- Catechol-Functionalized Polyolefins
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The incorporation of comonomers during ethylene polymerization can efficiently modulate important material properties of the polyolefins. Utilizing bioresourced comonomers for the generation of high-performance polyolefin materials is attractive from a sustainability point of view. In this contribution, bioresourced eugenol and related comonomers were incorporated into polyolefins through palladium-catalyzed copolymerization and terpolymerization reactions. Importantly, high-molecular-weight catechol-functionalized polyolefins can be generated. The introduction of different metal ions induces efficient interactions with the incorporated catechol groups, leading to enhanced mechanical properties and self-healing properties. Moreover, the catechol functionality can greatly improve other properties such as surface properties, adhesion properties, and compatibilizing properties. The catechol-functionalized polyolefin was demonstrated as a versatile platform polymer for accessing various materials with dramatically different properties.
- Chen, Changle,Na, Yinna
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- Thiol-ene adhesives from clove oil derivatives
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This paper reports the synthesis of catechol-functionalized thiol-ene polymer networks as photocurable adhesives, where the adhesive interactions are derived from 4-allylpyrocatechol - a monofunctional alkene readily obtained from natural products of Syzygium aromaticum flower buds (clove). The thiol-ene photopolymerization process enables rapid cure times, low energy input, and solvent-free processing. The resulting polymer networks show improved macroscopic adhesion to a variety of substrates - including glass, marble, aluminum, and steel - by varying the concentration of 4-allylpyrocatechol in the network. Additionally, the effects of the catechol moiety on polymerization kinetics, thermomechanical, and mechanical properties were determined by comparing the synthesized catechol moiety to a series of control monomers such as eugenol (one phenol group) and methyl eugenol (no phenol groups).
- Donovan, Brian R.,Cobb, Jared S.,Hoff, Ethan F. T.,Patton, Derek L.
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- Utilization of catecholic functionality in natural safrole and eugenol to synthesize mussel-inspired polymers
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Naturally occurring safrole I upon epoxidation gave safrole oxide II, which underwent ring opening polymerization using a Lewis acid initiator/catalyst comprising of triphenylmethylphosphonium bromide/triisobutylaluminum to afford new polyether III in excellent yields. Epoxy monomer II and allyl glycidyl ether IV in various proportions have been randomly copolymerized to obtain copolymer V. A mechanism has been proposed for the polymerization reaction involving chain transfer to the monomers. A strategy has been developed for the deprotection of the methylene acetal of V using Pb(OAc)4 whereby one of the methylene protons is replaced with a labile OAc group to give VI. The pendant allyl groups in VI have been elaborated via a thiol-ene reaction using cysteamine hydrochloride and thioglycolic acid to obtain cationic VII and anionic VIII polymers, both containing a mussel-inspired Dopa-based catechol moiety. During aqueous work up, the protecting group containing OAc was deprotected under mild conditions. Cationic VII and anionic VIII were also obtained via an alternate route using epoxide IX derived from 3,4-bis[tert-butyldimethylsilyloxy]allylbenzene. Monomer IX was homo- as well as copolymerized with IV using Lewis acid initiator/catalyst system to obtain homopolymer X and copolymer X1. Copolymer XI was then elaborated using a thiol-ene reaction followed by F- catalysed silyl deprotection to obtain mussel inspired polymers VII and VIII, which by virtue of having charges of opposite algebraic signs were used to form their coacervate.
- Alhaffar, Mouheddin T.,Akhtar, Mohammad N.,Ali, Shaikh A.
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- Pyridine Improves Aluminum Triiodide Induced Selective Cleavage of Alkyl o -Hydroxyphenyl Ethers: A Practical and Efficient Procedure for the Preparation of Hydroxychavicol by Demethylation of Eugenol
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Demethylation of eugenol with aluminum triiodide is complicated by an unexpected hydrogenation side reaction. The hydrogenation proceeds through a cascade deprotonation, hydroiodination, and hydrogen-halogen exchange process, and can be prevented by suppressing the hydroiodination in advance. A practical demethylation procedure is thus developed that delivers hydryoxychavicol in essentially quantitative yield by using pyridine as an additive. The method is selective towards cleaving alkyl o-hydroxyphenyl ethers and is compatible with a variety of functional groups.
