Redalyc.Reactivity Indexes and O-H Bond Dissociation Energies of A

Total Page:16

File Type:pdf, Size:1020Kb

Redalyc.Reactivity Indexes and O-H Bond Dissociation Energies of A Journal of the Mexican Chemical Society ISSN: 1870-249X [email protected] Sociedad Química de México México Pérez-González, Adriana; Rebollar-Zepeda, Aida Mariana; León-Carmona, Jorge Rafael; Galano, Annia Reactivity Indexes and O-H Bond Dissociation Energies of a Large Series of Polyphenols: Implications for their Free Radical Scavenging Activity Journal of the Mexican Chemical Society, vol. 56, núm. 3, julio-septiembre, 2012, pp. 241-249 Sociedad Química de México Distrito Federal, México Available in: http://www.redalyc.org/articulo.oa?id=47524533003 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative J. Mex. Chem. Soc. 2012, 56(3), 241-249 ArticleReactivity Indexes and O-H Bond Dissociation Energies of a Large Series of Polyphenols: Implications ©for 2012, their SociedadFree Radical Química de México241 ISSN 1870-249X Reactivity Indexes and O-H Bond Dissociation Energies of a Large Series of Polyphenols: Implications for their Free Radical Scavenging Activity Adriana Pérez-González, Aida Mariana Rebollar-Zepeda, Jorge Rafael León-Carmona, and Annia Galano∗ Departamento de Química. Universidad Autónoma Metropolitana-Iztapalapa. San Rafael Atlixco 186, Col. Vicentina. Iztapalapa. C. P. 09340. México D. F. México. [email protected] To Professor José Luis Gázquez Mateos for being a great example and a constant motivation. We sincerely thank him for sharing his kindness and knowledge with all of us. Received September 19, 2011; accepted February 20, 2012 Abstract. Several chemical descriptors have been evaluated for thirty Resumen. Varios descriptores químicos fueron evaluados para treinta polyphenols within the frame of the Density Functional Theory (DFT). polifenoles, dentro del marco de la Teoría de Funcionales de la Den- They were used to investigate the donor and accepting electron ca- sidad. Fueron utilizados para investigar la capacidad electrodonadora pabilities, the fractional charge transfer feasibility, and the H trans- y electroaceptora, la facilidad de donación parcial de carga y la trans- fer ability of these compounds. It was found that for deactivating ferabilidad de H de estos compuestos. Se encontró que la miricetina free radicals Myricetin has the highest activity via H transfer, while presenta la mayor actividad vía transferencia de H, mientras que la Galangin and piceatannol are the best scavengers through the single galangina y el piceatanol son los mejores desactivantes vía transfe- electron transfer mechanism for nucleophilic and electrophilic free rencia electrónica simple para radicales nucleofílicos y electrofílicos, radicals, respectively. respectivamente. Key words: Electrodonating Power, Electroaccepting Power, Ioniza- Palabras clave: Poder electrodonador, poder electroaceptor, energía tion Energies, Electron Affinities, Bond Dissociation Energies, An- de ionization, afinidad electrónica, energías de disociación de enlace, tioxidant. antioxidantes. Introduction phenolic sites [16-25] and by single electron transfer (SET) from the phenol to the oxidant [21, 24, 25-27]. Therefore O- Oxidative stress (OS) is a chemical stress that can be defined H bond dissociation energies (BDE) and ionization energies as the imbalance between biochemical processes leading to (IE) are relevant to the evaluation of the antioxidant activity the production of free radicals and those responsible for their of these compounds. Accordingly it is the main goal of the removal [1]. It has attracted great deal of attention in the last present work to evaluate the O-H BDEs and the IEs of a series decades due to the increasing evidence supporting its role in of 30 polyphenols with different structural features. BDE have the development of a large number of health disorders such as been analyzed for the homolytic bond cleavage since proton cancer [2], cardiovascular disorders [3], atherosclerosis [4], and transfers are not studied in this work. In addition, it has been Alzheimer’s disease [5]. Since OS involves reactions between proven that in the particular case of the superoxide radical anion •- free radicals and molecules of high biological importance such (O2 ) the electron transfer actually takes place from this spe- as DNA and proteins, the study of compounds with free radical cies to the free radical scavenger [28]. The same mechanism scavenging activity becomes an important area of research aim- was also proposed for the NO radical [29]. Therefore to analyze ing to prevent OS and the consequent molecular damage. this particular reaction path we have also studied the electron Polyphenols are consumed in human diet in a wide variety affinity (EA). of foods and beverages, such as: fruits, vegetables, wine, cof- In addition Gázquez et al. [30]. have recently proposed fee, tea, etc. [6]. They are ubiquitous and versatile substances, the