- Molecular cloning, expression, and characterization of acyltransferase from Pseudomonas protegens
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The formation of C-C bonds by using CoA independent acyltransferases may have significant impact for novel methods for biotechnology. We report the identification of Pseudomonas strains with CoA-independent acyltransferase activity as well as the heterolo
- Schmidt, Nina G.,??d?o-Dobrowolska, Anna,Ruppert, Valerie,H?flehner, Christian,Wiltschi, Birgit,Kroutil, Wolfgang
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- Molecular and catalytic properties of monoacetylphloroglucinol acetyltransferase from pseudomonas sp. YGJ3
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Monoacetylphloroglucinol (MAPG) acetyltransferase, catalyzing the conversion of MAPG to 2,4-diacetylphloroglucinol (DAPG), was purified from Pseudomonas sp. YGJ3 grown without Cl-. Cl- and pyoluteorin repressed expression of the enzyme. SDS-polyacrylamide gel electrophoresis showed that the purified enzyme (Mr = 330 kDa) was composed of three subunits of 17, 38, and 43 kDa, and protein sequencing identified these as PhlB, PhlA, and PhlC respectively. The enzyme catalyzed the reversible disproportionation of 2 moles of MAPG to phloroglucinol (PG) and DAPG. The equilibrium constant K (=[DAPG][PG]/[MAPG]2) was estimated to be about 1.0 at 25°C. A KpnI 20-kb DNA fragment was cloned from the genomic DNA of strain YGJ3, and a 12,598-bp long DNA region containing the phl gene cluster phlACBDEFGHI was sequenced. PCR cloning and expression of the phl genes in Escherichia coli confirmed that expression of phlACB genes produced MAPG ATase.
- Hayashi, Asuka,Saitou, Hiroki,Mori, Tomomi,Matano, Ikue,Sugisaki, Hiroyuki,Maruyama, Kiyofumi
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- Biosynthesis of phloroglucinol
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Substantial concentrations of phloroglucinol were synthesized by Pseudomonas fluorescens Pf-5 expressing the plasmid-localized phlACBDE gene cluster responsible for biosynthesis of 2,4-diacetylphloroglucinol. Expression in Escherichia coli of a single gene in this cluster, P. fluorescens Pf-5 phlD, led to extracellular accumulation of phloroglucinol. Purification of PhlD to homogeneity afforded an enzyme that catalyzed the conversion of malonyl-CoA into phloroglucinol with Km = 5.6 μM and kcat = 10 min-1. Acetylase and deacetylase activities were observed with the catalyzed interconversions of phloroglucinol, 2-acetylphloroglucinol, and 2,4-diacetylphloroglucinol when phlACB was expressed in E. coli. Beyond the mechanistic implications attendant with the identification of an enzyme that catalyzes the conversion of malonyl-CoA into phloroglucinol, PhlD provides the basis for environmentally benign syntheses of phloroglucinol and resorcinol from glucose. Copyright
- Achkar, Jihane,Xian, Mo,Zhao, Huimin,Frost
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- A FLAVONE GLYCOSIDE FROM THE STEM OF IXORA ARBOREA
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A new flavone glycoside isolated from the stem of Ixora arborea has been characterized as chrysin 5-O-β-D-xylopyranoside on the basis of spectral data, colour reactions and degradation studies.Key Word Index - Ixora arborea; Rubiaceae; stem; chrysin 5-O-β-D-xylopyranoside
- Chauhan, J. S.,Kumar, Santosh,Chaturvedi, Rajesh
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- Identification of the products of oxidation of quercetin by air oxygen at ambient temperature
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Oxidation of quercetin by air oxygen takes place in water and aqueous ethanol solutions under mild conditions, namely in moderately-basic media (pH ～ 8-10) at ambient temperature and in the absence of any radical initiators, without enzymatic catalysis or irradiation of the reaction media by light. The principal reaction products are typical of other oxidative degradation processes of quercetin, namely 3,4-dihydroxy-benzoic (protocatechuic) and 2,4,6-trihydroxybenzoic (phloroglucinic) acids, as well as the decarboxylation product of the latter - 1,3,5-trihydroxybenzene (phloroglucinol). In accordance with the literature data, this process involves the cleavage of the γ-pyrone fragment (ring C) of the quercetin molecule by oxygen, with primary formation of 4,6-dihydroxy-2-(3,4-dihydroxybenzoyloxy)benzoic acid (depside). However under such mild conditions the accepted mechanism of this reaction (oxidative decarbonylation with formation of carbon monoxide, CO) should be reconsidered as preferably an oxidative decarboxylation with formation of carbon dioxide, CO2. Direct head-space analysis of the gaseous components formed during quercetin oxidation in aqueous solution at ambient temperature indicates that the ratio of carbon dioxide/carbon monoxide in the gas phase after acidification of the reaction media is ca. 96:4 %. Oxidation under these mild conditions is typical for other flavonols having OH groups at C3 (e.g., kaempferol), but it is completely suppressed if this hydroxyl group is substituted by a glycoside fragment (as in rutin), or a methyl substituent. An alternative oxidation mechanism involving the direct cleavage of the C2-C3 bond in the diketo-tautomer of quercetin is proposed.
