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Yui Harauchi, Tadashi Kajimoto, Emi Ohta, Hiroyuki Kawachi, Aya Imamura-Jinda, Shinji Ohta
Three previously undescribed isoguanine glycosides with an N(3)-prenyl group, designated locustoside B, saikachinoside B, and saikachinoside C, have been isolated from the seed of Gleditsia japonica Miquel (Fabaceae) along with two known compounds, locustoside A and saikachinoside A. Their structures were determined from spectroscopic data and X-ray crystallographic analysis. The inhibitory activity against acid phosphatase was evaluated.
August 13, 2017: Phytochemistry
Shih-Fen Chen, Pei-Yi Chen, Hao-Jen Hsu, Ming-Jiuan Wu, Jui-Hung Yen
Xanthohumol, a prenylated flavonoid found in hops (Humulus lupulus L.), exhibits multiple biological activities such as anti-atherosclerosis and hypolipidemic activities. In this study, we aim to investigate the hypocholesterolemic effects and molecular mechanisms of xanthohumol in hepatic cells. We found that xanthohumol (10 and 20 μM) increased the amount of cell-surface low-density lipoprotein receptor (LDLR) from 100.0 ± 2.1% to 115.0±1.3% and 135.2±2.7%, and enhanced the LDL uptake activity from 100...
August 16, 2017: Journal of Agricultural and Food Chemistry
Satomi Tanaka, Shinya Shiomi, Hayato Ishikawa
Isoprene units derived from dimethylallyl diphosphate (DMAPP) are an important motif in many natural products including terpenoids, carotenoids, steroids, and natural rubber. Understanding the chemical characteristics of DMAPP is an important topic in natural products chemistry, organic chemistry, and biochemistry. We have developed a direct bioinspired indole prenylation reaction using DMAPP or its equivalents as the electrophile in homogeneous aqueous acidic media in the absence of enzyme to provide prenylated indole products...
August 13, 2017: Journal of Natural Products
Viliam Brezáni, Karel Šmejkal, Jan Hošek, Veronika Tomášová
BACKGROUND: Natural phenolics are secondary plant metabolites, which can be divided into several categories with the common structural feature of phenolic hydroxyl. The biological activity of phenolics is often modified and enhanced by prenylation by prenyl and geranyl; higher terpenoid chains are rare. The type of prenyl connection and modification affects their biological activity. OBJECTIVE: This review summarizes information about prenylated phenols and some of their potential sources, and provides an overview of their anti-inflammatory potential in vitro and in vivo...
August 10, 2017: Current Medicinal Chemistry
Zora Vochyánová, Marie Pokorná, Dominik Rotrekl, Václav Smékal, Petr Fictum, Pavel Suchý, Jan Gajdziok, Karel Šmejkal, Jan Hošek
Morusin is a prenylated flavonoid isolated from the root bark of Morus alba. Many studies have shown the ability of flavonoids to act as anti-inflammatory agents. The aim of this study was to evaluate the effect of morusin on experimentally colitis induced by 2,4,6-trinitrobenzensulfonic acid in Wistar rats and to compare it with sulfasalazine, a drug conventionally used in the treatment of inflammatory bowel disease. Morusin was administered by gavage at doses of 12.5, 25, or 50 mg/kg/day for five days. The colonic tissue was evaluated macroscopically, histologically, and by performing immunodetection and zymographic analysis to determine the levels of antioxidant enzymes [superoxide dismutase (SOD) and catalase (CAT)], interleukin (IL)-1β, and transforming growth factor (TGF)-β1 and the activities of matrix metalloproteinases (MMP) 2 and 9...
2017: PloS One
Tiphaine Péresse, Nicolas Elie, David Touboul, Van Cuong Pham, Vincent Dumontet, Fanny Roussi, Marc Litaudon, Alain Brunelle
Using a time-of-flight secondary ion mass spectrometer equipped with an argon cluster ion for sputtering and a bismuth liquid metal ion source for analysis, both surfaces of leaves and fruits of Macaranga vedeliana, an endemic New Caledonian species have been for the first time analyzed by a dual beam depth profiling. To prevent in-vacuum evaporation of the liquid content of the small glandular trichomes covering fruits and leaves surfaces, and also to be able to analyze their liquid content while preventing any sublimation of the latter, the samples were kept frozen during the whole experiment using a nitrogen cooled sample holder...
August 6, 2017: Analytical Chemistry
Dionne Turnbull, Piers A Hemsley
The post-translational lipid modifications N-myristoylation, prenylation and S-acylation are traditionally associated with increasing protein membrane affinity and localisation. However this is an over-simplification, with evidence now implicating these modifications in a variety of roles such as membrane microdomain partitioning, protein trafficking, protein complex assembly and polarity maintenance. Evidence for a regulatory role is also emerging, with changes or manipulation of lipid modifications offering a means of directly controlling various aspects of protein function...