electroaccepting power (ϖ+) and the electrodonating power which have been identified to play multiple biological roles, (ϖ-) indexes. They are ideal for describing the propensity of a including cardioprotective [7] effects, and anti-inflammatory given chemical species to accept or donate fractional amounts [8], antimicrobial and antiviral [9] activities. They are also used of charge. They are expected to show a similar behavior to to prevent and treat cancer [10] and neurodegenerative diseases that of the first ionization potential and the electron affinity, [11] and to prevent skin damage [12] and osteoporosis [13]. respectively. However, while IE and EA measure the capabil- They are also reported to have excellent antioxidant activity ity of a chemical system to donate or accept one electron, ϖ+ [14], which is the focus of the present study. This particular and ϖ- measure the capability of a chemical system to donate activity is so important that more than 7500 scientific reports or to accept a small fractional amount of charge [31]. Polyphe- have been devoted to it in the last two decades [15]. However, nols have polar groups and consequently they can form weak to our best knowledge there is no previous systematic study on bonded complexes with the molecules in their environment. a large series of polyphenols testing chemical descriptors as In physiological media there are abundant compounds which indicators of their potential antioxidant activity. can interact in this way with polyphenols. Since this kind of It has been demonstrated that the antioxidant activity of interactions usually takes place by fractional charge transfer we polyphenols takes place mainly by H transfer (HT) from the have used ϖ+ and ϖ- to evaluate the propensity of polyphenols 242 J. Mex. Chem. Soc. 2012, 56(3) Adriana Pérez-González et al. to participate in such chemical interactions driven by donor-ac- Table 1. Name and acronyms of the polyphenols studied in this ceptor processes. work. Acronym Name Acronym Name 1 Luteolin 16 Aromadedrin Computational Details 2 Apigenin 17 Genistein 3 Kaempferide 18 Daidzein All the electronic calculations have been carried out with the package of programs Gaussian 09 [32], using the PBE0 func- 4 Quercetin 19 Glycitein tional [33] and the 6-31+G(d,p) basis set. This functional has 5 Kaempferol 20 Catechin been chosen for being parameter-free. Full geometry optimiza- 6 Myricetin 21 Gallocatechin tions, without any symmetry constraints, and frequency cal- 7 Fisetin 22 Resveratrol culations were performed for all the species and local minima 8 Isorhamnetin 23 Laricitrin were identified by the absence of imaginary frequencies. Vertical ionization energies (IE) and electron affinities 9 Pachypodol 24 Syringetin (EA) were calculated as: 10 Rhamnazin 25 Piceatannol 11 Hesperetin 26 Aesculetin IE = EN-1(gN) - EN(gN) (1) 12 Naringenin 27 Galangin 13 Eriodictyol 28 Morin EA = E (g ) - E (g ) (2) N N N+1 N 14 Homoeriodictyol 29 Azaleatin 15 Taxifolin 30 Gossypetin Where EN(gN) is the energy of the N-electron system cal- culated at the geometry gN and EN-1(gN) and EN+1(gN) are the energies of the (N - 1) and (N + 1) electron systems, calculated also at the gN geometry. The O-H bond dissociation energies (BDE) have been cal- The electroaccepting power (ϖ+) and the electrodonat- culated for every O-H site, and their values are reported in - ing power (ϖ ) indices have been calculated as proposed by Table 2. The lowest BDE value for each compound has been Gázquez et al. [30]: highlighted in bold letters. As the values in this table show, for ()IE 3 EA 2 those families that contain O-H sites in the B ring the lowest (3) BDE always corresponds to one of these sites, regardless of 16()IE EA the other structural features, with the exception of flavonols. and This strongly supports the hypothesis that for these families the ()3 IE EA 2 hydroxyl groups in the B ring are responsible for the antioxi- (4) dant activity of polyphenols, through the H transfer mechanism 16()IE EA (HT). For flavonols, on the other hand, site 3 is the one that The O-H bond dissociation energies (BDE) have been most frequently corresponds to the lowest value of BDE. The computed as the energy evolution associated with the homo- other families with an OH group in site 3 are flavanonols and lytic rupture of the OH bond: flavanols. However for them the BDE of this OH group is higher than those of the OH groups in the B ring. The main dif- R - OH → R - O• + H• ference between these two families and flavonols is that for the latter there is a double bond between C2 and C3. Therefore it BDE values have been calculated for all the OH moieties in seems that this structural feature is mandatory for the increased the studied polyphenols, and the most favored process has been reactivity of site 3. identified. They are reported in terms of Gibbs free energies For the studied flavones, the lowest BDE corresponds to (ΔG), at 298.15 K, to take into account the entropy changes.