- Sang, Dayong,Yao, Ming,Tian, Juan,Chen, Xiaoman,Li, Li,Zhan, Hongju,You, Linhong
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- Expeditious synthesis of bioactive allylphenol constituents of the genus Piper through a metal-free photoallylation procedure
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Nine bioactive allylphenol (anisole) derivatives (e.g. eugenol, safrole and asaricin) present in several plants of the genus Piper have been synthesized in medium to high yield via aryl cation intermediates. This expeditious metal-free procedure involves the irradiation of the corresponding chlorophenols or chloroanisoles in a polar solvent (MeCN or, better, TFE or aqueous acetonitrile) in the presence of allyltrimethylsilane. Estragole has also been synthesized starting from the corresponding fluoroderivative and diazonium salt, though in a lower yield. The Royal Society of Chemistry 2005.
- Protti, Stefano,Fagnoni, Maurizio,Albini, Angelo
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- Allyl/propenyl phenol synthases from the creosote bush and engineering production of specialty/commodity chemicals, eugenol/isoeugenol, in Escherichia coli
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The creosote bush (Larrea tridentata) harbors members of the monolignol acyltransferase, allylphenol synthase, and propenylphenol synthase gene families, whose products together are able to catalyze distinct regiospecific conversions of various monolignols into their corresponding allyl- and propenyl-phenols, respectively. In this study, co-expression of a monolignol acyltransferase with either substrate versatile allylphenol or propenylphenol synthases in Escherichia coli established that various monolignol substrates were efficiently converted into their corresponding allyl/propenyl phenols, as well as providing proof of concept for efficacious conversion in a bacterial platform. This capability thus potentially provides an alternate source to these important plant phytochemicals, whether for flavor/fragrance and fine chemicals, or ultimately as commodities, e.g.; for renewable energy or other intermediate chemical purposes. Previous reports had indicated that specific and highly conserved amino acid residues 84 (Phe or Val) and 87 (Ile or Tyr) of two highly homologous allyl/propenyl phenol synthases (circa 96% identity) from a Clarkia species mainly dictate their distinct regiospecific catalyzed conversions to afford either allyl- or propenyl-phenols, respectively. However, several other allyl/propenyl phenol synthase homologs isolated by us have established that the two corresponding amino acid 84 and 87 residues are not, in fact, conserved.
- Kim, Sung-Jin,Vassao, Daniel G.,Moinuddin, Syed G.A.,Bedgar, Diana L.,Davin, Laurence B.,Lewis, Norman G.
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- Chemical analysis and in vitro bioactivity of essential oil of laurelia sempervirens and safrole derivatives against oomycete fish pathogens
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In this study, the essential oil (EO) from Laurelia sempervirens was analyzed by GC/MS and safrole (1) was identified as the major metabolite 1, was subjected to direct reactions on the oxygenated groups in the aromatic ring and in the side chain, and eight compounds (4 to 12) were obtained by the process. EO and compounds 4–12 were subjected to biological assays on 24 strains of the genus Saprolegnia, specifically of the species 12 S. parasitica and 12 S. australis. EO showed a significant effect against Saprolegnia strains. Compound 6 presents the highest activity against two resistant strains, with minimum inhibitory concentration (MIC) and minimum oomyceticidal concentration (MOC) values of 25 to 100 and 75 to 125 μg/mL, respectively. The results show that compound 6 exhibited superior activities compared to the commercial controls bronopol and azoxystrobin used to combat these pathogens.
- Caro, Nelson,Cuellar, Mauricio A.,Godoy, Patricio,Madrid, Alejandro,Melo, Mirna,Montenegro, Iván,Morales, Ana Lizeth,Saffirio, Valentina,Said, Bastián,Werner, Enrique
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- Anchimerically Assisted Selective Cleavage of Acid-Labile Aryl Alkyl Ethers by Aluminum Triiodide and N, N-Dimethylformamide Dimethyl Acetal
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Aluminum triiodide is harnessed by N,N-dimethylformamide dimethyl acetal (DMF-DMA) for the selective cleavage of ethers via neighboring group participation. Various acid-labile functional groups, including carboxylate, allyl, tert-butyldimethylsilyl (TBS), and tert-butoxycarbonyl (Boc), suffer the conditions intact. The method offers an efficient approach to cleaving catechol monoalkyl ethers and to uncovering phenols from acetal-type protecting groups such as methoxymethyl (MOM), methoxyethoxymethyl (MEM), and tetrahydropyranyl (THP) chemoselectively.