- Zenkevich, Igor G.,Eshchenko, Anna Yu.,Makarova, Svetlana V.,Vitenberg, Alexander G.,Dobryakov, Yuri G.,Utsal, Viktor A.
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- Flavonoid oligosides from georgian astragalus falcatus
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New flavonoid oligosides were isolated from leaves and flowers of Astragalus falcatus Lam. It was found on the basis of chemical transformations, UV, IR, PMR, 13C NMR, HMBC, HSQC, 1D-TOCSY, and mass spectral properties that falcoside C had the structure quercetin 3-O-[β-D- glucopyranosyl(1→3)-α-Lrhamnopyranosyl( 1→6)]-β-D- galactopyranoside 7-O-β-D-glucopyranoside; falcoside D, isorhamnetin 3-O-[β-D-xylopyranosyl(1→3)-α-L-rhamnopyranosyl(1→6)] -β-D-galactopyranoside 7-O-α-Lrhamnopyranoside.
- Alaniya,Kavtaradze,Skhirtladze,Sutiashvili
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- A NEW FLAVONOL GLYCOSIDE FROM Azara microphylla
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The leaves of Azara microphylla Hook., introduced into the Sukhami Botanical Garden of the Academy of Sciences of the Georgian SSR, have yielded a new glycoside, which has been called azamicroside and its structure has been established as myricetin 3-O-L-dirhamnoside.
- Sagareishvili, T. G.,Alaniya, M. D.,Kemertelidze, E. P.
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- Synthesis method of high-purity phloroglucinol compound
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The invention discloses a one-step chemical catalytic synthesis method of high-purity phloroglucinol by taking 3,5-dichlorophenol as a starting material and taking strong base and a catalyst as auxiliary materials. Through the method, the phloroglucinol compound with high molar yield, high purity and low cost can be effectively synthesized.
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- Preparation method of phloroglucinol
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The invention discloses a preparation method of phloroglucinol, the preparation method comprises the following steps: reacting 1, 3, 5-trimethoxybenzene serving as a raw material with boron trihalide to obtain a phloroglucinol crude product, removing boric acid through post-treatment, and purifying the product through refining, so that the reaction time is short, the reaction condition is mild, and the product purity is higher and the purification is convenient due to few side reactions, and good industrial production prospects are realized.
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Paragraph 0049-0080
(2021/10/27)
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- Preparation process of medicinal high-purity phloroglucinol
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The invention belongs to the technical field of medicine production, and particularly relates to a synthesis process of phloroglucinol, which comprises the following steps: reacting 1, 3, 5-trimethoxybenzene with boron trifluoride, quenching by using a mixed solution of methanol and dichloromethane after the reaction is completed, and purifying by filtering, leaching, pulping and the like to obtain the high-purity phloroglucinol (HPLC: 99.95%). According to the invention, the problem of violent heat release of the reaction system in a short time is solved, and the reaction energy consumption is reduced. The method has the advantages of mild reaction conditions, convenience of operation, convenience of post-treatment, good impurity removal effect and high product purity, and is suitable for industrial production.
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Paragraph 0006; 0016-0019
(2021/09/26)
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- Dynamic Nucleophilic Aromatic Substitution of Tetrazines
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A dynamic nucleophilic aromatic substitution of tetrazines (SNTz) is presented herein. It combines all the advantages of dynamic covalent chemistry with the versatility of the tetrazine moiety. Indeed, libraries of compounds or sophisticated molecular structures can be easily obtained, which are susceptible to post-functionalization by inverse electron demand Diels–Alder (IEDDA) reaction, which also locks the exchange. Additionally, the structures obtained can be disassembled upon the application of the right stimulus, either UV irradiation or a suitable chemical reagent. Moreover, SNTz is compatible with the imine chemistry of anilines. The high potential of this methodology has been proved by building two responsive supramolecular systems: A macrocycle that displays a light-induced release of acetylcholine; and a truncated [4+6] tetrahedral shape-persistent fluorescent cage, which is disassembled by thiols unless it is post-stabilized by IEDDA.
- Carrillo, Romen,Daranas, Antonio Hernández,Martín-Encinas, Endika,Pérez-Pérez, Yaiza,Pasán, Jorge,Rivero, David S.,Santos, Tanausú
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p. 18783 - 18791
(2021/07/20)
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- Phloroglucinol synthetic method
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The invention relates to the technical field of pharmaceutical and chemical industry, and concretely discloses a phloroglucinol synthetic method. The synthesis method is characterized in that 1,3,5-trimethoxybenzene and concentrated sulfuric acid are mixed, a mixture is heated to 60 to 65 DEG C, an insulation reaction is carried out for 1 to 2 hours, cooling is carried out to below 10 DEG C, sodium bicarbonate or sodium carbonate is slowly added while stirring, a pH value is adjusted to 2-3, and filtering is carried out to obtain a filtrate; the filtrate is extracted for three times with butylacetate, the extracts are combined and concentrated to 15% to 20% of an original volume, and a concentrate is obtained, cooling is carried out to below 10 DEG C, and steps of crystallization and filtering are carried out to obtain a phloroglucinol crude product; the phloroglucinol crude product is added to mixed liquor of purified water and an alcohol solvent for heating and solving, insulation is carried out, and the activated carbon is added to adsorb impurities, and the material is filtered, the filtrate is cooled to the temperature of lower than 10 DEG C, and the steps of crystallization,filtering, washing and vacuum drying are realized. The synthesis method has the advantages that the raw materials are easy to obtain, the reaction conditions are mild, the reaction time is short, andthe yield is high. The product has the advantages of high purity, simple process, convenient operation and less pollution, which is beneficial to industrial production.