Recommended publications
  • Theoretical and Kinetic Tools for Selecting Effective Antioxidants: Application to the Protection of Omega-3 Oils with Natural and Synthetic Phenols
    International Journal of Molecular Sciences Article Theoretical and Kinetic Tools for Selecting Effective Antioxidants: Application to the Protection of Omega-3 Oils with Natural and Synthetic Phenols Romain Guitard, Véronique Nardello-Rataj * and Jean-Marie Aubry * Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181–UCCS-Unité de Catalyse et Chimie du Solide, F-59000 Lille, France; [email protected] * Correspondence: [email protected] (V.N.-R.); [email protected] (J.-M.A.); Tel.: +33-3-2033-6369 (V.N.-R.); +33-3-2033-6364 (J.-M.A.) Academic Editor: Maria Laura Colombo Received: 3 June 2016; Accepted: 21 July 2016; Published: 29 July 2016 Abstract: Radical-scavenging antioxidants play crucial roles in the protection of unsaturated oils against autoxidation and, especially, edible oils rich in omega-3 because of their high sensitivity to oxygen. Two complementary tools are employed to select, among a large set of natural and synthetic phenols, the most promising antioxidants. On the one hand, density functional theory (DFT) calculations provide bond dissociation enthalpies (BDEs) of 70 natural (i.e., tocopherols, hydroxybenzoic and cinnamic acids, flavonoids, stilbenes, lignans, and coumarins) and synthetic (i.e., 2,6-di-tert-butyl-4-methylphenol (BHT), 3-tert-butyl-4-hydroxyanisol (BHA), and tert-butylhydroquinone (TBHQ)) phenols. These BDEs are discussed on the basis of structure–activity relationships with regard to their potential antioxidant activities. On the other hand, the kinetic rate constants and number of hydrogen atoms released per phenol molecule are measured by monitoring the reaction of phenols with 2,2-diphenyl-1-picrylhydrazyl (DPPH‚) radical.