- Sang, Dayong,Yue, Huaxin,Zhao, Zhengdong,Yang, Pengtao,Tian, Juan
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p. 6429 - 6440
(2020/07/14)
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- PROCESS FOR THE PREPARATION AND IDENTIFICATION OF DEUTERATED EUGENOL
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The present invention provides a novel, simple, unique and viable processes for the synthesis of deuterium incorporated eugenols, such as deuterated eugenol (II), regioisomeric deuterated eugenol (III), and deuterated variant of methyl eugenol (V).
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Page/Page column 14-15
(2021/01/22)
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- Selective ether bond breaking method of aryl alkyl ether
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The invention discloses a selective aryl alkyl ether cracking method, which comprises that aryl alkyl ether, aluminum iodide and an additive are subjected to a selective ether bond cleavage reaction in an organic solvent at a temperature of -20 DEG C to a reflux temperature to generate phenol and derivatives thereof. The method is mild in condition and simple and convenient to operate, is suitablefor cracking aryl alkyl ether containing o-hydroxyl and o-carbonyl and acetal ether, and can also be used for removing tertiary carbon hydroxyl protecting groups with higher steric hindrance, such astriphenylmethyl, tertiary butyl and the like.
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Paragraph 0024-0028; 0035-0040
(2020/09/16)
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- Structure–Activity Relationship of Anti-malarial Allylpyrocatechol Isolated from Piper betle
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Malaria disease remains a serious worldwide health problem. In South-East Asia, one of the malaria infection “hot-spots,” medicinal plants such as Piper betle have traditionally been used for the treatment of malaria, and allylpyrocatechol (1), a constituent of P. betle, has been shown to exhibit anti-malarial activities. In this study, we verified that 1 showed in vivo anti-malarial activity through not only intraperitoneal (i.p.) but also peroral (p.o.) administration. Additionally, some analogs of 1 were synthesized and the structure–activity relationship was analyzed to disclose the crucial sub-structures for the potent activity.
- Horii, Toshihiro,Itagaki, Sawako,Kawano, Tomikazu,Miyoshi, Akihito,Murakami, Nobutoshi,Tamura, Satoru
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p. 784 - 790
(2020/09/18)
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- Cleavage of Catechol Monoalkyl Ethers by Aluminum Triiodide-Dimethyl Sulfoxide
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Using eugenol and vanillin as model substrates, a practical method is developed for the cleavage o -hydroxyphenyl alkyl ethers. Aluminum oxide iodide (O=AlI), generated in situ from aluminum triiodide and dimethyl sulfoxide, is the reactive ether cleaving species. The method is applicable to catechol monoalkyl ethers as well as normal phenyl alkyl ethers for the removal of methyl, ethyl, isopropyl, and benzyl groups. A variety of functional groups such as alkenyl, allyl, amide, cyano, formyl, keto, nitro, and halogen are well tolerated under the optimum conditions. Partial hydrodebromination was observed during the demethylation of 4-bromoguaiacol, and was resolved using excess DMSO as an acid scavenger. This convenient and efficient procedure would be a practical tool for the preparation of catechols.