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Paragraph 0027-0041; 0044-0048
(2019/01/21)
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- Mechanism and Structure of γ-Resorcylate Decarboxylase
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γ-Resorcylate decarboxylase (γ-RSD) has evolved to catalyze the reversible decarboxylation of 2,6-dihydroxybenzoate to resorcinol in a nonoxidative fashion. This enzyme is of significant interest because of its potential for the production of γ-resorcylate and other benzoic acid derivatives under environmentally sustainable conditions. Kinetic constants for the decarboxylation of 2,6-dihydroxybenzoate catalyzed by γ-RSD from Polaromonas sp. JS666 are reported, and the enzyme is shown to be active with 2,3-dihydroxybenzoate, 2,4,6-trihydroxybenzoate, and 2,6-dihydroxy-4-methylbenzoate. The three-dimensional structure of γ-RSD with the inhibitor 2-nitroresorcinol (2-NR) bound in the active site is reported. 2-NR is directly ligated to a Mn2+ bound in the active site, and the nitro substituent of the inhibitor is tilted significantly from the plane of the phenyl ring. The inhibitor exhibits a binding mode different from that of the substrate bound in the previously determined structure of γ-RSD from Rhizobium sp. MTP-10005. On the basis of the crystal structure of the enzyme from Polaromonas sp. JS666, complementary density functional calculations were performed to investigate the reaction mechanism. In the proposed reaction mechanism, γ-RSD binds 2,6-dihydroxybenzoate by direct coordination of the active site manganese ion to the carboxylate anion of the substrate and one of the adjacent phenolic oxygens. The enzyme subsequently catalyzes the transfer of a proton to C1 of γ-resorcylate prior to the actual decarboxylation step. The reaction mechanism proposed previously, based on the structure of γ-RSD from Rhizobium sp. MTP-10005, is shown to be associated with high energies and thus less likely to be correct.
- Sheng, Xiang,Patskovsky, Yury,Vladimirova, Anna,Bonanno, Jeffrey B.,Almo, Steven C.,Himo, Fahmi,Raushel, Frank M.
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p. 3167 - 3175
(2018/06/11)
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- Promiscuous activity of C-acyltransferase from: Pseudomonas protegens: Synthesis of acetanilides in aqueous buffer
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Amide bond formation has considerable significance in synthetic chemistry. Although the C-acyltransferase from Pseudomonas protegens has been found to catalyze C-C bond formation in nature as well as in in vitro experiments with non-natural substrates, it is now shown that the enzyme is also able to catalyze amide formation using aniline derivatives as substrates with promiscuous activity. Importantly, the amide formation was enabled in aqueous buffer. Identifying phenyl acetate as the most suitable acetyl donor, the products were obtained with up to >99% conversion and up to 99% isolated yield.
- Zad?o-Dobrowolska, Anna,Schmidt, Nina G.,Kroutil, Wolfgang
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supporting information
p. 3387 - 3390
(2018/04/05)
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- Synthesizing technology of phloroglucinol
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The invention belongs to the technical field of medicine production, and particularly relates to a synthesizing technology of phloroglucinol. The synthesizing technology of the phloroglucinol comprises the following steps of using 1,3,5-trimethoxybenzene as a raw material, using chlorobenzene as a solvent, using an aluminum trichloride as a complex reagent, and heating to react; after the reaction is complete, adding the reaction system into an inorganic acid water solution to dissociate, and filtering; recrystallizing a crude product in the mixed solution of alcohol and water, so as to obtain the high-purity phloroglucinol at higher yield rate. The synthesizing technology has the advantages that the operation is simple and convenient, the controllability is strong, the synthesizing technology is suitable for large-scale production, and the like.
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Paragraph 0026; 0027; 0028
(2017/07/21)
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- Biocatalytic Friedel–Crafts Acylation and Fries Reaction
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The Friedel–Crafts acylation is commonly used for the synthesis of aryl ketones, and a biocatalytic version, which may benefit from the chemo- and regioselectivity of enzymes, has not yet been introduced. Described here is a bacterial acyltransferase which can catalyze Friedel–Crafts C-acylation of phenolic substrates in buffer without the need of CoA-activated reagents. Conversions reach up to >99 %, and various C- or O-acyl donors, such as DAPG or isopropenyl acetate, are accepted by this enzyme. Furthermore the enzyme enables a Fries rearrangement-like reaction of resorcinol derivatives. These findings open an avenue for the development of alternative and selective C?C bond formation methods.