    [Show full text]
  • Evaluation of the Antioxidant Activity of Extracts and Flavonoids Obtained from Bunium Alpinum Waldst
    DOI: 10.1515/cipms-2017-0001 Curr. Issues Pharm. Med. Sci., Vol. 30, No. 1, Pages 5-8 Current Issues in Pharmacy and Medical Sciences Formerly ANNALES UNIVERSITATIS MARIAE CURIE-SKLODOWSKA, SECTIO DDD, PHARMACIA journal homepage: http://www.curipms.umlub.pl/ Evaluation of the antioxidant activity of extracts and flavonoids obtained from Bunium alpinum Waldst. & Kit. (Apiaceae) and Tamarix gallica L. (Tamaricaceae) Mostefa Lefahal1, Nabila Zaabat1, Lakhdar Djarri1, Merzoug Benahmed2, Kamel Medjroubi1, Hocine Laouer3, Salah Akkal1* 1 Université de Constantine 1, Unité de Recherche Valorisation des Ressources Naturelles Molécules Bioactives et Analyses Physico- Chimiques et Biologiques, Département de Chimie, Facultés des Sciences Exactes, Algérie 2 Université Larbi Tébessi Tébessa Laboratoire des Molécules et Applications, Algérie 3 Université Ferhat Abbas Sétif 1, Laboratoire de Valorisation des Ressources Naturelles Biologiques. Le Département de Biologie et d'écologie Végétales, Algérie ARTICLE INFO ABSTRACT Received 19 October 2016 The aim of the present work was to evaluate the antioxidant activity of extracts and four Accepted 24 January 2017 flavonoids that had been isolated from the aerial parts of Bunium alpinum Waldst. et Kit. Keywords: (Apiaceae) and Tamarix gallica L. (Tamaricaceae). In this work, the four flavonoids were B. alpinum, first extracted via various solvents, then purified through column chromatography (CC) T. gallica, and thin layer chromatography (TLC). The four compounds were subsequently identified flavonoids, 1 13 antioxidant activity, by spectroscopic methods, including: UV, mass spectrum H NMR and C NMR. DPPH assay, The EtOAc extract ofBunium alpinum Waldst. et Kit yielded quercetin-3-O-β-glucoside EC50. (3',4',5,7-Tetrahydroxyflavone-3-β-D-glucopyranoside) (1), while the EtOAc and n-BuOH extracts of Tamarix gallica L.
    [Show full text]
  • Rhamnazin Inhibits Proliferation and Induces Apoptosis of Human Jurkat Leukemia Cells in Vitro
    експериментальні роботи UDC 577.152.3 + 576.38 doi: http://dx.doi.org/10.15407/ubj87.06.122 RHAMNAZIN INHIBITS PROLIFERATION AND INDUCES APOPTOSIS OF HUMAN JURKAT LEUKEMIA CELLS IN VITRO А. А. Philchenkov, М. P. Zavelevych R. e. kavetsky institute of experimental Pathology, oncology and Radiobiology, national academy of Sciences of Ukraine, kyiv; e-mail: [email protected] a ntiproliferative and apoptogenic effects of rhamnazin, a dimethoxylated derivative of quercetin, were studied in human acute lymphoblastic leukemia Jurkat cells. The cytotoxicity and apoptogenic activity of rhamnazin in vitro are inferior to that of quercetin. The apoptogenic activity of rhamnazin is realized via mitochondrial pathway and associated with activation of caspase-9 and -3. The additive apoptogenic effect of rhamnazin and suboptimal doses of etoposide, a Dna topoisomerase ii inhibitor, is demonstrated. Therefore, methylation of quercetin modifies its biological effects considerably. k e y w o r d s: acute lymphoblastic leukemia, flavonoids, cell cycle, apoptosis, caspases, flow cytometry. lavonoids constitute the largest class (over mon natural substances. Monomethylated deriva­ 6,500 compounds) of biologically active plant tives have been shown to inhibit proliferation and F polyphenols [1]. Most of them by far are de­ induce apoptosis in cancer cells [8], or to sensitize rivatives of 2-phenylbenzopyran (flavan) or 2-phe­ malignant cells to other cytotoxic agents [9]. Yet nylbenzopyran-4-one (flavone). Flavonoids display there is only a limited amount of data concerning antioxidant properties and may also induce apoptotic efficiency of rhamnazin (3′,7-dimethylquercetin), a cell death, depending on concentration [2]. It has quercetin derivative differing only by two methyl been demonstrated that the proapoptotic and cyto­ groups (Fig.