- Sang, Dayong,Tian, Juan,Tu, Xiaodong,He, Zhoujun,Yao, Ming
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p. 704 - 712
(2019/01/23)
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- Hybridization of β-Adrenergic Agonists and Antagonists Confers G Protein Bias
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Starting from the β-adrenoceptor agonist isoprenaline and beta-blocker carvedilol, we designed and synthesized three different chemotypes of agonist/antagonist hybrids. Investigations of ligand-mediated receptor activation using bioluminescence resonance energy transfer biosensors revealed a predominant effect of the aromatic head group on the intrinsic activity of our ligands, as ligands with a carvedilol head group were devoid of agonistic activity. Ligands composed of a catechol head group and an antagonist-like oxypropylene spacer possess significant intrinsic activity for the activation of Gαs, while they only show weak or even no β-arrestin-2 recruitment at both β1- and β2-AR. Molecular dynamics simulations suggest that the difference in G protein efficacy and β-arrestin recruitment of the hybrid (S)-22, the full agonist epinephrine, and the β2-selective, G protein-biased partial agonist salmeterol depends on specific hydrogen bonding between Ser5.46 and Asn6.55, and the aromatic head group of the ligands.
- Stanek, Markus,Picard, Louis-Philippe,Schmidt, Maximilian F.,Kaindl, Jonas M.,Hübner, Harald,Bouvier, Michel,Weikert, Dorothée,Gmeiner, Peter
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p. 5111 - 5131
(2019/05/28)
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- Structure–activity relationships and docking studies of hydroxychavicol and its analogs as xanthine oxidase inhibitors
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Hydroxychavicol (HC), which is obtained from the leaves of Piper betle LINN. (Piperaceae), inhibits xanthine oxidase (XO) with an IC50 value of 16.7μM, making it more potent than the clinically used allopurinol (IC50=30.7μM). Herein, a structure–activity relationship analysis of the polar part analogs of HC was conducted and an inhibitor was discovered with a potency 13 times that of HC. Kinetic studies have revealed that HC and its active analog inhibit XO in an uncompetitive manner. The binding structure prediction of these inhibitor molecules to the XO complex with xanthine suggested that both compounds (HC and its analog) could simultaneously form hydrogen bonds with xanthine and XO.
- Nishiwaki, Keiji,Ohigashi, Kanae,Deguchi, Takahiro,Murata, Kazuya,Nakamura, Shinya,Matsuda, Hideaki,Nakanishi, Isao
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p. 741 - 747
(2018/07/05)
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- Ether bond dissociation method of phenylalkyl ether
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The invention discloses an ether bond dissociation method of phenylalkyl ether. The ether bond dissociation method of phenylalkyl ether includes the following steps that in organic solvent, in the presence of aluminium trihalogen, metal iodide and acid scavenging agents, phenylalkyl ether is subjected to an ether bond dissociation reaction at -20 DEG C to reflux temperature to generate phenol andderivatives thereof. The ether bond dissociation method of phenylalkyl ether is mild in condition, convenient to operate, high in yield and wide in phenylalkyl ether applicable range.
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Paragraph 0027-0069
(2018/09/29)
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- Ether bond cracking method of phenylalkyl ether
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The invention discloses an ether bond cracking method of phenylalkyl ether. The method comprises the following steps: performing ether bond breaking reaction on phenylalkyl ether at -20 to reflux temperature in the presence of aluminium triiodide and dimethyl sulfoxide, thereby generating phenol and derivatives thereof. The method disclosed by the invention is mild in condition, simple and convenient for operation, high in yield, and extensive in applicable phenylalkyl ether range.
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Paragraph 0027-0029; 0033
(2018/11/26)
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- Ether bond rupturing method for ortho-hydroxyl phenyl alkyl ether
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The invention discloses an ether bond rupturing method for ortho-hydroxyl phenyl alkyl ether. The method comprises the following steps that in a solvent, an ether bond rupturing reaction occurs to ortho-hydroxyl aryl alky ether at the temperature ranging from minus 20 DEG C to the catalyst reflux temperature under the existence of alkali and a catalyst aluminum triiodide, and catechol and derivatives thereof are generated. The method is simple, reaction conditions are simple, and operation is easy; besides, the yield is high, and the applicable ortho-hydroxyl phenyl alkyl ether range is wide.
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Paragraph 0030-0040
(2017/05/27)
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- Carbodiimides as Acid Scavengers in Aluminum Triiodide Induced Cleavage of Alkyl Aryl Ethers
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A practical procedure for the cleavage of alkyl aryl ethers containing labile functional groups has been developed using aluminum triiodide as the ether cleaving reagent. Carbodiimides, typically used as dehydration reagents for the coupling of amines and carboxylic acids to yield amide bonds, are found to be effective hydrogen iodide scavengers that prevent acid-labile groups from deterioration. The method is applicable to variant alkyl aryl ethers such as eugenol, vanillin, ortho -vanillin and methyl eugenol. Suitable substrates are not limited to alkyl o -hydroxyphenyl ethers.
