Severity: Warning
Message: fopen(/var/lib/php/sessions/ci_sessionb8piqeop0cvdr9uu55qd91ef64b3v24e): Failed to open stream: No space left on device
Filename: drivers/Session_files_driver.php
Line Number: 177
Backtrace:
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)
Filename: Session/Session.php
Line Number: 137
Backtrace:
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "choices"
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: 8192
Message: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated
Filename: models/Detail_model.php
Line Number: 71
Backtrace:
File: /var/www/html/application/models/Detail_model.php
Line: 71
Function: strpos
File: /var/www/html/application/controllers/Detail.php
Line: 252
Function: insertAPISummary
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: 8192
Message: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
Filename: helpers/my_audit_helper.php
Line Number: 8919
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 8919
Function: str_replace
File: /var/www/html/application/controllers/Detail.php
Line: 255
Function: formatAIDetailSummary
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "choices"
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 257
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 257
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 257
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 257
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 258
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 258
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 258
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 258
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 259
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 259
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 259
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 259
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 260
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 260
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 260
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
The synthesis and study of a series of 6-substituted-2,4-dimethyl-3-pyridinols having interesting antioxidant properties is reported. The general synthetic strategy leading to the compounds involved a low-temperature aryl bromide-to-alcohol conversion as the last step. 2,4-dimethyl-3-pyridinol (1a), 2,4,6-trimethyl-3-pyridinol (1b), and 2,4-dimethyl-6-(dimethylamino)-3-pyridinol (1d) were thus prepared from the corresponding 3-bromopyridine precursor. The methoxy derivative 2,4-dimethyl-6-(methoxy)-3-pyridinol (1c) was also prepared by an alternate route via a Baeyer-Villiger reaction on the substituted benzaldehyde precursor. Novel bicyclic pyridinols 2 and 3 required prior construction of the ring structure. Thus, 2 was prepared by the use of a 6-step intramolecular Friedel-Crafts strategy, and 3 required an 11-step sequence with a thermolytic intramolecular inverse-demand Diels-Alder reaction between a pyrimidine ring and an alkyne as the key step. Basicities of the pyridinols approached physiological pH with increasing electron density in the ring. Pyridinols 1a-d were found to be indefinitely stable to air oxidation while 2 and 3 decomposed upon extended exposure to the atmosphere. The reactivities of the pyridinols toward chain-carrying peroxyl radicals in homogeneous organic solution were examined by studying the kinetics of radical-initiated styrene autoxidations under controlled conditions. These experiments revealed that some of the newly synthesized pyridinols are the most effective phenolic chain-breaking antioxidants reported to date.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jo048842u | DOI Listing |
J Food Sci
November 2024
Facultad de Ciencias Agropecuarias, Laboratorio de Tecnología de Alimentos (LabTA), Universidad Nacional de Córdoba, Córdoba, Argentina.
The use of antioxidants is known to reduce lipid oxidation. This study aimed to assess the interaction of two antioxidant mechanisms, namely, "chain-breaking" and "termination-enhancing" by combining natural antioxidants derived from "oregano" (Origanum vulgare L.) and "peperina" (Minthostachys mollis K.
View Article and Find Full Text PDFJ Agric Food Chem
October 2024
Department of Chemistry "G. Ciamician", University of Bologna, Via P. Gobetti 85, 40129 Bologna, Italy.
Essential oils (EOs) are gaining importance as sustainable food antioxidants, but kinetic data on peroxyl radical trapping are missing. Thirteen EOs from 11 botanical species were studied in the inhibited autoxidation of cumene by oxygen-uptake kinetics. EOs of , , , , , , and , containing 23-86% phenolic components by gas chromatography/mass spectrometry (GC-MS) analysis, afforded inhibition rate constants in the order of 10 M s at 30 °C similar to reference butylhydroxytoluene (2,6-di--butyl-4-methylphenol) (BHT).
View Article and Find Full Text PDFCell Mol Biol (Noisy-le-grand)
July 2024
Laboratory of Biochemistry and Environmental Toxicology, Department of Biochemistry, Faculty of Sciences, Badji Mokhtar University, Annaba, Algeria.
This investigation aimed to explore the antioxidant, anti-inflammatory effects of Cade oil and its efficacy within a Wistar allergic asthma model. The antioxidant activity was assessed through various in vitro tests using chain-breaking antioxidant effects (radical scavenging and reducing abilities assays). In vivo experiments involved Wistar rats categorized into four groups: negative control group, Ovalbumin-sensitised/challenged group, Cade oil-treated group, and Ovalbumin-sensitised/challenged Cade oil-treated group.
View Article and Find Full Text PDFOrg Biomol Chem
July 2024
Department of Chemistry "Ugo Schiff" - DICUS, University of Florence, Via Della Lastruccia 3-13, I-50019 Sesto Fiorentino, Firenze, Italy.
Three new α-tocopherol thiophene derivatives were efficiently synthesized, characterized and used for the first time as chain-breaking antioxidants for the inhibition of the autoxidation of reference oxidizable substrates. The rate constant of the reaction with alkylperoxyl (ROO˙) radicals and the stoichiometry of radical trapping () for the thiophene-tocopherol compounds were determined by measuring the oxygen consumption during the autoxidation of styrene or isopropylbenzene, using a differential pressure transducer. The measurement of the reaction with ROO˙ radicals in an apolar solvent at 30 °C showed inhibition rate constants () in the order of 10 M s.
View Article and Find Full Text PDFChemistry
July 2024
Centre of Experimental Medicine of Slovak Academy of Sciences, Dúbravská cesta 9, 84104, Bratislava, Slovakia.
Cationic Mn(III)-meso-tetraarylporphyrin derivatives, substituted in para position with different size alkyl chains, were investigated to function as antioxidants in free-radical degradation of high-molar-mass hyaluronan by the methods of rotational viscometry and oximetry. The results of rotational viscometry showed that MnTM-4-PyP, MnTE-4-PyP, MnTPr-4-PyP, MnTPen-4-PyP and MnTHep-4-PyP showed high efficiency in decomposing HO, and reducing of peroxidized hyaluronan. When using oxygen electrode, MnTE-4-PyP, MnTPr-4-PyP, MnTPen-4-PyP, and MnTHep-4-PyP applied to function as protective antioxidants in hyaluronan degradation, the uptake of dissolved oxygen from the reaction milieu was rapid, followed by continual increase in oxygen concentration up to the end of the measurement.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!