- Schmidt, Nina G.,Pavkov-Keller, Tea,Richter, Nina,Wiltschi, Birgit,Gruber, Karl,Kroutil, Wolfgang
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supporting information
p. 7615 - 7619
(2017/06/13)
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- Are of a kind of preparation are connected and method
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The invention belongs to the field of marine chemical industry medicine intermediates, and particularly relates to a method for preparing pyrogallol and phloroglucinol, wherein the preparation route that trimethoxybenzaldehyde is subjected to catalysis decarbonylation under a hydrogen atmosphere is adopted, the modified raney nickel is adopted as a catalyst to carry out a catalysis decarbonylation reaction in a solvent, the modified raney nickel is subjected to bulk phase and surface modification based on the conventional raney nickel preparation method, the modified component is one or a plurality of materials selected from Mn, Fe, Cr, Mo, Ti and W, and the modified component content (wt) is 0.5-10 wt%. The method has characteristics of environmental protection, easy operation, wide raw material source, short reaction step, simple catalyst preparation and capability of being repeatedly applied multiple times, and is suitable for industrialization.
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Paragraph 0038; 0040
(2017/02/24)
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- Transformation pathways of 2,4,6-trinitrobenzoic acid in the aqueous-phase hydrogenation over Pd/C catalyst
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Results of the catalytic hydrogenation of 2,4,6-trinitrobenzoic acid (TNBA) in the presence of 1% Pd/C catalyst with analysis of the reaction products at the steps corresponding to the consumption of 1, 3, 5, 6, 8 and 9 mols of hydrogen per mol of TNBA are presented. Numerous reaction intermediates were identified using the 1H and 13C NMR spectroscopy; the reaction mixture composition was assessed quantitatively at different steps of the hydrogenation. The data obtained were used to propose a scheme of TNBA transformations over the Pd/C catalyst in the aqueous-phase reaction conditions. The data on the component composition at different steps of TNBA hydrogenation are important to understand the process chemistry, to explore the possibility of selective formation of different types of intermediate nitroamino compounds, and to synthesize high-performance catalysts for the hydrogenation of aromatic polynitro compounds.
- Belskaya, Olga B.,Talsi, Valentin P.,Mironenko, Roman M.,Rodionov, Vladimir A.,Sysolyatin, Sergey V.,Likholobov, Vladimir A.
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p. 190 - 199
(2016/05/09)
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- Preparation, characterization and use of 1,3-disulfonic acid imidazolium hydrogen sulfate as an efficient, halogen-free and reusable ionic liquid catalyst for the trimethylsilyl protection of hydroxyl groups and deprotection of the obtained trimethylsilanes
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Novel 1,3-disulfonic acid imidazolium hydrogen sulfate, a halogen-free ionic liquid, is a recyclable and eco-benign catalyst for the trimethylsilyl protection of hydroxyl groups at room temperature under solvent free conditions to afford trimethylsilanes in excellent yields (92-100%) and in very short reaction times (1-5 min). Deprotection of the resulting trimethylsilanes can also be achieved using the same catalyst in methanol. The catalyst was characterized by IR, 1H NMR, 13C NMR and MS studies. All the products were extensively characterized by IR, 1H NMR, MS, and elemental and melting point analyses. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be recovered and reused for several times without loss of activity. The work-up of the reaction consists of a simple separation, followed by concentration of the crude product and purification.
- Shirini, Farhad,Khaligh, Nader Ghaffari,Akbari-Dadamahaleh, Somayeh
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- Nanocrystalline TiO2-HClO4 as a new, efficient and recyclable catalyst for the chemoselective trimethylsilylation of alcohols, phenols and deprotection of silyl ethers
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TiO2-HClO4, as a new solid acid, was found to be an efficient catalyst for the chemoselective trimethylsilylation of alcohols and phenols. Deprotection of the resulting trimethylsilylethers was achieved using the same catalyst in methanol solvent. The synthesized catalyst was characterized by FT-IR, SEM, TEM, BET and XRD analyses. Our novel synthetic method has the advantages of high yields, short reaction times, low cost and recyclability of the catalyst, simplicity and easy work-up compared to the conventional methods reported in the literature.
- Shirini, Farhad,Atghia, Seyyed Vahid,Jirdehi, Mojtaba Ghazi
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- New oligomeric proanthocyanidin glycosides platanoside-A and platanoside-B from Platanus orientalis trunk bark
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Two new oligomeric proanthocyanidin glycosides were isolated from trunk bark of Platanus orientalis. Their structures and relative configurations were found to be 7-O-β-D-Glcp-(-)-epicatechin-(4β-8)-(-)- epicatechin(4β-8)-(-)-epicatechin-3-O-gallate (plat
- Nishanbaev,Khidyrova,Vdovin,Abdullaev,Shakhidoyatov,Aripov
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experimental part
p. 357 - 362
(2010/10/03)
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- New oligomeric proanthocyanidins from Alhagi pseudalhagi
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Two new oligomeric proanthocyanidin glucosides were isolated from the aerial part and roots of Alhagi pseudalhagi. Their structures and relative configurations were elucidated as 7-O-β-D-Glc p→6 galloyl-(+)catechin-(4α-8)-(+)-catechin-(4α-8)-(-
- Alimova,Nishanbaev,Vdovin,Abdullaev,Aripova
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experimental part
p. 352 - 356
(2010/10/03)
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- COMPOSITIONS COMPRISING STILBENE POLYPHENOL DERIVATIVES AND USE THEREOF FOR COMBATING THE AGEING OF LIVING ORGANISMS AND DISEASES AFFECTING SAME
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The invention relates to compositions comprising pholyphenol derivatives, characterised in that said polyphenols contain monomers, oligomers or polymers with units having formula (I), said units being characterised by the simultaneous presence of a resorcinol nucleus (nucleus A) and a para-phenol nucleus (nucleus B) which are interconnected by a carbon bond C, said derivatives being over-activated, in respect of the nucleophilic power thereof, by alkylation of at least one phenol function of each constituent monomer unit and stabilised by sterification by mixtures of fatty acids in proportions reflecting those of vegetable oils formed mainly by unsaturated fatty acids of all of the other phenol functions. The invention is suitable for use in cosmetics, dietetics and therapeutics.
