Der Pharma Chemica
Journal for Medicinal Chemistry, Pharmaceutical Chemistry, Pharmaceutical Sciences and Computational Chemistry

Abstract

Determination of the Nutritional and Functional Metabolites of Nannochloropsis gaditana Produced in Algeria and Evaluation of Its Antioxidant Activity

Author(s): Asmaa Kherraf, Wafaa Tehami, Wahiba Boufeldja, Imène Yahla, Ghislaine Amira Dra, Insaf Fatima Zohra Mansour, Mohammed Benali

The aim of this work was to evaluate the microalgae Nannochloropsis gaditana grown in Algeria. The different analyzes of the primary metabolites showed an interesting nutritional profile. The microalgae has a fresh matter content of 9.33 ± 1.15%. The amount of ash (6.4 ± 0.23%) was high and reflects a mineral richness. Total sugars represent 7.13 ± 0.23%. Proteins and lipids represent 13.38 ± 0.2% and 7 ± 1%, respectively. The Ethanolic (EENg) and Methanolic (MENg) extracts obtained from 10 g of lyophilisates of N. gaditana represent respectively 24 ± 1.65% and 14.2 ± 0.7%. The evaluation of the polyphenols in these extracts shows interesting rates representing 41.53 ± 0.41 mg gallic acid equivalent (GAE)/g of EENg dry extract and 38.72 ± 0.33 mg GAE/g for the MENg. The flavonoid contents were 19.82 ± 1.65 and 18.61 ± 1.45 mg quercetin equivalent (QE)/g respectively for the ethanolic and methanolic extracts of these microalgae. The condensed and hydrolyzable tannins represent respectively 0.35 ± 0.04 and 0.63 ± 0.09 mg of tannic acid/g of dry EENg. They also represent respectively 0.50 ± 0.08 and 0.18 ± 0.02 mg of tannic acid/g of dry MENg. The concentrations of the EENg and MENg extracts allowing the reduction or inhibition (IC50) of the 2,2-Diphenyl-1-Picrylhydrazyl radicals (DPPH•) were comparable and represent 1.16 ± 0.06 and 2.02 ± 0.04 mg/ml, but remain significantly higher than that of ascorbic acid (0.1 ± 0.02 mg/ml). Evaluation of the antioxidant activities of the EENg, MENg and ascorbic acid extracts by the reducing power of iron yielded respectively 0.031 ± 0.03, 0.022 ± 0.009 and 1.67 ± 0.035 units of optical density at a concentration of 0.15 mg/ml and 0.349 ± 0.037, 0.414 ± 0.012 and 2.66 ± 0.007 units of optical density at the concentration of 5 mg/ml.


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