】Cyclocarya paliurus (Batal.) Iljinskaja natural populations from Anhui Jixi (S2), Guizhou Shijie (S15), Hubei Hefeng (S19) and Hubei Wufeng (S20) are excellent populations for preparing nutraceutical tea with a high content of key bioactive substances and strong antioxidant activity.
【Objective】 Cyclocarya paliurus (Batal.) Iljinskaja, a native species of China, is cultivated for its medicinal properties,fine timber and ornamental value. To form a theoretical framework of nitrogen fertilization management, this study investigated how variable levels of nitrogen influence the growth, accumulation of secondary metabolites and antioxidant capacity of C. paliurus (Batal.) Iljinskaja seedlings.【Method】The temperature and humidity were fixed in the artificial climate chamber, the stumping seedlings of C. paliurus (Batal.) Iljinskaja with two-year-old seedlings were treated by three nitrogen application levels as N1 (0 g/plant), N2 (3 g/plant) and N3 (6 g/plant). And then, the corresponding growth, total carbon, total nitrogen, secondary metabolites and antioxidant capacity of C. paliurus (Batal.) Iljinskaja leaves were measured and compared across treatments by single factor analysis of variance. 【Result】The seedlings height, ground diameter, biomass and secondary metabolite content of C. paliurus (Batal.) Iljinskaja leaves changed significantly across treatments (P < 0.05). With the increase in nitrogen level, the seedlings height, ground diameter and biomass variation of C. paliurus (Batal.) Iljinskaja were 27.33-39.67 cm, 6.65-9.19 mm, and 2.41-3.87 g, respectively; all the highest values were detected with N1 treatment. The highest content of secondary metabolites was observed in N0 treatment. However, the total nitrogen content in seedlings leaves increased with the nitrogen level, and the C/N ratio significantly decreased. In addition, there was a significant negative correlation between the total nitrogen content and C/N ratio in the leaves of C. paliurus (Batal.) Iljinskaja(P < 0.01), as well as between the IC 50 values of ABTS[2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate)] and DPPH(1,1-diphenyl-2-picrylhydrazyl) and the contents of total triterpenoids, total flavonoids, and total polyphenols in the leaves ofC. paliurus (Batal.) Iljinskaja(P < 0.05). With increasing nitrogen level, both the secondary metabolite contents measured and their antioxidant capacities in C. paliurus (Batal.) Iljinskaja leaves showed the tendency N0 > N2 > N1. 【Conclusion】The difference in nitrogen level significantly changed the growth, C/N ratio, secondary metabolites accumulation and antioxidant capacity of C. paliurus (Batal.) Iljinskaja seedlings. The C/N ratio had a significant positive correlation with total polyphenols, and no correlation with total flavonoids, total triterpenoids and antioxidant capacity. Both low and high nitrogen treatments contributed to the accumulation of secondary metabolites and an improvement in the antioxidant capacity ofC. paliurus (Batal.) Iljinskaja seedlings, but inhibited the growth of C. paliurus (Batal.) Iljinskaja seedlings. In conclusion, these results provide the theoretical basis for nitrogen fertilization management through C. paliurus (Batal.) Iljinskaja cultivation.
【Objective】This study aimed to identify the endophytic fungi produced flavonoids in Cyclocarya paliurus (Batal.) Iljinskaja and explore a new method to extract flavonoids. 【Method】The endophytic fungi in the branches, leaves, roots, and bark of C. paliurus (Batal.) Iljinskaja were isolated using the tissue separation method. By observing the morphological characteristics of the endophytes, the fermentation products of the endophytic fungi from C. paliurus (Batal.) Iljinskaja were identified using the chromogenic reaction method, thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC). The endophytic fungi produced flavonoids were screened, and the total flavonoid production was determined. Moreover, the strains were identified based on the morphological characteristics and the phylogenetic analysis of the intervening sequences of the fungal rDNA. 【Result】In total, 67 strains of endophytic fungi were obtained; through the identification of morphological characteristics, they were identified to belong to three classes, four orders, six families and ten genera. Four endophytic fungi producing flavonoids were finally identified: PZ06, CY12, CP06 and PP03. The most abundant flavonoids, with a yield of 3.61 mg/L, were produced by strain PZ06. Molecular identification combined with morphological identification indicated that PZ06, CP06 and PP03 belong to the genusAlternaria, whereas CY12 belongs to the genus Eupenicillium. The dominant flavonoid-producing endophytic fungi of C. paliurus (Batal.) Iljinskaja belong to the genus Alternaria. 【Conclusion】 The study of endophytic fungi in C. paliurus (Batal.) Iljinskaja is a key significance for the development and utilization of endophytes. In addition to identifying the endophytic fungi, the present study also provides a novel method for the extraction of active substances fromC. paliurus (Batal.) Iljinskaja plants.
【Objective】Light quality has a certain effect on the accumulation of phenolic compounds in plants. Cyclocarya paliurus (Batal.) Iljinskaja is a unique species in China, it is widely used as a material for wood, medicines and ornamentation. The objective of the present study was to investigate the effect of light quality on the accumulation of phenolic compounds in C. paliurus (Batal.) Iljinskaja leaves from different families and their antioxidant activity and thereby provide a basis for optimizing the light environment during seedling development and further development ofC. paliurus (Batal.) Iljinskaja healthcare products.【Method】Current-year seedlings of C. paliurus (Batal.) Iljinskaja from four families (Guangxi Jinzhongshan No. 7, Guangxi Jinzhongshan No. 6, Sichuan Muchuan No. 31 and Zhejiang Anji No. 1) were treated with four light quality groups (white light, blue light, green light and red light) with controlled temperature and humidity in an artificial climate chamber. Leaf biomass, phenolic content and yield in C. paliurus (Batal.) Iljinskaja leaves as well as phenolic antioxidant activity [DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical-scavenging ability and FRAP (ferric reducing power assay)]in vitro were measured, and the correlation between phenolic content and antioxidant activity was analyzed.【Result】Light quality and family and their interaction had significant effects on leaf biomass, phenolic content and yield per plant and antioxidant activity. However, there were no significant effects of family on the total flavonoid content and yield per plant. In general, white light treatment resulted in the highest value of leaf biomass but the lowest value of phenolic content and yield per plant and antioxidant activity. The seedlings treated with blue light and green light showed higher content of phenolics and antioxidant activity, but green light treatment resulted in the lowest value of leaf biomass. Therefore, blue light treatment was more beneficial in improving the accumulation of phenolics and their antioxidant capacity inC. paliurus (Batal.) Iljinskaja leaves. At the family’s level, the leaf biomass ofC. paliurus (Batal.) Iljinskaja from Anji No. 1 was the highest. However, the highest values of phenolic content and yield per plant and their antioxidant capacity were observed in Jinzhongshan No. 6. The correlation analysis showed that the content of total phenolics and phenolic acids significantly correlated with the antioxidant activity ( P < 0.05). 【Conclusion】Regulation of light quality significantly affected the accumulation of phenolics and their antioxidant activity in the leaves of C. paliurus (Batal.) Iljinskaja belonging to the different families. Leaves of C. paliurus (Batal.) Iljinskaja from Jinzhongshan No. 6 treated with blue light accumulated more phenolics and thereby exhibited higher antioxidant ability. The results provide a reference for the development of C. paliurus (Batal.) Iljinskaja healthcare products and light management for directional cultivation in C. paliurus (Batal.) Iljinskaja plantations.