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- Iridium-catalyzed C-H activation/borylation/oxidation for the preparation of bis-protected phloroglucinol derivatives
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The preparation of bis-protected phloroglucinol derivatives from a range of protected resorcinol substrates is presented. Functionalization was achieved via a two-step, one-pot iridium-catalyzed C-H activation/borylation/oxidation protocol. Our system gave high conversions to the arylboronic esters and good yields of the desired phenols following subsequent oxidation. A range of common protecting group categories was studied including alkyl, silyl, ether and ester.
- Marshall, Laura J.,Cable, Karl M.,Botting, Nigel P.
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scheme or table
p. 2690 - 2692
(2010/07/04)
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- Method for preparing 13 5-triaminobenzene and hydrolyzing it into high-purity phloroglucinal
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The invention concerns a method for method for preparing 1,3,5-triaminobenzene, characterized in that it comprises a step which consists in amination of a compound of formula (I), wherein: A represents a halogen atom or a NH2 group; X1 and X2, identical or different, represent each a halogen atom, the amination step being carried out in the presence of ammonia and a catalyst selected from the group consisting of copper salts, cupric and cuprous oxides or mixtures thereof at a temperature ranging between 150° C. and 250° C. and at a pressure higher that 35 bars.
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Page/Page column 4
(2008/06/13)
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- Aerobic oxidation of 1,3,5-triisopropylbenzene using N-hydroxyphthalimide (NHPI) as key catalyst
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The first systematic study on the aerobic oxidation of 1,3,5- triisopropylbenzene was examined by the use of N-hydroxyphthalimide (NHPI) as a key catalyst. It was found that 1,3,5-triisopropylbenzene was efficiently oxidized with O2 in the presence of a catalytic amount of NHPI and azobisisobutyronitrile (AIBN) at 75°C. Upon treatment of the resulting products with sulfuric acid followed by acetic anhydride led to 5-acetoxy-1,3-diisopropylbenzene and 3,5-diacetoxy-1-isopropylbenzene as major products and a small amount of 1,3,5-triacetoxybenzene. When t-butylperoxypivalate (BPP) was employed as a radical initiator, the oxidation could be achieved in good yield even at 50°C. This oxidation provides a facile method for preparing phenol derivatives bearing an isopropyl moiety, which can be used as pharmaceutical starting materials.
- Aoki, Yasuhiro,Hirai, Naruhisa,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 10995 - 10999
(2007/10/03)
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- Efficient, selective deprotection of aromatic acetates catalyzed by Amberlyst-15 or iodine
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Aromatic acetates were selectively deprotected in the presence of aliphatic acetates to the corresponding phenols in excellent yields using Amberlyst-15 or iodine as catalysts in methanol at room temperature. The first catalyst can be recovered.
- Das, Biswanath,Banerjee, Joydeep,Ramu,Pal, Rammohan,Ravindranath,Ramesh
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p. 5465 - 5468
(2007/10/03)
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- Deacetylation of activated acetophenones with tin(IV) chloride
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Activated acetophenones were deacetylated by treatment with an excess of tin(IV) chloride in 1,2-dichloroethane.
- Hadjeri, Mohamed,Mariotte, Anne-Marie,Boumendjel, Ahcene
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p. 463 - 464
(2007/10/03)
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- Deoxygenation of polyhydroxybenzenes: An alternative strategy for the benzene-free synthesis of aromatic chemicals
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New synthetic connections have been established between glucose and aromatic chemicals such as pyrogallol, hydroquinone, and resorcinol. The centerpiece of this approach is the removal of one oxygen atom from 1,2,3,4-tetrahydroxybenzene, hydroxyhydroquinone, and phloroglucinol methyl ether to form pyrogallol, hydroquinone, and resorcinol, respectively. Deoxygenations are accomplished by Rh-catalyzed hydrogenation of the starting polyhydroxybenzenes followed by acid-catalyzed dehydration of putative dihydro intermediates. Pyrogallol synthesis consists of converting glucose into myo-inositol, oxidation to myo-2-inosose, dehydration to 1,2,3,4-tetrahydroxybenzene, and deoxygenation to form pyrogallol. Synthesis of pyrogallol via myo-2-inosose requires 4 enzyme-catalyzed and 2 chemical steps. For comparison, synthesis of pyrogallol from glucose via gallic acid intermediacy and the shikimate pathway requires at least 20 enzyme-catalyzed steps. A new benzene-free synthesis of hydroquinone employs conversion of glucose into 2-deoxy-scyllo-inosose, dehydration of this inosose to hydroxyhydroquinone, and subsequent deoxygenation to form hydroquinone. Synthesis of hydroquinone via 2-deoxy-scyllo-inosose requires 2 enzyme-catalyzed and 2 chemical steps. By contrast, synthesis of hydroquinone using the shikimate pathway and intermediacy of quinic acid requires 18 enzyme-catalyzed steps and 1 chemical step. Methylation of triacetic acid lactone, cyclization, and regioselective deoxygenation of phloroglucinol methyl ether affords resorcinol. Given the ability to synthesize triacetic acid lactone from glucose, this constitutes the first benzene-free route for the synthesis of resorcinol. Copyright
- Hansen, Chad A.,Frost
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p. 5926 - 5927
(2007/10/03)
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- A simple preparation of 17(R)-hydroxyeicosatetraenoic and eicosapentaenoic acids from the eicosanoylphloroglucinols, components of the brown alga, Zonaria diesingiana
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The alkaline treatment of 17(R)-hydroxyeicosatetraenoylphloroglucinol and eicosapentaenoylphloroglucinol, which are the major components of the methanol extract of the brown alga, Zonaria diesingiana (Dictyota) afforded 17(R)-hydroxyeicosatetraenoic and eicosapentaenoic acids, respectively, in good yields. The conformation of methyl ester of the 17(R)-hydroxy acid in a solution was studied by using 2NMA, a chiral anisotropic reagent.