- Sang, Dayong,Wang, Jiahui,Zheng, Yun,He, Jianyuan,Yuan, Caili,An, Qing,Tian, Juan
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p. 2721 - 2726
(2017/06/13)
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- Ether bond breakage method for phenylalkyl ethers
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The invention discloses an ether bond breakage method for phenylalkyl ethers. The method comprises the step: subjecting the phenylalkyl ethers to an ether bond breakage reaction at the temperature of -20 DEG C to reflux temperature in an organic solvent in the presence of aluminum triiodide and carbodiimide, so as to produce phenols and derivatives thereof. The method is moderate in conditions, simple and convenient in operation, high in yield and wide in applicable phenylalkyl ether range.
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Paragraph 0048; 0050-0051
(2017/07/19)
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- A phenyl alkyl ether ether linkage breaking method (by machine translation)
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The invention discloses a phenyl alkyl ether ether linkage breaking method, the method is: in the organic solvent, in the presence of a mineral acid and the aluminium triiodide scavenging agent under the conditions of, phenyl ether in the - 20 °C to reflux temperature lower ether linkage breaking reaction, generating phenol and its derivatives. The mild conditions, the operation is simple, and the yield is high, the applicable phenyl ether range is wide. (by machine translation)
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Paragraph 0030-0032; 0035-0043
(2018/04/01)
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- Synthesis and evaluation of antiproliferative activity of a novel series of hydroxychavicol analogs
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We have recently demonstrated that hydroxychavicol is a major constituent and the most active biophenolic of Piper betel leaves with significant antiproliferative activity in the micro molar range. Herein we present the design, synthesis and evaluation of fifteen novel hydroxychavicol analogs with varying antiproliferative activities in cancer cell lines from two representative tissue types, namely, the prostate and cervix that show very encouraging results compared to the parent compounds. Our long range goal is to develop a structure-activity guided relationship to gain mechanistic insights into novel molecular targets of this class of bioactive molecules for rational drug development. Cytotoxicity-guided experimentation on these novel analogs yielded the following structural factors as the key activity regulators: 1) unlike the hydroxyl substituent at position-4, the position-3 hydroxyl is vital for enhanced activity 2) acetoxyl groups are dispensable for activity as corroborated earlier by others 3) allylic double bonds at 2′C-3′C serve to positively influence antiproliferative activity 4) long saturated side chains at 1′-position negatively regulate antiproliferative activity and 5) maneuvering position-4 with a benzyl group positively impacted the biological activity profile. Most amphiphilic compounds showed moderate to good therapeutic potential as expected on the basis of medicinal chemistry principles. Intriguingly, the most active compound with ten-fold higher activity than the parent molecule was realized by sheer serendipity to employ a silica gel based rearrangement that was further explored using nuclear magnetic resonance spectroscopy and density functional theory calculations. This is the first report to describe strategies for optimal synthesis of a novel series of 15 analogs based upon hydroxychavicol, a simple phytochemical of immense anticancer potential.
- Yadav, Yogesh,Owens, Eric A.,Sharma, Vibhuti,Aneja, Ritu,Henary, Maged
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- SUBSTITUTED CATHECHOLS AS INHIBITORS OF IL-4 AND IL-5 FOR THE TREATMENT BRONCHIAL ASTHMA
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The present invention relates to compounds of general formula 1 for the treatment of bronchial asthma by inhibition of IL-4 or IL-5 pathway inhibition. The present invention also relates to the use of compound of general formula 1 for the treatment of bronchial by inhibition of IL-4 or IL-5 pathway. The present invention also relates to the method of treating asthma by inhibition of IL-4 or IL-5 pathway by administration of compound or said composition through oral, intranasal, route or by inhalation to a mammal in need thereof. Compound of general formula 1 may be used for reducing perivascular and peribronchial inflammation.
