Aromatic Lactones Research Articles

Anionic alternating copolymerization of epoxide and six‐membered lactone bearing naphthyl moiety

AbstractThis article describes the anionic copolymerization of glycidyl phenyl ether (GPE) and 1,2‐dihydro‐3H‐naphtho[2,1‐b]pyran‐3‐one (DHNP), a six‐membered aromatic lactone bearing naphthyl moiety. The copolymerization proceeded in a 1:1 alternating manner, to afford the corresponding polyester. The ester linkage in the main chain was cleavable by reduction with lithium aluminum hydride to give the corresponding diol that inherited the structure of the alternating sequence. The copolymerization ability of DHNP permitted its addition as a comonomer to an imidazole‐initiated polymerization of bisphenol A diglycidyl ether. The resulting networked polymer, of which main chain was endowed with the DHNP‐derived rigid naphthalene moieties, showed a higher glass transition temperature than that obtained similarly with using 3,4‐dihydrocoumarin (DHCM) as a comonomer, an analogous aromatic lactone bearing phenylene moiety instead of naphthalene moiety of DHNP. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Structural elucidation and NMR assignments of four aromatic lactones from a mangrove endophytic fungus (No. GX4‐1B)

Two new aromatic lactones, 6-hydroxy-4-hydroxymethyl-8-methoxy-3- methylisocoumarin (1) and 1,10-dihydroxy-8-methyl-dibenz[b, e]oxepin-6,11-dione (2), together with two known compounds, 1,10-dihydroxy-dibenz[b, e]oxepin-6,11-dione (3) and 3-hydroxymethyl-6,8-dimethoxycoumarin (4), were isolated from a mangrove endophytic fungus (No. GX4-1B) collected from the South China Sea. Their structures were elucidated and the data of (1)H and (13)C NMR were assigned completely by HREIMS, 1D and 2D NMR experiments including HMQC, HMBC and NOESY.

Flavouring Group Evaluation 80, Revision 1 (FGE.80Rev1): Consideration of alicyclic, alicyclic‐fused and aromatic‐fused ring lactones evaluated by JECFA (61st meeting) structurally related to a aromatic lactone evaluated by EFSA in FGE.27 (2008)

EFSA JournalVolume 7, Issue 9 1169 OpinionOpen Access Flavouring Group Evaluation 80, Revision 1 (FGE.80Rev1): Consideration of alicyclic, alicyclic-fused and aromatic-fused ring lactones evaluated by JECFA (61st meeting) structurally related to a aromatic lactone evaluated by EFSA in FGE.27 (2008) EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids, EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing AidsSearch for more papers by this author EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids, EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing AidsSearch for more papers by this author First published: 09 September 2009 https://doi.org/10.2903/j.efsa.2009.1169 Panel members: Arturo Anadon, David Bell, Mona-Lise Binderup, Wilfried Bursch, Laurence Castle, Riccardo Crebelli, Karl-Heinz Engel, Roland Franz, Nathalie Gontard, Thomas Haertle, Trine Husøy, Klaus-Dieter Jany, Catherine Leclercq, Jean Claude Lhuguenot, Wim Mennes, Maria Rosaria Milana, Karla Pfaff, Kettil Svensson, Fidel Toldra, Rosemary Waring, Detlef Wölfle Adoption date: 17 June 2009 Published date: 9 September 2009 Question number: EFSA-Q-2009-00559 AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume7, Issue9September 20091169 ReferencesRelatedInformation

Leishmanicidal Activity of Aliphatic and Aromatic Lactones: Correlation Structure-Activity

Several aliphatic and aromatic lactones and two dimers were synthesized using the sequence: allylation - esterification - metathesis. These compounds were active in vitro against intracellular amastigotes of Leishmania panamensis. The structure-activity relationship showed the importance of the aliphatic side chain to enhance the biological activity and to obtain lower cytotoxicity. It was also observed that a decrease in the size of the lactone ring increases the selectivity index.

Cationic ring‐opening polymerization of 3‐isochromanone through formation of benzyl cationic intermediate and its Friedel‐Crafts reaction

3-Isochromanone (ICM), an aromatic lactone, underwent cationic ring opening polymerization to give a poly(phenylene-methylene) having a carboxyl acid moiety in the side chain. The polymerization of ICM proceeded through the formation of benzyl cationic intermediate and its successive Friedel-Crafts reaction. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

Flavouring Group Evaluation 80 (FGE.80) - Consideration of alicyclic, alicyclic-fused and aromatic-fused ring lactones evaluated by JECFA (61st meeting) structurally related to a aromatic lactone evaluated by EFSA in FGE.27 (2008) - Opinion of the Scienti

Flavouring Group Evaluation 80 (FGE.80) - Consideration of alicyclic, alicyclic-fused and aromatic-fused ring lactones evaluated by JECFA (61st meeting) structurally related to a aromatic lactone evaluated by EFSA in FGE.27 (2008) - Opinion of the Scienti

Flavouring Group Evaluation 27 (FGE.27): One aromatic lactone from chemical group 11 - Scientific Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food

Flavouring Group Evaluation 27 (FGE.27): One aromatic lactone from chemical group 11 - Scientific Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food

Anionic copolymerization of epoxide with bifunctional aromatic lactone derived from 2‐methylresorcinol

A bifunctional six-membered aromatic lactone, which was derived from 2-methylresorcinol by its double cycloadditions with acrylic acid, was applied as a comonomer to imidazole-catalyzed curing reactions of bifunctional epoxides. The lactone moiety and the epoxide underwent copolymerization efficiently to give the corresponding networked polymers with achieving high glass transition temperatures and small curing shrinkage values. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