July 31, 2017: Current Opinion in Plant Biology
Marshall B Elam, Gipsy Majumdar, Khyobeni Mozhui, Ivan C Gerling, Santiago R Vera, Hannah Fish-Trotter, Robert W Williams, Richard D Childress, Rajendra Raghow
Statins, the 3-hydroxy-3-methyl-glutaryl (HMG)-CoA reductase inhibitors, are widely prescribed for treatment of hypercholesterolemia. Although statins are generally well tolerated, up to ten percent of statin-treated patients experience myalgia symptoms, defined as muscle pain without elevated creatinine phosphokinase (CPK) levels. Myalgia is the most frequent reason for discontinuation of statin therapy. The mechanisms underlying statin myalgia are not clearly understood. To elucidate changes in gene expression associated with statin myalgia, we compared profiles of gene expression in skeletal muscle biopsies from patients with statin myalgia who were undergoing statin re-challenge (cases) versus those of statin-tolerant controls...
2017: PloS One
Imaobong Christopher Etti, Rasedee Abdullah, Arifah Kadir, Najihah Mohd Hashim, Swee Keong Yeap, Mustapha Umar Imam, Faiqah Ramli, Ibrahim Malami, Kian Lim Lam, Ubong Etti, Peter Waziri, Marsitoh Rahman
Nature has provided us with a wide spectrum of disease healing phytochemicals like Artonin E, obtained from the root bark of Artocarpus elasticus. This molecule had been predicted to be drug-like, possessing unique medicinal properties. Despite strides made in chemotherapy, prognosis of the heterogenous aggressive triple negative breast cancer is still poor. This study was conducted to investigate the mechanism of inhibition of Artonin E, a prenylated flavonoid on MDA-MB 231 triple negative breast cancer cell, with a view of mitigating the hallmarks displayed by these tumors...
2017: PloS One
Liliana Mammino
Arzanol is a naturally-occurring prenylated acylphloroglucinol isolated from Helichrysum italicum and exhibiting anti-oxidant, antibiotic and antiviral activities. The molecule contains an α-pyrone moiety attached to the phloroglucinol moiety through a methylene bridge. The presence of several hydrogen bond donor or acceptor sites makes intramolecular hydrogen bonding patterns the dominant stabilising factor. Conformers with all the possible different hydrogen bonding patterns were calculated at the HF/6-31G(d,p) and DFT/B3LYP/6-31+G(d,p) levels with fully relaxed geometry in vacuo and in three solvents-chloroform, acetonitrile and water (these levels being chosen to enable comparisons with previous studies on acylphloroglucinols)...
August 3, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Satyajit D Sarker, Lutfun Nahar
Coumarins are the largest group of 1-benzopyran derivatives found in plants. The initial member of this group of compounds, coumarin (2H-1-benzopyran-2-one), a fragrant colorless compound, was first isolated from the Tonka bean (Dipteryx odorata, family Fabaceae) in 1820. The name coumarin comes from a French term for the tonka bean, coumarou. Since the discovery of coumarin, several of its derivatives, with umbelliferone (7-hydroxycoumarin) being the most common one, have been reported from various natural sources...
2017: Progress in the Chemistry of Organic Natural Products
Stephen A Marshall, Karl A P Payne, David Leys
The UbiX-UbiD system consists of the flavin prenyltransferase UbiX that produces prenylated FMN that serves as the cofactor for the (de)carboxylase UbiD. Recent developments have provided structural insights into the mechanism of both enzymes, detailing unusual chemistry in each case. The proposed reversible 1,3-dipolar cycloaddition between the cofactor and substrate serves as a model to explain many of the key UbiD family features. However, considerable variation exists in the many branches of the UbiD family tree...
July 25, 2017: Archives of Biochemistry and Biophysics
Tomasz Tronina, Paulina Strugała, Jarosław Popłoński, Aleksandra Włoch, Sandra Sordon, Agnieszka Bartmańska, Ewa Huszcza
The synthesis of different classes of prenylated aglycones (α,β-dihydroxanthohumol (2) and (Z)-6,4'-dihydroxy-4-methoxy-7-prenylaurone (3)) was performed in one step reactions from xanthohumol (1)-major prenylated chalcone naturally occurring in hops. Obtained flavonoids (2-3) and xanthohumol (1) were used as substrates for regioselective fungal glycosylation catalyzed by two Absidia species and Beauveria bassiana. As a result six glycosides (4-9) were formed, of which four glycosides (6-9) have not been published so far...
July 21, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Kyle L Ferguson, Joseph D Eschweiler, Brandon T Ruotolo, E Neil G Marsh
Ferulic acid decarboxylase catalyzes the decarboxylation of phenylacrylic acid using a newly identified cofactor, prenylated flavin mononucleotide (prFMN). The proposed mechanism involves the formation of a putative pentacyclic intermediate formed by a 1,3 dipolar cyclo-addition of prFMN with the α-β double bond of the substrate, which serves to activate the substrate toward decarboxylation. However, enzyme-catalyzed 1,3 dipolar cyclo-additions are unprecedented and other mechanisms are plausible. Here we describe the use of a mechanism-based inhibitor, 2-fluoro-2-nitrovinylbenzene, to trap the putative cyclo-addition intermediate, thereby demonstrating that prFMN can function as a dipole in a 1,3 dipolar cyclo-addition reaction as the initial step in a novel type of enzymatic reaction...
