Structure-Functional Study of Tyrosine and Methionine Dipeptides: An Approach to Antioxidant Activity Prediction

Quantum chemical methods allow screening and prediction of peptide antioxidant activity on the basis of known experimental data. It can be used to design the selective proteolysis of protein sources in order to obtain products with antioxidant activity. Molecular geometry and electronic descriptors of redox-active amino acids, as well as tyrosine and methionine-containing dipeptides, were studied by Density Functional Theory method. The calculated data was used to reveal several descriptors responsible for the antioxidant capacities of the model compounds based on their experimentally obtained antioxidant capacities against ABTS (2,2′-Azino-bis-(3-ethyl-benzothiazoline-6-sulfonate)) and peroxyl radical. A formula to predict antioxidant activity of peptides was proposed

Balık kaynaklı biyo-aktif peptidler ve metabolik etkileri

Like many other organisms, fishes are also rich sources of bio-active compounds which were well studied by research focused on their antimicrobial, antihypertensive, antioxidant and antitumor activities. They can be used not only for good nutritional value, but also for peptides obtained with analytic processes that were developed in last decades. Aquatic organisms total the highest number of species in world, therefore discovering bio-active peptides in them is more possible than in others, which was clearly shown in previous studies. Abundance of native and obtained peptides from long chain polypeptides with proper enzymatic methods may open new horizons for medical researchDiğer tüm organizmalar gibi, balıklar da, araştırmalarda antimikrobiyal, antihipertensif, antioksidan ve antitümör aktivitelerine odaklanılan bio-aktif bileşiklerin zengin kaynağıdırlar. Bunlar, sadece yüksek besin değeri nedeniyle değil, özellikle son yirmi yılda geliştirilen analitik yöntemlerle elde edilen peptidleri açısından da kullanılabilirler. Akuatik canlılar dünya üzerinde en fazla tür sayısına sahiptir, dolayısıyla bunlardan bio-aktif peptidlerin eldesi diğerlerine göre oldukça olasıdır ve bu, önceki çalışmalarda açıkça ortaya konmuştur. Doğal peptidler ve uzun zincirli polipeptidlerden uygun enzimatik yöntemlerle elde edilen peptidler tıp alanında yeni ufuklar açabilirle

Structure-Functional Study of Tyrosine and Methionine Dipeptides: An Approach to Antioxidant Activity Prediction

Quantum chemical methods allow screening and prediction of peptide antioxidant activity on the basis of known experimental data. It can be used to design the selective proteolysis of protein sources in order to obtain products with antioxidant activity. Molecular geometry and electronic descriptors of redox-active amino acids, as well as tyrosine and methionine-containing dipeptides, were studied by Density Functional Theory method. The calculated data was used to reveal several descriptors responsible for the antioxidant capacities of the model compounds based on their experimentally obtained antioxidant capacities against ABTS (2,2′-Azino-bis-(3-ethyl-benzothiazoline-6-sulfonate)) and peroxyl radical. A formula to predict antioxidant activity of peptides was proposed

Evaluation of the Antiradical Properties of Phenolic Acids

Antioxidant capacity (AOC) against peroxyl radical and 2,2\u27-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation was measured for a series of p-hydroxybenzoic (HB) and p-hydroxycinnamic (HC) acids at different pH. Quantum-chemical computation was performed using Gaussian 3.0 software package to calculate the geometry and energy parameters of the same compounds. Significant correlations were revealed between AOC and a number of calculated parameters. The most significant AOC descriptors for the studied compounds against peroxyl radical were found to be HOMO energy, rigidity (η) and Mulliken charge on the carbon atom in m-position to the phenolic hydroxyl. The most significant descriptor of the antioxidant properties against the ABTS radical cation at рН 7.40 is electron transfer enthalpy from the phenolate ion. The mechanism of AOC realization has been proposed for HB and HC acids against both radicals

Physicochemical and functional properties of Cucurbita maxima pumpkin pectin and commercial citrus and apple pectins: A comparative evaluation.

The physicochemical characteristics and functional properties of pumpkin (Cucurbita maxima D. var. Cabello de Ángel) pectin obtained by cavitation facilitated extraction from pumpkin pulp have been evaluated and compared with commercial citrus and apple pectins. C. maxima pectin had an Mw value of 90 kDa and a high degree (72%) of esterification. The cytoprotective and antioxidant effects of citrus, apple and pumpkin pectin samples with different concentrations were studied in vitro in cell lines HT-29 (human colon adenocarcinoma) and MDCK1 (canine kidney epithelium). All pectin samples exhibited cytoprotective effect in HT-29 and MDCK1 cells after incubation with toxic concentrations of cadmium and mercury for 4 h. Pumpkin pectin increased the proliferation of cadmium-treated MDCK1 cells by 210%. The studied pectins also inhibited oxidative stress induced by 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) in cell cultures, as determined by measuring the production of intracellular reactive species using dihydrochlorofluorescein diacetate (DCFH-DA). Pectin from pumpkin pomace had the highest (p < 0.05) protective effect against reactive oxygen species generation in MDCK1 cells induced by AAPH. Distinctive features of pumpkin pectin were highly branched RG-I regions, the presence of RG-II regions and the highest galacturonic acid content among the studied samples of pectins. This correlates with a considerable protective effect of C. maxima pectin against oxidative stress and cytotoxicity induced by heavy metal ions. Thus, C. maxima pectin can be considered as a source of new functional foods of agricultural origin

An in vitro and in silico study on the antioxidant and cell culture-based study on the chemoprotective activities of fish muscle protein hydrolysates obtained from European seabass and gilthead seabream

WOS: 000444967800090PubMed ID: 30236737European seabass (Dicentrarchus labrax, Linnaeus, 1758) (L) and gilthead seabream (Spares aurata, Linnaeus, 1758) (C) muscles were hydrolysated by Alcalase (L-alc, C-alc) and Chymotrypsin (L-ch, C-ch) then hydrolysates were examined and their peptide profiles obtained. A total of 765, 794, 132 and 232 peptides were identified in C-alc, L-alc, C-ch, and L-ch, respectively. Although, L-ch and C-ch, were expected to have more antioxidant capacity because of their peptide profiles, Alcalase hydrolysates observed in vitro, were slightly higher (TEAC assay for C-alc: 848.11 +/- 60.78 cool TE/g protein). Maximum inhibition of oxidative stress was determined for L-alc (12.8% +/- 4.5%) in MDCK1 cell lines. Highest proliferative capacity observed for C-alc (147.0% +/- 3.1%) at MTT assay in MDCK1 cell culture. L-ch showed the highest chemopreventive effect with a 40-60% decrease for human colon adenocarcinoma cell line HT-29. This research points out the importance of aquatic sources as raw materials for peptide researches.Scientific and Technological Research Council of Turkey, Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [2219]; Russian Science Foundation, RussiaRussian Science Foundation (RSF) [14-24-00114]We wish to acknowledge The Scientific and Technological Research Council of Turkey, Turkey (TUBITAK) for support of Dr. Can Altinelataman by Grant # 2219 to join studies in Moscow. The part of research related to peptides identification by high resolution mass spectrometry measurements was supported by the Russian Science Foundation, Russia (Grant # 14-24-00114). This study was dedicated to memory of Prof. Dr. Olga Koroleva