Publications by authors named "Moacir Fernandes Queiroz"

The role of oxidative stress in health and homeostasis has generated interest in the scientific community due to its association with cardiovascular and neurodegenerative diseases, cancer, and other diseases. Therefore, extensive research seeks to identify new exogenous antioxidant compounds for supplementation. Polysaccharides are recognized for their antioxidant properties.

View Article and Find Full Text PDF

Antioxidant compounds decrease the amount of intracellular reactive oxygen species (ROS) and, consequently, reduce the deleterious effects of ROS in osteoblasts. Here, we modified a 21 kDa fucoidan (FucA) with gallic acid (GA) using the redox method, to potentiate its antioxidant/protective capacity on pre-osteoblast-like cells (MC3T3) against oxidative stress. The 20 kDa FucA-GA contains 37 ± 3.

View Article and Find Full Text PDF

Animal chitosan (Chit-A) is gaining more acceptance in daily activities. It is used in a range of products from food supplements for weight loss to even raw materials for producing nanoparticles and hydrogel drug carriers; however, it has low antioxidant activity. Fungal oligochitosan (OChit-F) was identified as a potential substitute for Chit-A.

View Article and Find Full Text PDF

Oxidative stress is the cause of numerous diseases in humans; therefore, there has been a continuous search for novel antioxidant molecules. Fungal chitosan is an attractive molecule that has several applications (antifungal, antibacterial, anticancer and antiparasitic action) owing to its unique characteristics; however, it exhibits low antioxidant activity. The aim of this study was to obtain fungal chitosan (Chit-F) from the fungus and synthesize its derivative, fungal chitosan-gallic acid (Chit-FGal), as a novel antioxidant chitosan derivative for biomedical use.

View Article and Find Full Text PDF

The genus synthesizes sulfated polysaccharides (SPs). Many of these SPs, including those synthesized by the edible seaweed , have not yet been adequately investigated for their use as potential pharmaceutical compounds. Previous studies have demonstrated the immunomodulatory effects of sulfated galactans from .

View Article and Find Full Text PDF

A novel derivative of dextran, dextran-gallic acid (Dex-Gal), obtained from simple conjugation with gallic acid, was synthesized by an efficient free radical-mediated method. To verify the synthesis of Dex-Gal, 1H-nuclear magnetic resonance (1H-NMR), Fourier transform infrared (FTIR) spectrometry, and high-performance size-exclusion chromatography (HPSEC) were employed. The results revealed the conjugation of gallic acid with the 15.

View Article and Find Full Text PDF
Article Synopsis
  • * Various extracts were analyzed for sugar, phenolic compounds, and protein content; thin layer chromatography (TLC) confirmed the presence of beneficial compounds such as terpenes and saponins.
  • * All extracts demonstrated strong antioxidant activity, with noteworthy effects against DPPH and biofilm formation, while also showing low cytotoxicity in cell lines, suggesting potential health benefits.
View Article and Find Full Text PDF

species are widely studied to identify their chemical composition and evaluate their biological activity. Since evidence supporting the potential antioxidant and antiproliferative activity of is lacking, the aim of this work was to evaluate these activities in six different leaf extracts: hexane (CHE), chloroform (CCE), ethanolic (CEE), methanolic (CME), aqueous final (CFAE), and only aqueous (CAE). The presence of phenolic compounds, tannin, saponin, and ursolic acid was determined by thin layer chromatography (TLC).

View Article and Find Full Text PDF

Urolithiasis affects approximately 10% of the world population and is strongly associated with calcium oxalate (CaOx) crystals. Currently, there is no efficient compound that can be used to prevent this disease. However, seaweeds' sulfated polysaccharides (SPs) can change the CaOx crystals surface's charge and thus modify the crystallization dynamics, due to the interaction of the negative charges of these polymers with the crystal surface during their synthesis.

View Article and Find Full Text PDF

It has recently been shown that chitosan (Chit) induces the formation of calcium oxalate (CaOx) crystals, which are mainly responsible for the appearance of kidney stones, and this might limit the use of Chit in vivo. Here, Chit was conjugated with gallic acid (Chit-Gal) to decrease the formation of CaOx crystal. This conjugation was confirmed by FTIR and NMR analyses.

View Article and Find Full Text PDF

is a brown seaweed used in the treatment of obesity. This seaweed synthesizes various bioactive molecules, one of them being a sulfated polysaccharide known as fucoidan (FF). This polymer can easily be found commercially, and has antiadipogenic and lipolytic activity.

View Article and Find Full Text PDF

Chitosan is widely used in the biomedical field due its chemical and pharmacological properties. However, intake of chitosan results in renal tissue accumulation of chitosan and promotes an increase in calcium excretion. On the other hand, the effect of chitosan on the formation of calcium oxalate crystals (CaOx) has not been described.

View Article and Find Full Text PDF

The sulfated polysaccharides (SP) from the edible red seaweed, Gracilaria birdiae, were obtained using five different extraction conditions: Gracilaria birdiae 1 (GB1)-water; GB1s-water/sonication; GB1sp-water/sonication/proteolysis; GB2s-NaOH/sonication; and GB2sp-NaOH/sonication/proteolysis. The yield (g) increased in the following order: GB2sp>GB1sp>GB2s>GB1s>GB1. However, the amount of SP extracted increased in a different way: GB2sp>GB1>GB1sp>GB1s>GB2s.

View Article and Find Full Text PDF

Oxalate crystals and other types of crystals are the cause of urolithiasis, and these are related to oxidative stress. The search for new compounds with antioxidant qualities and inhibitors of these crystal formations is therefore necessary. In this study, we extracted four sulfated polysaccharides, a fucoglucoxyloglucuronan (DJ-0.

View Article and Find Full Text PDF