August 16, 2017: Journal of the American Chemical Society
Mario Mergelsberg, Max Willistein, Heike Meyer, Hans-Joachim Stärk, Dominique Bechtel, Antonio Pierik, Matthias Boll
The degradation of the industrially produced and environmentally relevant phthalate esters by microorganisms is initiated by the hydrolysis to alcohols and phthalate (1,2-dicarboxybenzene). In the absence of oxygen the further degradation of phthalate proceeds via activation to phthaloyl-CoA followed by decarboxylation to benzoyl-CoA. Here we report on the first purification and characterization of a phthaloyl-CoA decarboxylase (PCD) from the denitrifying Thauera chlorobenzoica. Hexameric PCD belongs to the UbiD-family of (de)carboxylases and contains prenylated FMN (prFMN), K(+) , and, unlike other UbiD-like enzymes, Fe(2+) as cofactors...
July 28, 2017: Environmental Microbiology
Elisa Nuti, Barbara Bassani, Caterina Camodeca, Lea Rosalia, AnnaRita Cantelmo, Cristina Gallo, Denisa Baci, Antonino Bruno, Elisabetta Orlandini, Susanna Nencetti, Douglas M Noonan, Adriana Albini, Armando Rossello
Angiogenesis induction is a hallmark of cancer. Antiangiogenic properties of Xanthohumol (XN), a naturally occurring prenylated chalcone from hops, have been widely reported. Here we describe the synthesis and study the antiangiogenic activity in vitro of a series of XN derivatives, where different substituents on the B-ring of the chalcone scaffold were inserted. The new XN derivatives inhibited human umbilical-vein endothelial cell (HUVEC) proliferation, adhesion, migration, invasion and their ability to form capillary-like structures in vitro at 10 μM concentration...
July 17, 2017: European Journal of Medicinal Chemistry
Miguel Estravís, Sergio Antonio Rincón, Elvira Portales, Pilar Pérez, Beatriz Santos
Rho GTPases control polarized cell growth and are well-known regulators of exocytic and endocytic processes. Cdc42 is an essential GTPase, conserved from yeast to humans, that is critical for cell polarization. Cdc42 is negatively regulated by the GTPase-activating proteins (GAPs) and the GDP dissociation inhibitors (GDIs), and positively regulated by guanine nucleotide exchange factors (GEFs). Cdc42 GTPase can be found in a GTP- or GDP-bound state, which determines the ability to bind downstream effector proteins and activate signalling pathways...
July 26, 2017: Microbiology
Wolf-Rainer Abraham
BACKGROUND: Fumitremorgins are mycotoxins but can also inhibit cancer cells and reverse their drug resistance. OBJECTIVE: The bioactivity of prenylated cyclo-Trp-Pro dipeptides and their derivatives concerning their application in anti-cancer therapies will be discussed. METHOD: Reports on the discovery and assessment of this class of fungal compounds are compiled from literature using Google Scholar and PubMed. The bioactivities of the natural compounds are discussed with the aim of their improvement for cancer therapy...
July 24, 2017: Current Medicinal Chemistry
Phillip M Danby, Stephen G Withers
Enzymatic prenyl and glycosyl transfer are seemingly unrelated reactions that yield molecules and protein modifications with disparate biological functions. However, both reactions employ diphosphate-activated donors and each proceed via cationic species: allylic cations and oxocarbenium ions, respectively. In this study, we explore the relationship between these processes by preparing valienyl ethers to serve as glycoside mimics that are capable of allylic rather than oxocarbenium cation stabilization. Rate constants for spontaneous hydrolysis of aryl glycosides and their analogous valienyl ethers were found to be almost identical, as were the corresponding activation enthalpies and entropies...
July 26, 2017: Journal of the American Chemical Society
Morad Zayoud, Victoria Marcu-Malina, Einav Vax, Jasmine Jacob-Hirsch, Galit Elad-Sfadia, Iris Barshack, Yoel Kloog, Itamar Goldstein
The Ras family of GTPases plays an important role in signaling nodes downstream to T cell receptor and CD28 activation, potentially lowering the threshold for T-cell receptor activation by autoantigens. Somatic mutation in NRAS or KRAS may cause a rare autoimmune disorder coupled with abnormal expansion of lymphocytes. T cells from rheumatoid arthritis (RA) patients show excessive activation of Ras/MEK/ERK pathway. The small molecule farnesylthiosalicylic acid (FTS) interferes with the interaction between Ras GTPases and their prenyl-binding chaperones to inhibit proper plasma membrane localization...
2017: Frontiers in Immunology
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