Publications by authors named "Sindhu Mathew"

Hypoxemic respiratory failure is a common manifestation of COVID-19 pneumonia. Early in the COVID-19 pandemic, patients with hypoxemic respiratory failure were, at times, being intubated earlier than normal; in part because the options of heated humidified high flow nasal cannula (HFNC) and non-invasive ventilation (NIV) were considered potentially inadequate and to increase risk of virus aerosolization. To understand the benefits and factors that predict success and failure of HFNC in this population, we evaluated data from the first 30 sequential patients admitted with COVID-19 pneumonia to our center who were managed with HFNC.

View Article and Find Full Text PDF

Xylooligosaccharides (XOS) and arabinoxylooligosaccharides (AXOS) were produced from the insoluble arabinoxylan fraction of pretreated wheat bran by endoxylanases. The glycoside hydrolase (GH) family 10 xylanases GsXyn10A from Geobacillus stearothermophilus and RmXyn10A-CM from Rhodothermus marinus produced the AXOS AX, AXX and AXX in addition to XOS. RmXyn10A-CM also produced XAXX due to its non-conserved aglycone region accommodating additional arabinose substitutions in subsite +2.

View Article and Find Full Text PDF

Brewer's spent grain (BSG) accounts for around 85% of the solid by-products from beer production. BSG was first extracted to obtain water-soluble arabinoxylan (AX). Using subsequent alkali extraction (0.

View Article and Find Full Text PDF

The enzymatic, ecofriendly pretreatment of wheat bran with α-amylase from Bacillus amyloliquifaciens or B. licheniformis at 90°C for 1.5h followed by Neutrase at 50°C for 4h, aqueous liquefaction at 121°C for 15h and ethanol precipitation enabled the production of soluble arabinoxylan (AX) with purity of 70.

View Article and Find Full Text PDF

The free radical scavenging activity and reducing power of 16 phenolic compounds including four hydroxycinnamic acid derivatives namely ferulic acid, caffeic acid, sinapic acid and p-coumaric acid, benzoic acid and its derivatives namely protocatechuic acid, gallic acid and vanillic acid, benzene derivatives namely vanillin, vanillyl alcohol, veratryl alcohol, veratraldehyde, pyrogallol, guaiacol and two synthetic antioxidants, butylated hydroxy anisole (BHA) and propyl gallate were evaluated using 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH(•)), 2,2'-Azinobis-3- ethylbenzothiazoline-6-sulfonic acid radical (ABTS(+•)), Hydroxyl radical ((•)OH) and Superoxide radical (O2 (•-)) scavenging assays and reduction potential assay. By virtue of their hydrogen donating ability, phenolic compounds with multiple hydroxyl groups such as protocatechuic acid, pyrogallol, caffeic acid, gallic acid and propyl gallate exhibited higher free radical scavenging activity especially against DPPH(•) and O2 (•-). The hydroxylated cinnamates such as ferulic acid and caffeic acid were in general better scavengers than their benzoic acid counter parts such as vanillic acid and protocatechuic acid.

View Article and Find Full Text PDF

Pyroligneous acid (PA) is a complex highly oxygenated aqueous liquid fraction obtained by the condensation of pyrolysis vapors, which result from the thermochemical breakdown or pyrolysis of plant biomass components such as cellulose, hemicellulose, and lignin. PA produced by the slow pyrolysis of plant biomass is a yellowish brown or dark brown liquid with acidic pH and usually comprises a complex mixture of guaiacols, catechols, syringols, phenols, vanillins, furans, pyrans, carboxaldehydes, hydroxyketones, sugars, alkyl aryl ethers, nitrogenated derivatives, alcohols, acetic acid, and other carboxylic acids. The phenolic components, namely guaiacol, alkyl guaiacols, syringol, and alkyl syringols, contribute to the smoky odor of PA.

View Article and Find Full Text PDF

Dodecyl glucooligosides, a class of interesting non ionic surfactant molecules were synthesized by cyclodextrin glucanotransferase from Bacillus macerans using either α-cyclodextrin (α-CD) or soluble starch as glycosyl donor and dodecyl β-d-glucoside (CG) or dodecyl β-d-maltoside (CG) as acceptor substrates. The primary coupling products obtained in the respective reactions were identified as dodecyl glucoheptaoside and dodecyl maltooctaoside by mass spectrometry. Higher yields of coupling products were obtained using α-CD as donor, while more dispoportionation occurred with starch.

View Article and Find Full Text PDF

The primary hydroxyl groups in potato starch were selectively oxidized to the corresponding aldehyde and carboxylic acid functionalities by mediators like TEMPO, using laccase from fungi as catalytic oxidant and oxygen as the primary oxidant. Oxidized starch products with degree of substitution (DS(CHO) ranging from 0.16 to 16.

View Article and Find Full Text PDF

Ferulic acid is the most abundant hydroxycinnamic acid in the plant world and is ester linked to arabinose, in various plant polysaccharides such as arabinoxylans and pectins. It is a precursor to vanillin, one of the most important aromatic flavor compound used in foods, beverages, pharmaceuticals, and perfumes. This article presents an overview of the various biocatalytic routes, focusing on the relevant biotransformations of ferulic acid using plant sources, microorganisms, and enzymes.

View Article and Find Full Text PDF

Chitosan has wide range of applications as a biomaterial, but barriers still exist to its broader use due to its physical and chemical limitations. The present study evaluated the properties of the polymeric blend films obtained from chitosan and potato starch by the casting/solvent evaporation method. The swelling properties of the different films studied as a function of pH showed that the sorption ability of the blend films increased with the increasing content of starch.

View Article and Find Full Text PDF

The free radical scavenging capacity and antioxidant activities of the methanolic extract of Cinnamomum verum leaf (CLE) were studied and compared to antioxidant compounds like trolox, butylated hydroxyl anisole, gallic acid and ascorbic acid. The CLE exhibited free radical scavenging activity, especially against DPPH radical and ABTS radical cation. They also exhibited reducing power and metal ion chelating activity, along with hydroxyl radical scavenging activity.

View Article and Find Full Text PDF

Ferulic acid is the most abundant hydroxycinnamic acid in the plant world and maize bran with 3.1% (w/w) ferulic acid is one of the most promising sources of this antioxidant. The dehydrodimers of ferulic acid are important structural components in the plant cell wall and serve to enhance its rigidity and strength.

View Article and Find Full Text PDF