Variation in the Concentrations of Major Secondary Metabolites in Ginkgo Leaves from Different Geographical Populations

Qi Zhou,Xueying Ma,Jianwen Wang,Meng Xu,Kemin Mu,Li-An Xu,Zhouxian Ni

doi:10.3390/f8080266

Abstract

Ginkgo biloba L. is a well-known relict tree species and an important medicinal plant. Ginkgo is rich in secondary metabolites (SMs), mainly including flavonoids, lactones, and ginkgolic acid. The aim of this study was to determine variations in the concentrations of these SMs in Ginkgo leaves from different geographical populations. The SMs in the leaves of 298 clones from 10 geographical populations grafted under the same conditions were extracted and measured by high performance liquid chromatography (HPLC). The results showed that there were significant differences in concentrations of SMs in leaves from different populations (p < 0.01). The concentrations of both flavonoids and lactones were significantly negatively correlated with that of ginkgolic acid. Altitude and annual rainfall were important factors influencing the concentrations of lactones, and the frost-free period influenced the concentration of isorhamnetin. Population Yingdianjie (YDJ) was ideal for the plantations from which medicinal flavonoids and lactones are extracted, followed by populations Xiaopu (XP), Anlu (AL) and Wuchuan (WC). As variations within each population were found, attention should be paid to selection within populations.

Highlights

Ginkgo biloba L. is a unique species of Ginkgoatae and is known as the “living fossil”, as it is one of the oldest species on the planet
The secondary metabolites (SMs) contained in Ginkgo leaves can be divided into three main types: flavonoids, lactones and ginkgolic acid [2]
The clones were grafted under the same environmental condition; the variations were almost attributed to genetic factors

Summary

Introduction

Ginkgo biloba L. is a unique species of Ginkgoatae and is known as the “living fossil”, as it is one of the oldest species on the planet. The living history of Ginkgo dates back to the Permian 300 million years ago [1], and Ginkgo species were distributed almost worldwide during the Jurassic 190 million years ago. Only G. biloba survived and is the native plant of China. As the origin of existing Ginkgo trees in the world, China owns 90% of worldwide Ginkgo resources, and has natural populations with significant variations. In China and throughout the world, Ginkgo is a very important medicinal plant. The secondary metabolites (SMs) contained in Ginkgo leaves can be divided into three main types: flavonoids, lactones and ginkgolic acid [2]. The flavonoids are a series of compounds with two benzene rings and a phenol hydroxyl connected by the central three carbon atoms, and mainly include quercetin, kaempferol and isorhamnetin [3], which have immunity enhancement [4], anticancer [5,6,7] and anti-aging [8,9]

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