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Paragraph 3.2
(2014/05/20)
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- Biomimetic synthesis of santalin a,b and santarubin a,b, the major colorants of red sandalwood
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Better late than never! Almost 200 years after Pelletier's pioneering studies on the chemical constituents of red sandalwood, the major santalins and santarubins have been synthesized. This efficient approach integrates a Knochel isoflavonoid synthesis with Friedel-Crafts allylations or olefin metatheses, and a final biomimetic reaction cascade that furnishes the venerable benzoxanthenone dyes in a single operation (see scheme). Copyright
- Strych, Sebastian,Trauner, Dirk
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supporting information
p. 9509 - 9512
(2013/09/23)
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- New catechol derivatives of safrole and their antiproliferative activity towards breast cancer cells
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Catechols were synthesized from safrole. Nine derivatives were prepared and assessed for antiproliferative effects using different human cell lines. The in vitro growth inhibition assay was based on the sulphorhodamine dye to quantify cell viability. The derivatives 4-allylbenzene-1,2-diol (3), 4 4-[3-(acetyloxy)propyl]-1,2-phenylene diacetate (6) and 4-[3-(acetyloxy)propyl]- 5-nitro-1,2-phenylene diacetate (10) showed higher cytotoxicity than the parent compound 2 in tests performed on two breast cancer cell lines (MCF-7 and MDA-MB-231). The IC50 values of 40.2 ± 6.9 μM, 5.9 ± 0.8 μM and 33.8 ± 4.9 μM, respectively, were obtained without toxicity towards dermal human fibroblast (DHF cells).
- Villegas, Alejandro Madrid,Catalan, Luis Espinoza,Venegas, Ivan Montenegro,Garcia, Joan Villena,Altamirano, Hector Carrasco
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experimental part
p. 4632 - 4641
(2011/08/06)
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- Identification and initial SAR of silybin: An Hsp90 inhibitor
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Through Hsp90-dependent firefly luciferase refolding and Hsp90-dependent heme-regulated eIF2α kinase (HRI) activation assays, silybin was identified as a novel Hsp90 inhibitor. Subsequently, a library of silybin analogues was designed, synthesized and evaluated. Initial SAR studies identified the essential, non-essential and detrimental functionalities on silybin that contribute to Hsp90 inhibition.
- Zhao, Huiping,Brandt, Gary E.,Galam, Lakshmi,Matts, Robert L.,Blagg, Brian S.J.
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scheme or table
p. 2659 - 2664
(2011/06/22)
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- Hypervalent iodine-mediated oxygenative phenol dearomatization reactions
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Both λ3- and λ5-iodanes have proven to be useful reagents in the oxygenative dearomatization of phenols, and exploitations of their chemistry in the conception of both substrate- and reagent-controlled asymmetric variants of such a transformation of great value for natural product synthesis have shown evident signs of success. Moreover, the use of stabilized IBX (i.e., SIBX) in our methodology for O-demethylation of 2-methoxyphenols, which relies on the same key oxygenating dearomatization event, is reported here to be much more efficacious than that of IBX itself in the chemoselective one-step conversion of homovanillyl alcohol into hydroxytyrosol, and bergenin into norbergenin.
- Pouységu, Laurent,Sylla, Tahiri,Garnier, Tony,Rojas, Luis B.,Charris, Jaime,Deffieux, Denis,Quideau, Stéphane
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experimental part
p. 5908 - 5917
(2010/09/09)
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- INHIBITORS OF PHOSPHATIDYLINOSITOL-3-KINASE (PI3) AND INDUCERS OF NITRIC OXIDE (NO)
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The present invention relates to compounds of general formula 1 for the treatment of malignancy by inhibition of PI3-Akt pathway and or induction of NO. The present invention also relates to the use of compound of general formula 1 for the treatment of malignancy by inhibition of PI3-Akt pathway and or induction of NO. The present invention further relates to a method of treating malignancy by inhibition of PI3-Akt pathway and or induction of NO by administration of compound or said composition to a mammal in need thereof.
