Search results for " polysaccharides"

Algae and their extracts in medical treatment

2018

Scientific efforts undertaken in recent decades have undoubtedly proven that algae are an inestimable and, what is more, important renewable source of hundreds of chemical compounds characterized by a wide spectrum of biological activity. Polysaccharides, phenolic compounds and their derivatives, pigments, proteins, lipids, and fatty acids are the substances that can be isolated from seaweeds, possessing antimicrobial, antiviral, antifungal, antilipidemic, antitumor, antidiabetic, anticoagulant, antioxidant, and antiallergic properties, which can be successfully utilized for human needs. The majority of attention has been focused on marine polysaccharides and their application in medicine a…

SYNTHESIS OF INULIN-GRAFT COPOLYMERS VIA GRAFTING- FROM ATRP TECHNIQUE. A NEW FRONTIER FOR MODIFICATION OF NATURAL POLYSACCHARIDES

2012

Structural characterization of polysaccharides of a productive strain of the culinary-medicinal king oyster mushroom, pleurotus eryngii (Agaricomycet…

2018

A preliminary biological investigation of the dry basidiomata of strain C-142-c of Pleurotus eryngii has shown significant antioxidant activity. Two different polysaccharides (PEPS-A1 and PEPS-A2) were isolated from the cultivated edible mushroom, P. eryngii C-142-c strain. Based on acid hydrolysis, methylation analysis, and nuclear magnetic resonance experiments (1H, 13C, distortionless enhancement by polarization transfer, double quantum filtered correlation spectroscopy, total correlation spectroscopy, nuclear Overhauser effect spectroscopy, heteronuclear singlequantum correlation spectroscopy, and heteronuclear multiple-bond correlation spectroscopy), the structures of the repeating uni…

Radiation-tailored xyloglucan-doxorubicin nanoparticles for cancer therapy

2022

Polysaccharides are long chains of monosaccharides linked by glycosidic bonds. They are widely utilized in biomedical applications, for tissue engineering and wound management, and as excipients of pharmaceutical formulations. In cancer therapy, the development of nanoscale drug delivery systems aims at addressing issues related to the low efficacy of chemotherapeutics and protein drugs due to poor solubility and stability, and to off-target effects that severely affect patients’ body conditions. Biocompatibility, availability of functional groups, amenability of chemical derivatisation and multifunctional conjugation with drugs and targeting ligands make polysaccharide nanoparticles intere…

Pectin: A Long-Neglected Broad-Spectrum Antibacterial.

2020

First reported in the late 1930s and first partly explained in 1970, the antibacterial activity of pectin remained almost ignored until the late 1990s. The concomitant emergence of research on natural antibacterials and on new usages of pectin polysaccharides, including those in medicine widely researched in Russia, has led to a renaissance of research in the physiological properties of this uniquely versatile polysaccharide ubiquitous in plants and fruits. Collecting scattered information, this study provides an updated overview on the subtle factors affecting the behaviour of pectin as antimicrobial. Less degraded pectin extracted via acid-free routes, we argue in the conclusions, will so…

Drying enhances immunoactivity of spent brewer's yeast cell wall β-D-glucans.

2015

Due to immunological activity, microbial cell wall polysaccharides are defined as 'biological response modifiers' (BRM). Cell walls of spent brewer's yeast also have some BRM activity. However, up to date there is no consensus on the use of spent brewer's yeast D-glucan as specific BRM in humans or animals. The aim of this paper is to demonstrate the potential of spent brewer's yeast β-D-glucans as BRM, and drying as an efficient pretreatment to increase β-D-glucan's immunogenic activity. Our results revealed that drying does not change spent brewer's yeast biomass carbohydrate content as well as the chemical structure of purified β-D-glucan. However, drying increased purified β-D-glucan TN…

Fresh-Cut Mangoes: How to Increase Shelf Life by Using Neem Oil Edible Coating

2022

The mango is the most widely cultivated tropical fruit. Fresh-cut mango is very useful, but it is very perishable. The purpose of this study was to highlight the effects of neem oil on fresh-cut mango fruits kept for 9 days at 4 ± 1 °C and 80 ± 5% relative humidity. The neem plant (Azadirachta indica) has numerous antioxidant and antibacterial properties. Despite this, very few studies have been carried out on neem oil added to edible coatings (EC) to retard ripening processes. Two formulations were tested: EC1 (hydroxypropyl methylcellulose + CaCl2) and EC2 (hydroxypropyl methylcellulose + CaCl2 + neem oil), both compared with an untreated sample (control). Physicochemica…

Mycochemical investigation of Pleurotus eryngii var. eryngii

2017

The mycochemical composition and structural characterization of the whole aqueous and methanolic extracts from Pleurotus eryngii var. eryngii are investigated. Two water-soluble glucans were obtained from the fruiting bodies by hot water extraction, ethanol precipitation, dialysis and Sephadex G-200 gel filtration. On the basis of total hydrolysis, methylation analysis, and NMR studies (1H, 13C, DQF-COSY, TOCSY, HSQC and HMBC) two fractions PEPS-1 and PEPS-2 were characterized and the structure of the repeating unit of the glucan were determined as linear (1→6)--glucan and (1→6)--glucan, respectively. The methanolic extract of Pleurotus eryngii var. eryngii was also investigated and a com…

Influence of solvent-free reticulation treatment on edible film properties based on chitosan and gelatin, containing or not natural antioxidants : ph…

2015

This thesis aims to develop an edible packaging made of a mixture of chitosan and gelatin (beef or fish), to better understand the influence of the electron beam irradiation and of the incorporation of natural antioxidants on the physico-chemical and functional properties of the films. A study of the effect of irradiation on antioxidants release kinetics in a simple liquid medium was studied for validation. A preliminary study first showed that the densification of the film-forming solution and the gel during drying does not depend on the thickness or concentration or time and suggests a Fickian diffusion of water in the matrix. The permeability to water vapor increases linearly with film t…

Water-soluble polysaccharides from Opuntia stricta Haw. fruit peels: Recovery, identification and evaluation of their antioxidant activities

2015

Abstract Opuntia stricta Haw. is considered as one of the most common cactus plant growing in Tunisia. Extracting valuable compounds from its fruit peel, considered as by-product, is drawing more and more attention, making it on the verge of commercialization. Water-soluble polysaccharides were extracted from Opuntia stricta Haw. peels, and their chemical composition assessed using thin layer chromatography. The antioxidant activities of the extracted polysaccharides were assessed using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, total antioxidant activity and reducing power capacity. The extraction yield of water-soluble polysaccharides was 7.53±0.86%. The chemical comp…