    [Show full text]
  • The Role of Selected Flavonols in Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Receptor–1 (TRAIL-R1) Expression on Activated RAW 264.7 Macrophages
    Molecules 2015, 20, 900-912; doi:10.3390/molecules20010900 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Article The Role of Selected Flavonols in Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Receptor–1 (TRAIL-R1) Expression on Activated RAW 264.7 Macrophages Monika Warat 1, Tadeusz Sadowski 2, Ewelina Szliszka 1, Wojciech Król 1 and Zenon P. Czuba 1,* 1 School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia in Katowice, Chair and Department of Microbiology and Immunology, Jordana 19, 41-808 Zabrze, Poland; E-Mails: [email protected] (M.W.); [email protected] (E.S.); [email protected] (W.K.) 2 School of Public Health in Bytom, Medical University of Silesia in Katowice, Toxicology and Drug Addiction Division, Communal Department of Hygiene and Sanitary Supervision, Medyków 18, 40-752 Katowice, Poland; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel./Fax: +48-32-272-25-54. Academic Editor: Marcello Iriti Received: 24 November 2014 / Accepted: 5 January 2015 / Published: 8 January 2015 Abstract: Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Receptors (TRAIL-R) are an important factor of apoptosis in cancer cells. There are no data about the effect of flavonols on the receptor expression on a surface of macrophage like cells. In this study, the expression level of TRAIL-R1 on murine RAW264.7 macrophages in the presence of selected flavonols: galangin, kaempferol, kaempferide and quercetin, which differ from their phenyl ring substituents, were studied. The expression of TRAIL-R1 death receptors on non-stimulated and lipopolysaccharide (LPS)-stimulated macrophages was determined using flow cytometry.
    [Show full text]
  • On the Natural Diversity of Phenylacylated-Flavonoid and Their
    Phytochem Rev DOI 10.1007/s11101-017-9531-3 On the natural diversity of phenylacylated-flavonoid and their in planta function under conditions of stress Takayuki Tohge . Leonardo Perez de Souza . Alisdair R. Fernie Received: 23 November 2016 / Accepted: 26 August 2017 © The Author(s) 2017. This article is an open access publication Abstract Plants contain light signaling systems and Keywords Flavonoid · Natural diversity · undergo metabolic perturbation and reprogramming Phenelyacylation · Species conservation · under light stress in order to adapt to environmental UV-B changes. Flavonoids are one of the largest classes of natural phytochemical compounds having several Abbreviations biological functions conferring stress defense to ANS Anthocyanidin synthase plants and health benefits in animal diets. A recent BAHD BEAT/AHCT/HCBT/DAT study of phenylacylated-flavonoids (also called BGLU Beta glucosidase hydroxycinnamoylated-flavonoids) of natural acces- CHI Chalcone isomerase sions of Arabidopsis suggested that phenylacylation CHS Naringenin-chalcone synthase of flavonoids relates to selection under different COP1 CONSTITUTIVE natural light conditions. Phenylacylated-flavonoids PHOTOMORPHOGENIC 1 which are decorated with hydroxycinnamoyl units, CPD Cyclobutane pyrimidine dimers namely cinnamoyl, 4-coumaroyl, caffeoyl, feruloyl CRY CRYPTOCHROME and sinapoyl moieties, are widely distributed in the CUL4 CULLIN 4 plant kingdom. Currently, more than 400 phenylacy- DDB UV-damaged DNA binding protein lated flavonoids have been reported. Phenylacylation
    [Show full text]
  • Antithrombotic Activity of Flavonoids and Polyphenols Rich Plant Species
    Acta Pharm. 69 (2019) 483–495 Review https://doi.org/10.2478/acph-2019-0050 Antithrombotic activity of flavonoids and polyphenols rich plant species MIRZA BOJIĆ1,* Cardiovascular diseases represent one of the most notable 2 ŽELJAN MALEŠ health problems of the modern civilization. Stroke and ANDREA ANTOLIĆ3 IVANA BABIĆ4 heart attack often lead to lethal outcome; essential problem MAJA TOMIČIĆ4 underneath being thrombus formation. Prophylactic appro- aches include acetylsalicylic acid and clopidogrel therapy 1 University of Zagreb Faculty on the level of primary hemostasis, i.e., primary clot forma- of Pharmacy and Biochemistry tion. In the last five years, in the USA, health care expenses Department of Medicinal Chemistry related to cardiovascular diseases have increased 50 %, to HR-10000 Zagreb, Croatia over 350 billion dollars. Thus, application of plant species 2 University of Zagreb Faculty and medicinal plants rich in polyphenols in prevention of of Pharmacy and Biochemistry thrombus formation are of interest. This is supported by the Department of Pharmaceutical Botany fact that the number of publications on antiaggregatory HR-10000 Zagreb, Croatia effect of polyphenols has doubled in the last decade. In this review we focus on antiaggregatory effect of most abundant 3 University of Zagreb Faculty of Science polyphenols – flavonoids, the effect of plant extracts rich in PDS Biology, HR-10000 Zagreb, Croatia polyphenols (propolis, species Salvia sp., Calamintha nepeta L., Lavandula angustifolia Mill., Melissa officinalis L, Mentha x 4 Croatian Institute of Transfusion piperita L., Ocimum basilicum L., Origanum vulgare L., Rosmarinus Medicine, HR-10000 Zagreb, Croatia officinalis L.) on platelet aggregation, association of chemical composition and antioxidant properties with the observed biological effect, and possible clinical significance of the published results.
