Thiol groups of cysteine (Cys) residues in proteins react with quinones, oxidation products of polyphenols, to form protein-polyphenol adducts. The aim of the present work was to quantify the amount of adduct formed between Cys residues and 4-methylcatechol (4MC) in minced beef. A Cys-4MC adduct standard was electrochemically synthesized and characterized by liquid chromatography-mass spectrometry (LC-MS) as well as NMR spectroscopy. Cys-4MC adducts were quantified after acidic hydrolysis of myofibrillar protein isolates (MPIs) and LC-MS/MS analysis of meat containing either 500 or 1500 ppm 4MC and stored at 4 °C for 7 days under a nitrogen or oxygen atmosphere. The concentrations of Cys-4MC were found to be 2.2 ± 0.3 nmol/mg MPI and 8.1 ± 0.9 nmol/mg MPI in meat containing 500 and 1500 ppm 4MC, respectively, and stored for 7 days under oxygen. The formation of the Cys-4MC adduct resulted in protein thiol loss, and ca. 62% of the thiol loss was estimated to account for the formation of the Cys-4MC adduct for meat containing 1500 ppm 4MC. Furthermore, protein polymerization increased in samples containing 4MC as evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the polymerization was found to originate from protein-polyphenol interactions as evaluated by a blotting assay with staining by nitroblue tetrazolium.
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. PA finds application in diverse areas, as antioxidant, antimicrobial, antiinflammatory, plant growth stimulator, coagulant for natural rubber, and termiticidal and pesticidal agent; is a source for valuable chemicals; and imparts a smoky flavor for food.
Molecules that target the deoxyribonucleic acid (DNA) minor groove are relatively sequence specific and they can be excellent carrier structures for cytotoxic chemotherapeutic compounds which can help to minimize side effects. Two novel isomeric derivatives of diaminobenzene Schiff base [N,N'-bis (2-hydroxy-3-methoxybenzylidene)-1,2-diaminobenzene (2MJ) and N,N'-bis(2-hydroxy-3-methoxybenzylidene)-1,3-diaminobenzene (2MH)] were analyzed for their DNA minor groove binding (MGB) ability using viscometry, UV and fluorescence spectroscopy, computational modeling and clonogenic assay. The result shows that 2MJ and 2MH are strong DNA MGBs with the latter being more potent. 2MH can form interstrand hydrogen bond linkages at its oxygens with N3 of adenines. Changing the 2-hydroxy-3-methoxybenzylidene binding position to the 1,3 location on the diaminobenzene structure (2MJ) completely removed any viable hydrogen bond formation with the DNA and caused significant decrease in binding strength and minor groove binding potency. Neither compound showed any significant cytotoxicity towards human breast, colon or liver cancer cell lines.
Humans have been using natural products for medicinal use for ages. Natural products of therapeutic importance are compounds derived from plants, animals, or any microorganism. Ginger is also one of the most commonly used condiments and a natural drug in vogue. It is a traditional medicine, having some active ingredients used for the treatment of numerous diseases. During recent research on ginger, various ingredients like zingerone, shogaol, and paradol have been obtained from it. Zingerone (4-(4-hydroxy-3-methoxyphenyl)-2-butanone) is a nontoxic and inexpensive compound with varied pharmacological activities. It is the least pungent component of Zingiber officinale. Zingerone is absent in fresh ginger but cooking or heating transforms gingerol to zingerone. Zingerone closely related to vanillin from vanilla and eugenol from clove. Zingerone has potent anti-inflammatory, antidiabetic, antilipolytic, antidiarrhoeic, antispasmodic, and so forth properties. Besides, it displays the property of enhancing growth and immune stimulation. It behaves as appetite stimulant, anxiolytic, antithrombotic, radiation protective, and antimicrobial. Also, it inhibits the reactive nitrogen species which are important in causing Alzheimer's disease and many other disorders. This review is written to shed light on the various pharmacological properties of zingerone and its role in alleviating numerous human and animal diseases.