Japanese and Bohemian Knotweeds as Sustainable Sources of Carotenoids.

Valentina Metličar,Alen Albreht,Irena Vovk

doi:10.3390/plants8100384

Valentina Metličar, Alen Albreht + Show 1 more

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https://doi.org/10.3390/plants8100384

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Abstract

Japanese knotweed (Fallopia japonica Houtt.) and Bohemian knotweed (Fallopia x bohemica) are invasive alien plant species, causing great global ecological and economic damage. Mechanical excavation of plant material represents an effective containment method, but it is not economically and environmentally sustainable as it produces an excessive amount of waste. Thus, practical uses of these plants are actively being sought. In this study, we explored the carotenoid profiles and carotenoid content of mature (green) and senescing leaves of both knotweeds. Both plants showed similar pigment profiles. By means of high performance thin-layer chromatography with densitometry and high performance liquid chromatography coupled to photodiode array and mass spectrometric detector, 11 carotenoids (and their derivatives) and 4 chlorophylls were identified in green leaves, whereas 16 distinct carotenoids (free carotenoids and xanthophyll esters) were found in senescing leaves. Total carotenoid content in green leaves of Japanese knotweed and Bohemian knotweed (378 and 260 mg of lutein equivalent (LE)/100 g dry weight (DW), respectively) was comparable to that of spinach (384 mg LE/100 g DW), a well-known rich source of carotenoids. A much lower total carotenoid content was found for senescing leaves of Japanese and Bohemian knotweed (67 and 70 mg LE/100 g DW, respectively). Thus, green leaves of both studied knotweeds represent a rich and sustainable natural source of bioactive carotenoids. Exploitation of these invaders for the production of high value-added products should consequently promote their mechanical control.

Highlights

Japanese (Fallopia japonica Houtt.) and Bohemian (Fallopia x bohemica) knotweeds are large herbaceous plants which belong to the Polygonaceae family [1]
Japanese and Bohemian knotweed leaf extracts were screened for carotenoids by high performance thin-layer chromatography (HPTLC) (Figure 1)
Carotenoids from mature and senescing leaves of Japanese and Bohemian knotweeds were explored, and we show that these plants contain a variety of carotenoids, but mainly-lutein, violaxanthin, and-β-carotene

Summary

Introduction

Japanese (Fallopia japonica Houtt.) and Bohemian (Fallopia x bohemica) knotweeds are large herbaceous plants which belong to the Polygonaceae family [1]. Bohemian knotweed emerged thereafter as a hybrid between Japanese knotweed and Giant (Fallopia sachalinensis) knotweed—another member of Fallopia spp [1,2]. Due to their fast spread and strong resilience to extermination, knotweeds were soon classified as aggressive alien plant invaders [1,2]. Today, they pose a great economic and environmental threat as they cause loss of native biodiversity, affect agriculture and forestry, and they endanger certain animal species [2,3]. Invasive knotweeds thrive alongside water bodies and their banks, and can raise problems with water quality, accessibility, and flow rate [3,4]

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