    [Show full text]
  • Vine Growth, Berry Ripening, Flavonoids, and Aromatic Profiles
    International Journal of Molecular Sciences Article Rootstock-Mediated Effects on Cabernet Sauvignon Performance: Vine Growth, Berry Ripening, Flavonoids, and Aromatic Profiles Yu Wang 1,2, Wei-Kai Chen 1,2, Xiao-Tong Gao 1,2, Lei He 1,2, Xiao-Hui Yang 1,2, Fei He 1,2, Chang-Qing Duan 1,2 and Jun Wang 1,2,* 1 Center for Viticulture & Enology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; [email protected] (Y.W.); [email protected] (W.-K.C.); [email protected] (X.-T.G.); [email protected] (L.H.); [email protected] (X.-H.Y.); [email protected] (F.H.); [email protected] (C.-Q.D.) 2 Key Laboratory of Viticultural and Enology, Ministry of Agriculture and Rural Affairs, Beijing 100083, China * Correspondence: [email protected]; Tel.: +86-10-62738537 Received: 25 December 2018; Accepted: 15 January 2019; Published: 18 January 2019 Abstract: Rootstocks are widely used in viticulture due to their resistance to biotic and abiotic stress. Additionally, rootstocks can affect vine growth and berry quality. This study evaluated the effects of eight rootstocks (101-14, 110R, 5A, 5BB, Ganzin 1, Harmony, Riparia Gloire, and SO4) on the vine growth, berry ripening, and flavonoids and aromatic profiles of Cabernet Sauvignon in two consecutive seasons (2015–2016). With few exceptions, minor differences were observed among grafted and own-rooted vines. Own-rooted vines produced the least pruning weight but the highest yield. 101-14, 5BB, and SO4 slightly reduced total soluble solids, but increased acidity, showing tendencies for retarding maturation.
    [Show full text]
  • Flavonol Glycosides and Their Distribution in the Perianths of Gladiolus×Grandiflora Cultivars
    Bull. Natl. Mus. Nat. Sci., Ser. B, 45(1), pp. 29–40, February 22, 2019 Flavonol Glycosides and their Distribution in the Perianths of Gladiolus×grandiflora Cultivars Tomoko Takemura1 and Tsukasa Iwashina2,* 1 United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Saiwai-cho, Fuchu 183–8509, Japan 2 Department of Botany, National Museum of Nature and Science, Amakubo 4–1–1, Tsukuba, Ibaraki 305–0005, Japan * E-mail: [email protected] (Received 16 October 2018; accepted 26 December 2018) Abstract Fifteen flavonol glycosides were isolated from the perianths of two Gladiolus×grandiflora cultivars “Ariake” and “Christmas” by various chromatography. Of their flavonols, eight glycosides were identified as kaempferol 3-O-sophoroside, 3-O-glucoside, 3-O-rutinoside and 3-O-glucosyl-(1→2)-rhamnoside, quercetin 3-O-rutinoside and myricetin 3-O-rutinoside, 3-O-glucoside and 3-O-rhamnoside by UV spectra, LC-MS, acid hydrolysis, 1H and 13C NMR, and TLC and HPLC comparisons with authentic samples. Other seven flavonols were characterized as kaempferol 3-O-pentosylglucoside, 3-O-rhamnosylrhamnosylglucoside and 3-O-glucosylrhamnoside, laricitrin 3-O-diglucoside, 3-O-rhamnosylglucoside and 3-O-rhamnosyl- hexoside, and syringetin 3-O-rhamnosylglucoside. Flavonol composition of the perianths of 89 Gladiolus×grandiflora cultivars including 12 purple, 13 reddish purple, 13 pink, 19 red, 2 orange, 16 white, 11 yellow and 3 green flower cultivars was surveyed by HPLC. Moreover, correlation between flower colors and flavonol
    [Show full text]
  • Analysis of the Binding and Interaction Patterns of 100 Flavonoids with the Pneumococcal Virulent Protein Pneumolysin: an in Silico Virtual Screening Approach