- Munakata, Tatsuo,Ooi, Takashi,Kusumi, Takenori
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p. 249 - 250
(2007/10/03)
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- Proanthocyanidins from Lotus Corniculatus
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The chemical structure of the purified proanthocyanidin polymers of Lotus corniculatus was analysed by 13CNMR and by mild acid catalysed degradation in the presence of excess of phloroglucinol. The NMR data showed that the polymer was partially glycosidated with a number average Mr in the range 1800-2100 (six to seven flavanoid units). The products from phloroglucinol scission reaction indicated the extender flavan units to consist mostly of epicatechin (67%) and epigallocatechin (30%), with minor amounts of catechin and epiafzelechin units, which were linked together predominantly by C-4/C-8 interflavanoid bonds. The polymer chains were terminated mostly by catechin (83%) and, to a lesser extent, by epicatechin (16%). Copyright
- Foo,Newman,Waghorn,Mcnabb,Ulyatt
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p. 617 - 624
(2007/10/03)
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- Flame-resistant polycarbonates containing units deriving from halogenated pyrimidine compounds in their polymer chain
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Flame-resistant thermoplastic branched polycarbonates of high molecular weight are prepared from: (1) a carbonate precursor; (2) at least one dihydroxyaromatic compound of formula: where:, R is a single bond, or a substituted or non-substituted linear or branched C1-C5 alkylene radical, or a group chosen from O, S, SO2 and CO;, X and Y, which may be the same or different, are H or CH3;, m and n, which may be the same or different, are whole numbers from 1 to 4; (3) at last one halogenated pyrimidine compound of formula: where: R2, R3, R4, which may be the same or different, are chlorine or bromine or hydrogen, on condition that at least one is chlorine or bromine;, R1 is chlorine or bromine, or a radical of formula: where Z is NH or S or O; (4) at least one polyfunctional organic compound as branching agent, characterized by possessing at least three equal or different groups chosen from the groups OH, COOH, COCl and SO2Cl.
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- Counterattack Reagents Sodium Trimethylsilanethiolate and Hexamethyldisilathiane in the Bis-O-demethylation of Aryl Methyl Ethers
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New methods were developed for removal of two methyl groups from aryl methyl ethers.Treatment of an aryl methyl ether containing two methoxy units (i. e., 1, 3, 5, 7, 9, 11, or 13) with ca. 2.5 equiv of Me3SiSNa in 1,3-dimethyl-2-imidazolidinone at 185 deg C in a sealed tube gave the corresponding aryl alcohol (i. e. 2, 4, 6, 8, 10, 12 or 14) in 78-96percent yields after aqueous workup.Also, Me3SiSSiMe3 was found useful for bis-O-demethylation of aromatic compounds containing one free hydroxyl group and two methoxy units (e. g., 11 and 13).Thus 11 and 13 reacted with 1.5 equiv of NaH and then with 1.5 equiv of Me3SiSSiMe3 at 185 deg C in a sealed tube to afford triols 13 (75percent) and 14 (72percent), respectively.In these bis-O-demethylations, Me3SiSNa and Me3SiSSiMe3 act as counterattack reagents.
- Hwu, Jih Ru,Tsay, Shwu-Chen
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p. 5987 - 5991
(2007/10/02)
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- PROCYANIDIN POLYMERS OF DOUGLAS FIR BARK: STRUCTURE FROM DEGRADATION WITH PHLOROGLUCINOL
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Reaction of the condensed tannin polymers of Douglas fir inner bark with phloroglucinol yielded catechin, epicatechin, procyanidin B-2, catechin-(4α->2)-phloroglucinol, epicatechin-(4β->2)-phloroglucinol, the novel compound epicatechin-(4α->2)-phloroglucinol and 1,3-di-(2,4,6-trihydroxyphenyl)-1-(3,4-di-hydroxyphenyl)-propan-2-ol.Also isolated were epicatechin-(4β->8)-epicatechin-(4β->2)-phloroglucinol, epicatechin-(4β->6)-epicatechin-(4β->2)-phloroglucinol, and three other novel phloroglucinol adducts, catechin-(4α->8)-epicatechin-(4β->2)-phloroglucinol, epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin-(4β->2)-phloroglucinol and epicatechin-(4β->6)-epicatechin-(4β->8)-epicatechin-(4β->2)-phloroglucinol.The results suggest that the configuration of the extender units is almost exclusively 2,3-cis, while the terminal units are mixed, with 2,3-cis slightly predominating.The C-4 to C-8 interflavonoid linkage predominates over the C-4 to C-6 linkage by a 4:1 ratio. Key Word Index Pseudotsuga menziesii; Pinaceae; Douglas fir; procyanidin; degradation; phloroglucinol-adducts.
