ABSTRACT
A method was established for content determination of two kinds of phenolic acids, including rosmarinic acid)(RA) and caffeic acid(CA), and six kinds of flavonoids including scutellarein-7-O-diglucuronide(SDG), luteolin-7-O-diglucuronide(LDG), apigenin-7-O-diglucuronide(ADG), scutellarin-7-O-glucuronide(SG), luteolin-7-O-glucuronide(LG), and apigenin-7-O-glucuronide(AG) in Perilla frutescens leaves. The content of eight chemical components was measured based on ten P. frutescens germplasms of different chemotypes of volatile oil, different cultivated years, and different harvesting periods. The results showed that there was a great difference between the two kinds of constituents of different germplasms. The total content of the two phenolic acids was 2.24-34.44 mg·g~(-1), and the total content of the six flavonoids was 11.55-34.71 mg·g~(-1). Then according to content from most to least, the order of each component was RA(2.13-33.97 mg·g~(-1)), LDG(1.31-14.80 mg·g~(-1)), SG(1.97-8.45 mg·g~(-1)), ADG(2.68-7.60 mg·g~(-1)), SDG(1.16-5.87 mg·g~(-1)), LG(0.78-1.91 mg·g~(-1)), AG(0.56-1.00 mg·g~(-1)), and CA(0.11-0.68 mg·g~(-1)). The chemical contents of the 5 PA-type germplasms in 2017 were mostly higher than those in 2018 showing a large variation with the cultivation years. These contents of two kinds of phenolic acids of 9 germplasms fluctuated with the harvesting time. The content decreased before early flower spike(the 3~(rd) to 18~(th) in August) at first and began to increase in flowering and fruiting period(the 18~(th) in August to 2~(nd) in September). However, these contents had slowly decreasing trend after 2~(nd) in September till 17~(th) in the same month. Interestingly, the content raised again in the maturity of fruits. The variation tendency of contents in six kinds of flavonoids components was inconsistent in different germplasms with the variation of harvesting time. The content of flavonoids in part of germplasms was negatively correlated with the fluctuation of phenolic acids. There was no correlation between phenolic acids and chemical type of the volatile oil. This paper may provide a reference for the high-quality germplasm of P. frutescens cultivation.
Subject(s)
Flavonoids , Oils, Volatile , Perilla frutescens , Phenols , Plant LeavesABSTRACT
In this study, the growth index including plant height, compound leaf area, specific leaf area, leaf water content, number of branches, and leaf biomass per plant and the icariin flavonoids such as epimedin A, epimedin B, epimedin C and icariin of Epimedium pseudowushanense were determined on 30 d and 60 d under light intensity(18.2±2.5) μmol·m~(-2)·s~(-1)(L1) and(90.9 ±2.5) μmol·m~(-2)·s~(-1)(L2), and white light as control, red light, blue light and yellow light were used as three light quality treatments, to study the effect of light quality on the growth and flavonoids accumulation of E. pseudowushanense. The E. pseudowushanense was sui-table for growth under L1 light intensity, the blue light treatment significantly reduced the leaf area, but had little effect on the stem height, the red light treatment and the yellow light treatment had no obvious effect on the stem height and leaf area, but the yellow light treatment significantly increased the germination of new branches, and had a sustained promoting effect, and the biomass was significantly higher than the white light treatment at 60 d. The content of icariin flavonoids in red light, blue light and yellow light treatment was higher than that in white light treatment at 30 d and 60 d under L1 light intensity, while yellow light treatment promoted the synthesis of icariin flavonoids to the largest extent, which was 1.8 and 1.9 times of white light treatment(30 d and 60 d).Under L2 light intensity, the effect of strong light on promoting stem germination became the main factor, while the yellow light treatment showed no significant effect on promoting stem germination, and the red light treatment exhibited a significant effect on reducing leaf area. Icariin flavonoids under red light, blue light and yellow light treatment were all lower than that under white light treatment, that is, the effect of white light treatment on the synthesis of icariin flavonoids is better than red light, blue light and yellow light treatment. When the time of strong light treatment was longer, the degradation range of icariin flavonoids in other light treatment appeared, while red light treatment promotes the synthesis of icariin flavonoids. Therefore, the influence of light quality on E. pseudowushanense is quite different under different light intensity, no matter from growth index or flavonoid content index. The results support that the biomass and icariin flavonoid content can be increased by providing appropriate red and yellow light.