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Page/Page column 20-21
(2010/08/04)
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- Total synthesis of cimiracemate B and analogs
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The synthesis of the biologically active cimiracemate B and some analogs is described. The key step of the synthesis is a coupling between a bromoketone and a cinnamic acid derivative.
- Fache, Fabienne,Suzan, Nicolas,Piva, Olivier
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p. 5261 - 5266
(2007/10/03)
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- A stabilized formulation of IBX (SIBX) for safe oxidation reactions including a new oxidative demethylation of phenolic methyl aryl ethers
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(Matrix presented) SIBX is a nonexplosive formulation of IBX that can be used as a suspension in a variety of standard organic solvents such as refluxing EtOAc and THF to oxidize safely alcohols into aldehydes and ketones. The use of hot THF is limited to the oxidation of allylic and benzylic alcohols. Most yields are comparable to those obtained with IBX or DMP. SIBX can also be used to perform oxygenative demethylation of 2-methoxyarenols into orthoquinones and catechols.
- Ozanne, Aurelie,Pouysegu, Laurent,Depernet, Dominique,Francois, Bruno,Quideau, Stephane
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p. 2903 - 2906
(2007/10/03)
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- Conception, characterization and correlation of new marine odorants
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Via a synthetic sequence consisting of PPA-mediated Friedel-Crafts acylation of veratrol (8), Clemmensen reduction, demethylation with TMSI, Williamson ether synthesis employing 3-chloro-2-(chloromethyl)prop-1-ene and in-situ ruthenium tetroxide oxidation, numerous substituted benzo[b][1,4]dioxepinones 15-27 and 2,3-dihydro-1H-5,9-di-oxacyclohepta[f]indenones 7, 13 and 14 were prepared to study their odor-structure correlation. In the course of these studies, we discovered the extremely powerful new marine odorant 7-(3′ -methylbutyl)benzo[b][1,4]dioxepin-3-one (16). On the basis of the measured odor threshold data, an olfactophore model was constructed that rationalizes the observed odor intensities, and indicates an aliphatic hydrophobe at a distance of 6.3 A from the centre of the aromatic-ring binding site. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Kraft, Philip,Eichenberger, Walter
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p. 3735 - 3743
(2007/10/03)
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- Substrate selective catalysis by rhodium metallohosts
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A novel supramolecular catalyst functioning according to the principles of enzymatic catalysis is described. It consists of a basket-shaped molecule to which a catalytically active Rh(I) complex is attached. The catalyst selectively hydrogenates and isomerizes allyl-substituted dihydroxyarene substrates that are bound in its cavity. The reactivity of this supramolecular catalyst and its affinity for several substrates is compared with that of the corresponding catalyst without a binding site. Features known from enzymatic catalysis, e.g. Michaelis-Menten kinetics and rate enhancement by cooperative binding, are described and discussed.
- Coolen, Hein K. A. C.,Meeuwis, Johannes A. M.,Van Leeuwen, Piet W. N. M.,Nolte, Roeland J. M.
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p. 11906 - 11913
(2007/10/03)
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- Chavicol and Related Compounds as Nematocides
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In a search for nematocidal compounds from wild plant sources, chavicol and demethyleugenol were found from V. furcatum, and 4-vinylphenol was found from three Rosaceae species.These three compounds each contained both p-hydroxyphenyl and exo-methylene moieties, and several related compounds were prepared and tested for nematocidal activity.The results show that the hydroxyphenyl group was essential for the activity, while the aliphatic substituents on the benzene ring enhanced it.The strongest activity was found with 4-propenylphenol.
- Yoshizawa, Yuko,Kawaii, Satoru,Kanauchi, Masatoshi,Chida, Manami,Mizutani, Junya
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p. 1572 - 1574
(2007/10/02)
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- A CONVENIENT ALLYLATION OF ORTHO-QUINONES. AN EXTENSION ON THE UTILITY OF ALLYLTIN REAGENTS
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Lewis acid catalyzed allylation of 1,2-naphthoquinones and o-benzoquinones with allyltributyltins gave monoallylation products in reasonable to high yields.
- Maruyama, Kazuhiro,Takuwa, Akio,Naruta, Yoshinori,Satao, Kuniaki,Soga, Osamu
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