Cyclocarya paliurus has been used for drug formulations and ingredients in functional foods in China. Field studies were conducted to examine the relationships between environmental factors and flavonoid accumulation. A split-plot randomized design was used to establish three shading treatments and three fertilization levels, and growth parameters and flavonoid contents were detected. The greatest biomass production was achieved in intermediate shade and fertilization treatment, and leaf production per seedling increased by 139.5% compared to the treatment without shade and fertilization. Overall, shade and fertilization had a significantly negative effect on contents of total flavonoid, kaempferol, quercetin, and isoquercitrin in leaves of C. paliurus. However, the greatest accumulation of total flavonoid in the leaves was observed in intermediate shade and fertilization treatment, achieving 364.4 g/plant. The results suggest that manipulating the field growing conditions and optimizing the silvicultural system would be important for obtaining the greatest yield of targeted health-promoting substances.

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(1-2) As a highly valued and multiple function tree species, Cyclocarya paliurus is planted and managed for timber production and medical use. Responses of growth, photosynthesis and phytochemical accumulation to light environment are useful informations to determine suitable habitat conditions for the cultivation of C. paliurus. A split-plot design with five light quality and three light intensity levels was adopted to compare the variations in plant growth, photosynthesis and water-soluble polysaccharide yield in C. paliurus leaves. Both light intensity and quality treatments significantly affected total biomass, photosynthetic rate and water-soluble polysaccharide yield in C. paliurus leaves. Treatments under red light and blue light with 1000 μmol m -2 s -1 achieved the highest values of biomass growth, photosynthetic rate, specific dry leaf mass per area and accumulation of water-soluble polysaccharide. These results indicate that red light and blue light with higher light intensity level were effective for increasing plant growth, photosynthesis and production of water-soluble polysaccharide in C. paliurus leaves. Manipulating light conditions might be an effective means to improve biomass and achieve higher water-soluble polysaccharide yield in C. paliurus plantations.

Background: Cyclocarya paliurus is an endangered plant and endemic to China. The leaves of C. paliurus have been used in drug formulations and as ingredients in functional foods in China. The aim of this study was to develop an effective method to extract most of the compounds and to establish a simplified HPLC analytical method to determine the contents of major bioactive compounds simultaneously. Materials and methods:High-performance liquid chromatography (HPLC) coupled with a photodiode array detector (PDA) was used for the simultaneous determination of the major flavonoids and triterpenoids in C. paliurus leaves.Results: Ultrasonic extraction in 100% methanol for 30 min was adopted as the optimal extraction method for C. paliurus leaves. The separation conditions were optimized using a Phenomenex C18 ODS column (250 mm × 4.6 mm, 5 µm) with a mobile phase of acetonitrile and 0.02% formic acid and a detection wavelength of 205 nm. The validation data indicated that this new HPLC analytical method successfully quantified the provenance and seasonal variations of seven major compounds (three flavonoids and four triterpenoids) in C. paliurus leaves. Conclusion:The study provided a novel and simplified approach to simultaneously determine the quantity of major flavonoids and triterpenoids in C. paliurus leaves. The results could promote the optimization of silvicultural systems for quality control of C. paliurus. Key words: Cyclocarya paliurus; HPLC; flavonoids; triterpenoidsAbbreviations: High-performance liquid chromatography (HPLC); photodiode array detector (PDA); total flavonoids content (TFC); total triterpenoids content (TTC). IntroductionCyclocarya paliurus (Batal.) Iljinskaja is an endangered plant endemic to China and a monotypic genus of the Juglandaceae family. C. paliurus is commonly called "sweet tea tree" because of the sweet taste of its leaves (Fang et al., 2006). Sweet tea tree is naturally distributed in many provinces of Southern China, including Anhui, Fujian, Guangxi, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Guizhou and Zhejiang (Fang and Fu, 2007). The leaves of C. paliurus have been used as herbal tea for hundreds of years He et al., 2013), and were used for drug formulations in traditional Chinese medicine (TCM) or as ingredient of functional foods in China (Xie et al., 2010). The main chemical composition of C. paliurus leaves include flavonoids, triterpenoids, and polysaccharides . The extracts of C. paliurus were reported to have multiple beneficial effects, such as antihypertensive ), antihyperlipidemic (Wang et al., 2013Kurihara et al., 2003), antihyperglycemic (Wang et al.，2013；Li et al.，2011), antioxidant activity (Wang et al.，2013), and inhibitors of PTP1B (protein tyrosine phosphatase 1B) .Up to now, the raw materials of C. paliurus were harvested in the wild for herbal tea or nutraceutical products. As the market demand increased, the natural resources were seriously destroyed. More leaves must be produced within the plantation. Recently, a number of such plant...

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