Anionic Alternating Copolymerizability of Epoxide and 3,4-Dihydrocoumarin by Imidazole

This paper describes the alternating character in the copolymerization of glycidyl phenyl ether (GPE) and 3,4-dihydrocoumarin (DHCM) by 2-ethyl-4-methylimidazole (EMI) as an initiator. DHCM, which is an aromatic lactone that does not undergo its homopolymerization under anionic conditions, underwent the copolymerization with GPE by EMI. In the present copolymerization, formation of the GPE−DHCM alternating sequence and that of the GPE−GPE sequence competed, and the former was always the predominant one. The maximum content of the alternating sequence (90%) was achieved when the feed ratio GPE/DHCM was 1. The obtained copolymer was a polyester, for which the ester linkage was cleavable by reduction with lithium aluminum hydride. The resulting compound inherited the structure of the alternating sequence, and its high yield (90%) supported the high alternating character of the copolymerization.

Fast and Efficient Synthesis of 10‐Aryl‐2,7‐dimethyl‐4,5‐dioxo‐3,6,9‐trioxa‐3,4,5,6,9,10‐hexahydroanthracene under Microwave Irradiation without Catalyst

A fast and efficient synthetic method for the title compounds is described. By heating aromatic aldehyde and triacetic acid lactone in ethylene glycol under microwave irradiation without catalyst for 3–5 min, 10‐aryl‐2,7‐dimethyl‐4,5‐dioxo‐3,6,9‐trioxa‐3,4,5,6,9,10‐hexahydroanthracenes were afforded with high yields.

Access to a New Family of Medium Ring Aromatic Lactones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Access to a new family of medium ring aromatic lactones

We report a new method for preparation of hydroxyacids as precursors of benzolactones using a simple and an efficient electrochemical step. This gives in only four steps six- to eleven-membered lactones with high isolated yields from conveniently substituted aryl bromides. The lactonisation was performed according to the Yamamoto's process.

Synthesis of Precursors for Medium‐Ring Aromatic Lactones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Human paraoxonases (PON1, PON2, and PON3) are lactonases with overlapping and distinct substrate specificities

The paraoxonase (PON) gene family in humans has three members, PON1, PON2, and PON3. Their physiological role(s) and natural substrates are uncertain. We developed a baculovirus-mediated expression system, suitable for all three human PONs, and optimized procedures for their purification. The recombinant PONs are glycosylated with high-mannose-type sugars, which are important for protein stability but are not essential for their enzymatic activities. Enzymatic characterization of the purified PONs has revealed them to be lactonases/lactonizing enzymes, with some overlapping substrates (e.g., aromatic lactones), but also to have distinctive substrate specificities. All three PONs metabolized very efficiently 5-hydroxy-eicosatetraenoic acid 1,5-lactone and 4-hydroxy-docosahexaenoic acid, which are products of both enzymatic and nonenzymatic oxidation of arachidonic acid and docosahexaenoic acid, respectively, and may represent the PONs' endogenous substrates. Organophosphates are hydrolyzed almost exclusively by PON1, whereas bulky drug substrates such as lovastatin and spironolactone are hydrolyzed only by PON3. Of special interest is the ability of the human PONs, especially PON2, to hydrolyze and thereby inactivate N-acyl-homoserine lactones, which are quorum-sensing signals of pathogenic bacteria. None of the recombinant PONs protected low density lipoprotein against copper-induced oxidation in vitro.

Synthesis of Precursors for Medium-Ring Aromatic Lactones

Hydroxyacids have been prepared via the nickel-cata­lysed electrochemical arylation of ethyl acrylate from an ortho-substituted aryl bromide. Protection and deprotection steps have been selected in terms of suitability and efficiency. The lactonisation was performed according to an already reported method. Two-dimensional NMR analysis has been used to ascertain the structure of the lactones formed.

Synthesis of New Medium Ring Aromatic Lactones via Halocyclization of 2‐Hydroxyphenylalkanoic Acid Allylic Esters.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Inhibitors of Sir2: evaluation of splitomicin analogues.

Splitomicin (1) and 41 analogues were prepared and evaluated in cell-based Sir2 inhibition and toxicity assays and an in vitro Sir2 inhibition assay. Lactone ring or naphthalene (positions 7-9) substituents decrease activity, but other naphthalene substitutions (positions 5 and 6) are well-tolerated. The hydrolytically unstable aromatic lactone is important for activity. Lactone hydrolysis rates were used as a measure of reactivity; hydrolysis rates correlate with inhibitory activity. The most potent Sir2 inhibitors were structurally similar to and had hydrolysis rates similar to 1.

Synthesis of New Medium Ring Aromatic Lactones via Halocyclization of 2-Hydroxyphenylalkanoic Acid Allylic Esters

Stable medium size ring aromatic lactones have been synthesized through electrophilic heteroatom cyclization reactions in moderate yields.

A New Entry for the Preparation of Substituted Aromatic Carbonyl Compounds Mediated by Samarium(II) Iodide.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A New Entry for the Preparation of Substituted Aromatic Carbonyl Compounds Mediated by Samarium(II) Iodide

A new route to substituted aromatic lactones and lactams via SmI2-promoted desulfurization is described. Direct replacement of the phenylthio substituent by hydroxyalkylated groups featuring the novel accessible process for the construction of continuous quaternary carbon centers could be accomplished when the same type of reactions was undertaken with carbonyl compounds in the presence of SmI2.