resumo
This work studies the extraction and purification of a novel arabinogalactan from pistachio external hull. It was extracted with a simple method from pistachio hull which is considered as unexploited waste. Based on the results of sugar analysis by GC-FID, glycosidic linkage by GC-MS, NMR spectroscopy, and molecular weight by Size Exclusion Chromatography, pistachio hull water soluble polysaccharides (PHWSP) were identified as a type II arabinogalactan (AG), with characteristic terminally linked alpha-Araf, (alpha 1 -> 5)-Araf, (alpha 1 -> 3,5)-Araf, terminally linked beta-Galp, (beta 1 -> 6)-Galp, and (beta 1 -> 3,6)-Galp. DEPT-135, HSQC, HMBC and COSY NMR data suggested the presence of (beta 1 -> 3)-Galp mainly branched at O-6 with (beta 1 -> 6)-Galp chains, alpha-Araf chains, and terminally linked alpha-Araf. These AG from pistachio external hulls showed in vitro stimulatory activity for B cells, suggesting their possible use as an immunological stimulant in nutraceutical and biomedical applications.
palavras-chave
WATER-SOLUBLE POLYSACCHARIDES; STRUCTURAL CHARACTERISTICS
categoria
Chemistry; Food Science & Technology; Nutrition & Dietetics
autores
Hamed, M; Coelho, E; Bastos, R; Evtuguin, DV; Ferreira, SS; Lima, T; Vilanova, M; Sila, A; Coimbra, MA; Bougatef, A
nossos autores
Dmitry Evtyugin
Professor Associado com Agregação
Sónia dos Santos Ferreira
Bolseiro de pós-Doutoramentoagradecimentos
This work was funded by the Ministry of Higher Education and Scientific Research, Tunisia. Thanks are due to the University of Aveiro and FCT/MCT for the financial support for LAQV-REQUIMTE (UIDB/50006/2020) and CICECO-Aveiro Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020), through national funds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement. Rita Bastos (PD/BD/114579/2016) was supported by FCT/MEC grants. Elisabete Coelho thanks the research contract funded by national funds (OE), through FCT, in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the articles 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.