- Foo, Lai Yeap,Karchesy, Joseph J.
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p. 3185 - 3190
(2007/10/02)
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- Bromophloroglucinols and their methyl ethers
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All 16 bromination products of phloroglucinol and its methyl ethers, as well as five bromoresorcinols and three of their dimethyl ethers, were synthesized and analyzed by nuclear magnetic resonance spectroscopy.Two or three equivalents of bromine convert phloroglucinol to di- and tribromophloroglucinol, 5-methoxyresorcinol to the tri- and 2,4-dibromo, 3,5-dimethoxyphenol to the tri- and 2,6-dibromo, and 1,3,5-trimethoxybenzene to the dibromo compound.With one equivalent of bromine, 3,5-dimethoxyphenol reacts preferentially at C-2 while 5-methoxyresorcinol gives both monobromo isomers.Partial debromination with sodium sulfite yields successively 2,4-dibromo- and 2-bromo-5-methoxyresorcinol from the tribromo compound but fails with brominated 3,5-dimethoxyphenol.In the resorcinol series, C-2 is invariably the least reactive position. 4,6-Dibromo-5-methoxyresorcinol and 2,4-dibromo-3,5-dimethoxyphenol are accessible by methylation of dibromophloroglucinol, obtained from 3,5-dibromo-2,4,6-trihydroxybenzoic acid by decarboxylation.In contrast to resorcinol and tribromoresorcinol, the partial bromination of pholoroglucinol and debromination of tribromopholoroglucinol are not selective.The 13Cnmr spectra of bromophloroglucinol methyl ethers show characteristic downfield shifts for methoxy groups orthogonal to the aromatic ring plane.
- Kiehlmann, E.,Lauener, R. W.
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p. 335 - 344
(2007/10/02)
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- Synthesis of Condensed Tannins. Part 17. Oligomeric (2R,3S)-3,3',4',7,8-Pentahydroxyflavans: Atropisomerism and Conformation of Biphenyl and m-Terphenyl Analogues from Prosopis glandulosa ('Mesquite')
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(2R,3S)-2,3-trans-3',4',7,8-Tetrahydroxyflavan-3-ol , the predominant metabolite in the heartwood of Prosopis glandulosa, represents a putative precursor of a variety of oligomers, including conventional - and -biflavan-3-ols, a -1,3-diarylpropylflavan-3-ol, - and atropisomeric -biphenyl-type biflavan-3-ols, and -m-terphenyl-type triflavan-3-ols.Other participants in these condensations are mainly (+)-catechin, and also the flavan-3,4-diol analogue of (+)-mesquitol.Oligomeric structures were confirmed by biomimetic oxidative and acid-induced couplings, and by nuclear Overhauser effect difference spectroscopy.These applications enabled correction of previous structural assignments for atropisomeric -(+)-mesquitol-(+)-catechins and -bis--(+)-catechins, and determination of their conformations.
- Young, Esme,Brandt, Edward V.,Young, Desmond A.,Ferreira, Daneel,Roux, David G.
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p. 1737 - 1750
(2007/10/02)
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- Method for producing phloroglucin
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In a method for producing phloroglucin by a decomposition of 1,3,5-triisopropylbenzene trihydroperoxide (hereinafter referred to as THPO), a method for producing phloroglucin wherein an acid catalytic decomposition is carried out under the condition that: (1) at least one member selected from the group consisting of perchloric acid, sulfuric anhydride and boron trifluoride be used as a catalyst, (2) the amount of the catalyst above in the reaction solution be 1 to 100 ppm, (3) the water content in the reaction solution be not more than 2% by weight, and (4) the total amount of the carbinol group of carbinols (having a structure in which part or all of the three hydroperoxy groups of THPO have been replaced by hydroxyl groups) contaminating the raw material for reaction be not more than 1/5 equivalent based on THPO. The phloroglucin is useful as a starting material of medicines and photosensitizers.
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- Method for purifying phloroglucin
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A method for purifying phloroglucin wherein crude phloroglucin obtained by an acid-decomposition of 1,3,5-triisopropylbenzene trihydroperoxide in the presence of a solvent and removal of the formed acetone and the solvent by evaporation, is extraction-treated within a pH range of 7.5 to 12 in the coexistence of an aqueous alkali liquor of 4 to 25 times by weight based on the crude phloroglucin and an organic solvent of 0.05 to 6 times by weight based on said aqueous alkali liquor selected from ketones and esters which are separable from the aqueous alkali liquor, and after acidifying the separated aqueous alkali extract, the deposited crystal is recrystalized. The phloroglucin is useful as a starting material of medicines and photosensitizers.