    Available online a t www.scholarsresearchlibrary.com Scholars Research Library Der Pharmacia Lettre, 2016, 8 (16):40-51 (http://scholarsresearchlibrary.com/archive.html) ISSN 0975-5071 USA CODEN: DPLEB4 Analysis of the binding and interaction patterns of 100 flavonoids with the Pneumococcal virulent protein pneumolysin: An in silico virtual screening approach Udhaya Lavinya B., Manisha P., Sangeetha N., Premkumar N., Asha Devi S., Gunaseelan D. and Sabina E. P.* 1School of Biosciences and Technology, VIT University, Vellore - 632014, Tamilnadu, India 2Department of Computer Science, College of Computer Science & Information Systems, JAZAN University, JAZAN-82822-6694, Kingdom of Saudi Arabia. _____________________________________________________________________________________________ ABSTRACT Pneumococcal infection is one of the major causes of morbidity and mortality among children below 2 years of age in under-developed countries. Current study involves the screening and identification of potent inhibitors of the pneumococcal virulence factor pneumolysin. About 100 flavonoids were chosen from scientific literature and docked with pnuemolysin (PDB Id.: 4QQA) using Patch Dockprogram for molecular docking. The results obtained were analysed and the docked structures visualized using LigPlus software. It was found that flavonoids amurensin, diosmin, robinin, rutin, sophoroflavonoloside, spiraeoside and icariin had hydrogen bond interactions with the receptor protein pneumolysin (4QQA). Among others, robinin had the highest score (7710) revealing that it had the best geometrical fit to the receptor molecule forming 12 hydrogen bonds ranging from 0.8-3.3 Å. Keywords : Pneumococci, pneumolysin, flavonoids, antimicrobial, virtual screening _____________________________________________________________________________________________ INTRODUCTION Streptococcus pneumoniae is a gram positive pathogenic bacterium causing opportunistic infections that may be life-threating[1]. Pneumococcus is the causative agent of pneumonia and is the most common agent causing meningitis.
    [Show full text]
  • Anti-Cov-2 Spike Protein Directed Druggable Inhibitors
    OPEN ACCESS ECOCYCLES Scientific journal of the ISSN 2416-2140 European Ecocycles Society Ecocycles, Vol. 6, No. 2, pp. 38-45 (2020) DOI: 10.19040/ecocycles.v6i2.176 ORIGINAL PAPER Effective natural food complements: anti-CoV-2 spike protein directed druggable inhibitors Oláh, Zoltán1-3*; Ökrész, László1; Török, Ibolya1; Pestenácz, Anikó1; Harkai, Anikó1; Kocsis, Éva1-3 1Acheuron Ltd., Szeged, Hungary 2Forget-Me-Not B2B Ltd., Szeged, Hungary 3 Vásárhely’s Landscaping (VATES) Folks- School Society, Hódmezővásárhely, Hungary *corresponding author, e-mail: [email protected] Abstract – There is a number of photosynthetically produced small molecules that have previously been validated through SARS- CoV spike protein interaction assays for selectivity and effectivity in our database. Our specialty database, the AVIRA-DB, has been built from scientific papers that published results regarding selective & effective CoV-2 spike protein binding inhibitors that prevent virus binding to the Angiotensin Converting Enzyme type 2 (ACE2). These data have been accumulated since 2003, the time of the first well documented coronavirus pandemic. To develop our anti-viral nutraceutical capsule we favoured small molecules (Mw <1000 Dalton) from edible plant parts that are enriched in experimentally evaluated coronavirus inhibitors. From this “AVIRA-DB” we screened for local culture varieties of vegetables and spices that are enriched in the anti-viral hits. Thus, AVIRA is the first knowledge-based nutraceutical composition that was validated by selective anti-CoV-2’s spike protein assays, performed in silico, -vitro & -vivo. From Chemo- & Bio-text-mined meta-data from literature and patents resulted in druggable flavonoids and flavonols, which were validated as anti-CoV-2 spike protein directed small molecules that are preventing the binding of the virus to ACE2.
