Title: Tricin‐lignins: occurrence and quantitation of tricin in relation to phylogeny

Abstract

Summary Tricin [5,7‐dihydroxy‐2‐(4‐hydroxy‐3,5‐dimethoxyphenyl)‐4H‐chromen‐4‐one], a flavone, was recently established as an authentic monomer in grass lignification that likely functions as a nucleation site. It is linked onto lignin as an aryl alkyl ether by radical coupling with monolignols or their acylated analogs. However, the level of tricin that incorporates into lignin remains unclear. Herein, three lignin characterization methods: acidolysis; thioacidolysis; and derivatization followed by reductive cleavage; were applied to quantitatively assess the amount of lignin‐integrated tricin. Their efficiencies at cleaving the tricin‐(4′– O– β)‐ether bonds and the degradation of tricin under the corresponding reaction conditions were evaluated. A hexadeuterated tricin analog was synthesized as an internal standard for accurate quantitation purposes. Thioacidolysis proved to be the most efficient method, liberating more than 91% of the tricin with little degradation. A survey of different seed‐plant species for the occurrence and content of tricin showed that it is widely distributed in the lignin from species in the family Poaceae (order Poales). Tricin occurs at low levels in some commelinid monocotyledon families outside the Poaceae, such as the Arecaceae (the palms, order Arecales) and Bromeliaceae (Poales), and the non‐commelinid monocotyledon family Orchidaceae (Orchidales). One eudicotyledon was found to have tricin ( Medicago sativa ,more » Fabaceae). The content of lignin‐integrated tricin is much higher than the extractable tricin level in all cases. Lignins, including waste lignin streams from biomass processing, could therefore provide a large and alternative source of this valuable flavone, reducing the costs, and encouraging studies into its application beyond its current roles.« less

Authors:

Lan, Wu ^[1]; Rencoret, Jorge ^[2]; Lu, Fachuang ^[3]; Karlen, Steven D. ^[4]; Smith, Bronwen G. ^[5]; Harris, Philip J. ^[6]; del Río, José Carlos ^[2]; Ralph, John ^[7]

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+ Show Author Affiliations

1. DOE Great Lakes Bioenergy Research Center Wisconsin Energy Institute University of Wisconsin Madison WI USA, Department of Biological System Engineering University of Wisconsin Madison WI USA
2. Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), CSIC Avenida de la Reina Mercedes, 10 41012 Seville Spain
3. DOE Great Lakes Bioenergy Research Center Wisconsin Energy Institute University of Wisconsin Madison WI USA, Department of Biochemistry University of Wisconsin Madison WI USA, State Key Laboratory of Pulp and Paper Engineering South China University of Technology Guangzhou China
4. DOE Great Lakes Bioenergy Research Center Wisconsin Energy Institute University of Wisconsin Madison WI USA, Department of Biochemistry University of Wisconsin Madison WI USA
5. School of Chemical Sciences The University of Auckland Auckland New Zealand
6. School of Biological Sciences The University of Auckland Auckland New Zealand
7. DOE Great Lakes Bioenergy Research Center Wisconsin Energy Institute University of Wisconsin Madison WI USA, Department of Biological System Engineering University of Wisconsin Madison WI USA, Department of Biochemistry University of Wisconsin Madison WI USA

Publication Date:

Thu Nov 03 00:00:00 EDT 2016

Research Org.:

Univ. of Wisconsin, Madison, WI (United States); Agricultural Research Service, MD (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER)

OSTI Identifier:

1330903

Alternate Identifier(s):

OSTI ID: 1330904; OSTI ID: 1427721

Grant/Contract Number:  

DE‐AI02‐06ER64299; FC02-07ER64494; AI02-06ER64299

Resource Type:

Published Article

Journal Name:

The Plant Journal

Additional Journal Information:

Journal Name: The Plant Journal Journal Volume: 88 Journal Issue: 6; Journal ID: ISSN 0960-7412

Publisher:

Wiley-Blackwell

Country of Publication:

United Kingdom

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; thioacidolysis; acidolysis; derivatization followed by reductive cleavage; Poaceae; tricin-d6; stable isotopically labeled internal standard; liquid chromatography-mass spectrometry; multiple reaction monitoring