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- Synthesis of trinitrophloroglucinol
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A one pot process for the preparation of trinitrophloroglucinol by the addition of a nitric acid and sulfuric acid mixture to phloroglucinol in sulfuric acid where the nitric acid and phloroglucinol are present in stoichiometric amounts.
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- Process for producing 1,3,5-triaminobenzene
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An aminobenzene is produced by reacting a chlorobenzene with ammonia in the presence of a copper type catalyst, namely by reacting ammonia with 3,5-diaminochlorobenzene to produce 1,3,5-triaminobenzene at a temperature of 150° to 250° C. at a molar ratio of ammonia of 2 to 10 to 3,5-diaminochlorobenzene in the presence of a copper compound catalyst.
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- NIVYASIDE - A NEW GLYCOSIDE FROM Leucanthemum vulgare
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From the ligulate flowers of Leucanthemum vulgare Lam. growing on the territory of the Georgian SSR a new glycoside has been isolated which has been called nivyaside and has the structure 8-(1-α-D-glucopyranosyl-5-deoxyquercit-5-yl)-4',5,7-trihydroxyflavone.
- Sagareishvili, T. G.,Alaniya, M. D.,Kikoladze, V. S.,Kemertelidze, E. P.
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p. 408 - 412
(2007/10/02)
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- BIOSYNTHESIS OF MANGIFERIN IN ANEMARRHENA ASPHODELOIDES BUNGE. II. C-GLUCOSYLATION OF MANGIFERIN
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A benzophenone, maclurin-1,3,5-14C3 (3), was efficiently incorporated into C-glucosylxanthones (mangiferin (1) and isomangiferin (2)) of Anemarrhena asphodeloides without randomization, but the labelled aglycone of 1 and 2 (1,3,6,7-tetrahydroxyxanthone-2,4,9a-14C3) (4) was essentially not incorporated.Furthermore, the incorporation of phenylalanine-3-14C into 1 and 2 was clearly suppressed by the addition of non-labelled maclurin (3) to the precursor solution.These results indicate that C-glucosylation of 1 and 2 occurs at the stage of maclurin (3), prior to the formation of the xanthone nucleus, and that 1 and 2 may be biosynthesized via 3-C-glucosylmaclurin (6).A biosynthetic route is proposed for mangiferin (1) and related C-glucosylxanthones.Keywords-Anemarrhena asphodeloides Bunge; biosynthesis; C-glucosylation of xanthone; mangiferin; isomangiferin; maclurin-1,3,5-14C3; 1,3,6,7-tetrahydroxyxanthone-2,4,9a-14C3; phloroglucinol-2,4,6-14C3.
- Fujita, Masao,Inoue, Takao
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p. 2482 - 2486
(2007/10/02)
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- BIOSYNTHESIS OF MANGIFERIN IN ANEMARRHENA ASPHODELOIDES BUNGE. I. THE ORIGIN OF THE XANTHONE NUCLEUS
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Phenylalanine-1-14C,-2-14C and -3-14C, and malonic acid-2-14C were efficiently incorporated into mangiferin (1) in Anemarrhena asphodeloides.In the case of feeding with phenylalanine-1-14C, -2-14C and malonic acid-2-14C, the radioactivity of 1 was localized in the phloroglucinol ring.Furthermore, cinnamic acid-3-14C and p-coumaric acid-2-14C were also incorporated into 1 and isomangiferin (2), but benzoic acid-, p-hydroxybenzoic acid- and protocatechuic acid-(carboxyl-14C) were essentially not incorporated into 1 or 2.In addition to the above data, doubly labelled p-coumaric acid was incorporated into 1 without change of the T/14C ratio.These results show that the aglycone of 1 and 2 was biosynthesized from p-coumarate (C6-C3) and two malonates (C4).Keywords-Anemarrhena asphodeloides Bunge; biosynthesis of xanthones; mangiferin; isomangiferin; p-coumaric acid-2-14C and-(ring-3,5-T2); p-hydroxybenzoic acid-(carboxyl-14C) and -3,5-T2; protocatechuic acid-(carboxyl-14C); benzoic acid-(carboxyl-14C); phenylalanine-1-14C, -2-14C and -3-14C; malonic acid-2-14C
- Fujita, Masao,Inoue, Takao
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p. 2476 - 2481
(2007/10/02)
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- Process for preparing polyphenols
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Polyphenols of the general formula: STR1 wherein R represents a readily cleavable ether group and R' represents a hydrogen atom or a lower alkoxycarbonyl, such as the methoxycarbonyl or ethoxycarbonyl group, and of phloroglucinol, are made by heating a compound of the general formula: STR2 wherein R and R' have the same significance given above, with an alkali metal alcoholate and, if desired, converting the resulting compound of formula I into pholoroglucinol by ether-cleavage and removal of any ester group denoted by R' which may be present in accordance with methods known per se.
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- Benzene-1,3,5-tris-acetoxime and the process for making phloroglucinol therewith
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Phloroglucinol may be produced by converting s-triacetyl benzene to benzene-1,3,5-tris-acetoxime which is a novel compound. Said acetoxime is subjected to a Beckmann rearrangement and the resulting mixture subsequently hydrolyzed to produce phloroglucinol.
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