Original Research ARTICLE
Chemical structure and localization of levan, the predominant fructan type in underground systems of Gomphrena marginata (Amaranthaceae)
- 1Department of Plant Physiology and Biochemistry, Instituto de Botânica, Brazil
- 2Department of Food and Nutrition Sciences, Rakuno Gakuen University, Japan
- 3Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Federal University of São Paulo, Brazil
- 4Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Brazil
Gomphrena marginata Seub. (Amaranthaceae) is an endemic species from Brazilian campos rupestres. Previous studies suggested that the reserve carbohydrate present in the underground system of this species could be levan-type fructans, similar to that identified in G. macrocephala. High performance anion exchange chromatography (HPAEC–PAD) revealed the presence of the soluble carbohydrates glucose, fructose, sucrose, 1-kestose, 6-kestose, nystose and fructans with degree of polymerization up to approximately 50 fructose units. Two-dimensional nuclear magnetic resonance spectroscopy (2D NMR), HSQC (heteronuclear single-quantum correlation) and HMBC (heretonuclear multiple-bonds correlation) data showed the predominance of levan-type fructans, a linear molecule with β- 2,6 linkages, based on 6-kestose, corroborating with the results previously shown. Structural analyses of the underground system using light microscopy revealed mainly a gemmiferous tuberous root with the upper region formed by short stems, both presenting vascular cylinders with unusual growth patterns. Fructan spherocrystals were visualized under polarized light and SEM mostly in the cortex and vascular cylinder. In addition to data reported in the literature concerning the Amaranthaceae, the results presented here suggest that fructans are a trait in this family while the levan-type fructan prevail in Gomphrena species.
Keywords: Amaranthaceae, soluble carbohydrates, plant anatomy, campos rupestres, Fructo-polysaccharides
Received: 17 Aug 2018;
Accepted: 09 Nov 2018.
Edited by:Kevin Davies, The New Zealand Institute for Plant & Food Research Ltd, New Zealand
Reviewed by:Hiroshi Noguchi, Nihon Pharmaceutical University, Japan
Andrea Matros, University of Adelaide, Australia
Copyright: © 2018 Joaquim, Hayashi, Torres, Figueiredo-Ribeiro, Shiomi, Sousa, Lago and Carvalho. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Maria Angela M. Carvalho, Instituto de Botânica, Department of Plant Physiology and Biochemistry, São Paulo, 04301-902, São Paulo, Brazil, email@example.com