    [Show full text]
  • Phenolics and Flavonoids Contents of Medicinal Plants, As Natural Ingredients for Many Therapeutic Purposes- a Review
    IOSR Journal Of Pharmacy (e)-ISSN: 2250-3013, (p)-ISSN: 2319-4219 Volume 10, Issue 7 Series. II (July 2020), PP. 42-81 www.iosrphr.org Phenolics and flavonoids contents of medicinal plants, as natural ingredients for many therapeutic purposes- A review Ali Esmail Al-Snafi Department of Pharmacology, College of Medicine, Thi qar University, Iraq. Received 06 July 2020; Accepted 21-July 2020 Abstract: The use of dietary or medicinal plant based natural compounds to disease treatment has become a unique trend in clinical research. Polyphenolic compounds, were classified as flavones, flavanones, catechins and anthocyanins. They were possessed wide range of pharmacological and biochemical effects, such as inhibition of aldose reductase, cycloxygenase, Ca+2 -ATPase, xanthine oxidase, phosphodiesterase, lipoxygenase in addition to their antioxidant, antidiabetic, neuroprotective antimicrobial anti-inflammatory, immunomodullatory, gastroprotective, regulatory role on hormones synthesis and releasing…. etc. The current review was design to discuss the medicinal plants contained phenolics and flavonoids, as natural ingredients for many therapeutic purposes. Keywords: Medicinal plants, phenolics, flavonoids, pharmacology I. INTRODUCTION: Phenolic compounds specially flavonoids are widely distributed in almost all plants. Phenolic exerted antioxidant, anticancer, antidiabetes, cardiovascular effect, anti-inflammatory, protective effects in neurodegenerative disorders and many others therapeutic effects . Flavonoids possess a wide range of pharmacological
    [Show full text]
  • Identification of the Anti-COVID-19 Mechanism of Action of Han-Shi Blocking Lung Using Network Pharmacology- Integrated Molecular Docking
    Yuan et al Tropical Journal of Pharmaceutical Research June 2021; 20 (6): 1241-1249 ISSN: 1596-5996 (print); 1596-9827 (electronic) © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. Available online at http://www.tjpr.org http://dx.doi.org/10.4314/tjpr.v20i6.21 Original Research Article Identification of the anti-COVID-19 mechanism of action of Han-Shi Blocking Lung using network pharmacology- integrated molecular docking Chong Yuan1, Fei Wang1, Peng-Yu Chen1, Zong-Chao Hong1, Yan-Fang Yang1,2, He-Zhen Wu1,2* 1Faculty of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, 2Key Laboratory of Traditional Chinese Medicine Resources and Chemistry of Hubei Province, Wuhan 430061, China *For correspondence: Email: [email protected], [email protected]; Tel: +86-13667237629, +86-13545341663 Sent for review: 30 June 2020 Revised accepted: 16 May 2021 Abstract Purpose: To investigate the bio-active components and the potential mechanism of the prescription remedy, Han-Shi blocking lung, with network pharmacology with a view to expanding its application. Methods: Chemical components were first collected from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Pharmmapper database and GeneCards were used to predict the targets related to active components and COVID-19. Using DAVIDE and KOBAS 3.0 databases, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were enriched. A “components-targets-pathways” (C-T-P) network was conducted by Cytoscape 3.7.1 software. With the aid of Discovery Studio 2016 software, bio-active components were selected to dock with SARS-COV-2 3CL and ACE2.
    [Show full text]